Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[linux-stable.git] / drivers / mfd / ucb1x00-core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  linux/drivers/mfd/ucb1x00-core.c
 *
 *  Copyright (C) 2001 Russell King, All Rights Reserved.
 *
 *  The UCB1x00 core driver provides basic services for handling IO,
 *  the ADC, interrupts, and accessing registers.  It is designed
 *  such that everything goes through this layer, thereby providing
 *  a consistent locking methodology, as well as allowing the drivers
 *  to be used on other non-MCP-enabled hardware platforms.
 *
 *  Note that all locks are private to this file.  Nothing else may
 *  touch them.
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/mfd/ucb1x00.h>
#include <linux/pm.h>
#include <linux/gpio/driver.h>

static DEFINE_MUTEX(ucb1x00_mutex);
static LIST_HEAD(ucb1x00_drivers);
static LIST_HEAD(ucb1x00_devices);

/**
 *      ucb1x00_io_set_dir - set IO direction
 *      @ucb: UCB1x00 structure describing chip
 *      @in:  bitfield of IO pins to be set as inputs
 *      @out: bitfield of IO pins to be set as outputs
 *
 *      Set the IO direction of the ten general purpose IO pins on
 *      the UCB1x00 chip.  The @in bitfield has priority over the
 *      @out bitfield, in that if you specify a pin as both input
 *      and output, it will end up as an input.
 *
 *      ucb1x00_enable must have been called to enable the comms
 *      before using this function.
 *
 *      This function takes a spinlock, disabling interrupts.
 */
void ucb1x00_io_set_dir(struct ucb1x00 *ucb, unsigned int in, unsigned int out)
{
        unsigned long flags;

        spin_lock_irqsave(&ucb->io_lock, flags);
        ucb->io_dir |= out;
        ucb->io_dir &= ~in;

        ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
        spin_unlock_irqrestore(&ucb->io_lock, flags);
}

/**
 *      ucb1x00_io_write - set or clear IO outputs
 *      @ucb:   UCB1x00 structure describing chip
 *      @set:   bitfield of IO pins to set to logic '1'
 *      @clear: bitfield of IO pins to set to logic '0'
 *
 *      Set the IO output state of the specified IO pins.  The value
 *      is retained if the pins are subsequently configured as inputs.
 *      The @clear bitfield has priority over the @set bitfield -
 *      outputs will be cleared.
 *
 *      ucb1x00_enable must have been called to enable the comms
 *      before using this function.
 *
 *      This function takes a spinlock, disabling interrupts.
 */
void ucb1x00_io_write(struct ucb1x00 *ucb, unsigned int set, unsigned int clear)
{
        unsigned long flags;

        spin_lock_irqsave(&ucb->io_lock, flags);
        ucb->io_out |= set;
        ucb->io_out &= ~clear;

        ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
        spin_unlock_irqrestore(&ucb->io_lock, flags);
}

/**
 *      ucb1x00_io_read - read the current state of the IO pins
 *      @ucb: UCB1x00 structure describing chip
 *
 *      Return a bitfield describing the logic state of the ten
 *      general purpose IO pins.
 *
 *      ucb1x00_enable must have been called to enable the comms
 *      before using this function.
 *
 *      This function does not take any mutexes or spinlocks.
 */
unsigned int ucb1x00_io_read(struct ucb1x00 *ucb)
{
        return ucb1x00_reg_read(ucb, UCB_IO_DATA);
}

static void ucb1x00_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
        struct ucb1x00 *ucb = gpiochip_get_data(chip);
        unsigned long flags;

        spin_lock_irqsave(&ucb->io_lock, flags);
        if (value)
                ucb->io_out |= 1 << offset;
        else
                ucb->io_out &= ~(1 << offset);

        ucb1x00_enable(ucb);
        ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
        ucb1x00_disable(ucb);
        spin_unlock_irqrestore(&ucb->io_lock, flags);
}

static int ucb1x00_gpio_get(struct gpio_chip *chip, unsigned offset)
{
        struct ucb1x00 *ucb = gpiochip_get_data(chip);
        unsigned val;

        ucb1x00_enable(ucb);
        val = ucb1x00_reg_read(ucb, UCB_IO_DATA);
        ucb1x00_disable(ucb);

        return !!(val & (1 << offset));
}

static int ucb1x00_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
        struct ucb1x00 *ucb = gpiochip_get_data(chip);
        unsigned long flags;

        spin_lock_irqsave(&ucb->io_lock, flags);
        ucb->io_dir &= ~(1 << offset);
        ucb1x00_enable(ucb);
        ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
        ucb1x00_disable(ucb);
        spin_unlock_irqrestore(&ucb->io_lock, flags);

        return 0;
}

static int ucb1x00_gpio_direction_output(struct gpio_chip *chip, unsigned offset
                , int value)
{
        struct ucb1x00 *ucb = gpiochip_get_data(chip);
        unsigned long flags;
        unsigned old, mask = 1 << offset;

        spin_lock_irqsave(&ucb->io_lock, flags);
        old = ucb->io_out;
        if (value)
                ucb->io_out |= mask;
        else
                ucb->io_out &= ~mask;

        ucb1x00_enable(ucb);
        if (old != ucb->io_out)
                ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);

        if (!(ucb->io_dir & mask)) {
                ucb->io_dir |= mask;
                ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);
        }
        ucb1x00_disable(ucb);
        spin_unlock_irqrestore(&ucb->io_lock, flags);

        return 0;
}

static int ucb1x00_to_irq(struct gpio_chip *chip, unsigned offset)
{
        struct ucb1x00 *ucb = gpiochip_get_data(chip);

        return ucb->irq_base > 0 ? ucb->irq_base + offset : -ENXIO;
}

/*
 * UCB1300 data sheet says we must:
 *  1. enable ADC       => 5us (including reference startup time)
 *  2. select input     => 51*tsibclk  => 4.3us
 *  3. start conversion => 102*tsibclk => 8.5us
 * (tsibclk = 1/11981000)
 * Period between SIB 128-bit frames = 10.7us
 */

/**
 *      ucb1x00_adc_enable - enable the ADC converter
 *      @ucb: UCB1x00 structure describing chip
 *
 *      Enable the ucb1x00 and ADC converter on the UCB1x00 for use.
 *      Any code wishing to use the ADC converter must call this
 *      function prior to using it.
 *
 *      This function takes the ADC mutex to prevent two or more
 *      concurrent uses, and therefore may sleep.  As a result, it
 *      can only be called from process context, not interrupt
 *      context.
 *
 *      You should release the ADC as soon as possible using
 *      ucb1x00_adc_disable.
 */
void ucb1x00_adc_enable(struct ucb1x00 *ucb)
{
        mutex_lock(&ucb->adc_mutex);

        ucb->adc_cr |= UCB_ADC_ENA;

        ucb1x00_enable(ucb);
        ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
}

/**
 *      ucb1x00_adc_read - read the specified ADC channel
 *      @ucb: UCB1x00 structure describing chip
 *      @adc_channel: ADC channel mask
 *      @sync: wait for syncronisation pulse.
 *
 *      Start an ADC conversion and wait for the result.  Note that
 *      synchronised ADC conversions (via the ADCSYNC pin) must wait
 *      until the trigger is asserted and the conversion is finished.
 *
 *      This function currently spins waiting for the conversion to
 *      complete (2 frames max without sync).
 *
 *      If called for a synchronised ADC conversion, it may sleep
 *      with the ADC mutex held.
 */
unsigned int ucb1x00_adc_read(struct ucb1x00 *ucb, int adc_channel, int sync)
{
        unsigned int val;

        if (sync)
                adc_channel |= UCB_ADC_SYNC_ENA;

        ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel);
        ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr | adc_channel | UCB_ADC_START);

        for (;;) {
                val = ucb1x00_reg_read(ucb, UCB_ADC_DATA);
                if (val & UCB_ADC_DAT_VAL)
                        break;
                /* yield to other processes */
                set_current_state(TASK_INTERRUPTIBLE);
                schedule_timeout(1);
        }

        return UCB_ADC_DAT(val);
}

/**
 *      ucb1x00_adc_disable - disable the ADC converter
 *      @ucb: UCB1x00 structure describing chip
 *
 *      Disable the ADC converter and release the ADC mutex.
 */
void ucb1x00_adc_disable(struct ucb1x00 *ucb)
{
        ucb->adc_cr &= ~UCB_ADC_ENA;
        ucb1x00_reg_write(ucb, UCB_ADC_CR, ucb->adc_cr);
        ucb1x00_disable(ucb);

        mutex_unlock(&ucb->adc_mutex);
}

/*
 * UCB1x00 Interrupt handling.
 *
 * The UCB1x00 can generate interrupts when the SIBCLK is stopped.
 * Since we need to read an internal register, we must re-enable
 * SIBCLK to talk to the chip.  We leave the clock running until
 * we have finished processing all interrupts from the chip.
 */
static void ucb1x00_irq(struct irq_desc *desc)
{
        struct ucb1x00 *ucb = irq_desc_get_handler_data(desc);
        unsigned int isr, i;

        ucb1x00_enable(ucb);
        isr = ucb1x00_reg_read(ucb, UCB_IE_STATUS);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, isr);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);

        for (i = 0; i < 16 && isr; i++, isr >>= 1)
                if (isr & 1)
                        generic_handle_irq(ucb->irq_base + i);
        ucb1x00_disable(ucb);
}

static void ucb1x00_irq_update(struct ucb1x00 *ucb, unsigned mask)
{
        ucb1x00_enable(ucb);
        if (ucb->irq_ris_enbl & mask)
                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
                                  ucb->irq_mask);
        if (ucb->irq_fal_enbl & mask)
                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
                                  ucb->irq_mask);
        ucb1x00_disable(ucb);
}

static void ucb1x00_irq_noop(struct irq_data *data)
{
}

static void ucb1x00_irq_mask(struct irq_data *data)
{
        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
        unsigned mask = 1 << (data->irq - ucb->irq_base);

        raw_spin_lock(&ucb->irq_lock);
        ucb->irq_mask &= ~mask;
        ucb1x00_irq_update(ucb, mask);
        raw_spin_unlock(&ucb->irq_lock);
}

static void ucb1x00_irq_unmask(struct irq_data *data)
{
        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
        unsigned mask = 1 << (data->irq - ucb->irq_base);

        raw_spin_lock(&ucb->irq_lock);
        ucb->irq_mask |= mask;
        ucb1x00_irq_update(ucb, mask);
        raw_spin_unlock(&ucb->irq_lock);
}

static int ucb1x00_irq_set_type(struct irq_data *data, unsigned int type)
{
        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
        unsigned mask = 1 << (data->irq - ucb->irq_base);

        raw_spin_lock(&ucb->irq_lock);
        if (type & IRQ_TYPE_EDGE_RISING)
                ucb->irq_ris_enbl |= mask;
        else
                ucb->irq_ris_enbl &= ~mask;

        if (type & IRQ_TYPE_EDGE_FALLING)
                ucb->irq_fal_enbl |= mask;
        else
                ucb->irq_fal_enbl &= ~mask;
        if (ucb->irq_mask & mask) {
                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
                                  ucb->irq_mask);
                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
                                  ucb->irq_mask);
        }
        raw_spin_unlock(&ucb->irq_lock);

        return 0;
}

static int ucb1x00_irq_set_wake(struct irq_data *data, unsigned int on)
{
        struct ucb1x00 *ucb = irq_data_get_irq_chip_data(data);
        struct ucb1x00_plat_data *pdata = ucb->mcp->attached_device.platform_data;
        unsigned mask = 1 << (data->irq - ucb->irq_base);

        if (!pdata || !pdata->can_wakeup)
                return -EINVAL;

        raw_spin_lock(&ucb->irq_lock);
        if (on)
                ucb->irq_wake |= mask;
        else
                ucb->irq_wake &= ~mask;
        raw_spin_unlock(&ucb->irq_lock);

        return 0;
}

static struct irq_chip ucb1x00_irqchip = {
        .name = "ucb1x00",
        .irq_ack = ucb1x00_irq_noop,
        .irq_mask = ucb1x00_irq_mask,
        .irq_unmask = ucb1x00_irq_unmask,
        .irq_set_type = ucb1x00_irq_set_type,
        .irq_set_wake = ucb1x00_irq_set_wake,
};

static int ucb1x00_add_dev(struct ucb1x00 *ucb, struct ucb1x00_driver *drv)
{
        struct ucb1x00_dev *dev;
        int ret;

        dev = kmalloc(sizeof(struct ucb1x00_dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        dev->ucb = ucb;
        dev->drv = drv;

        ret = drv->add(dev);
        if (ret) {
                kfree(dev);
                return ret;
        }

        list_add_tail(&dev->dev_node, &ucb->devs);
        list_add_tail(&dev->drv_node, &drv->devs);

        return ret;
}

static void ucb1x00_remove_dev(struct ucb1x00_dev *dev)
{
        dev->drv->remove(dev);
        list_del(&dev->dev_node);
        list_del(&dev->drv_node);
        kfree(dev);
}

/*
 * Try to probe our interrupt, rather than relying on lots of
 * hard-coded machine dependencies.  For reference, the expected
 * IRQ mappings are:
 *
 *      Machine         Default IRQ
 *      adsbitsy        IRQ_GPCIN4
 *      cerf            IRQ_GPIO_UCB1200_IRQ
 *      flexanet        IRQ_GPIO_GUI
 *      freebird        IRQ_GPIO_FREEBIRD_UCB1300_IRQ
 *      graphicsclient  ADS_EXT_IRQ(8)
 *      graphicsmaster  ADS_EXT_IRQ(8)
 *      lart            LART_IRQ_UCB1200
 *      omnimeter       IRQ_GPIO23
 *      pfs168          IRQ_GPIO_UCB1300_IRQ
 *      simpad          IRQ_GPIO_UCB1300_IRQ
 *      shannon         SHANNON_IRQ_GPIO_IRQ_CODEC
 *      yopy            IRQ_GPIO_UCB1200_IRQ
 */
static int ucb1x00_detect_irq(struct ucb1x00 *ucb)
{
        unsigned long mask;

        mask = probe_irq_on();

        /*
         * Enable the ADC interrupt.
         */
        ucb1x00_reg_write(ucb, UCB_IE_RIS, UCB_IE_ADC);
        ucb1x00_reg_write(ucb, UCB_IE_FAL, UCB_IE_ADC);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);

        /*
         * Cause an ADC interrupt.
         */
        ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA);
        ucb1x00_reg_write(ucb, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);

        /*
         * Wait for the conversion to complete.
         */
        while ((ucb1x00_reg_read(ucb, UCB_ADC_DATA) & UCB_ADC_DAT_VAL) == 0);
        ucb1x00_reg_write(ucb, UCB_ADC_CR, 0);

        /*
         * Disable and clear interrupt.
         */
        ucb1x00_reg_write(ucb, UCB_IE_RIS, 0);
        ucb1x00_reg_write(ucb, UCB_IE_FAL, 0);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0xffff);
        ucb1x00_reg_write(ucb, UCB_IE_CLEAR, 0);

        /*
         * Read triggered interrupt.
         */
        return probe_irq_off(mask);
}

static void ucb1x00_release(struct device *dev)
{
        struct ucb1x00 *ucb = classdev_to_ucb1x00(dev);
        kfree(ucb);
}

static struct class ucb1x00_class = {
        .name           = "ucb1x00",
        .dev_release    = ucb1x00_release,
};

static int ucb1x00_probe(struct mcp *mcp)
{
        struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
        struct ucb1x00_driver *drv;
        struct ucb1x00 *ucb;
        unsigned id, i, irq_base;
        int ret = -ENODEV;

        /* Tell the platform to deassert the UCB1x00 reset */
        if (pdata && pdata->reset)
                pdata->reset(UCB_RST_PROBE);

        mcp_enable(mcp);
        id = mcp_reg_read(mcp, UCB_ID);
        mcp_disable(mcp);

        if (id != UCB_ID_1200 && id != UCB_ID_1300 && id != UCB_ID_TC35143) {
                printk(KERN_WARNING "UCB1x00 ID not found: %04x\n", id);
                goto out;
        }

        ucb = kzalloc(sizeof(struct ucb1x00), GFP_KERNEL);
        ret = -ENOMEM;
        if (!ucb)
                goto out;

        device_initialize(&ucb->dev);
        ucb->dev.class = &ucb1x00_class;
        ucb->dev.parent = &mcp->attached_device;
        dev_set_name(&ucb->dev, "ucb1x00");

        raw_spin_lock_init(&ucb->irq_lock);
        spin_lock_init(&ucb->io_lock);
        mutex_init(&ucb->adc_mutex);

        ucb->id  = id;
        ucb->mcp = mcp;

        ret = device_add(&ucb->dev);
        if (ret)
                goto err_dev_add;

        ucb1x00_enable(ucb);
        ucb->irq = ucb1x00_detect_irq(ucb);
        ucb1x00_disable(ucb);
        if (!ucb->irq) {
                dev_err(&ucb->dev, "IRQ probe failed\n");
                ret = -ENODEV;
                goto err_no_irq;
        }

        ucb->gpio.base = -1;
        irq_base = pdata ? pdata->irq_base : 0;
        ucb->irq_base = irq_alloc_descs(-1, irq_base, 16, -1);
        if (ucb->irq_base < 0) {
                dev_err(&ucb->dev, "unable to allocate 16 irqs: %d\n",
                        ucb->irq_base);
                ret = ucb->irq_base;
                goto err_irq_alloc;
        }

        for (i = 0; i < 16; i++) {
                unsigned irq = ucb->irq_base + i;

                irq_set_chip_and_handler(irq, &ucb1x00_irqchip, handle_edge_irq);
                irq_set_chip_data(irq, ucb);
                irq_clear_status_flags(irq, IRQ_NOREQUEST);
        }

        irq_set_irq_type(ucb->irq, IRQ_TYPE_EDGE_RISING);
        irq_set_chained_handler_and_data(ucb->irq, ucb1x00_irq, ucb);

        if (pdata && pdata->gpio_base) {
                ucb->gpio.label = dev_name(&ucb->dev);
                ucb->gpio.parent = &ucb->dev;
                ucb->gpio.owner = THIS_MODULE;
                ucb->gpio.base = pdata->gpio_base;
                ucb->gpio.ngpio = 10;
                ucb->gpio.set = ucb1x00_gpio_set;
                ucb->gpio.get = ucb1x00_gpio_get;
                ucb->gpio.direction_input = ucb1x00_gpio_direction_input;
                ucb->gpio.direction_output = ucb1x00_gpio_direction_output;
                ucb->gpio.to_irq = ucb1x00_to_irq;
                ret = gpiochip_add_data(&ucb->gpio, ucb);
                if (ret)
                        goto err_gpio_add;
        } else
                dev_info(&ucb->dev, "gpio_base not set so no gpiolib support");

        mcp_set_drvdata(mcp, ucb);

        if (pdata)
                device_set_wakeup_capable(&ucb->dev, pdata->can_wakeup);

        INIT_LIST_HEAD(&ucb->devs);
        mutex_lock(&ucb1x00_mutex);
        list_add_tail(&ucb->node, &ucb1x00_devices);
        list_for_each_entry(drv, &ucb1x00_drivers, node) {
                ucb1x00_add_dev(ucb, drv);
        }
        mutex_unlock(&ucb1x00_mutex);

        return ret;

 err_gpio_add:
        irq_set_chained_handler(ucb->irq, NULL);
 err_irq_alloc:
        if (ucb->irq_base > 0)
                irq_free_descs(ucb->irq_base, 16);
 err_no_irq:
        device_del(&ucb->dev);
 err_dev_add:
        put_device(&ucb->dev);
 out:
        if (pdata && pdata->reset)
                pdata->reset(UCB_RST_PROBE_FAIL);
        return ret;
}

static void ucb1x00_remove(struct mcp *mcp)
{
        struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
        struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
        struct list_head *l, *n;

        mutex_lock(&ucb1x00_mutex);
        list_del(&ucb->node);
        list_for_each_safe(l, n, &ucb->devs) {
                struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, dev_node);
                ucb1x00_remove_dev(dev);
        }
        mutex_unlock(&ucb1x00_mutex);

        if (ucb->gpio.base != -1)
                gpiochip_remove(&ucb->gpio);

        irq_set_chained_handler(ucb->irq, NULL);
        irq_free_descs(ucb->irq_base, 16);
        device_unregister(&ucb->dev);

        if (pdata && pdata->reset)
                pdata->reset(UCB_RST_REMOVE);
}

int ucb1x00_register_driver(struct ucb1x00_driver *drv)
{
        struct ucb1x00 *ucb;

        INIT_LIST_HEAD(&drv->devs);
        mutex_lock(&ucb1x00_mutex);
        list_add_tail(&drv->node, &ucb1x00_drivers);
        list_for_each_entry(ucb, &ucb1x00_devices, node) {
                ucb1x00_add_dev(ucb, drv);
        }
        mutex_unlock(&ucb1x00_mutex);
        return 0;
}

void ucb1x00_unregister_driver(struct ucb1x00_driver *drv)
{
        struct list_head *n, *l;

        mutex_lock(&ucb1x00_mutex);
        list_del(&drv->node);
        list_for_each_safe(l, n, &drv->devs) {
                struct ucb1x00_dev *dev = list_entry(l, struct ucb1x00_dev, drv_node);
                ucb1x00_remove_dev(dev);
        }
        mutex_unlock(&ucb1x00_mutex);
}

static int ucb1x00_suspend(struct device *dev)
{
        struct ucb1x00_plat_data *pdata = dev_get_platdata(dev);
        struct ucb1x00 *ucb = dev_get_drvdata(dev);
        struct ucb1x00_dev *udev;

        mutex_lock(&ucb1x00_mutex);
        list_for_each_entry(udev, &ucb->devs, dev_node) {
                if (udev->drv->suspend)
                        udev->drv->suspend(udev);
        }
        mutex_unlock(&ucb1x00_mutex);

        if (ucb->irq_wake) {
                unsigned long flags;

                raw_spin_lock_irqsave(&ucb->irq_lock, flags);
                ucb1x00_enable(ucb);
                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
                                  ucb->irq_wake);
                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
                                  ucb->irq_wake);
                ucb1x00_disable(ucb);
                raw_spin_unlock_irqrestore(&ucb->irq_lock, flags);

                enable_irq_wake(ucb->irq);
        } else if (pdata && pdata->reset)
                pdata->reset(UCB_RST_SUSPEND);

        return 0;
}

static int ucb1x00_resume(struct device *dev)
{
        struct ucb1x00_plat_data *pdata = dev_get_platdata(dev);
        struct ucb1x00 *ucb = dev_get_drvdata(dev);
        struct ucb1x00_dev *udev;

        if (!ucb->irq_wake && pdata && pdata->reset)
                pdata->reset(UCB_RST_RESUME);

        ucb1x00_enable(ucb);
        ucb1x00_reg_write(ucb, UCB_IO_DATA, ucb->io_out);
        ucb1x00_reg_write(ucb, UCB_IO_DIR, ucb->io_dir);

        if (ucb->irq_wake) {
                unsigned long flags;

                raw_spin_lock_irqsave(&ucb->irq_lock, flags);
                ucb1x00_reg_write(ucb, UCB_IE_RIS, ucb->irq_ris_enbl &
                                  ucb->irq_mask);
                ucb1x00_reg_write(ucb, UCB_IE_FAL, ucb->irq_fal_enbl &
                                  ucb->irq_mask);
                raw_spin_unlock_irqrestore(&ucb->irq_lock, flags);

                disable_irq_wake(ucb->irq);
        }
        ucb1x00_disable(ucb);

        mutex_lock(&ucb1x00_mutex);
        list_for_each_entry(udev, &ucb->devs, dev_node) {
                if (udev->drv->resume)
                        udev->drv->resume(udev);
        }
        mutex_unlock(&ucb1x00_mutex);
        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(ucb1x00_pm_ops,
                                ucb1x00_suspend, ucb1x00_resume);

static struct mcp_driver ucb1x00_driver = {
        .drv            = {
                .name   = "ucb1x00",
                .owner  = THIS_MODULE,
                .pm     = pm_sleep_ptr(&ucb1x00_pm_ops),
        },
        .probe          = ucb1x00_probe,
        .remove         = ucb1x00_remove,
};

static int __init ucb1x00_init(void)
{
        int ret = class_register(&ucb1x00_class);
        if (ret == 0) {
                ret = mcp_driver_register(&ucb1x00_driver);
                if (ret)
                        class_unregister(&ucb1x00_class);
        }
        return ret;
}

static void __exit ucb1x00_exit(void)
{
        mcp_driver_unregister(&ucb1x00_driver);
        class_unregister(&ucb1x00_class);
}

module_init(ucb1x00_init);
module_exit(ucb1x00_exit);

EXPORT_SYMBOL(ucb1x00_io_set_dir);
EXPORT_SYMBOL(ucb1x00_io_write);
EXPORT_SYMBOL(ucb1x00_io_read);

EXPORT_SYMBOL(ucb1x00_adc_enable);
EXPORT_SYMBOL(ucb1x00_adc_read);
EXPORT_SYMBOL(ucb1x00_adc_disable);

EXPORT_SYMBOL(ucb1x00_register_driver);
EXPORT_SYMBOL(ucb1x00_unregister_driver);

MODULE_ALIAS("mcp:ucb1x00");
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("UCB1x00 core driver");
MODULE_LICENSE("GPL");