dma40: combine mem and slave prep_sg functions

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / dma / ste_dma40.c

/*
 * Copyright (C) Ericsson AB 2007-2008
 * Copyright (C) ST-Ericsson SA 2008-2010
 * Author: Per Forlin <per.forlin@stericsson.com> for ST-Ericsson
 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
 * License terms: GNU General Public License (GPL) version 2
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/dmaengine.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>

#include <plat/ste_dma40.h>

#include "ste_dma40_ll.h"

#define D40_NAME "dma40"

#define D40_PHY_CHAN -1

/* For masking out/in 2 bit channel positions */
#define D40_CHAN_POS(chan)  (2 * (chan / 2))
#define D40_CHAN_POS_MASK(chan) (0x3 << D40_CHAN_POS(chan))

/* Maximum iterations taken before giving up suspending a channel */
#define D40_SUSPEND_MAX_IT 500

/* Hardware requirement on LCLA alignment */
#define LCLA_ALIGNMENT 0x40000

/* Max number of links per event group */
#define D40_LCLA_LINK_PER_EVENT_GRP 128
#define D40_LCLA_END D40_LCLA_LINK_PER_EVENT_GRP

/* Attempts before giving up to trying to get pages that are aligned */
#define MAX_LCLA_ALLOC_ATTEMPTS 256

/* Bit markings for allocation map */
#define D40_ALLOC_FREE          (1 << 31)
#define D40_ALLOC_PHY           (1 << 30)
#define D40_ALLOC_LOG_FREE      0

/* Hardware designer of the block */
#define D40_HW_DESIGNER 0x8

/**
 * enum 40_command - The different commands and/or statuses.
 *
 * @D40_DMA_STOP: DMA channel command STOP or status STOPPED,
 * @D40_DMA_RUN: The DMA channel is RUNNING of the command RUN.
 * @D40_DMA_SUSPEND_REQ: Request the DMA to SUSPEND as soon as possible.
 * @D40_DMA_SUSPENDED: The DMA channel is SUSPENDED.
 */
enum d40_command {
        D40_DMA_STOP            = 0,
        D40_DMA_RUN             = 1,
        D40_DMA_SUSPEND_REQ     = 2,
        D40_DMA_SUSPENDED       = 3
};

/**
 * struct d40_lli_pool - Structure for keeping LLIs in memory
 *
 * @base: Pointer to memory area when the pre_alloc_lli's are not large
 * enough, IE bigger than the most common case, 1 dst and 1 src. NULL if
 * pre_alloc_lli is used.
 * @dma_addr: DMA address, if mapped
 * @size: The size in bytes of the memory at base or the size of pre_alloc_lli.
 * @pre_alloc_lli: Pre allocated area for the most common case of transfers,
 * one buffer to one buffer.
 */
struct d40_lli_pool {
        void    *base;
        int      size;
        dma_addr_t      dma_addr;
        /* Space for dst and src, plus an extra for padding */
        u8       pre_alloc_lli[3 * sizeof(struct d40_phy_lli)];
};

/**
 * struct d40_desc - A descriptor is one DMA job.
 *
 * @lli_phy: LLI settings for physical channel. Both src and dst=
 * points into the lli_pool, to base if lli_len > 1 or to pre_alloc_lli if
 * lli_len equals one.
 * @lli_log: Same as above but for logical channels.
 * @lli_pool: The pool with two entries pre-allocated.
 * @lli_len: Number of llis of current descriptor.
 * @lli_current: Number of transfered llis.
 * @lcla_alloc: Number of LCLA entries allocated.
 * @txd: DMA engine struct. Used for among other things for communication
 * during a transfer.
 * @node: List entry.
 * @is_in_client_list: true if the client owns this descriptor.
 * the previous one.
 *
 * This descriptor is used for both logical and physical transfers.
 */
struct d40_desc {
        /* LLI physical */
        struct d40_phy_lli_bidir         lli_phy;
        /* LLI logical */
        struct d40_log_lli_bidir         lli_log;

        struct d40_lli_pool              lli_pool;
        int                              lli_len;
        int                              lli_current;
        int                              lcla_alloc;

        struct dma_async_tx_descriptor   txd;
        struct list_head                 node;

        bool                             is_in_client_list;
};

/**
 * struct d40_lcla_pool - LCLA pool settings and data.
 *
 * @base: The virtual address of LCLA. 18 bit aligned.
 * @base_unaligned: The orignal kmalloc pointer, if kmalloc is used.
 * This pointer is only there for clean-up on error.
 * @pages: The number of pages needed for all physical channels.
 * Only used later for clean-up on error
 * @lock: Lock to protect the content in this struct.
 * @alloc_map: big map over which LCLA entry is own by which job.
 */
struct d40_lcla_pool {
        void            *base;
        dma_addr_t      dma_addr;
        void            *base_unaligned;
        int              pages;
        spinlock_t       lock;
        struct d40_desc **alloc_map;
};

/**
 * struct d40_phy_res - struct for handling eventlines mapped to physical
 * channels.
 *
 * @lock: A lock protection this entity.
 * @num: The physical channel number of this entity.
 * @allocated_src: Bit mapped to show which src event line's are mapped to
 * this physical channel. Can also be free or physically allocated.
 * @allocated_dst: Same as for src but is dst.
 * allocated_dst and allocated_src uses the D40_ALLOC* defines as well as
 * event line number.
 */
struct d40_phy_res {
        spinlock_t lock;
        int        num;
        u32        allocated_src;
        u32        allocated_dst;
};

struct d40_base;

/**
 * struct d40_chan - Struct that describes a channel.
 *
 * @lock: A spinlock to protect this struct.
 * @log_num: The logical number, if any of this channel.
 * @completed: Starts with 1, after first interrupt it is set to dma engine's
 * current cookie.
 * @pending_tx: The number of pending transfers. Used between interrupt handler
 * and tasklet.
 * @busy: Set to true when transfer is ongoing on this channel.
 * @phy_chan: Pointer to physical channel which this instance runs on. If this
 * point is NULL, then the channel is not allocated.
 * @chan: DMA engine handle.
 * @tasklet: Tasklet that gets scheduled from interrupt context to complete a
 * transfer and call client callback.
 * @client: Cliented owned descriptor list.
 * @active: Active descriptor.
 * @queue: Queued jobs.
 * @dma_cfg: The client configuration of this dma channel.
 * @configured: whether the dma_cfg configuration is valid
 * @base: Pointer to the device instance struct.
 * @src_def_cfg: Default cfg register setting for src.
 * @dst_def_cfg: Default cfg register setting for dst.
 * @log_def: Default logical channel settings.
 * @lcla: Space for one dst src pair for logical channel transfers.
 * @lcpa: Pointer to dst and src lcpa settings.
 *
 * This struct can either "be" a logical or a physical channel.
 */
struct d40_chan {
        spinlock_t                       lock;
        int                              log_num;
        /* ID of the most recent completed transfer */
        int                              completed;
        int                              pending_tx;
        bool                             busy;
        struct d40_phy_res              *phy_chan;
        struct dma_chan                  chan;
        struct tasklet_struct            tasklet;
        struct list_head                 client;
        struct list_head                 active;
        struct list_head                 queue;
        struct stedma40_chan_cfg         dma_cfg;
        bool                             configured;
        struct d40_base                 *base;
        /* Default register configurations */
        u32                              src_def_cfg;
        u32                              dst_def_cfg;
        struct d40_def_lcsp              log_def;
        struct d40_log_lli_full         *lcpa;
        /* Runtime reconfiguration */
        dma_addr_t                      runtime_addr;
        enum dma_data_direction         runtime_direction;
};

/**
 * struct d40_base - The big global struct, one for each probe'd instance.
 *
 * @interrupt_lock: Lock used to make sure one interrupt is handle a time.
 * @execmd_lock: Lock for execute command usage since several channels share
 * the same physical register.
 * @dev: The device structure.
 * @virtbase: The virtual base address of the DMA's register.
 * @rev: silicon revision detected.
 * @clk: Pointer to the DMA clock structure.
 * @phy_start: Physical memory start of the DMA registers.
 * @phy_size: Size of the DMA register map.
 * @irq: The IRQ number.
 * @num_phy_chans: The number of physical channels. Read from HW. This
 * is the number of available channels for this driver, not counting "Secure
 * mode" allocated physical channels.
 * @num_log_chans: The number of logical channels. Calculated from
 * num_phy_chans.
 * @dma_both: dma_device channels that can do both memcpy and slave transfers.
 * @dma_slave: dma_device channels that can do only do slave transfers.
 * @dma_memcpy: dma_device channels that can do only do memcpy transfers.
 * @log_chans: Room for all possible logical channels in system.
 * @lookup_log_chans: Used to map interrupt number to logical channel. Points
 * to log_chans entries.
 * @lookup_phy_chans: Used to map interrupt number to physical channel. Points
 * to phy_chans entries.
 * @plat_data: Pointer to provided platform_data which is the driver
 * configuration.
 * @phy_res: Vector containing all physical channels.
 * @lcla_pool: lcla pool settings and data.
 * @lcpa_base: The virtual mapped address of LCPA.
 * @phy_lcpa: The physical address of the LCPA.
 * @lcpa_size: The size of the LCPA area.
 * @desc_slab: cache for descriptors.
 */
struct d40_base {
        spinlock_t                       interrupt_lock;
        spinlock_t                       execmd_lock;
        struct device                    *dev;
        void __iomem                     *virtbase;
        u8                                rev:4;
        struct clk                       *clk;
        phys_addr_t                       phy_start;
        resource_size_t                   phy_size;
        int                               irq;
        int                               num_phy_chans;
        int                               num_log_chans;
        struct dma_device                 dma_both;
        struct dma_device                 dma_slave;
        struct dma_device                 dma_memcpy;
        struct d40_chan                  *phy_chans;
        struct d40_chan                  *log_chans;
        struct d40_chan                 **lookup_log_chans;
        struct d40_chan                 **lookup_phy_chans;
        struct stedma40_platform_data    *plat_data;
        /* Physical half channels */
        struct d40_phy_res               *phy_res;
        struct d40_lcla_pool              lcla_pool;
        void                             *lcpa_base;
        dma_addr_t                        phy_lcpa;
        resource_size_t                   lcpa_size;
        struct kmem_cache                *desc_slab;
};

/**
 * struct d40_interrupt_lookup - lookup table for interrupt handler
 *
 * @src: Interrupt mask register.
 * @clr: Interrupt clear register.
 * @is_error: true if this is an error interrupt.
 * @offset: start delta in the lookup_log_chans in d40_base. If equals to
 * D40_PHY_CHAN, the lookup_phy_chans shall be used instead.
 */
struct d40_interrupt_lookup {
        u32 src;
        u32 clr;
        bool is_error;
        int offset;
};

/**
 * struct d40_reg_val - simple lookup struct
 *
 * @reg: The register.
 * @val: The value that belongs to the register in reg.
 */
struct d40_reg_val {
        unsigned int reg;
        unsigned int val;
};

static struct device *chan2dev(struct d40_chan *d40c)
{
        return &d40c->chan.dev->device;
}

static bool chan_is_physical(struct d40_chan *chan)
{
        return chan->log_num == D40_PHY_CHAN;
}

static bool chan_is_logical(struct d40_chan *chan)
{
        return !chan_is_physical(chan);
}

static void __iomem *chan_base(struct d40_chan *chan)
{
        return chan->base->virtbase + D40_DREG_PCBASE +
               chan->phy_chan->num * D40_DREG_PCDELTA;
}

#define d40_err(dev, format, arg...)            \
        dev_err(dev, "[%s] " format, __func__, ## arg)

#define chan_err(d40c, format, arg...)          \
        d40_err(chan2dev(d40c), format, ## arg)

static int d40_pool_lli_alloc(struct d40_chan *d40c, struct d40_desc *d40d,
                              int lli_len)
{
        bool is_log = chan_is_logical(d40c);
        u32 align;
        void *base;

        if (is_log)
                align = sizeof(struct d40_log_lli);
        else
                align = sizeof(struct d40_phy_lli);

        if (lli_len == 1) {
                base = d40d->lli_pool.pre_alloc_lli;
                d40d->lli_pool.size = sizeof(d40d->lli_pool.pre_alloc_lli);
                d40d->lli_pool.base = NULL;
        } else {
                d40d->lli_pool.size = lli_len * 2 * align;

                base = kmalloc(d40d->lli_pool.size + align, GFP_NOWAIT);
                d40d->lli_pool.base = base;

                if (d40d->lli_pool.base == NULL)
                        return -ENOMEM;
        }

        if (is_log) {
                d40d->lli_log.src = PTR_ALIGN(base, align);
                d40d->lli_log.dst = d40d->lli_log.src + lli_len;

                d40d->lli_pool.dma_addr = 0;
        } else {
                d40d->lli_phy.src = PTR_ALIGN(base, align);
                d40d->lli_phy.dst = d40d->lli_phy.src + lli_len;

                d40d->lli_pool.dma_addr = dma_map_single(d40c->base->dev,
                                                         d40d->lli_phy.src,
                                                         d40d->lli_pool.size,
                                                         DMA_TO_DEVICE);

                if (dma_mapping_error(d40c->base->dev,
                                      d40d->lli_pool.dma_addr)) {
                        kfree(d40d->lli_pool.base);
                        d40d->lli_pool.base = NULL;
                        d40d->lli_pool.dma_addr = 0;
                        return -ENOMEM;
                }
        }

        return 0;
}

static void d40_pool_lli_free(struct d40_chan *d40c, struct d40_desc *d40d)
{
        if (d40d->lli_pool.dma_addr)
                dma_unmap_single(d40c->base->dev, d40d->lli_pool.dma_addr,
                                 d40d->lli_pool.size, DMA_TO_DEVICE);

        kfree(d40d->lli_pool.base);
        d40d->lli_pool.base = NULL;
        d40d->lli_pool.size = 0;
        d40d->lli_log.src = NULL;
        d40d->lli_log.dst = NULL;
        d40d->lli_phy.src = NULL;
        d40d->lli_phy.dst = NULL;
}

static int d40_lcla_alloc_one(struct d40_chan *d40c,
                              struct d40_desc *d40d)
{
        unsigned long flags;
        int i;
        int ret = -EINVAL;
        int p;

        spin_lock_irqsave(&d40c->base->lcla_pool.lock, flags);

        p = d40c->phy_chan->num * D40_LCLA_LINK_PER_EVENT_GRP;

        /*
         * Allocate both src and dst at the same time, therefore the half
         * start on 1 since 0 can't be used since zero is used as end marker.
         */
        for (i = 1 ; i < D40_LCLA_LINK_PER_EVENT_GRP / 2; i++) {
                if (!d40c->base->lcla_pool.alloc_map[p + i]) {
                        d40c->base->lcla_pool.alloc_map[p + i] = d40d;
                        d40d->lcla_alloc++;
                        ret = i;
                        break;
                }
        }

        spin_unlock_irqrestore(&d40c->base->lcla_pool.lock, flags);

        return ret;
}

static int d40_lcla_free_all(struct d40_chan *d40c,
                             struct d40_desc *d40d)
{
        unsigned long flags;
        int i;
        int ret = -EINVAL;

        if (chan_is_physical(d40c))
                return 0;

        spin_lock_irqsave(&d40c->base->lcla_pool.lock, flags);

        for (i = 1 ; i < D40_LCLA_LINK_PER_EVENT_GRP / 2; i++) {
                if (d40c->base->lcla_pool.alloc_map[d40c->phy_chan->num *
                                                    D40_LCLA_LINK_PER_EVENT_GRP + i] == d40d) {
                        d40c->base->lcla_pool.alloc_map[d40c->phy_chan->num *
                                                        D40_LCLA_LINK_PER_EVENT_GRP + i] = NULL;
                        d40d->lcla_alloc--;
                        if (d40d->lcla_alloc == 0) {
                                ret = 0;
                                break;
                        }
                }
        }

        spin_unlock_irqrestore(&d40c->base->lcla_pool.lock, flags);

        return ret;

}

static void d40_desc_remove(struct d40_desc *d40d)
{
        list_del(&d40d->node);
}

static struct d40_desc *d40_desc_get(struct d40_chan *d40c)
{
        struct d40_desc *desc = NULL;

        if (!list_empty(&d40c->client)) {
                struct d40_desc *d;
                struct d40_desc *_d;

                list_for_each_entry_safe(d, _d, &d40c->client, node)
                        if (async_tx_test_ack(&d->txd)) {
                                d40_pool_lli_free(d40c, d);
                                d40_desc_remove(d);
                                desc = d;
                                memset(desc, 0, sizeof(*desc));
                                break;
                        }
        }

        if (!desc)
                desc = kmem_cache_zalloc(d40c->base->desc_slab, GFP_NOWAIT);

        if (desc)
                INIT_LIST_HEAD(&desc->node);

        return desc;
}

static void d40_desc_free(struct d40_chan *d40c, struct d40_desc *d40d)
{

        d40_pool_lli_free(d40c, d40d);
        d40_lcla_free_all(d40c, d40d);
        kmem_cache_free(d40c->base->desc_slab, d40d);
}

static void d40_desc_submit(struct d40_chan *d40c, struct d40_desc *desc)
{
        list_add_tail(&desc->node, &d40c->active);
}

static void d40_desc_load(struct d40_chan *d40c, struct d40_desc *d40d)
{
        int curr_lcla = -EINVAL, next_lcla;

        if (chan_is_physical(d40c)) {
                d40_phy_lli_write(d40c->base->virtbase,
                                  d40c->phy_chan->num,
                                  d40d->lli_phy.dst,
                                  d40d->lli_phy.src);
                d40d->lli_current = d40d->lli_len;
        } else {

                if ((d40d->lli_len - d40d->lli_current) > 1)
                        curr_lcla = d40_lcla_alloc_one(d40c, d40d);

                d40_log_lli_lcpa_write(d40c->lcpa,
                                       &d40d->lli_log.dst[d40d->lli_current],
                                       &d40d->lli_log.src[d40d->lli_current],
                                       curr_lcla);

                d40d->lli_current++;
                for (; d40d->lli_current < d40d->lli_len; d40d->lli_current++) {
                        unsigned int lcla_offset = d40c->phy_chan->num * 1024 +
                                                   8 * curr_lcla * 2;
                        struct d40_lcla_pool *pool = &d40c->base->lcla_pool;
                        struct d40_log_lli *lcla = pool->base + lcla_offset;

                        if (d40d->lli_current + 1 < d40d->lli_len)
                                next_lcla = d40_lcla_alloc_one(d40c, d40d);
                        else
                                next_lcla = -EINVAL;

                        d40_log_lli_lcla_write(lcla,
                                               &d40d->lli_log.dst[d40d->lli_current],
                                               &d40d->lli_log.src[d40d->lli_current],
                                               next_lcla);

                        dma_sync_single_range_for_device(d40c->base->dev,
                                                pool->dma_addr, lcla_offset,
                                                2 * sizeof(struct d40_log_lli),
                                                DMA_TO_DEVICE);

                        curr_lcla = next_lcla;

                        if (curr_lcla == -EINVAL) {
                                d40d->lli_current++;
                                break;
                        }

                }
        }
}

static struct d40_desc *d40_first_active_get(struct d40_chan *d40c)
{
        struct d40_desc *d;

        if (list_empty(&d40c->active))
                return NULL;

        d = list_first_entry(&d40c->active,
                             struct d40_desc,
                             node);
        return d;
}

static void d40_desc_queue(struct d40_chan *d40c, struct d40_desc *desc)
{
        list_add_tail(&desc->node, &d40c->queue);
}

static struct d40_desc *d40_first_queued(struct d40_chan *d40c)
{
        struct d40_desc *d;

        if (list_empty(&d40c->queue))
                return NULL;

        d = list_first_entry(&d40c->queue,
                             struct d40_desc,
                             node);
        return d;
}

static int d40_psize_2_burst_size(bool is_log, int psize)
{
        if (is_log) {
                if (psize == STEDMA40_PSIZE_LOG_1)
                        return 1;
        } else {
                if (psize == STEDMA40_PSIZE_PHY_1)
                        return 1;
        }

        return 2 << psize;
}

/*
 * The dma only supports transmitting packages up to
 * STEDMA40_MAX_SEG_SIZE << data_width. Calculate the total number of
 * dma elements required to send the entire sg list
 */
static int d40_size_2_dmalen(int size, u32 data_width1, u32 data_width2)
{
        int dmalen;
        u32 max_w = max(data_width1, data_width2);
        u32 min_w = min(data_width1, data_width2);
        u32 seg_max = ALIGN(STEDMA40_MAX_SEG_SIZE << min_w, 1 << max_w);

        if (seg_max > STEDMA40_MAX_SEG_SIZE)
                seg_max -= (1 << max_w);

        if (!IS_ALIGNED(size, 1 << max_w))
                return -EINVAL;

        if (size <= seg_max)
                dmalen = 1;
        else {
                dmalen = size / seg_max;
                if (dmalen * seg_max < size)
                        dmalen++;
        }
        return dmalen;
}

static int d40_sg_2_dmalen(struct scatterlist *sgl, int sg_len,
                           u32 data_width1, u32 data_width2)
{
        struct scatterlist *sg;
        int i;
        int len = 0;
        int ret;

        for_each_sg(sgl, sg, sg_len, i) {
                ret = d40_size_2_dmalen(sg_dma_len(sg),
                                        data_width1, data_width2);
                if (ret < 0)
                        return ret;
                len += ret;
        }
        return len;
}

/* Support functions for logical channels */

static int d40_channel_execute_command(struct d40_chan *d40c,
                                       enum d40_command command)
{
        u32 status;
        int i;
        void __iomem *active_reg;
        int ret = 0;
        unsigned long flags;
        u32 wmask;

        spin_lock_irqsave(&d40c->base->execmd_lock, flags);

        if (d40c->phy_chan->num % 2 == 0)
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
        else
                active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;

        if (command == D40_DMA_SUSPEND_REQ) {
                status = (readl(active_reg) &
                          D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                        D40_CHAN_POS(d40c->phy_chan->num);

                if (status == D40_DMA_SUSPENDED || status == D40_DMA_STOP)
                        goto done;
        }

        wmask = 0xffffffff & ~(D40_CHAN_POS_MASK(d40c->phy_chan->num));
        writel(wmask | (command << D40_CHAN_POS(d40c->phy_chan->num)),
               active_reg);

        if (command == D40_DMA_SUSPEND_REQ) {

                for (i = 0 ; i < D40_SUSPEND_MAX_IT; i++) {
                        status = (readl(active_reg) &
                                  D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                                D40_CHAN_POS(d40c->phy_chan->num);

                        cpu_relax();
                        /*
                         * Reduce the number of bus accesses while
                         * waiting for the DMA to suspend.
                         */
                        udelay(3);

                        if (status == D40_DMA_STOP ||
                            status == D40_DMA_SUSPENDED)
                                break;
                }

                if (i == D40_SUSPEND_MAX_IT) {
                        chan_err(d40c,
                                "unable to suspend the chl %d (log: %d) status %x\n",
                                d40c->phy_chan->num, d40c->log_num,
                                status);
                        dump_stack();
                        ret = -EBUSY;
                }

        }
done:
        spin_unlock_irqrestore(&d40c->base->execmd_lock, flags);
        return ret;
}

static void d40_term_all(struct d40_chan *d40c)
{
        struct d40_desc *d40d;

        /* Release active descriptors */
        while ((d40d = d40_first_active_get(d40c))) {
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        }

        /* Release queued descriptors waiting for transfer */
        while ((d40d = d40_first_queued(d40c))) {
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        }


        d40c->pending_tx = 0;
        d40c->busy = false;
}

static void __d40_config_set_event(struct d40_chan *d40c, bool enable,
                                   u32 event, int reg)
{
        void __iomem *addr = chan_base(d40c) + reg;
        int tries;

        if (!enable) {
                writel((D40_DEACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
                       | ~D40_EVENTLINE_MASK(event), addr);
                return;
        }

        /*
         * The hardware sometimes doesn't register the enable when src and dst
         * event lines are active on the same logical channel.  Retry to ensure
         * it does.  Usually only one retry is sufficient.
         */
        tries = 100;
        while (--tries) {
                writel((D40_ACTIVATE_EVENTLINE << D40_EVENTLINE_POS(event))
                       | ~D40_EVENTLINE_MASK(event), addr);

                if (readl(addr) & D40_EVENTLINE_MASK(event))
                        break;
        }

        if (tries != 99)
                dev_dbg(chan2dev(d40c),
                        "[%s] workaround enable S%cLNK (%d tries)\n",
                        __func__, reg == D40_CHAN_REG_SSLNK ? 'S' : 'D',
                        100 - tries);

        WARN_ON(!tries);
}

static void d40_config_set_event(struct d40_chan *d40c, bool do_enable)
{
        unsigned long flags;

        spin_lock_irqsave(&d40c->phy_chan->lock, flags);

        /* Enable event line connected to device (or memcpy) */
        if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH)) {
                u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);

                __d40_config_set_event(d40c, do_enable, event,
                                       D40_CHAN_REG_SSLNK);
        }

        if (d40c->dma_cfg.dir !=  STEDMA40_PERIPH_TO_MEM) {
                u32 event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);

                __d40_config_set_event(d40c, do_enable, event,
                                       D40_CHAN_REG_SDLNK);
        }

        spin_unlock_irqrestore(&d40c->phy_chan->lock, flags);
}

static u32 d40_chan_has_events(struct d40_chan *d40c)
{
        void __iomem *chanbase = chan_base(d40c);
        u32 val;

        val = readl(chanbase + D40_CHAN_REG_SSLNK);
        val |= readl(chanbase + D40_CHAN_REG_SDLNK);

        return val;
}

static u32 d40_get_prmo(struct d40_chan *d40c)
{
        static const unsigned int phy_map[] = {
                [STEDMA40_PCHAN_BASIC_MODE]
                        = D40_DREG_PRMO_PCHAN_BASIC,
                [STEDMA40_PCHAN_MODULO_MODE]
                        = D40_DREG_PRMO_PCHAN_MODULO,
                [STEDMA40_PCHAN_DOUBLE_DST_MODE]
                        = D40_DREG_PRMO_PCHAN_DOUBLE_DST,
        };
        static const unsigned int log_map[] = {
                [STEDMA40_LCHAN_SRC_PHY_DST_LOG]
                        = D40_DREG_PRMO_LCHAN_SRC_PHY_DST_LOG,
                [STEDMA40_LCHAN_SRC_LOG_DST_PHY]
                        = D40_DREG_PRMO_LCHAN_SRC_LOG_DST_PHY,
                [STEDMA40_LCHAN_SRC_LOG_DST_LOG]
                        = D40_DREG_PRMO_LCHAN_SRC_LOG_DST_LOG,
        };

        if (chan_is_physical(d40c))
                return phy_map[d40c->dma_cfg.mode_opt];
        else
                return log_map[d40c->dma_cfg.mode_opt];
}

static void d40_config_write(struct d40_chan *d40c)
{
        u32 addr_base;
        u32 var;

        /* Odd addresses are even addresses + 4 */
        addr_base = (d40c->phy_chan->num % 2) * 4;
        /* Setup channel mode to logical or physical */
        var = ((u32)(chan_is_logical(d40c)) + 1) <<
                D40_CHAN_POS(d40c->phy_chan->num);
        writel(var, d40c->base->virtbase + D40_DREG_PRMSE + addr_base);

        /* Setup operational mode option register */
        var = d40_get_prmo(d40c) << D40_CHAN_POS(d40c->phy_chan->num);

        writel(var, d40c->base->virtbase + D40_DREG_PRMOE + addr_base);

        if (chan_is_logical(d40c)) {
                int lidx = (d40c->phy_chan->num << D40_SREG_ELEM_LOG_LIDX_POS)
                           & D40_SREG_ELEM_LOG_LIDX_MASK;
                void __iomem *chanbase = chan_base(d40c);

                /* Set default config for CFG reg */
                writel(d40c->src_def_cfg, chanbase + D40_CHAN_REG_SSCFG);
                writel(d40c->dst_def_cfg, chanbase + D40_CHAN_REG_SDCFG);

                /* Set LIDX for lcla */
                writel(lidx, chanbase + D40_CHAN_REG_SSELT);
                writel(lidx, chanbase + D40_CHAN_REG_SDELT);
        }
}

static u32 d40_residue(struct d40_chan *d40c)
{
        u32 num_elt;

        if (chan_is_logical(d40c))
                num_elt = (readl(&d40c->lcpa->lcsp2) & D40_MEM_LCSP2_ECNT_MASK)
                        >> D40_MEM_LCSP2_ECNT_POS;
        else {
                u32 val = readl(chan_base(d40c) + D40_CHAN_REG_SDELT);
                num_elt = (val & D40_SREG_ELEM_PHY_ECNT_MASK)
                          >> D40_SREG_ELEM_PHY_ECNT_POS;
        }

        return num_elt * (1 << d40c->dma_cfg.dst_info.data_width);
}

static bool d40_tx_is_linked(struct d40_chan *d40c)
{
        bool is_link;

        if (chan_is_logical(d40c))
                is_link = readl(&d40c->lcpa->lcsp3) &  D40_MEM_LCSP3_DLOS_MASK;
        else
                is_link = readl(chan_base(d40c) + D40_CHAN_REG_SDLNK)
                          & D40_SREG_LNK_PHYS_LNK_MASK;

        return is_link;
}

static int d40_pause(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int res = 0;
        unsigned long flags;

        if (!d40c->busy)
                return 0;

        spin_lock_irqsave(&d40c->lock, flags);

        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
        if (res == 0) {
                if (chan_is_logical(d40c)) {
                        d40_config_set_event(d40c, false);
                        /* Resume the other logical channels if any */
                        if (d40_chan_has_events(d40c))
                                res = d40_channel_execute_command(d40c,
                                                                  D40_DMA_RUN);
                }
        }

        spin_unlock_irqrestore(&d40c->lock, flags);
        return res;
}

static int d40_resume(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int res = 0;
        unsigned long flags;

        if (!d40c->busy)
                return 0;

        spin_lock_irqsave(&d40c->lock, flags);

        if (d40c->base->rev == 0)
                if (chan_is_logical(d40c)) {
                        res = d40_channel_execute_command(d40c,
                                                          D40_DMA_SUSPEND_REQ);
                        goto no_suspend;
                }

        /* If bytes left to transfer or linked tx resume job */
        if (d40_residue(d40c) || d40_tx_is_linked(d40c)) {

                if (chan_is_logical(d40c))
                        d40_config_set_event(d40c, true);

                res = d40_channel_execute_command(d40c, D40_DMA_RUN);
        }

no_suspend:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return res;
}

static dma_cookie_t d40_tx_submit(struct dma_async_tx_descriptor *tx)
{
        struct d40_chan *d40c = container_of(tx->chan,
                                             struct d40_chan,
                                             chan);
        struct d40_desc *d40d = container_of(tx, struct d40_desc, txd);
        unsigned long flags;

        spin_lock_irqsave(&d40c->lock, flags);

        d40c->chan.cookie++;

        if (d40c->chan.cookie < 0)
                d40c->chan.cookie = 1;

        d40d->txd.cookie = d40c->chan.cookie;

        d40_desc_queue(d40c, d40d);

        spin_unlock_irqrestore(&d40c->lock, flags);

        return tx->cookie;
}

static int d40_start(struct d40_chan *d40c)
{
        if (d40c->base->rev == 0) {
                int err;

                if (chan_is_logical(d40c)) {
                        err = d40_channel_execute_command(d40c,
                                                          D40_DMA_SUSPEND_REQ);
                        if (err)
                                return err;
                }
        }

        if (chan_is_logical(d40c))
                d40_config_set_event(d40c, true);

        return d40_channel_execute_command(d40c, D40_DMA_RUN);
}

static struct d40_desc *d40_queue_start(struct d40_chan *d40c)
{
        struct d40_desc *d40d;
        int err;

        /* Start queued jobs, if any */
        d40d = d40_first_queued(d40c);

        if (d40d != NULL) {
                d40c->busy = true;

                /* Remove from queue */
                d40_desc_remove(d40d);

                /* Add to active queue */
                d40_desc_submit(d40c, d40d);

                /* Initiate DMA job */
                d40_desc_load(d40c, d40d);

                /* Start dma job */
                err = d40_start(d40c);

                if (err)
                        return NULL;
        }

        return d40d;
}

/* called from interrupt context */
static void dma_tc_handle(struct d40_chan *d40c)
{
        struct d40_desc *d40d;

        /* Get first active entry from list */
        d40d = d40_first_active_get(d40c);

        if (d40d == NULL)
                return;

        d40_lcla_free_all(d40c, d40d);

        if (d40d->lli_current < d40d->lli_len) {
                d40_desc_load(d40c, d40d);
                /* Start dma job */
                (void) d40_start(d40c);
                return;
        }

        if (d40_queue_start(d40c) == NULL)
                d40c->busy = false;

        d40c->pending_tx++;
        tasklet_schedule(&d40c->tasklet);

}

static void dma_tasklet(unsigned long data)
{
        struct d40_chan *d40c = (struct d40_chan *) data;
        struct d40_desc *d40d;
        unsigned long flags;
        dma_async_tx_callback callback;
        void *callback_param;

        spin_lock_irqsave(&d40c->lock, flags);

        /* Get first active entry from list */
        d40d = d40_first_active_get(d40c);

        if (d40d == NULL)
                goto err;

        d40c->completed = d40d->txd.cookie;

        /*
         * If terminating a channel pending_tx is set to zero.
         * This prevents any finished active jobs to return to the client.
         */
        if (d40c->pending_tx == 0) {
                spin_unlock_irqrestore(&d40c->lock, flags);
                return;
        }

        /* Callback to client */
        callback = d40d->txd.callback;
        callback_param = d40d->txd.callback_param;

        if (async_tx_test_ack(&d40d->txd)) {
                d40_pool_lli_free(d40c, d40d);
                d40_desc_remove(d40d);
                d40_desc_free(d40c, d40d);
        } else {
                if (!d40d->is_in_client_list) {
                        d40_desc_remove(d40d);
                        d40_lcla_free_all(d40c, d40d);
                        list_add_tail(&d40d->node, &d40c->client);
                        d40d->is_in_client_list = true;
                }
        }

        d40c->pending_tx--;

        if (d40c->pending_tx)
                tasklet_schedule(&d40c->tasklet);

        spin_unlock_irqrestore(&d40c->lock, flags);

        if (callback && (d40d->txd.flags & DMA_PREP_INTERRUPT))
                callback(callback_param);

        return;

 err:
        /* Rescue manouver if receiving double interrupts */
        if (d40c->pending_tx > 0)
                d40c->pending_tx--;
        spin_unlock_irqrestore(&d40c->lock, flags);
}

static irqreturn_t d40_handle_interrupt(int irq, void *data)
{
        static const struct d40_interrupt_lookup il[] = {
                {D40_DREG_LCTIS0, D40_DREG_LCICR0, false,  0},
                {D40_DREG_LCTIS1, D40_DREG_LCICR1, false, 32},
                {D40_DREG_LCTIS2, D40_DREG_LCICR2, false, 64},
                {D40_DREG_LCTIS3, D40_DREG_LCICR3, false, 96},
                {D40_DREG_LCEIS0, D40_DREG_LCICR0, true,   0},
                {D40_DREG_LCEIS1, D40_DREG_LCICR1, true,  32},
                {D40_DREG_LCEIS2, D40_DREG_LCICR2, true,  64},
                {D40_DREG_LCEIS3, D40_DREG_LCICR3, true,  96},
                {D40_DREG_PCTIS,  D40_DREG_PCICR,  false, D40_PHY_CHAN},
                {D40_DREG_PCEIS,  D40_DREG_PCICR,  true,  D40_PHY_CHAN},
        };

        int i;
        u32 regs[ARRAY_SIZE(il)];
        u32 idx;
        u32 row;
        long chan = -1;
        struct d40_chan *d40c;
        unsigned long flags;
        struct d40_base *base = data;

        spin_lock_irqsave(&base->interrupt_lock, flags);

        /* Read interrupt status of both logical and physical channels */
        for (i = 0; i < ARRAY_SIZE(il); i++)
                regs[i] = readl(base->virtbase + il[i].src);

        for (;;) {

                chan = find_next_bit((unsigned long *)regs,
                                     BITS_PER_LONG * ARRAY_SIZE(il), chan + 1);

                /* No more set bits found? */
                if (chan == BITS_PER_LONG * ARRAY_SIZE(il))
                        break;

                row = chan / BITS_PER_LONG;
                idx = chan & (BITS_PER_LONG - 1);

                /* ACK interrupt */
                writel(1 << idx, base->virtbase + il[row].clr);

                if (il[row].offset == D40_PHY_CHAN)
                        d40c = base->lookup_phy_chans[idx];
                else
                        d40c = base->lookup_log_chans[il[row].offset + idx];
                spin_lock(&d40c->lock);

                if (!il[row].is_error)
                        dma_tc_handle(d40c);
                else
                        d40_err(base->dev, "IRQ chan: %ld offset %d idx %d\n",
                                chan, il[row].offset, idx);

                spin_unlock(&d40c->lock);
        }

        spin_unlock_irqrestore(&base->interrupt_lock, flags);

        return IRQ_HANDLED;
}

static int d40_validate_conf(struct d40_chan *d40c,
                             struct stedma40_chan_cfg *conf)
{
        int res = 0;
        u32 dst_event_group = D40_TYPE_TO_GROUP(conf->dst_dev_type);
        u32 src_event_group = D40_TYPE_TO_GROUP(conf->src_dev_type);
        bool is_log = conf->mode == STEDMA40_MODE_LOGICAL;

        if (!conf->dir) {
                chan_err(d40c, "Invalid direction.\n");
                res = -EINVAL;
        }

        if (conf->dst_dev_type != STEDMA40_DEV_DST_MEMORY &&
            d40c->base->plat_data->dev_tx[conf->dst_dev_type] == 0 &&
            d40c->runtime_addr == 0) {

                chan_err(d40c, "Invalid TX channel address (%d)\n",
                         conf->dst_dev_type);
                res = -EINVAL;
        }

        if (conf->src_dev_type != STEDMA40_DEV_SRC_MEMORY &&
            d40c->base->plat_data->dev_rx[conf->src_dev_type] == 0 &&
            d40c->runtime_addr == 0) {
                chan_err(d40c, "Invalid RX channel address (%d)\n",
                        conf->src_dev_type);
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_MEM_TO_PERIPH &&
            dst_event_group == STEDMA40_DEV_DST_MEMORY) {
                chan_err(d40c, "Invalid dst\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_MEM &&
            src_event_group == STEDMA40_DEV_SRC_MEMORY) {
                chan_err(d40c, "Invalid src\n");
                res = -EINVAL;
        }

        if (src_event_group == STEDMA40_DEV_SRC_MEMORY &&
            dst_event_group == STEDMA40_DEV_DST_MEMORY && is_log) {
                chan_err(d40c, "No event line\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_PERIPH &&
            (src_event_group != dst_event_group)) {
                chan_err(d40c, "Invalid event group\n");
                res = -EINVAL;
        }

        if (conf->dir == STEDMA40_PERIPH_TO_PERIPH) {
                /*
                 * DMAC HW supports it. Will be added to this driver,
                 * in case any dma client requires it.
                 */
                chan_err(d40c, "periph to periph not supported\n");
                res = -EINVAL;
        }

        if (d40_psize_2_burst_size(is_log, conf->src_info.psize) *
            (1 << conf->src_info.data_width) !=
            d40_psize_2_burst_size(is_log, conf->dst_info.psize) *
            (1 << conf->dst_info.data_width)) {
                /*
                 * The DMAC hardware only supports
                 * src (burst x width) == dst (burst x width)
                 */

                chan_err(d40c, "src (burst x width) != dst (burst x width)\n");
                res = -EINVAL;
        }

        return res;
}

static bool d40_alloc_mask_set(struct d40_phy_res *phy, bool is_src,
                               int log_event_line, bool is_log)
{
        unsigned long flags;
        spin_lock_irqsave(&phy->lock, flags);
        if (!is_log) {
                /* Physical interrupts are masked per physical full channel */
                if (phy->allocated_src == D40_ALLOC_FREE &&
                    phy->allocated_dst == D40_ALLOC_FREE) {
                        phy->allocated_dst = D40_ALLOC_PHY;
                        phy->allocated_src = D40_ALLOC_PHY;
                        goto found;
                } else
                        goto not_found;
        }

        /* Logical channel */
        if (is_src) {
                if (phy->allocated_src == D40_ALLOC_PHY)
                        goto not_found;

                if (phy->allocated_src == D40_ALLOC_FREE)
                        phy->allocated_src = D40_ALLOC_LOG_FREE;

                if (!(phy->allocated_src & (1 << log_event_line))) {
                        phy->allocated_src |= 1 << log_event_line;
                        goto found;
                } else
                        goto not_found;
        } else {
                if (phy->allocated_dst == D40_ALLOC_PHY)
                        goto not_found;

                if (phy->allocated_dst == D40_ALLOC_FREE)
                        phy->allocated_dst = D40_ALLOC_LOG_FREE;

                if (!(phy->allocated_dst & (1 << log_event_line))) {
                        phy->allocated_dst |= 1 << log_event_line;
                        goto found;
                } else
                        goto not_found;
        }

not_found:
        spin_unlock_irqrestore(&phy->lock, flags);
        return false;
found:
        spin_unlock_irqrestore(&phy->lock, flags);
        return true;
}

static bool d40_alloc_mask_free(struct d40_phy_res *phy, bool is_src,
                               int log_event_line)
{
        unsigned long flags;
        bool is_free = false;

        spin_lock_irqsave(&phy->lock, flags);
        if (!log_event_line) {
                phy->allocated_dst = D40_ALLOC_FREE;
                phy->allocated_src = D40_ALLOC_FREE;
                is_free = true;
                goto out;
        }

        /* Logical channel */
        if (is_src) {
                phy->allocated_src &= ~(1 << log_event_line);
                if (phy->allocated_src == D40_ALLOC_LOG_FREE)
                        phy->allocated_src = D40_ALLOC_FREE;
        } else {
                phy->allocated_dst &= ~(1 << log_event_line);
                if (phy->allocated_dst == D40_ALLOC_LOG_FREE)
                        phy->allocated_dst = D40_ALLOC_FREE;
        }

        is_free = ((phy->allocated_src | phy->allocated_dst) ==
                   D40_ALLOC_FREE);

out:
        spin_unlock_irqrestore(&phy->lock, flags);

        return is_free;
}

static int d40_allocate_channel(struct d40_chan *d40c)
{
        int dev_type;
        int event_group;
        int event_line;
        struct d40_phy_res *phys;
        int i;
        int j;
        int log_num;
        bool is_src;
        bool is_log = d40c->dma_cfg.mode == STEDMA40_MODE_LOGICAL;

        phys = d40c->base->phy_res;

        if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                dev_type = d40c->dma_cfg.src_dev_type;
                log_num = 2 * dev_type;
                is_src = true;
        } else if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
                   d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                /* dst event lines are used for logical memcpy */
                dev_type = d40c->dma_cfg.dst_dev_type;
                log_num = 2 * dev_type + 1;
                is_src = false;
        } else
                return -EINVAL;

        event_group = D40_TYPE_TO_GROUP(dev_type);
        event_line = D40_TYPE_TO_EVENT(dev_type);

        if (!is_log) {
                if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                        /* Find physical half channel */
                        for (i = 0; i < d40c->base->num_phy_chans; i++) {

                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       0, is_log))
                                        goto found_phy;
                        }
                } else
                        for (j = 0; j < d40c->base->num_phy_chans; j += 8) {
                                int phy_num = j  + event_group * 2;
                                for (i = phy_num; i < phy_num + 2; i++) {
                                        if (d40_alloc_mask_set(&phys[i],
                                                               is_src,
                                                               0,
                                                               is_log))
                                                goto found_phy;
                                }
                        }
                return -EINVAL;
found_phy:
                d40c->phy_chan = &phys[i];
                d40c->log_num = D40_PHY_CHAN;
                goto out;
        }
        if (dev_type == -1)
                return -EINVAL;

        /* Find logical channel */
        for (j = 0; j < d40c->base->num_phy_chans; j += 8) {
                int phy_num = j + event_group * 2;
                /*
                 * Spread logical channels across all available physical rather
                 * than pack every logical channel at the first available phy
                 * channels.
                 */
                if (is_src) {
                        for (i = phy_num; i < phy_num + 2; i++) {
                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       event_line, is_log))
                                        goto found_log;
                        }
                } else {
                        for (i = phy_num + 1; i >= phy_num; i--) {
                                if (d40_alloc_mask_set(&phys[i], is_src,
                                                       event_line, is_log))
                                        goto found_log;
                        }
                }
        }
        return -EINVAL;

found_log:
        d40c->phy_chan = &phys[i];
        d40c->log_num = log_num;
out:

        if (is_log)
                d40c->base->lookup_log_chans[d40c->log_num] = d40c;
        else
                d40c->base->lookup_phy_chans[d40c->phy_chan->num] = d40c;

        return 0;

}

static int d40_config_memcpy(struct d40_chan *d40c)
{
        dma_cap_mask_t cap = d40c->chan.device->cap_mask;

        if (dma_has_cap(DMA_MEMCPY, cap) && !dma_has_cap(DMA_SLAVE, cap)) {
                d40c->dma_cfg = *d40c->base->plat_data->memcpy_conf_log;
                d40c->dma_cfg.src_dev_type = STEDMA40_DEV_SRC_MEMORY;
                d40c->dma_cfg.dst_dev_type = d40c->base->plat_data->
                        memcpy[d40c->chan.chan_id];

        } else if (dma_has_cap(DMA_MEMCPY, cap) &&
                   dma_has_cap(DMA_SLAVE, cap)) {
                d40c->dma_cfg = *d40c->base->plat_data->memcpy_conf_phy;
        } else {
                chan_err(d40c, "No memcpy\n");
                return -EINVAL;
        }

        return 0;
}


static int d40_free_dma(struct d40_chan *d40c)
{

        int res = 0;
        u32 event;
        struct d40_phy_res *phy = d40c->phy_chan;
        bool is_src;
        struct d40_desc *d;
        struct d40_desc *_d;


        /* Terminate all queued and active transfers */
        d40_term_all(d40c);

        /* Release client owned descriptors */
        if (!list_empty(&d40c->client))
                list_for_each_entry_safe(d, _d, &d40c->client, node) {
                        d40_pool_lli_free(d40c, d);
                        d40_desc_remove(d);
                        d40_desc_free(d40c, d);
                }

        if (phy == NULL) {
                chan_err(d40c, "phy == null\n");
                return -EINVAL;
        }

        if (phy->allocated_src == D40_ALLOC_FREE &&
            phy->allocated_dst == D40_ALLOC_FREE) {
                chan_err(d40c, "channel already free\n");
                return -EINVAL;
        }

        if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
            d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
                is_src = false;
        } else if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
                is_src = true;
        } else {
                chan_err(d40c, "Unknown direction\n");
                return -EINVAL;
        }

        res = d40_channel_execute_command(d40c, D40_DMA_SUSPEND_REQ);
        if (res) {
                chan_err(d40c, "suspend failed\n");
                return res;
        }

        if (chan_is_logical(d40c)) {
                /* Release logical channel, deactivate the event line */

                d40_config_set_event(d40c, false);
                d40c->base->lookup_log_chans[d40c->log_num] = NULL;

                /*
                 * Check if there are more logical allocation
                 * on this phy channel.
                 */
                if (!d40_alloc_mask_free(phy, is_src, event)) {
                        /* Resume the other logical channels if any */
                        if (d40_chan_has_events(d40c)) {
                                res = d40_channel_execute_command(d40c,
                                                                  D40_DMA_RUN);
                                if (res) {
                                        chan_err(d40c,
                                                "Executing RUN command\n");
                                        return res;
                                }
                        }
                        return 0;
                }
        } else {
                (void) d40_alloc_mask_free(phy, is_src, 0);
        }

        /* Release physical channel */
        res = d40_channel_execute_command(d40c, D40_DMA_STOP);
        if (res) {
                chan_err(d40c, "Failed to stop channel\n");
                return res;
        }
        d40c->phy_chan = NULL;
        d40c->configured = false;
        d40c->base->lookup_phy_chans[phy->num] = NULL;

        return 0;
}

static bool d40_is_paused(struct d40_chan *d40c)
{
        void __iomem *chanbase = chan_base(d40c);
        bool is_paused = false;
        unsigned long flags;
        void __iomem *active_reg;
        u32 status;
        u32 event;

        spin_lock_irqsave(&d40c->lock, flags);

        if (chan_is_physical(d40c)) {
                if (d40c->phy_chan->num % 2 == 0)
                        active_reg = d40c->base->virtbase + D40_DREG_ACTIVE;
                else
                        active_reg = d40c->base->virtbase + D40_DREG_ACTIVO;

                status = (readl(active_reg) &
                          D40_CHAN_POS_MASK(d40c->phy_chan->num)) >>
                        D40_CHAN_POS(d40c->phy_chan->num);
                if (status == D40_DMA_SUSPENDED || status == D40_DMA_STOP)
                        is_paused = true;

                goto _exit;
        }

        if (d40c->dma_cfg.dir == STEDMA40_MEM_TO_PERIPH ||
            d40c->dma_cfg.dir == STEDMA40_MEM_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.dst_dev_type);
                status = readl(chanbase + D40_CHAN_REG_SDLNK);
        } else if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM) {
                event = D40_TYPE_TO_EVENT(d40c->dma_cfg.src_dev_type);
                status = readl(chanbase + D40_CHAN_REG_SSLNK);
        } else {
                chan_err(d40c, "Unknown direction\n");
                goto _exit;
        }

        status = (status & D40_EVENTLINE_MASK(event)) >>
                D40_EVENTLINE_POS(event);

        if (status != D40_DMA_RUN)
                is_paused = true;
_exit:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return is_paused;

}


static u32 stedma40_residue(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        u32 bytes_left;
        unsigned long flags;

        spin_lock_irqsave(&d40c->lock, flags);
        bytes_left = d40_residue(d40c);
        spin_unlock_irqrestore(&d40c->lock, flags);

        return bytes_left;
}

static int
d40_prep_sg_log(struct d40_chan *chan, struct d40_desc *desc,
                struct scatterlist *sg_src, struct scatterlist *sg_dst,
                unsigned int sg_len, enum dma_data_direction direction,
                dma_addr_t dev_addr)
{
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct stedma40_half_channel_info *src_info = &cfg->src_info;
        struct stedma40_half_channel_info *dst_info = &cfg->dst_info;

        if (direction == DMA_NONE) {
                /* memcpy */
                (void) d40_log_sg_to_lli(sg_src, sg_len,
                                         desc->lli_log.src,
                                         chan->log_def.lcsp1,
                                         src_info->data_width,
                                         dst_info->data_width);

                (void) d40_log_sg_to_lli(sg_dst, sg_len,
                                         desc->lli_log.dst,
                                         chan->log_def.lcsp3,
                                         dst_info->data_width,
                                         src_info->data_width);
        } else {
                unsigned int total_size;

                total_size = d40_log_sg_to_dev(sg_src, sg_len,
                                               &desc->lli_log,
                                               &chan->log_def,
                                               src_info->data_width,
                                               dst_info->data_width,
                                               direction, dev_addr);
                if (total_size < 0)
                        return -EINVAL;
        }

        return 0;
}

static int
d40_prep_sg_phy(struct d40_chan *chan, struct d40_desc *desc,
                struct scatterlist *sg_src, struct scatterlist *sg_dst,
                unsigned int sg_len, enum dma_data_direction direction,
                dma_addr_t dev_addr)
{
        dma_addr_t src_dev_addr = direction == DMA_FROM_DEVICE ? dev_addr : 0;
        dma_addr_t dst_dev_addr = direction == DMA_TO_DEVICE ? dev_addr : 0;
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct stedma40_half_channel_info *src_info = &cfg->src_info;
        struct stedma40_half_channel_info *dst_info = &cfg->dst_info;
        int ret;

        ret = d40_phy_sg_to_lli(sg_src, sg_len, src_dev_addr,
                                desc->lli_phy.src,
                                virt_to_phys(desc->lli_phy.src),
                                chan->src_def_cfg,
                                src_info->data_width,
                                dst_info->data_width,
                                src_info->psize);

        ret = d40_phy_sg_to_lli(sg_dst, sg_len, dst_dev_addr,
                                desc->lli_phy.dst,
                                virt_to_phys(desc->lli_phy.dst),
                                chan->dst_def_cfg,
                                dst_info->data_width,
                                src_info->data_width,
                                dst_info->psize);

        dma_sync_single_for_device(chan->base->dev, desc->lli_pool.dma_addr,
                                   desc->lli_pool.size, DMA_TO_DEVICE);

        return ret < 0 ? ret : 0;
}


static struct d40_desc *
d40_prep_desc(struct d40_chan *chan, struct scatterlist *sg,
              unsigned int sg_len, unsigned long dma_flags)
{
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        struct d40_desc *desc;
        int ret;

        desc = d40_desc_get(chan);
        if (!desc)
                return NULL;

        desc->lli_len = d40_sg_2_dmalen(sg, sg_len, cfg->src_info.data_width,
                                        cfg->dst_info.data_width);
        if (desc->lli_len < 0) {
                chan_err(chan, "Unaligned size\n");
                goto err;
        }

        ret = d40_pool_lli_alloc(chan, desc, desc->lli_len);
        if (ret < 0) {
                chan_err(chan, "Could not allocate lli\n");
                goto err;
        }


        desc->lli_current = 0;
        desc->txd.flags = dma_flags;
        desc->txd.tx_submit = d40_tx_submit;

        dma_async_tx_descriptor_init(&desc->txd, &chan->chan);

        return desc;

err:
        d40_desc_free(chan, desc);
        return NULL;
}

static dma_addr_t
d40_get_dev_addr(struct d40_chan *chan, enum dma_data_direction direction)
{
        struct stedma40_platform_data *plat = chan->base->plat_data;
        struct stedma40_chan_cfg *cfg = &chan->dma_cfg;
        dma_addr_t addr;

        if (chan->runtime_addr)
                return chan->runtime_addr;

        if (direction == DMA_FROM_DEVICE)
                addr = plat->dev_rx[cfg->src_dev_type];
        else if (direction == DMA_TO_DEVICE)
                addr = plat->dev_tx[cfg->dst_dev_type];

        return addr;
}

static struct dma_async_tx_descriptor *
d40_prep_sg(struct dma_chan *dchan, struct scatterlist *sg_src,
            struct scatterlist *sg_dst, unsigned int sg_len,
            enum dma_data_direction direction, unsigned long dma_flags)
{
        struct d40_chan *chan = container_of(dchan, struct d40_chan, chan);
        dma_addr_t dev_addr = 0;
        struct d40_desc *desc;
        unsigned long flags;
        int ret;

        if (!chan->phy_chan) {
                chan_err(chan, "Cannot prepare unallocated channel\n");
                return NULL;
        }

        spin_lock_irqsave(&chan->lock, flags);

        desc = d40_prep_desc(chan, sg_src, sg_len, dma_flags);
        if (desc == NULL)
                goto err;

        if (direction != DMA_NONE)
                dev_addr = d40_get_dev_addr(chan, direction);

        if (chan_is_logical(chan))
                ret = d40_prep_sg_log(chan, desc, sg_src, sg_dst,
                                      sg_len, direction, dev_addr);
        else
                ret = d40_prep_sg_phy(chan, desc, sg_src, sg_dst,
                                      sg_len, direction, dev_addr);

        if (ret) {
                chan_err(chan, "Failed to prepare %s sg job: %d\n",
                         chan_is_logical(chan) ? "log" : "phy", ret);
                goto err;
        }

        spin_unlock_irqrestore(&chan->lock, flags);

        return &desc->txd;

err:
        if (desc)
                d40_desc_free(chan, desc);
        spin_unlock_irqrestore(&chan->lock, flags);
        return NULL;
}

bool stedma40_filter(struct dma_chan *chan, void *data)
{
        struct stedma40_chan_cfg *info = data;
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int err;

        if (data) {
                err = d40_validate_conf(d40c, info);
                if (!err)
                        d40c->dma_cfg = *info;
        } else
                err = d40_config_memcpy(d40c);

        if (!err)
                d40c->configured = true;

        return err == 0;
}
EXPORT_SYMBOL(stedma40_filter);

static void __d40_set_prio_rt(struct d40_chan *d40c, int dev_type, bool src)
{
        bool realtime = d40c->dma_cfg.realtime;
        bool highprio = d40c->dma_cfg.high_priority;
        u32 prioreg = highprio ? D40_DREG_PSEG1 : D40_DREG_PCEG1;
        u32 rtreg = realtime ? D40_DREG_RSEG1 : D40_DREG_RCEG1;
        u32 event = D40_TYPE_TO_EVENT(dev_type);
        u32 group = D40_TYPE_TO_GROUP(dev_type);
        u32 bit = 1 << event;

        /* Destination event lines are stored in the upper halfword */
        if (!src)
                bit <<= 16;

        writel(bit, d40c->base->virtbase + prioreg + group * 4);
        writel(bit, d40c->base->virtbase + rtreg + group * 4);
}

static void d40_set_prio_realtime(struct d40_chan *d40c)
{
        if (d40c->base->rev < 3)
                return;

        if ((d40c->dma_cfg.dir ==  STEDMA40_PERIPH_TO_MEM) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH))
                __d40_set_prio_rt(d40c, d40c->dma_cfg.src_dev_type, true);

        if ((d40c->dma_cfg.dir ==  STEDMA40_MEM_TO_PERIPH) ||
            (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_PERIPH))
                __d40_set_prio_rt(d40c, d40c->dma_cfg.dst_dev_type, false);
}

/* DMA ENGINE functions */
static int d40_alloc_chan_resources(struct dma_chan *chan)
{
        int err;
        unsigned long flags;
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        bool is_free_phy;
        spin_lock_irqsave(&d40c->lock, flags);

        d40c->completed = chan->cookie = 1;

        /* If no dma configuration is set use default configuration (memcpy) */
        if (!d40c->configured) {
                err = d40_config_memcpy(d40c);
                if (err) {
                        chan_err(d40c, "Failed to configure memcpy channel\n");
                        goto fail;
                }
        }
        is_free_phy = (d40c->phy_chan == NULL);

        err = d40_allocate_channel(d40c);
        if (err) {
                chan_err(d40c, "Failed to allocate channel\n");
                goto fail;
        }

        /* Fill in basic CFG register values */
        d40_phy_cfg(&d40c->dma_cfg, &d40c->src_def_cfg,
                    &d40c->dst_def_cfg, chan_is_logical(d40c));

        d40_set_prio_realtime(d40c);

        if (chan_is_logical(d40c)) {
                d40_log_cfg(&d40c->dma_cfg,
                            &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);

                if (d40c->dma_cfg.dir == STEDMA40_PERIPH_TO_MEM)
                        d40c->lcpa = d40c->base->lcpa_base +
                          d40c->dma_cfg.src_dev_type * D40_LCPA_CHAN_SIZE;
                else
                        d40c->lcpa = d40c->base->lcpa_base +
                          d40c->dma_cfg.dst_dev_type *
                          D40_LCPA_CHAN_SIZE + D40_LCPA_CHAN_DST_DELTA;
        }

        /*
         * Only write channel configuration to the DMA if the physical
         * resource is free. In case of multiple logical channels
         * on the same physical resource, only the first write is necessary.
         */
        if (is_free_phy)
                d40_config_write(d40c);
fail:
        spin_unlock_irqrestore(&d40c->lock, flags);
        return err;
}

static void d40_free_chan_resources(struct dma_chan *chan)
{
        struct d40_chan *d40c =
                container_of(chan, struct d40_chan, chan);
        int err;
        unsigned long flags;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Cannot free unallocated channel\n");
                return;
        }


        spin_lock_irqsave(&d40c->lock, flags);

        err = d40_free_dma(d40c);

        if (err)
                chan_err(d40c, "Failed to free channel\n");
        spin_unlock_irqrestore(&d40c->lock, flags);
}

static struct dma_async_tx_descriptor *d40_prep_memcpy(struct dma_chan *chan,
                                                       dma_addr_t dst,
                                                       dma_addr_t src,
                                                       size_t size,
                                                       unsigned long dma_flags)
{
        struct scatterlist dst_sg;
        struct scatterlist src_sg;

        sg_init_table(&dst_sg, 1);
        sg_init_table(&src_sg, 1);

        sg_dma_address(&dst_sg) = dst;
        sg_dma_address(&src_sg) = src;

        sg_dma_len(&dst_sg) = size;
        sg_dma_len(&src_sg) = size;

        return d40_prep_sg(chan, &src_sg, &dst_sg, 1, DMA_NONE, dma_flags);
}

static struct dma_async_tx_descriptor *
d40_prep_memcpy_sg(struct dma_chan *chan,
                   struct scatterlist *dst_sg, unsigned int dst_nents,
                   struct scatterlist *src_sg, unsigned int src_nents,
                   unsigned long dma_flags)
{
        if (dst_nents != src_nents)
                return NULL;

        return d40_prep_sg(chan, src_sg, dst_sg, src_nents, DMA_NONE, dma_flags);
}

static struct dma_async_tx_descriptor *d40_prep_slave_sg(struct dma_chan *chan,
                                                         struct scatterlist *sgl,
                                                         unsigned int sg_len,
                                                         enum dma_data_direction direction,
                                                         unsigned long dma_flags)
{
        if (direction != DMA_FROM_DEVICE && direction != DMA_TO_DEVICE)
                return NULL;

        return d40_prep_sg(chan, sgl, sgl, sg_len, direction, dma_flags);
}

static enum dma_status d40_tx_status(struct dma_chan *chan,
                                     dma_cookie_t cookie,
                                     struct dma_tx_state *txstate)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        dma_cookie_t last_used;
        dma_cookie_t last_complete;
        int ret;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Cannot read status of unallocated channel\n");
                return -EINVAL;
        }

        last_complete = d40c->completed;
        last_used = chan->cookie;

        if (d40_is_paused(d40c))
                ret = DMA_PAUSED;
        else
                ret = dma_async_is_complete(cookie, last_complete, last_used);

        dma_set_tx_state(txstate, last_complete, last_used,
                         stedma40_residue(chan));

        return ret;
}

static void d40_issue_pending(struct dma_chan *chan)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        unsigned long flags;

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Channel is not allocated!\n");
                return;
        }

        spin_lock_irqsave(&d40c->lock, flags);

        /* Busy means that pending jobs are already being processed */
        if (!d40c->busy)
                (void) d40_queue_start(d40c);

        spin_unlock_irqrestore(&d40c->lock, flags);
}

/* Runtime reconfiguration extension */
static void d40_set_runtime_config(struct dma_chan *chan,
                               struct dma_slave_config *config)
{
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
        struct stedma40_chan_cfg *cfg = &d40c->dma_cfg;
        enum dma_slave_buswidth config_addr_width;
        dma_addr_t config_addr;
        u32 config_maxburst;
        enum stedma40_periph_data_width addr_width;
        int psize;

        if (config->direction == DMA_FROM_DEVICE) {
                dma_addr_t dev_addr_rx =
                        d40c->base->plat_data->dev_rx[cfg->src_dev_type];

                config_addr = config->src_addr;
                if (dev_addr_rx)
                        dev_dbg(d40c->base->dev,
                                "channel has a pre-wired RX address %08x "
                                "overriding with %08x\n",
                                dev_addr_rx, config_addr);
                if (cfg->dir != STEDMA40_PERIPH_TO_MEM)
                        dev_dbg(d40c->base->dev,
                                "channel was not configured for peripheral "
                                "to memory transfer (%d) overriding\n",
                                cfg->dir);
                cfg->dir = STEDMA40_PERIPH_TO_MEM;

                config_addr_width = config->src_addr_width;
                config_maxburst = config->src_maxburst;

        } else if (config->direction == DMA_TO_DEVICE) {
                dma_addr_t dev_addr_tx =
                        d40c->base->plat_data->dev_tx[cfg->dst_dev_type];

                config_addr = config->dst_addr;
                if (dev_addr_tx)
                        dev_dbg(d40c->base->dev,
                                "channel has a pre-wired TX address %08x "
                                "overriding with %08x\n",
                                dev_addr_tx, config_addr);
                if (cfg->dir != STEDMA40_MEM_TO_PERIPH)
                        dev_dbg(d40c->base->dev,
                                "channel was not configured for memory "
                                "to peripheral transfer (%d) overriding\n",
                                cfg->dir);
                cfg->dir = STEDMA40_MEM_TO_PERIPH;

                config_addr_width = config->dst_addr_width;
                config_maxburst = config->dst_maxburst;

        } else {
                dev_err(d40c->base->dev,
                        "unrecognized channel direction %d\n",
                        config->direction);
                return;
        }

        switch (config_addr_width) {
        case DMA_SLAVE_BUSWIDTH_1_BYTE:
                addr_width = STEDMA40_BYTE_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_2_BYTES:
                addr_width = STEDMA40_HALFWORD_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_4_BYTES:
                addr_width = STEDMA40_WORD_WIDTH;
                break;
        case DMA_SLAVE_BUSWIDTH_8_BYTES:
                addr_width = STEDMA40_DOUBLEWORD_WIDTH;
                break;
        default:
                dev_err(d40c->base->dev,
                        "illegal peripheral address width "
                        "requested (%d)\n",
                        config->src_addr_width);
                return;
        }

        if (chan_is_logical(d40c)) {
                if (config_maxburst >= 16)
                        psize = STEDMA40_PSIZE_LOG_16;
                else if (config_maxburst >= 8)
                        psize = STEDMA40_PSIZE_LOG_8;
                else if (config_maxburst >= 4)
                        psize = STEDMA40_PSIZE_LOG_4;
                else
                        psize = STEDMA40_PSIZE_LOG_1;
        } else {
                if (config_maxburst >= 16)
                        psize = STEDMA40_PSIZE_PHY_16;
                else if (config_maxburst >= 8)
                        psize = STEDMA40_PSIZE_PHY_8;
                else if (config_maxburst >= 4)
                        psize = STEDMA40_PSIZE_PHY_4;
                else if (config_maxburst >= 2)
                        psize = STEDMA40_PSIZE_PHY_2;
                else
                        psize = STEDMA40_PSIZE_PHY_1;
        }

        /* Set up all the endpoint configs */
        cfg->src_info.data_width = addr_width;
        cfg->src_info.psize = psize;
        cfg->src_info.big_endian = false;
        cfg->src_info.flow_ctrl = STEDMA40_NO_FLOW_CTRL;
        cfg->dst_info.data_width = addr_width;
        cfg->dst_info.psize = psize;
        cfg->dst_info.big_endian = false;
        cfg->dst_info.flow_ctrl = STEDMA40_NO_FLOW_CTRL;

        /* Fill in register values */
        if (chan_is_logical(d40c))
                d40_log_cfg(cfg, &d40c->log_def.lcsp1, &d40c->log_def.lcsp3);
        else
                d40_phy_cfg(cfg, &d40c->src_def_cfg,
                            &d40c->dst_def_cfg, false);

        /* These settings will take precedence later */
        d40c->runtime_addr = config_addr;
        d40c->runtime_direction = config->direction;
        dev_dbg(d40c->base->dev,
                "configured channel %s for %s, data width %d, "
                "maxburst %d bytes, LE, no flow control\n",
                dma_chan_name(chan),
                (config->direction == DMA_FROM_DEVICE) ? "RX" : "TX",
                config_addr_width,
                config_maxburst);
}

static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
                       unsigned long arg)
{
        unsigned long flags;
        struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);

        if (d40c->phy_chan == NULL) {
                chan_err(d40c, "Channel is not allocated!\n");
                return -EINVAL;
        }

        switch (cmd) {
        case DMA_TERMINATE_ALL:
                spin_lock_irqsave(&d40c->lock, flags);
                d40_term_all(d40c);
                spin_unlock_irqrestore(&d40c->lock, flags);
                return 0;
        case DMA_PAUSE:
                return d40_pause(chan);
        case DMA_RESUME:
                return d40_resume(chan);
        case DMA_SLAVE_CONFIG:
                d40_set_runtime_config(chan,
                        (struct dma_slave_config *) arg);
                return 0;
        default:
                break;
        }

        /* Other commands are unimplemented */
        return -ENXIO;
}

/* Initialization functions */

static void __init d40_chan_init(struct d40_base *base, struct dma_device *dma,
                                 struct d40_chan *chans, int offset,
                                 int num_chans)
{
        int i = 0;
        struct d40_chan *d40c;

        INIT_LIST_HEAD(&dma->channels);

        for (i = offset; i < offset + num_chans; i++) {
                d40c = &chans[i];
                d40c->base = base;
                d40c->chan.device = dma;

                spin_lock_init(&d40c->lock);

                d40c->log_num = D40_PHY_CHAN;

                INIT_LIST_HEAD(&d40c->active);
                INIT_LIST_HEAD(&d40c->queue);
                INIT_LIST_HEAD(&d40c->client);

                tasklet_init(&d40c->tasklet, dma_tasklet,
                             (unsigned long) d40c);

                list_add_tail(&d40c->chan.device_node,
                              &dma->channels);
        }
}

static int __init d40_dmaengine_init(struct d40_base *base,
                                     int num_reserved_chans)
{
        int err ;

        d40_chan_init(base, &base->dma_slave, base->log_chans,
                      0, base->num_log_chans);

        dma_cap_zero(base->dma_slave.cap_mask);
        dma_cap_set(DMA_SLAVE, base->dma_slave.cap_mask);

        base->dma_slave.device_alloc_chan_resources = d40_alloc_chan_resources;
        base->dma_slave.device_free_chan_resources = d40_free_chan_resources;
        base->dma_slave.device_prep_dma_memcpy = d40_prep_memcpy;
        base->dma_slave.device_prep_dma_sg = d40_prep_memcpy_sg;
        base->dma_slave.device_prep_slave_sg = d40_prep_slave_sg;
        base->dma_slave.device_tx_status = d40_tx_status;
        base->dma_slave.device_issue_pending = d40_issue_pending;
        base->dma_slave.device_control = d40_control;
        base->dma_slave.dev = base->dev;

        err = dma_async_device_register(&base->dma_slave);

        if (err) {
                d40_err(base->dev, "Failed to register slave channels\n");
                goto failure1;
        }

        d40_chan_init(base, &base->dma_memcpy, base->log_chans,
                      base->num_log_chans, base->plat_data->memcpy_len);

        dma_cap_zero(base->dma_memcpy.cap_mask);
        dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
        dma_cap_set(DMA_SG, base->dma_slave.cap_mask);

        base->dma_memcpy.device_alloc_chan_resources = d40_alloc_chan_resources;
        base->dma_memcpy.device_free_chan_resources = d40_free_chan_resources;
        base->dma_memcpy.device_prep_dma_memcpy = d40_prep_memcpy;
        base->dma_slave.device_prep_dma_sg = d40_prep_memcpy_sg;
        base->dma_memcpy.device_prep_slave_sg = d40_prep_slave_sg;
        base->dma_memcpy.device_tx_status = d40_tx_status;
        base->dma_memcpy.device_issue_pending = d40_issue_pending;
        base->dma_memcpy.device_control = d40_control;
        base->dma_memcpy.dev = base->dev;
        /*
         * This controller can only access address at even
         * 32bit boundaries, i.e. 2^2
         */
        base->dma_memcpy.copy_align = 2;

        err = dma_async_device_register(&base->dma_memcpy);

        if (err) {
                d40_err(base->dev,
                        "Failed to regsiter memcpy only channels\n");
                goto failure2;
        }

        d40_chan_init(base, &base->dma_both, base->phy_chans,
                      0, num_reserved_chans);

        dma_cap_zero(base->dma_both.cap_mask);
        dma_cap_set(DMA_SLAVE, base->dma_both.cap_mask);
        dma_cap_set(DMA_MEMCPY, base->dma_both.cap_mask);
        dma_cap_set(DMA_SG, base->dma_slave.cap_mask);

        base->dma_both.device_alloc_chan_resources = d40_alloc_chan_resources;
        base->dma_both.device_free_chan_resources = d40_free_chan_resources;
        base->dma_both.device_prep_dma_memcpy = d40_prep_memcpy;
        base->dma_slave.device_prep_dma_sg = d40_prep_memcpy_sg;
        base->dma_both.device_prep_slave_sg = d40_prep_slave_sg;
        base->dma_both.device_tx_status = d40_tx_status;
        base->dma_both.device_issue_pending = d40_issue_pending;
        base->dma_both.device_control = d40_control;
        base->dma_both.dev = base->dev;
        base->dma_both.copy_align = 2;
        err = dma_async_device_register(&base->dma_both);

        if (err) {
                d40_err(base->dev,
                        "Failed to register logical and physical capable channels\n");
                goto failure3;
        }
        return 0;
failure3:
        dma_async_device_unregister(&base->dma_memcpy);
failure2:
        dma_async_device_unregister(&base->dma_slave);
failure1:
        return err;
}

/* Initialization functions. */

static int __init d40_phy_res_init(struct d40_base *base)
{
        int i;
        int num_phy_chans_avail = 0;
        u32 val[2];
        int odd_even_bit = -2;

        val[0] = readl(base->virtbase + D40_DREG_PRSME);
        val[1] = readl(base->virtbase + D40_DREG_PRSMO);

        for (i = 0; i < base->num_phy_chans; i++) {
                base->phy_res[i].num = i;
                odd_even_bit += 2 * ((i % 2) == 0);
                if (((val[i % 2] >> odd_even_bit) & 3) == 1) {
                        /* Mark security only channels as occupied */
                        base->phy_res[i].allocated_src = D40_ALLOC_PHY;
                        base->phy_res[i].allocated_dst = D40_ALLOC_PHY;
                } else {
                        base->phy_res[i].allocated_src = D40_ALLOC_FREE;
                        base->phy_res[i].allocated_dst = D40_ALLOC_FREE;
                        num_phy_chans_avail++;
                }
                spin_lock_init(&base->phy_res[i].lock);
        }

        /* Mark disabled channels as occupied */
        for (i = 0; base->plat_data->disabled_channels[i] != -1; i++) {
                int chan = base->plat_data->disabled_channels[i];

                base->phy_res[chan].allocated_src = D40_ALLOC_PHY;
                base->phy_res[chan].allocated_dst = D40_ALLOC_PHY;
                num_phy_chans_avail--;
        }

        dev_info(base->dev, "%d of %d physical DMA channels available\n",
                 num_phy_chans_avail, base->num_phy_chans);

        /* Verify settings extended vs standard */
        val[0] = readl(base->virtbase + D40_DREG_PRTYP);

        for (i = 0; i < base->num_phy_chans; i++) {

                if (base->phy_res[i].allocated_src == D40_ALLOC_FREE &&
                    (val[0] & 0x3) != 1)
                        dev_info(base->dev,
                                 "[%s] INFO: channel %d is misconfigured (%d)\n",
                                 __func__, i, val[0] & 0x3);

                val[0] = val[0] >> 2;
        }

        return num_phy_chans_avail;
}

static struct d40_base * __init d40_hw_detect_init(struct platform_device *pdev)
{
        static const struct d40_reg_val dma_id_regs[] = {
                /* Peripheral Id */
                { .reg = D40_DREG_PERIPHID0, .val = 0x0040},
                { .reg = D40_DREG_PERIPHID1, .val = 0x0000},
                /*
                 * D40_DREG_PERIPHID2 Depends on HW revision:
                 *  DB8500ed has 0x0008,
                 *  ? has 0x0018,
                 *  DB8500v1 has 0x0028
                 *  DB8500v2 has 0x0038
                 */
                { .reg = D40_DREG_PERIPHID3, .val = 0x0000},

                /* PCell Id */
                { .reg = D40_DREG_CELLID0, .val = 0x000d},
                { .reg = D40_DREG_CELLID1, .val = 0x00f0},
                { .reg = D40_DREG_CELLID2, .val = 0x0005},
                { .reg = D40_DREG_CELLID3, .val = 0x00b1}
        };
        struct stedma40_platform_data *plat_data;
        struct clk *clk = NULL;
        void __iomem *virtbase = NULL;
        struct resource *res = NULL;
        struct d40_base *base = NULL;
        int num_log_chans = 0;
        int num_phy_chans;
        int i;
        u32 val;
        u32 rev;

        clk = clk_get(&pdev->dev, NULL);

        if (IS_ERR(clk)) {
                d40_err(&pdev->dev, "No matching clock found\n");
                goto failure;
        }

        clk_enable(clk);

        /* Get IO for DMAC base address */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "base");
        if (!res)
                goto failure;

        if (request_mem_region(res->start, resource_size(res),
                               D40_NAME " I/O base") == NULL)
                goto failure;

        virtbase = ioremap(res->start, resource_size(res));
        if (!virtbase)
                goto failure;

        /* HW version check */
        for (i = 0; i < ARRAY_SIZE(dma_id_regs); i++) {
                if (dma_id_regs[i].val !=
                    readl(virtbase + dma_id_regs[i].reg)) {
                        d40_err(&pdev->dev,
                                "Unknown hardware! Expected 0x%x at 0x%x but got 0x%x\n",
                                dma_id_regs[i].val,
                                dma_id_regs[i].reg,
                                readl(virtbase + dma_id_regs[i].reg));
                        goto failure;
                }
        }

        /* Get silicon revision and designer */
        val = readl(virtbase + D40_DREG_PERIPHID2);

        if ((val & D40_DREG_PERIPHID2_DESIGNER_MASK) !=
            D40_HW_DESIGNER) {
                d40_err(&pdev->dev, "Unknown designer! Got %x wanted %x\n",
                        val & D40_DREG_PERIPHID2_DESIGNER_MASK,
                        D40_HW_DESIGNER);
                goto failure;
        }

        rev = (val & D40_DREG_PERIPHID2_REV_MASK) >>
                D40_DREG_PERIPHID2_REV_POS;

        /* The number of physical channels on this HW */
        num_phy_chans = 4 * (readl(virtbase + D40_DREG_ICFG) & 0x7) + 4;

        dev_info(&pdev->dev, "hardware revision: %d @ 0x%x\n",
                 rev, res->start);

        plat_data = pdev->dev.platform_data;

        /* Count the number of logical channels in use */
        for (i = 0; i < plat_data->dev_len; i++)
                if (plat_data->dev_rx[i] != 0)
                        num_log_chans++;

        for (i = 0; i < plat_data->dev_len; i++)
                if (plat_data->dev_tx[i] != 0)
                        num_log_chans++;

        base = kzalloc(ALIGN(sizeof(struct d40_base), 4) +
                       (num_phy_chans + num_log_chans + plat_data->memcpy_len) *
                       sizeof(struct d40_chan), GFP_KERNEL);

        if (base == NULL) {
                d40_err(&pdev->dev, "Out of memory\n");
                goto failure;
        }

        base->rev = rev;
        base->clk = clk;
        base->num_phy_chans = num_phy_chans;
        base->num_log_chans = num_log_chans;
        base->phy_start = res->start;
        base->phy_size = resource_size(res);
        base->virtbase = virtbase;
        base->plat_data = plat_data;
        base->dev = &pdev->dev;
        base->phy_chans = ((void *)base) + ALIGN(sizeof(struct d40_base), 4);
        base->log_chans = &base->phy_chans[num_phy_chans];

        base->phy_res = kzalloc(num_phy_chans * sizeof(struct d40_phy_res),
                                GFP_KERNEL);
        if (!base->phy_res)
                goto failure;

        base->lookup_phy_chans = kzalloc(num_phy_chans *
                                         sizeof(struct d40_chan *),
                                         GFP_KERNEL);
        if (!base->lookup_phy_chans)
                goto failure;

        if (num_log_chans + plat_data->memcpy_len) {
                /*
                 * The max number of logical channels are event lines for all
                 * src devices and dst devices
                 */
                base->lookup_log_chans = kzalloc(plat_data->dev_len * 2 *
                                                 sizeof(struct d40_chan *),
                                                 GFP_KERNEL);
                if (!base->lookup_log_chans)
                        goto failure;
        }

        base->lcla_pool.alloc_map = kzalloc(num_phy_chans *
                                            sizeof(struct d40_desc *) *
                                            D40_LCLA_LINK_PER_EVENT_GRP,
                                            GFP_KERNEL);
        if (!base->lcla_pool.alloc_map)
                goto failure;

        base->desc_slab = kmem_cache_create(D40_NAME, sizeof(struct d40_desc),
                                            0, SLAB_HWCACHE_ALIGN,
                                            NULL);
        if (base->desc_slab == NULL)
                goto failure;

        return base;

failure:
        if (!IS_ERR(clk)) {
                clk_disable(clk);
                clk_put(clk);
        }
        if (virtbase)
                iounmap(virtbase);
        if (res)
                release_mem_region(res->start,
                                   resource_size(res));
        if (virtbase)
                iounmap(virtbase);

        if (base) {
                kfree(base->lcla_pool.alloc_map);
                kfree(base->lookup_log_chans);
                kfree(base->lookup_phy_chans);
                kfree(base->phy_res);
                kfree(base);
        }

        return NULL;
}

static void __init d40_hw_init(struct d40_base *base)
{

        static const struct d40_reg_val dma_init_reg[] = {
                /* Clock every part of the DMA block from start */
                { .reg = D40_DREG_GCC,    .val = 0x0000ff01},

                /* Interrupts on all logical channels */
                { .reg = D40_DREG_LCMIS0, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCMIS1, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCMIS2, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCMIS3, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCICR0, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCICR1, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCICR2, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCICR3, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCTIS0, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCTIS1, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCTIS2, .val = 0xFFFFFFFF},
                { .reg = D40_DREG_LCTIS3, .val = 0xFFFFFFFF}
        };
        int i;
        u32 prmseo[2] = {0, 0};
        u32 activeo[2] = {0xFFFFFFFF, 0xFFFFFFFF};
        u32 pcmis = 0;
        u32 pcicr = 0;

        for (i = 0; i < ARRAY_SIZE(dma_init_reg); i++)
                writel(dma_init_reg[i].val,
                       base->virtbase + dma_init_reg[i].reg);

        /* Configure all our dma channels to default settings */
        for (i = 0; i < base->num_phy_chans; i++) {

                activeo[i % 2] = activeo[i % 2] << 2;

                if (base->phy_res[base->num_phy_chans - i - 1].allocated_src
                    == D40_ALLOC_PHY) {
                        activeo[i % 2] |= 3;
                        continue;
                }

                /* Enable interrupt # */
                pcmis = (pcmis << 1) | 1;

                /* Clear interrupt # */
                pcicr = (pcicr << 1) | 1;

                /* Set channel to physical mode */
                prmseo[i % 2] = prmseo[i % 2] << 2;
                prmseo[i % 2] |= 1;

        }

        writel(prmseo[1], base->virtbase + D40_DREG_PRMSE);
        writel(prmseo[0], base->virtbase + D40_DREG_PRMSO);
        writel(activeo[1], base->virtbase + D40_DREG_ACTIVE);
        writel(activeo[0], base->virtbase + D40_DREG_ACTIVO);

        /* Write which interrupt to enable */
        writel(pcmis, base->virtbase + D40_DREG_PCMIS);

        /* Write which interrupt to clear */
        writel(pcicr, base->virtbase + D40_DREG_PCICR);

}

static int __init d40_lcla_allocate(struct d40_base *base)
{
        struct d40_lcla_pool *pool = &base->lcla_pool;
        unsigned long *page_list;
        int i, j;
        int ret = 0;

        /*
         * This is somewhat ugly. We need 8192 bytes that are 18 bit aligned,
         * To full fill this hardware requirement without wasting 256 kb
         * we allocate pages until we get an aligned one.
         */
        page_list = kmalloc(sizeof(unsigned long) * MAX_LCLA_ALLOC_ATTEMPTS,
                            GFP_KERNEL);

        if (!page_list) {
                ret = -ENOMEM;
                goto failure;
        }

        /* Calculating how many pages that are required */
        base->lcla_pool.pages = SZ_1K * base->num_phy_chans / PAGE_SIZE;

        for (i = 0; i < MAX_LCLA_ALLOC_ATTEMPTS; i++) {
                page_list[i] = __get_free_pages(GFP_KERNEL,
                                                base->lcla_pool.pages);
                if (!page_list[i]) {

                        d40_err(base->dev, "Failed to allocate %d pages.\n",
                                base->lcla_pool.pages);

                        for (j = 0; j < i; j++)
                                free_pages(page_list[j], base->lcla_pool.pages);
                        goto failure;
                }

                if ((virt_to_phys((void *)page_list[i]) &
                     (LCLA_ALIGNMENT - 1)) == 0)
                        break;
        }

        for (j = 0; j < i; j++)
                free_pages(page_list[j], base->lcla_pool.pages);

        if (i < MAX_LCLA_ALLOC_ATTEMPTS) {
                base->lcla_pool.base = (void *)page_list[i];
        } else {
                /*
                 * After many attempts and no succees with finding the correct
                 * alignment, try with allocating a big buffer.
                 */
                dev_warn(base->dev,
                         "[%s] Failed to get %d pages @ 18 bit align.\n",
                         __func__, base->lcla_pool.pages);
                base->lcla_pool.base_unaligned = kmalloc(SZ_1K *
                                                         base->num_phy_chans +
                                                         LCLA_ALIGNMENT,
                                                         GFP_KERNEL);
                if (!base->lcla_pool.base_unaligned) {
                        ret = -ENOMEM;
                        goto failure;
                }

                base->lcla_pool.base = PTR_ALIGN(base->lcla_pool.base_unaligned,
                                                 LCLA_ALIGNMENT);
        }

        pool->dma_addr = dma_map_single(base->dev, pool->base,
                                        SZ_1K * base->num_phy_chans,
                                        DMA_TO_DEVICE);
        if (dma_mapping_error(base->dev, pool->dma_addr)) {
                pool->dma_addr = 0;
                ret = -ENOMEM;
                goto failure;
        }

        writel(virt_to_phys(base->lcla_pool.base),
               base->virtbase + D40_DREG_LCLA);
failure:
        kfree(page_list);
        return ret;
}

static int __init d40_probe(struct platform_device *pdev)
{
        int err;
        int ret = -ENOENT;
        struct d40_base *base;
        struct resource *res = NULL;
        int num_reserved_chans;
        u32 val;

        base = d40_hw_detect_init(pdev);

        if (!base)
                goto failure;

        num_reserved_chans = d40_phy_res_init(base);

        platform_set_drvdata(pdev, base);

        spin_lock_init(&base->interrupt_lock);
        spin_lock_init(&base->execmd_lock);

        /* Get IO for logical channel parameter address */
        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "lcpa");
        if (!res) {
                ret = -ENOENT;
                d40_err(&pdev->dev, "No \"lcpa\" memory resource\n");
                goto failure;
        }
        base->lcpa_size = resource_size(res);
        base->phy_lcpa = res->start;

        if (request_mem_region(res->start, resource_size(res),
                               D40_NAME " I/O lcpa") == NULL) {
                ret = -EBUSY;
                d40_err(&pdev->dev,
                        "Failed to request LCPA region 0x%x-0x%x\n",
                        res->start, res->end);
                goto failure;
        }

        /* We make use of ESRAM memory for this. */
        val = readl(base->virtbase + D40_DREG_LCPA);
        if (res->start != val && val != 0) {
                dev_warn(&pdev->dev,
                         "[%s] Mismatch LCPA dma 0x%x, def 0x%x\n",
                         __func__, val, res->start);
        } else
                writel(res->start, base->virtbase + D40_DREG_LCPA);

        base->lcpa_base = ioremap(res->start, resource_size(res));
        if (!base->lcpa_base) {
                ret = -ENOMEM;
                d40_err(&pdev->dev, "Failed to ioremap LCPA region\n");
                goto failure;
        }

        ret = d40_lcla_allocate(base);
        if (ret) {
                d40_err(&pdev->dev, "Failed to allocate LCLA area\n");
                goto failure;
        }

        spin_lock_init(&base->lcla_pool.lock);

        base->irq = platform_get_irq(pdev, 0);

        ret = request_irq(base->irq, d40_handle_interrupt, 0, D40_NAME, base);
        if (ret) {
                d40_err(&pdev->dev, "No IRQ defined\n");
                goto failure;
        }

        err = d40_dmaengine_init(base, num_reserved_chans);
        if (err)
                goto failure;

        d40_hw_init(base);

        dev_info(base->dev, "initialized\n");
        return 0;

failure:
        if (base) {
                if (base->desc_slab)
                        kmem_cache_destroy(base->desc_slab);
                if (base->virtbase)
                        iounmap(base->virtbase);

                if (base->lcla_pool.dma_addr)
                        dma_unmap_single(base->dev, base->lcla_pool.dma_addr,
                                         SZ_1K * base->num_phy_chans,
                                         DMA_TO_DEVICE);

                if (!base->lcla_pool.base_unaligned && base->lcla_pool.base)
                        free_pages((unsigned long)base->lcla_pool.base,
                                   base->lcla_pool.pages);

                kfree(base->lcla_pool.base_unaligned);

                if (base->phy_lcpa)
                        release_mem_region(base->phy_lcpa,
                                           base->lcpa_size);
                if (base->phy_start)
                        release_mem_region(base->phy_start,
                                           base->phy_size);
                if (base->clk) {
                        clk_disable(base->clk);
                        clk_put(base->clk);
                }

                kfree(base->lcla_pool.alloc_map);
                kfree(base->lookup_log_chans);
                kfree(base->lookup_phy_chans);
                kfree(base->phy_res);
                kfree(base);
        }

        d40_err(&pdev->dev, "probe failed\n");
        return ret;
}

static struct platform_driver d40_driver = {
        .driver = {
                .owner = THIS_MODULE,
                .name  = D40_NAME,
        },
};

static int __init stedma40_init(void)
{
        return platform_driver_probe(&d40_driver, d40_probe);
}
arch_initcall(stedma40_init);