rcu: Make rcu_assign_pointer() unconditionally insert a memory barrier

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

/*
 *  intel_mid_dma.c - Intel Langwell DMA Drivers
 *
 *  Copyright (C) 2008-10 Intel Corp
 *  Author: Vinod Koul <vinod.koul@intel.com>
 *  The driver design is based on dw_dmac driver
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *
 */
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/pm_runtime.h>
#include <linux/intel_mid_dma.h>

#define MAX_CHAN        4 /*max ch across controllers*/
#include "intel_mid_dma_regs.h"

#define INTEL_MID_DMAC1_ID              0x0814
#define INTEL_MID_DMAC2_ID              0x0813
#define INTEL_MID_GP_DMAC2_ID           0x0827
#define INTEL_MFLD_DMAC1_ID             0x0830
#define LNW_PERIPHRAL_MASK_BASE         0xFFAE8008
#define LNW_PERIPHRAL_MASK_SIZE         0x10
#define LNW_PERIPHRAL_STATUS            0x0
#define LNW_PERIPHRAL_MASK              0x8

struct intel_mid_dma_probe_info {
        u8 max_chan;
        u8 ch_base;
        u16 block_size;
        u32 pimr_mask;
};

#define INFO(_max_chan, _ch_base, _block_size, _pimr_mask) \
        ((kernel_ulong_t)&(struct intel_mid_dma_probe_info) {   \
                .max_chan = (_max_chan),                        \
                .ch_base = (_ch_base),                          \
                .block_size = (_block_size),                    \
                .pimr_mask = (_pimr_mask),                      \
        })

/*****************************************************************************
Utility Functions*/
/**
 * get_ch_index -       convert status to channel
 * @status: status mask
 * @base: dma ch base value
 *
 * Modify the status mask and return the channel index needing
 * attention (or -1 if neither)
 */
static int get_ch_index(int *status, unsigned int base)
{
        int i;
        for (i = 0; i < MAX_CHAN; i++) {
                if (*status & (1 << (i + base))) {
                        *status = *status & ~(1 << (i + base));
                        pr_debug("MDMA: index %d New status %x\n", i, *status);
                        return i;
                }
        }
        return -1;
}

/**
 * get_block_ts -       calculates dma transaction length
 * @len: dma transfer length
 * @tx_width: dma transfer src width
 * @block_size: dma controller max block size
 *
 * Based on src width calculate the DMA trsaction length in data items
 * return data items or FFFF if exceeds max length for block
 */
static int get_block_ts(int len, int tx_width, int block_size)
{
        int byte_width = 0, block_ts = 0;

        switch (tx_width) {
        case DMA_SLAVE_BUSWIDTH_1_BYTE:
                byte_width = 1;
                break;
        case DMA_SLAVE_BUSWIDTH_2_BYTES:
                byte_width = 2;
                break;
        case DMA_SLAVE_BUSWIDTH_4_BYTES:
        default:
                byte_width = 4;
                break;
        }

        block_ts = len/byte_width;
        if (block_ts > block_size)
                block_ts = 0xFFFF;
        return block_ts;
}

/*****************************************************************************
DMAC1 interrupt Functions*/

/**
 * dmac1_mask_periphral_intr -  mask the periphral interrupt
 * @midc: dma channel for which masking is required
 *
 * Masks the DMA periphral interrupt
 * this is valid for DMAC1 family controllers only
 * This controller should have periphral mask registers already mapped
 */
static void dmac1_mask_periphral_intr(struct intel_mid_dma_chan *midc)
{
        u32 pimr;
        struct middma_device *mid = to_middma_device(midc->chan.device);

        if (mid->pimr_mask) {
                pimr = readl(mid->mask_reg + LNW_PERIPHRAL_MASK);
                pimr |= mid->pimr_mask;
                writel(pimr, mid->mask_reg + LNW_PERIPHRAL_MASK);
        }
        return;
}

/**
 * dmac1_unmask_periphral_intr -        unmask the periphral interrupt
 * @midc: dma channel for which masking is required
 *
 * UnMasks the DMA periphral interrupt,
 * this is valid for DMAC1 family controllers only
 * This controller should have periphral mask registers already mapped
 */
static void dmac1_unmask_periphral_intr(struct intel_mid_dma_chan *midc)
{
        u32 pimr;
        struct middma_device *mid = to_middma_device(midc->chan.device);

        if (mid->pimr_mask) {
                pimr = readl(mid->mask_reg + LNW_PERIPHRAL_MASK);
                pimr &= ~mid->pimr_mask;
                writel(pimr, mid->mask_reg + LNW_PERIPHRAL_MASK);
        }
        return;
}

/**
 * enable_dma_interrupt -       enable the periphral interrupt
 * @midc: dma channel for which enable interrupt is required
 *
 * Enable the DMA periphral interrupt,
 * this is valid for DMAC1 family controllers only
 * This controller should have periphral mask registers already mapped
 */
static void enable_dma_interrupt(struct intel_mid_dma_chan *midc)
{
        dmac1_unmask_periphral_intr(midc);

        /*en ch interrupts*/
        iowrite32(UNMASK_INTR_REG(midc->ch_id), midc->dma_base + MASK_TFR);
        iowrite32(UNMASK_INTR_REG(midc->ch_id), midc->dma_base + MASK_ERR);
        return;
}

/**
 * disable_dma_interrupt -      disable the periphral interrupt
 * @midc: dma channel for which disable interrupt is required
 *
 * Disable the DMA periphral interrupt,
 * this is valid for DMAC1 family controllers only
 * This controller should have periphral mask registers already mapped
 */
static void disable_dma_interrupt(struct intel_mid_dma_chan *midc)
{
        /*Check LPE PISR, make sure fwd is disabled*/
        dmac1_mask_periphral_intr(midc);
        iowrite32(MASK_INTR_REG(midc->ch_id), midc->dma_base + MASK_BLOCK);
        iowrite32(MASK_INTR_REG(midc->ch_id), midc->dma_base + MASK_TFR);
        iowrite32(MASK_INTR_REG(midc->ch_id), midc->dma_base + MASK_ERR);
        return;
}

/*****************************************************************************
DMA channel helper Functions*/
/**
 * mid_desc_get         -       get a descriptor
 * @midc: dma channel for which descriptor is required
 *
 * Obtain a descriptor for the channel. Returns NULL if none are free.
 * Once the descriptor is returned it is private until put on another
 * list or freed
 */
static struct intel_mid_dma_desc *midc_desc_get(struct intel_mid_dma_chan *midc)
{
        struct intel_mid_dma_desc *desc, *_desc;
        struct intel_mid_dma_desc *ret = NULL;

        spin_lock_bh(&midc->lock);
        list_for_each_entry_safe(desc, _desc, &midc->free_list, desc_node) {
                if (async_tx_test_ack(&desc->txd)) {
                        list_del(&desc->desc_node);
                        ret = desc;
                        break;
                }
        }
        spin_unlock_bh(&midc->lock);
        return ret;
}

/**
 * mid_desc_put         -       put a descriptor
 * @midc: dma channel for which descriptor is required
 * @desc: descriptor to put
 *
 * Return a descriptor from lwn_desc_get back to the free pool
 */
static void midc_desc_put(struct intel_mid_dma_chan *midc,
                        struct intel_mid_dma_desc *desc)
{
        if (desc) {
                spin_lock_bh(&midc->lock);
                list_add_tail(&desc->desc_node, &midc->free_list);
                spin_unlock_bh(&midc->lock);
        }
}
/**
 * midc_dostart         -               begin a DMA transaction
 * @midc: channel for which txn is to be started
 * @first: first descriptor of series
 *
 * Load a transaction into the engine. This must be called with midc->lock
 * held and bh disabled.
 */
static void midc_dostart(struct intel_mid_dma_chan *midc,
                        struct intel_mid_dma_desc *first)
{
        struct middma_device *mid = to_middma_device(midc->chan.device);

        /*  channel is idle */
        if (midc->busy && test_ch_en(midc->dma_base, midc->ch_id)) {
                /*error*/
                pr_err("ERR_MDMA: channel is busy in start\n");
                /* The tasklet will hopefully advance the queue... */
                return;
        }
        midc->busy = true;
        /*write registers and en*/
        iowrite32(first->sar, midc->ch_regs + SAR);
        iowrite32(first->dar, midc->ch_regs + DAR);
        iowrite32(first->lli_phys, midc->ch_regs + LLP);
        iowrite32(first->cfg_hi, midc->ch_regs + CFG_HIGH);
        iowrite32(first->cfg_lo, midc->ch_regs + CFG_LOW);
        iowrite32(first->ctl_lo, midc->ch_regs + CTL_LOW);
        iowrite32(first->ctl_hi, midc->ch_regs + CTL_HIGH);
        pr_debug("MDMA:TX SAR %x,DAR %x,CFGL %x,CFGH %x,CTLH %x, CTLL %x\n",
                (int)first->sar, (int)first->dar, first->cfg_hi,
                first->cfg_lo, first->ctl_hi, first->ctl_lo);
        first->status = DMA_IN_PROGRESS;

        iowrite32(ENABLE_CHANNEL(midc->ch_id), mid->dma_base + DMA_CHAN_EN);
}

/**
 * midc_descriptor_complete     -       process completed descriptor
 * @midc: channel owning the descriptor
 * @desc: the descriptor itself
 *
 * Process a completed descriptor and perform any callbacks upon
 * the completion. The completion handling drops the lock during the
 * callbacks but must be called with the lock held.
 */
static void midc_descriptor_complete(struct intel_mid_dma_chan *midc,
               struct intel_mid_dma_desc *desc)
{
        struct dma_async_tx_descriptor  *txd = &desc->txd;
        dma_async_tx_callback callback_txd = NULL;
        struct intel_mid_dma_lli        *llitem;
        void *param_txd = NULL;

        midc->completed = txd->cookie;
        callback_txd = txd->callback;
        param_txd = txd->callback_param;

        if (desc->lli != NULL) {
                /*clear the DONE bit of completed LLI in memory*/
                llitem = desc->lli + desc->current_lli;
                llitem->ctl_hi &= CLEAR_DONE;
                if (desc->current_lli < desc->lli_length-1)
                        (desc->current_lli)++;
                else
                        desc->current_lli = 0;
        }
        spin_unlock_bh(&midc->lock);
        if (callback_txd) {
                pr_debug("MDMA: TXD callback set ... calling\n");
                callback_txd(param_txd);
        }
        if (midc->raw_tfr) {
                desc->status = DMA_SUCCESS;
                if (desc->lli != NULL) {
                        pci_pool_free(desc->lli_pool, desc->lli,
                                                desc->lli_phys);
                        pci_pool_destroy(desc->lli_pool);
                }
                list_move(&desc->desc_node, &midc->free_list);
                midc->busy = false;
        }
        spin_lock_bh(&midc->lock);

}
/**
 * midc_scan_descriptors -              check the descriptors in channel
 *                                      mark completed when tx is completete
 * @mid: device
 * @midc: channel to scan
 *
 * Walk the descriptor chain for the device and process any entries
 * that are complete.
 */
static void midc_scan_descriptors(struct middma_device *mid,
                                struct intel_mid_dma_chan *midc)
{
        struct intel_mid_dma_desc *desc = NULL, *_desc = NULL;

        /*tx is complete*/
        list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
                if (desc->status == DMA_IN_PROGRESS)
                        midc_descriptor_complete(midc, desc);
        }
        return;
        }
/**
 * midc_lli_fill_sg -           Helper function to convert
 *                              SG list to Linked List Items.
 *@midc: Channel
 *@desc: DMA descriptor
 *@sglist: Pointer to SG list
 *@sglen: SG list length
 *@flags: DMA transaction flags
 *
 * Walk through the SG list and convert the SG list into Linked
 * List Items (LLI).
 */
static int midc_lli_fill_sg(struct intel_mid_dma_chan *midc,
                                struct intel_mid_dma_desc *desc,
                                struct scatterlist *sglist,
                                unsigned int sglen,
                                unsigned int flags)
{
        struct intel_mid_dma_slave *mids;
        struct scatterlist  *sg;
        dma_addr_t lli_next, sg_phy_addr;
        struct intel_mid_dma_lli *lli_bloc_desc;
        union intel_mid_dma_ctl_lo ctl_lo;
        union intel_mid_dma_ctl_hi ctl_hi;
        int i;

        pr_debug("MDMA: Entered midc_lli_fill_sg\n");
        mids = midc->mid_slave;

        lli_bloc_desc = desc->lli;
        lli_next = desc->lli_phys;

        ctl_lo.ctl_lo = desc->ctl_lo;
        ctl_hi.ctl_hi = desc->ctl_hi;
        for_each_sg(sglist, sg, sglen, i) {
                /*Populate CTL_LOW and LLI values*/
                if (i != sglen - 1) {
                        lli_next = lli_next +
                                sizeof(struct intel_mid_dma_lli);
                } else {
                /*Check for circular list, otherwise terminate LLI to ZERO*/
                        if (flags & DMA_PREP_CIRCULAR_LIST) {
                                pr_debug("MDMA: LLI is configured in circular mode\n");
                                lli_next = desc->lli_phys;
                        } else {
                                lli_next = 0;
                                ctl_lo.ctlx.llp_dst_en = 0;
                                ctl_lo.ctlx.llp_src_en = 0;
                        }
                }
                /*Populate CTL_HI values*/
                ctl_hi.ctlx.block_ts = get_block_ts(sg->length,
                                                        desc->width,
                                                        midc->dma->block_size);
                /*Populate SAR and DAR values*/
                sg_phy_addr = sg_phys(sg);
                if (desc->dirn ==  DMA_TO_DEVICE) {
                        lli_bloc_desc->sar  = sg_phy_addr;
                        lli_bloc_desc->dar  = mids->dma_slave.dst_addr;
                } else if (desc->dirn ==  DMA_FROM_DEVICE) {
                        lli_bloc_desc->sar  = mids->dma_slave.src_addr;
                        lli_bloc_desc->dar  = sg_phy_addr;
                }
                /*Copy values into block descriptor in system memroy*/
                lli_bloc_desc->llp = lli_next;
                lli_bloc_desc->ctl_lo = ctl_lo.ctl_lo;
                lli_bloc_desc->ctl_hi = ctl_hi.ctl_hi;

                lli_bloc_desc++;
        }
        /*Copy very first LLI values to descriptor*/
        desc->ctl_lo = desc->lli->ctl_lo;
        desc->ctl_hi = desc->lli->ctl_hi;
        desc->sar = desc->lli->sar;
        desc->dar = desc->lli->dar;

        return 0;
}
/*****************************************************************************
DMA engine callback Functions*/
/**
 * intel_mid_dma_tx_submit -    callback to submit DMA transaction
 * @tx: dma engine descriptor
 *
 * Submit the DMA trasaction for this descriptor, start if ch idle
 */
static dma_cookie_t intel_mid_dma_tx_submit(struct dma_async_tx_descriptor *tx)
{
        struct intel_mid_dma_desc       *desc = to_intel_mid_dma_desc(tx);
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(tx->chan);
        dma_cookie_t            cookie;

        spin_lock_bh(&midc->lock);
        cookie = midc->chan.cookie;

        if (++cookie < 0)
                cookie = 1;

        midc->chan.cookie = cookie;
        desc->txd.cookie = cookie;


        if (list_empty(&midc->active_list))
                list_add_tail(&desc->desc_node, &midc->active_list);
        else
                list_add_tail(&desc->desc_node, &midc->queue);

        midc_dostart(midc, desc);
        spin_unlock_bh(&midc->lock);

        return cookie;
}

/**
 * intel_mid_dma_issue_pending -        callback to issue pending txn
 * @chan: chan where pending trascation needs to be checked and submitted
 *
 * Call for scan to issue pending descriptors
 */
static void intel_mid_dma_issue_pending(struct dma_chan *chan)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);

        spin_lock_bh(&midc->lock);
        if (!list_empty(&midc->queue))
                midc_scan_descriptors(to_middma_device(chan->device), midc);
        spin_unlock_bh(&midc->lock);
}

/**
 * intel_mid_dma_tx_status -    Return status of txn
 * @chan: chan for where status needs to be checked
 * @cookie: cookie for txn
 * @txstate: DMA txn state
 *
 * Return status of DMA txn
 */
static enum dma_status intel_mid_dma_tx_status(struct dma_chan *chan,
                                                dma_cookie_t cookie,
                                                struct dma_tx_state *txstate)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);
        dma_cookie_t            last_used;
        dma_cookie_t            last_complete;
        int                             ret;

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

        ret = dma_async_is_complete(cookie, last_complete, last_used);
        if (ret != DMA_SUCCESS) {
                midc_scan_descriptors(to_middma_device(chan->device), midc);

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

                ret = dma_async_is_complete(cookie, last_complete, last_used);
        }

        if (txstate) {
                txstate->last = last_complete;
                txstate->used = last_used;
                txstate->residue = 0;
        }
        return ret;
}

static int dma_slave_control(struct dma_chan *chan, unsigned long arg)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);
        struct dma_slave_config  *slave = (struct dma_slave_config *)arg;
        struct intel_mid_dma_slave *mid_slave;

        BUG_ON(!midc);
        BUG_ON(!slave);
        pr_debug("MDMA: slave control called\n");

        mid_slave = to_intel_mid_dma_slave(slave);

        BUG_ON(!mid_slave);

        midc->mid_slave = mid_slave;
        return 0;
}
/**
 * intel_mid_dma_device_control -       DMA device control
 * @chan: chan for DMA control
 * @cmd: control cmd
 * @arg: cmd arg value
 *
 * Perform DMA control command
 */
static int intel_mid_dma_device_control(struct dma_chan *chan,
                        enum dma_ctrl_cmd cmd, unsigned long arg)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);
        struct middma_device    *mid = to_middma_device(chan->device);
        struct intel_mid_dma_desc       *desc, *_desc;
        union intel_mid_dma_cfg_lo cfg_lo;

        if (cmd == DMA_SLAVE_CONFIG)
                return dma_slave_control(chan, arg);

        if (cmd != DMA_TERMINATE_ALL)
                return -ENXIO;

        spin_lock_bh(&midc->lock);
        if (midc->busy == false) {
                spin_unlock_bh(&midc->lock);
                return 0;
        }
        /*Suspend and disable the channel*/
        cfg_lo.cfg_lo = ioread32(midc->ch_regs + CFG_LOW);
        cfg_lo.cfgx.ch_susp = 1;
        iowrite32(cfg_lo.cfg_lo, midc->ch_regs + CFG_LOW);
        iowrite32(DISABLE_CHANNEL(midc->ch_id), mid->dma_base + DMA_CHAN_EN);
        midc->busy = false;
        /* Disable interrupts */
        disable_dma_interrupt(midc);
        midc->descs_allocated = 0;

        spin_unlock_bh(&midc->lock);
        list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
                if (desc->lli != NULL) {
                        pci_pool_free(desc->lli_pool, desc->lli,
                                                desc->lli_phys);
                        pci_pool_destroy(desc->lli_pool);
                }
                list_move(&desc->desc_node, &midc->free_list);
        }
        return 0;
}


/**
 * intel_mid_dma_prep_memcpy -  Prep memcpy txn
 * @chan: chan for DMA transfer
 * @dest: destn address
 * @src: src address
 * @len: DMA transfer len
 * @flags: DMA flags
 *
 * Perform a DMA memcpy. Note we support slave periphral DMA transfers only
 * The periphral txn details should be filled in slave structure properly
 * Returns the descriptor for this txn
 */
static struct dma_async_tx_descriptor *intel_mid_dma_prep_memcpy(
                        struct dma_chan *chan, dma_addr_t dest,
                        dma_addr_t src, size_t len, unsigned long flags)
{
        struct intel_mid_dma_chan *midc;
        struct intel_mid_dma_desc *desc = NULL;
        struct intel_mid_dma_slave *mids;
        union intel_mid_dma_ctl_lo ctl_lo;
        union intel_mid_dma_ctl_hi ctl_hi;
        union intel_mid_dma_cfg_lo cfg_lo;
        union intel_mid_dma_cfg_hi cfg_hi;
        enum dma_slave_buswidth width;

        pr_debug("MDMA: Prep for memcpy\n");
        BUG_ON(!chan);
        if (!len)
                return NULL;

        midc = to_intel_mid_dma_chan(chan);
        BUG_ON(!midc);

        mids = midc->mid_slave;
        BUG_ON(!mids);

        pr_debug("MDMA:called for DMA %x CH %d Length %zu\n",
                                midc->dma->pci_id, midc->ch_id, len);
        pr_debug("MDMA:Cfg passed Mode %x, Dirn %x, HS %x, Width %x\n",
                        mids->cfg_mode, mids->dma_slave.direction,
                        mids->hs_mode, mids->dma_slave.src_addr_width);

        /*calculate CFG_LO*/
        if (mids->hs_mode == LNW_DMA_SW_HS) {
                cfg_lo.cfg_lo = 0;
                cfg_lo.cfgx.hs_sel_dst = 1;
                cfg_lo.cfgx.hs_sel_src = 1;
        } else if (mids->hs_mode == LNW_DMA_HW_HS)
                cfg_lo.cfg_lo = 0x00000;

        /*calculate CFG_HI*/
        if (mids->cfg_mode == LNW_DMA_MEM_TO_MEM) {
                /*SW HS only*/
                cfg_hi.cfg_hi = 0;
        } else {
                cfg_hi.cfg_hi = 0;
                if (midc->dma->pimr_mask) {
                        cfg_hi.cfgx.protctl = 0x0; /*default value*/
                        cfg_hi.cfgx.fifo_mode = 1;
                        if (mids->dma_slave.direction == DMA_TO_DEVICE) {
                                cfg_hi.cfgx.src_per = 0;
                                if (mids->device_instance == 0)
                                        cfg_hi.cfgx.dst_per = 3;
                                if (mids->device_instance == 1)
                                        cfg_hi.cfgx.dst_per = 1;
                        } else if (mids->dma_slave.direction == DMA_FROM_DEVICE) {
                                if (mids->device_instance == 0)
                                        cfg_hi.cfgx.src_per = 2;
                                if (mids->device_instance == 1)
                                        cfg_hi.cfgx.src_per = 0;
                                cfg_hi.cfgx.dst_per = 0;
                        }
                } else {
                        cfg_hi.cfgx.protctl = 0x1; /*default value*/
                        cfg_hi.cfgx.src_per = cfg_hi.cfgx.dst_per =
                                        midc->ch_id - midc->dma->chan_base;
                }
        }

        /*calculate CTL_HI*/
        ctl_hi.ctlx.reser = 0;
        ctl_hi.ctlx.done  = 0;
        width = mids->dma_slave.src_addr_width;

        ctl_hi.ctlx.block_ts = get_block_ts(len, width, midc->dma->block_size);
        pr_debug("MDMA:calc len %d for block size %d\n",
                                ctl_hi.ctlx.block_ts, midc->dma->block_size);
        /*calculate CTL_LO*/
        ctl_lo.ctl_lo = 0;
        ctl_lo.ctlx.int_en = 1;
        ctl_lo.ctlx.dst_msize = mids->dma_slave.src_maxburst;
        ctl_lo.ctlx.src_msize = mids->dma_slave.dst_maxburst;

        /*
         * Here we need some translation from "enum dma_slave_buswidth"
         * to the format for our dma controller
         *              standard        intel_mid_dmac's format
         *               1 Byte                 0b000
         *               2 Bytes                0b001
         *               4 Bytes                0b010
         */
        ctl_lo.ctlx.dst_tr_width = mids->dma_slave.dst_addr_width / 2;
        ctl_lo.ctlx.src_tr_width = mids->dma_slave.src_addr_width / 2;

        if (mids->cfg_mode == LNW_DMA_MEM_TO_MEM) {
                ctl_lo.ctlx.tt_fc = 0;
                ctl_lo.ctlx.sinc = 0;
                ctl_lo.ctlx.dinc = 0;
        } else {
                if (mids->dma_slave.direction == DMA_TO_DEVICE) {
                        ctl_lo.ctlx.sinc = 0;
                        ctl_lo.ctlx.dinc = 2;
                        ctl_lo.ctlx.tt_fc = 1;
                } else if (mids->dma_slave.direction == DMA_FROM_DEVICE) {
                        ctl_lo.ctlx.sinc = 2;
                        ctl_lo.ctlx.dinc = 0;
                        ctl_lo.ctlx.tt_fc = 2;
                }
        }

        pr_debug("MDMA:Calc CTL LO %x, CTL HI %x, CFG LO %x, CFG HI %x\n",
                ctl_lo.ctl_lo, ctl_hi.ctl_hi, cfg_lo.cfg_lo, cfg_hi.cfg_hi);

        enable_dma_interrupt(midc);

        desc = midc_desc_get(midc);
        if (desc == NULL)
                goto err_desc_get;
        desc->sar = src;
        desc->dar = dest ;
        desc->len = len;
        desc->cfg_hi = cfg_hi.cfg_hi;
        desc->cfg_lo = cfg_lo.cfg_lo;
        desc->ctl_lo = ctl_lo.ctl_lo;
        desc->ctl_hi = ctl_hi.ctl_hi;
        desc->width = width;
        desc->dirn = mids->dma_slave.direction;
        desc->lli_phys = 0;
        desc->lli = NULL;
        desc->lli_pool = NULL;
        return &desc->txd;

err_desc_get:
        pr_err("ERR_MDMA: Failed to get desc\n");
        midc_desc_put(midc, desc);
        return NULL;
}
/**
 * intel_mid_dma_prep_slave_sg -        Prep slave sg txn
 * @chan: chan for DMA transfer
 * @sgl: scatter gather list
 * @sg_len: length of sg txn
 * @direction: DMA transfer dirtn
 * @flags: DMA flags
 *
 * Prepares LLI based periphral transfer
 */
static struct dma_async_tx_descriptor *intel_mid_dma_prep_slave_sg(
                        struct dma_chan *chan, struct scatterlist *sgl,
                        unsigned int sg_len, enum dma_data_direction direction,
                        unsigned long flags)
{
        struct intel_mid_dma_chan *midc = NULL;
        struct intel_mid_dma_slave *mids = NULL;
        struct intel_mid_dma_desc *desc = NULL;
        struct dma_async_tx_descriptor *txd = NULL;
        union intel_mid_dma_ctl_lo ctl_lo;

        pr_debug("MDMA: Prep for slave SG\n");

        if (!sg_len) {
                pr_err("MDMA: Invalid SG length\n");
                return NULL;
        }
        midc = to_intel_mid_dma_chan(chan);
        BUG_ON(!midc);

        mids = midc->mid_slave;
        BUG_ON(!mids);

        if (!midc->dma->pimr_mask) {
                /* We can still handle sg list with only one item */
                if (sg_len == 1) {
                        txd = intel_mid_dma_prep_memcpy(chan,
                                                mids->dma_slave.dst_addr,
                                                mids->dma_slave.src_addr,
                                                sgl->length,
                                                flags);
                        return txd;
                } else {
                        pr_warn("MDMA: SG list is not supported by this controller\n");
                        return  NULL;
                }
        }

        pr_debug("MDMA: SG Length = %d, direction = %d, Flags = %#lx\n",
                        sg_len, direction, flags);

        txd = intel_mid_dma_prep_memcpy(chan, 0, 0, sgl->length, flags);
        if (NULL == txd) {
                pr_err("MDMA: Prep memcpy failed\n");
                return NULL;
        }

        desc = to_intel_mid_dma_desc(txd);
        desc->dirn = direction;
        ctl_lo.ctl_lo = desc->ctl_lo;
        ctl_lo.ctlx.llp_dst_en = 1;
        ctl_lo.ctlx.llp_src_en = 1;
        desc->ctl_lo = ctl_lo.ctl_lo;
        desc->lli_length = sg_len;
        desc->current_lli = 0;
        /* DMA coherent memory pool for LLI descriptors*/
        desc->lli_pool = pci_pool_create("intel_mid_dma_lli_pool",
                                midc->dma->pdev,
                                (sizeof(struct intel_mid_dma_lli)*sg_len),
                                32, 0);
        if (NULL == desc->lli_pool) {
                pr_err("MID_DMA:LLI pool create failed\n");
                return NULL;
        }

        desc->lli = pci_pool_alloc(desc->lli_pool, GFP_KERNEL, &desc->lli_phys);
        if (!desc->lli) {
                pr_err("MID_DMA: LLI alloc failed\n");
                pci_pool_destroy(desc->lli_pool);
                return NULL;
        }

        midc_lli_fill_sg(midc, desc, sgl, sg_len, flags);
        if (flags & DMA_PREP_INTERRUPT) {
                iowrite32(UNMASK_INTR_REG(midc->ch_id),
                                midc->dma_base + MASK_BLOCK);
                pr_debug("MDMA:Enabled Block interrupt\n");
        }
        return &desc->txd;
}

/**
 * intel_mid_dma_free_chan_resources -  Frees dma resources
 * @chan: chan requiring attention
 *
 * Frees the allocated resources on this DMA chan
 */
static void intel_mid_dma_free_chan_resources(struct dma_chan *chan)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);
        struct middma_device    *mid = to_middma_device(chan->device);
        struct intel_mid_dma_desc       *desc, *_desc;

        if (true == midc->busy) {
                /*trying to free ch in use!!!!!*/
                pr_err("ERR_MDMA: trying to free ch in use\n");
        }
        pm_runtime_put(&mid->pdev->dev);
        spin_lock_bh(&midc->lock);
        midc->descs_allocated = 0;
        list_for_each_entry_safe(desc, _desc, &midc->active_list, desc_node) {
                list_del(&desc->desc_node);
                pci_pool_free(mid->dma_pool, desc, desc->txd.phys);
        }
        list_for_each_entry_safe(desc, _desc, &midc->free_list, desc_node) {
                list_del(&desc->desc_node);
                pci_pool_free(mid->dma_pool, desc, desc->txd.phys);
        }
        list_for_each_entry_safe(desc, _desc, &midc->queue, desc_node) {
                list_del(&desc->desc_node);
                pci_pool_free(mid->dma_pool, desc, desc->txd.phys);
        }
        spin_unlock_bh(&midc->lock);
        midc->in_use = false;
        midc->busy = false;
        /* Disable CH interrupts */
        iowrite32(MASK_INTR_REG(midc->ch_id), mid->dma_base + MASK_BLOCK);
        iowrite32(MASK_INTR_REG(midc->ch_id), mid->dma_base + MASK_ERR);
}

/**
 * intel_mid_dma_alloc_chan_resources - Allocate dma resources
 * @chan: chan requiring attention
 *
 * Allocates DMA resources on this chan
 * Return the descriptors allocated
 */
static int intel_mid_dma_alloc_chan_resources(struct dma_chan *chan)
{
        struct intel_mid_dma_chan       *midc = to_intel_mid_dma_chan(chan);
        struct middma_device    *mid = to_middma_device(chan->device);
        struct intel_mid_dma_desc       *desc;
        dma_addr_t              phys;
        int     i = 0;

        pm_runtime_get_sync(&mid->pdev->dev);

        if (mid->state == SUSPENDED) {
                if (dma_resume(mid->pdev)) {
                        pr_err("ERR_MDMA: resume failed");
                        return -EFAULT;
                }
        }

        /* ASSERT:  channel is idle */
        if (test_ch_en(mid->dma_base, midc->ch_id)) {
                /*ch is not idle*/
                pr_err("ERR_MDMA: ch not idle\n");
                pm_runtime_put(&mid->pdev->dev);
                return -EIO;
        }
        midc->completed = chan->cookie = 1;

        spin_lock_bh(&midc->lock);
        while (midc->descs_allocated < DESCS_PER_CHANNEL) {
                spin_unlock_bh(&midc->lock);
                desc = pci_pool_alloc(mid->dma_pool, GFP_KERNEL, &phys);
                if (!desc) {
                        pr_err("ERR_MDMA: desc failed\n");
                        pm_runtime_put(&mid->pdev->dev);
                        return -ENOMEM;
                        /*check*/
                }
                dma_async_tx_descriptor_init(&desc->txd, chan);
                desc->txd.tx_submit = intel_mid_dma_tx_submit;
                desc->txd.flags = DMA_CTRL_ACK;
                desc->txd.phys = phys;
                spin_lock_bh(&midc->lock);
                i = ++midc->descs_allocated;
                list_add_tail(&desc->desc_node, &midc->free_list);
        }
        spin_unlock_bh(&midc->lock);
        midc->in_use = true;
        midc->busy = false;
        pr_debug("MID_DMA: Desc alloc done ret: %d desc\n", i);
        return i;
}

/**
 * midc_handle_error -  Handle DMA txn error
 * @mid: controller where error occurred
 * @midc: chan where error occurred
 *
 * Scan the descriptor for error
 */
static void midc_handle_error(struct middma_device *mid,
                struct intel_mid_dma_chan *midc)
{
        midc_scan_descriptors(mid, midc);
}

/**
 * dma_tasklet -        DMA interrupt tasklet
 * @data: tasklet arg (the controller structure)
 *
 * Scan the controller for interrupts for completion/error
 * Clear the interrupt and call for handling completion/error
 */
static void dma_tasklet(unsigned long data)
{
        struct middma_device *mid = NULL;
        struct intel_mid_dma_chan *midc = NULL;
        u32 status, raw_tfr, raw_block;
        int i;

        mid = (struct middma_device *)data;
        if (mid == NULL) {
                pr_err("ERR_MDMA: tasklet Null param\n");
                return;
        }
        pr_debug("MDMA: in tasklet for device %x\n", mid->pci_id);
        raw_tfr = ioread32(mid->dma_base + RAW_TFR);
        raw_block = ioread32(mid->dma_base + RAW_BLOCK);
        status = raw_tfr | raw_block;
        status &= mid->intr_mask;
        while (status) {
                /*txn interrupt*/
                i = get_ch_index(&status, mid->chan_base);
                if (i < 0) {
                        pr_err("ERR_MDMA:Invalid ch index %x\n", i);
                        return;
                }
                midc = &mid->ch[i];
                if (midc == NULL) {
                        pr_err("ERR_MDMA:Null param midc\n");
                        return;
                }
                pr_debug("MDMA:Tx complete interrupt %x, Ch No %d Index %d\n",
                                status, midc->ch_id, i);
                midc->raw_tfr = raw_tfr;
                midc->raw_block = raw_block;
                spin_lock_bh(&midc->lock);
                /*clearing this interrupts first*/
                iowrite32((1 << midc->ch_id), mid->dma_base + CLEAR_TFR);
                if (raw_block) {
                        iowrite32((1 << midc->ch_id),
                                mid->dma_base + CLEAR_BLOCK);
                }
                midc_scan_descriptors(mid, midc);
                pr_debug("MDMA:Scan of desc... complete, unmasking\n");
                iowrite32(UNMASK_INTR_REG(midc->ch_id),
                                mid->dma_base + MASK_TFR);
                if (raw_block) {
                        iowrite32(UNMASK_INTR_REG(midc->ch_id),
                                mid->dma_base + MASK_BLOCK);
                }
                spin_unlock_bh(&midc->lock);
        }

        status = ioread32(mid->dma_base + RAW_ERR);
        status &= mid->intr_mask;
        while (status) {
                /*err interrupt*/
                i = get_ch_index(&status, mid->chan_base);
                if (i < 0) {
                        pr_err("ERR_MDMA:Invalid ch index %x\n", i);
                        return;
                }
                midc = &mid->ch[i];
                if (midc == NULL) {
                        pr_err("ERR_MDMA:Null param midc\n");
                        return;
                }
                pr_debug("MDMA:Tx complete interrupt %x, Ch No %d Index %d\n",
                                status, midc->ch_id, i);

                iowrite32((1 << midc->ch_id), mid->dma_base + CLEAR_ERR);
                spin_lock_bh(&midc->lock);
                midc_handle_error(mid, midc);
                iowrite32(UNMASK_INTR_REG(midc->ch_id),
                                mid->dma_base + MASK_ERR);
                spin_unlock_bh(&midc->lock);
        }
        pr_debug("MDMA:Exiting takslet...\n");
        return;
}

static void dma_tasklet1(unsigned long data)
{
        pr_debug("MDMA:in takslet1...\n");
        return dma_tasklet(data);
}

static void dma_tasklet2(unsigned long data)
{
        pr_debug("MDMA:in takslet2...\n");
        return dma_tasklet(data);
}

/**
 * intel_mid_dma_interrupt -    DMA ISR
 * @irq: IRQ where interrupt occurred
 * @data: ISR cllback data (the controller structure)
 *
 * See if this is our interrupt if so then schedule the tasklet
 * otherwise ignore
 */
static irqreturn_t intel_mid_dma_interrupt(int irq, void *data)
{
        struct middma_device *mid = data;
        u32 tfr_status, err_status;
        int call_tasklet = 0;

        tfr_status = ioread32(mid->dma_base + RAW_TFR);
        err_status = ioread32(mid->dma_base + RAW_ERR);
        if (!tfr_status && !err_status)
                return IRQ_NONE;

        /*DMA Interrupt*/
        pr_debug("MDMA:Got an interrupt on irq %d\n", irq);
        pr_debug("MDMA: Status %x, Mask %x\n", tfr_status, mid->intr_mask);
        tfr_status &= mid->intr_mask;
        if (tfr_status) {
                /*need to disable intr*/
                iowrite32((tfr_status << INT_MASK_WE), mid->dma_base + MASK_TFR);
                iowrite32((tfr_status << INT_MASK_WE), mid->dma_base + MASK_BLOCK);
                pr_debug("MDMA: Calling tasklet %x\n", tfr_status);
                call_tasklet = 1;
        }
        err_status &= mid->intr_mask;
        if (err_status) {
                iowrite32(MASK_INTR_REG(err_status), mid->dma_base + MASK_ERR);
                call_tasklet = 1;
        }
        if (call_tasklet)
                tasklet_schedule(&mid->tasklet);

        return IRQ_HANDLED;
}

static irqreturn_t intel_mid_dma_interrupt1(int irq, void *data)
{
        return intel_mid_dma_interrupt(irq, data);
}

static irqreturn_t intel_mid_dma_interrupt2(int irq, void *data)
{
        return intel_mid_dma_interrupt(irq, data);
}

/**
 * mid_setup_dma -      Setup the DMA controller
 * @pdev: Controller PCI device structure
 *
 * Initialize the DMA controller, channels, registers with DMA engine,
 * ISR. Initialize DMA controller channels.
 */
static int mid_setup_dma(struct pci_dev *pdev)
{
        struct middma_device *dma = pci_get_drvdata(pdev);
        int err, i;

        /* DMA coherent memory pool for DMA descriptor allocations */
        dma->dma_pool = pci_pool_create("intel_mid_dma_desc_pool", pdev,
                                        sizeof(struct intel_mid_dma_desc),
                                        32, 0);
        if (NULL == dma->dma_pool) {
                pr_err("ERR_MDMA:pci_pool_create failed\n");
                err = -ENOMEM;
                goto err_dma_pool;
        }

        INIT_LIST_HEAD(&dma->common.channels);
        dma->pci_id = pdev->device;
        if (dma->pimr_mask) {
                dma->mask_reg = ioremap(LNW_PERIPHRAL_MASK_BASE,
                                        LNW_PERIPHRAL_MASK_SIZE);
                if (dma->mask_reg == NULL) {
                        pr_err("ERR_MDMA:Can't map periphral intr space !!\n");
                        return -ENOMEM;
                }
        } else
                dma->mask_reg = NULL;

        pr_debug("MDMA:Adding %d channel for this controller\n", dma->max_chan);
        /*init CH structures*/
        dma->intr_mask = 0;
        dma->state = RUNNING;
        for (i = 0; i < dma->max_chan; i++) {
                struct intel_mid_dma_chan *midch = &dma->ch[i];

                midch->chan.device = &dma->common;
                midch->chan.cookie =  1;
                midch->chan.chan_id = i;
                midch->ch_id = dma->chan_base + i;
                pr_debug("MDMA:Init CH %d, ID %d\n", i, midch->ch_id);

                midch->dma_base = dma->dma_base;
                midch->ch_regs = dma->dma_base + DMA_CH_SIZE * midch->ch_id;
                midch->dma = dma;
                dma->intr_mask |= 1 << (dma->chan_base + i);
                spin_lock_init(&midch->lock);

                INIT_LIST_HEAD(&midch->active_list);
                INIT_LIST_HEAD(&midch->queue);
                INIT_LIST_HEAD(&midch->free_list);
                /*mask interrupts*/
                iowrite32(MASK_INTR_REG(midch->ch_id),
                        dma->dma_base + MASK_BLOCK);
                iowrite32(MASK_INTR_REG(midch->ch_id),
                        dma->dma_base + MASK_SRC_TRAN);
                iowrite32(MASK_INTR_REG(midch->ch_id),
                        dma->dma_base + MASK_DST_TRAN);
                iowrite32(MASK_INTR_REG(midch->ch_id),
                        dma->dma_base + MASK_ERR);
                iowrite32(MASK_INTR_REG(midch->ch_id),
                        dma->dma_base + MASK_TFR);

                disable_dma_interrupt(midch);
                list_add_tail(&midch->chan.device_node, &dma->common.channels);
        }
        pr_debug("MDMA: Calc Mask as %x for this controller\n", dma->intr_mask);

        /*init dma structure*/
        dma_cap_zero(dma->common.cap_mask);
        dma_cap_set(DMA_MEMCPY, dma->common.cap_mask);
        dma_cap_set(DMA_SLAVE, dma->common.cap_mask);
        dma_cap_set(DMA_PRIVATE, dma->common.cap_mask);
        dma->common.dev = &pdev->dev;
        dma->common.chancnt = dma->max_chan;

        dma->common.device_alloc_chan_resources =
                                        intel_mid_dma_alloc_chan_resources;
        dma->common.device_free_chan_resources =
                                        intel_mid_dma_free_chan_resources;

        dma->common.device_tx_status = intel_mid_dma_tx_status;
        dma->common.device_prep_dma_memcpy = intel_mid_dma_prep_memcpy;
        dma->common.device_issue_pending = intel_mid_dma_issue_pending;
        dma->common.device_prep_slave_sg = intel_mid_dma_prep_slave_sg;
        dma->common.device_control = intel_mid_dma_device_control;

        /*enable dma cntrl*/
        iowrite32(REG_BIT0, dma->dma_base + DMA_CFG);

        /*register irq */
        if (dma->pimr_mask) {
                pr_debug("MDMA:Requesting irq shared for DMAC1\n");
                err = request_irq(pdev->irq, intel_mid_dma_interrupt1,
                        IRQF_SHARED, "INTEL_MID_DMAC1", dma);
                if (0 != err)
                        goto err_irq;
        } else {
                dma->intr_mask = 0x03;
                pr_debug("MDMA:Requesting irq for DMAC2\n");
                err = request_irq(pdev->irq, intel_mid_dma_interrupt2,
                        IRQF_SHARED, "INTEL_MID_DMAC2", dma);
                if (0 != err)
                        goto err_irq;
        }
        /*register device w/ engine*/
        err = dma_async_device_register(&dma->common);
        if (0 != err) {
                pr_err("ERR_MDMA:device_register failed: %d\n", err);
                goto err_engine;
        }
        if (dma->pimr_mask) {
                pr_debug("setting up tasklet1 for DMAC1\n");
                tasklet_init(&dma->tasklet, dma_tasklet1, (unsigned long)dma);
        } else {
                pr_debug("setting up tasklet2 for DMAC2\n");
                tasklet_init(&dma->tasklet, dma_tasklet2, (unsigned long)dma);
        }
        return 0;

err_engine:
        free_irq(pdev->irq, dma);
err_irq:
        pci_pool_destroy(dma->dma_pool);
err_dma_pool:
        pr_err("ERR_MDMA:setup_dma failed: %d\n", err);
        return err;

}

/**
 * middma_shutdown -    Shutdown the DMA controller
 * @pdev: Controller PCI device structure
 *
 * Called by remove
 * Unregister DMa controller, clear all structures and free interrupt
 */
static void middma_shutdown(struct pci_dev *pdev)
{
        struct middma_device *device = pci_get_drvdata(pdev);

        dma_async_device_unregister(&device->common);
        pci_pool_destroy(device->dma_pool);
        if (device->mask_reg)
                iounmap(device->mask_reg);
        if (device->dma_base)
                iounmap(device->dma_base);
        free_irq(pdev->irq, device);
        return;
}

/**
 * intel_mid_dma_probe -        PCI Probe
 * @pdev: Controller PCI device structure
 * @id: pci device id structure
 *
 * Initialize the PCI device, map BARs, query driver data.
 * Call setup_dma to complete contoller and chan initilzation
 */
static int __devinit intel_mid_dma_probe(struct pci_dev *pdev,
                                        const struct pci_device_id *id)
{
        struct middma_device *device;
        u32 base_addr, bar_size;
        struct intel_mid_dma_probe_info *info;
        int err;

        pr_debug("MDMA: probe for %x\n", pdev->device);
        info = (void *)id->driver_data;
        pr_debug("MDMA: CH %d, base %d, block len %d, Periphral mask %x\n",
                                info->max_chan, info->ch_base,
                                info->block_size, info->pimr_mask);

        err = pci_enable_device(pdev);
        if (err)
                goto err_enable_device;

        err = pci_request_regions(pdev, "intel_mid_dmac");
        if (err)
                goto err_request_regions;

        err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
        if (err)
                goto err_set_dma_mask;

        err = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
        if (err)
                goto err_set_dma_mask;

        device = kzalloc(sizeof(*device), GFP_KERNEL);
        if (!device) {
                pr_err("ERR_MDMA:kzalloc failed probe\n");
                err = -ENOMEM;
                goto err_kzalloc;
        }
        device->pdev = pci_dev_get(pdev);

        base_addr = pci_resource_start(pdev, 0);
        bar_size  = pci_resource_len(pdev, 0);
        device->dma_base = ioremap_nocache(base_addr, DMA_REG_SIZE);
        if (!device->dma_base) {
                pr_err("ERR_MDMA:ioremap failed\n");
                err = -ENOMEM;
                goto err_ioremap;
        }
        pci_set_drvdata(pdev, device);
        pci_set_master(pdev);
        device->max_chan = info->max_chan;
        device->chan_base = info->ch_base;
        device->block_size = info->block_size;
        device->pimr_mask = info->pimr_mask;

        err = mid_setup_dma(pdev);
        if (err)
                goto err_dma;

        pm_runtime_put_noidle(&pdev->dev);
        pm_runtime_allow(&pdev->dev);
        return 0;

err_dma:
        iounmap(device->dma_base);
err_ioremap:
        pci_dev_put(pdev);
        kfree(device);
err_kzalloc:
err_set_dma_mask:
        pci_release_regions(pdev);
        pci_disable_device(pdev);
err_request_regions:
err_enable_device:
        pr_err("ERR_MDMA:Probe failed %d\n", err);
        return err;
}

/**
 * intel_mid_dma_remove -       PCI remove
 * @pdev: Controller PCI device structure
 *
 * Free up all resources and data
 * Call shutdown_dma to complete contoller and chan cleanup
 */
static void __devexit intel_mid_dma_remove(struct pci_dev *pdev)
{
        struct middma_device *device = pci_get_drvdata(pdev);

        pm_runtime_get_noresume(&pdev->dev);
        pm_runtime_forbid(&pdev->dev);
        middma_shutdown(pdev);
        pci_dev_put(pdev);
        kfree(device);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
}

/* Power Management */
/*
* dma_suspend - PCI suspend function
*
* @pci: PCI device structure
* @state: PM message
*
* This function is called by OS when a power event occurs
*/
int dma_suspend(struct pci_dev *pci, pm_message_t state)
{
        int i;
        struct middma_device *device = pci_get_drvdata(pci);
        pr_debug("MDMA: dma_suspend called\n");

        for (i = 0; i < device->max_chan; i++) {
                if (device->ch[i].in_use)
                        return -EAGAIN;
        }
        device->state = SUSPENDED;
        pci_save_state(pci);
        pci_disable_device(pci);
        pci_set_power_state(pci, PCI_D3hot);
        return 0;
}

/**
* dma_resume - PCI resume function
*
* @pci: PCI device structure
*
* This function is called by OS when a power event occurs
*/
int dma_resume(struct pci_dev *pci)
{
        int ret;
        struct middma_device *device = pci_get_drvdata(pci);

        pr_debug("MDMA: dma_resume called\n");
        pci_set_power_state(pci, PCI_D0);
        pci_restore_state(pci);
        ret = pci_enable_device(pci);
        if (ret) {
                pr_err("MDMA: device can't be enabled for %x\n", pci->device);
                return ret;
        }
        device->state = RUNNING;
        iowrite32(REG_BIT0, device->dma_base + DMA_CFG);
        return 0;
}

static int dma_runtime_suspend(struct device *dev)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        struct middma_device *device = pci_get_drvdata(pci_dev);

        device->state = SUSPENDED;
        return 0;
}

static int dma_runtime_resume(struct device *dev)
{
        struct pci_dev *pci_dev = to_pci_dev(dev);
        struct middma_device *device = pci_get_drvdata(pci_dev);

        device->state = RUNNING;
        iowrite32(REG_BIT0, device->dma_base + DMA_CFG);
        return 0;
}

static int dma_runtime_idle(struct device *dev)
{
        struct pci_dev *pdev = to_pci_dev(dev);
        struct middma_device *device = pci_get_drvdata(pdev);
        int i;

        for (i = 0; i < device->max_chan; i++) {
                if (device->ch[i].in_use)
                        return -EAGAIN;
        }

        return pm_schedule_suspend(dev, 0);
}

/******************************************************************************
* PCI stuff
*/
static struct pci_device_id intel_mid_dma_ids[] = {
        { PCI_VDEVICE(INTEL, INTEL_MID_DMAC1_ID),       INFO(2, 6, 4095, 0x200020)},
        { PCI_VDEVICE(INTEL, INTEL_MID_DMAC2_ID),       INFO(2, 0, 2047, 0)},
        { PCI_VDEVICE(INTEL, INTEL_MID_GP_DMAC2_ID),    INFO(2, 0, 2047, 0)},
        { PCI_VDEVICE(INTEL, INTEL_MFLD_DMAC1_ID),      INFO(4, 0, 4095, 0x400040)},
        { 0, }
};
MODULE_DEVICE_TABLE(pci, intel_mid_dma_ids);

static const struct dev_pm_ops intel_mid_dma_pm = {
        .runtime_suspend = dma_runtime_suspend,
        .runtime_resume = dma_runtime_resume,
        .runtime_idle = dma_runtime_idle,
};

static struct pci_driver intel_mid_dma_pci_driver = {
        .name           =       "Intel MID DMA",
        .id_table       =       intel_mid_dma_ids,
        .probe          =       intel_mid_dma_probe,
        .remove         =       __devexit_p(intel_mid_dma_remove),
#ifdef CONFIG_PM
        .suspend = dma_suspend,
        .resume = dma_resume,
        .driver = {
                .pm = &intel_mid_dma_pm,
        },
#endif
};

static int __init intel_mid_dma_init(void)
{
        pr_debug("INFO_MDMA: LNW DMA Driver Version %s\n",
                        INTEL_MID_DMA_DRIVER_VERSION);
        return pci_register_driver(&intel_mid_dma_pci_driver);
}
fs_initcall(intel_mid_dma_init);

static void __exit intel_mid_dma_exit(void)
{
        pci_unregister_driver(&intel_mid_dma_pci_driver);
}
module_exit(intel_mid_dma_exit);

MODULE_AUTHOR("Vinod Koul <vinod.koul@intel.com>");
MODULE_DESCRIPTION("Intel (R) MID DMAC Driver");
MODULE_LICENSE("GPL v2");
MODULE_VERSION(INTEL_MID_DMA_DRIVER_VERSION);