gpio-tc3589x.c

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/*
 * Copyright (C) ST-Ericsson SA 2010
 *
 * License Terms: GNU General Public License, version 2
 * Author: Hanumath Prasad <[email protected]> for ST-Ericsson
 * Author: Rabin Vincent <[email protected]> for ST-Ericsson
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/interrupt.h>
#include <linux/mfd/tc3589x.h>

/*
 * These registers are modified under the irq bus lock and cached to avoid
 * unnecessary writes in bus_sync_unlock.
 */
enum { REG_IBE, REG_IEV, REG_IS, REG_IE };

#define CACHE_NR_REGS   4
#define CACHE_NR_BANKS  3

struct tc3589x_gpio {
    struct gpio_chip chip;
    struct tc3589x *tc3589x;
    struct device *dev;
    struct mutex irq_lock;
    struct irq_domain *domain;

    int irq_base;

    /* Caches of interrupt control registers for bus_lock */
    u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
    u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
};

static inline struct tc3589x_gpio *to_tc3589x_gpio(struct gpio_chip *chip)
{
    return container_of(chip, struct tc3589x_gpio, chip);
}

static int tc3589x_gpio_get(struct gpio_chip *chip, unsigned offset)
{
    struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
    u8 mask = 1 << (offset % 8);
    int ret;

    ret = tc3589x_reg_read(tc3589x, reg);
    if (ret < 0)
        return ret;

    return ret & mask;
}

static void tc3589x_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
    struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    u8 reg = TC3589x_GPIODATA0 + (offset / 8) * 2;
    unsigned pos = offset % 8;
    u8 data[] = {!!val << pos, 1 << pos};

    tc3589x_block_write(tc3589x, reg, ARRAY_SIZE(data), data);
}

static int tc3589x_gpio_direction_output(struct gpio_chip *chip,
                     unsigned offset, int val)
{
    struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    u8 reg = TC3589x_GPIODIR0 + offset / 8;
    unsigned pos = offset % 8;

    tc3589x_gpio_set(chip, offset, val);

    return tc3589x_set_bits(tc3589x, reg, 1 << pos, 1 << pos);
}

static int tc3589x_gpio_direction_input(struct gpio_chip *chip,
                    unsigned offset)
{
    struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    u8 reg = TC3589x_GPIODIR0 + offset / 8;
    unsigned pos = offset % 8;

    return tc3589x_set_bits(tc3589x, reg, 1 << pos, 0);
}

static int tc3589x_gpio_irq_get_virq(struct tc3589x_gpio *tc3589x_gpio,
                     int irq)
{
    if (!tc3589x_gpio)
        return -EINVAL;

    return irq_create_mapping(tc3589x_gpio->domain, irq);
}

static int tc3589x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
    struct tc3589x_gpio *tc3589x_gpio = to_tc3589x_gpio(chip);

    return tc3589x_gpio_irq_get_virq(tc3589x_gpio, offset);
}

static struct gpio_chip template_chip = {
    .label          = "tc3589x",
    .owner          = THIS_MODULE,
    .direction_input    = tc3589x_gpio_direction_input,
    .get            = tc3589x_gpio_get,
    .direction_output   = tc3589x_gpio_direction_output,
    .set            = tc3589x_gpio_set,
    .to_irq         = tc3589x_gpio_to_irq,
    .can_sleep      = 1,
};

static int tc3589x_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
    struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
    int offset = d->hwirq;
    int regoffset = offset / 8;
    int mask = 1 << (offset % 8);

    if (type == IRQ_TYPE_EDGE_BOTH) {
        tc3589x_gpio->regs[REG_IBE][regoffset] |= mask;
        return 0;
    }

    tc3589x_gpio->regs[REG_IBE][regoffset] &= ~mask;

    if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
        tc3589x_gpio->regs[REG_IS][regoffset] |= mask;
    else
        tc3589x_gpio->regs[REG_IS][regoffset] &= ~mask;

    if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
        tc3589x_gpio->regs[REG_IEV][regoffset] |= mask;
    else
        tc3589x_gpio->regs[REG_IEV][regoffset] &= ~mask;

    return 0;
}

static void tc3589x_gpio_irq_lock(struct irq_data *d)
{
    struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);

    mutex_lock(&tc3589x_gpio->irq_lock);
}

static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
{
    struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    static const u8 regmap[] = {
        [REG_IBE]   = TC3589x_GPIOIBE0,
        [REG_IEV]   = TC3589x_GPIOIEV0,
        [REG_IS]    = TC3589x_GPIOIS0,
        [REG_IE]    = TC3589x_GPIOIE0,
    };
    int i, j;

    for (i = 0; i < CACHE_NR_REGS; i++) {
        for (j = 0; j < CACHE_NR_BANKS; j++) {
            u8 old = tc3589x_gpio->oldregs[i][j];
            u8 new = tc3589x_gpio->regs[i][j];

            if (new == old)
                continue;

            tc3589x_gpio->oldregs[i][j] = new;
            tc3589x_reg_write(tc3589x, regmap[i] + j * 8, new);
        }
    }

    mutex_unlock(&tc3589x_gpio->irq_lock);
}

static void tc3589x_gpio_irq_mask(struct irq_data *d)
{
    struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
    int offset = d->hwirq;
    int regoffset = offset / 8;
    int mask = 1 << (offset % 8);

    tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
}

static void tc3589x_gpio_irq_unmask(struct irq_data *d)
{
    struct tc3589x_gpio *tc3589x_gpio = irq_data_get_irq_chip_data(d);
    int offset = d->hwirq;
    int regoffset = offset / 8;
    int mask = 1 << (offset % 8);

    tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
}

static struct irq_chip tc3589x_gpio_irq_chip = {
    .name           = "tc3589x-gpio",
    .irq_bus_lock       = tc3589x_gpio_irq_lock,
    .irq_bus_sync_unlock    = tc3589x_gpio_irq_sync_unlock,
    .irq_mask       = tc3589x_gpio_irq_mask,
    .irq_unmask     = tc3589x_gpio_irq_unmask,
    .irq_set_type       = tc3589x_gpio_irq_set_type,
};

static irqreturn_t tc3589x_gpio_irq(int irq, void *dev)
{
    struct tc3589x_gpio *tc3589x_gpio = dev;
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    u8 status[CACHE_NR_BANKS];
    int ret;
    int i;

    ret = tc3589x_block_read(tc3589x, TC3589x_GPIOMIS0,
                 ARRAY_SIZE(status), status);
    if (ret < 0)
        return IRQ_NONE;

    for (i = 0; i < ARRAY_SIZE(status); i++) {
        unsigned int stat = status[i];
        if (!stat)
            continue;

        while (stat) {
            int bit = __ffs(stat);
            int line = i * 8 + bit;
            int virq = tc3589x_gpio_irq_get_virq(tc3589x_gpio, line);

            handle_nested_irq(virq);
            stat &= ~(1 << bit);
        }

        tc3589x_reg_write(tc3589x, TC3589x_GPIOIC0 + i, status[i]);
    }

    return IRQ_HANDLED;
}

static int tc3589x_gpio_irq_map(struct irq_domain *d, unsigned int virq,
                irq_hw_number_t hwirq)
{
    struct tc3589x *tc3589x_gpio = d->host_data;

    irq_set_chip_data(virq, tc3589x_gpio);
    irq_set_chip_and_handler(virq, &tc3589x_gpio_irq_chip,
                handle_simple_irq);
    irq_set_nested_thread(virq, 1);
#ifdef CONFIG_ARM
    set_irq_flags(virq, IRQF_VALID);
#else
    irq_set_noprobe(virq);
#endif

    return 0;
}

static void tc3589x_gpio_irq_unmap(struct irq_domain *d, unsigned int virq)
{
#ifdef CONFIG_ARM
    set_irq_flags(virq, 0);
#endif
    irq_set_chip_and_handler(virq, NULL, NULL);
    irq_set_chip_data(virq, NULL);
}

static struct irq_domain_ops tc3589x_irq_ops = {
        .map    = tc3589x_gpio_irq_map,
        .unmap  = tc3589x_gpio_irq_unmap,
        .xlate  = irq_domain_xlate_twocell,
};

static int tc3589x_gpio_irq_init(struct tc3589x_gpio *tc3589x_gpio,
                struct device_node *np)
{
    int base = tc3589x_gpio->irq_base;

    if (base) {
        tc3589x_gpio->domain = irq_domain_add_legacy(
            NULL, tc3589x_gpio->chip.ngpio, base,
            0, &tc3589x_irq_ops, tc3589x_gpio);
    }
    else {
        tc3589x_gpio->domain = irq_domain_add_linear(
            np, tc3589x_gpio->chip.ngpio,
            &tc3589x_irq_ops, tc3589x_gpio);
    }

    if (!tc3589x_gpio->domain) {
        dev_err(tc3589x_gpio->dev, "Failed to create irqdomain\n");
        return -ENOSYS;
    }

    return 0;
}

static int __devinit tc3589x_gpio_probe(struct platform_device *pdev)
{
    struct tc3589x *tc3589x = dev_get_drvdata(pdev->dev.parent);
    struct tc3589x_gpio_platform_data *pdata;
    struct device_node *np = pdev->dev.of_node;
    struct tc3589x_gpio *tc3589x_gpio;
    int ret;
    int irq;

    pdata = tc3589x->pdata->gpio;

    if (!(pdata || np)) {
        dev_err(&pdev->dev, "No platform data or Device Tree found\n");
        return -EINVAL;
    }

    irq = platform_get_irq(pdev, 0);
    if (irq < 0)
        return irq;

    tc3589x_gpio = kzalloc(sizeof(struct tc3589x_gpio), GFP_KERNEL);
    if (!tc3589x_gpio)
        return -ENOMEM;

    mutex_init(&tc3589x_gpio->irq_lock);

    tc3589x_gpio->dev = &pdev->dev;
    tc3589x_gpio->tc3589x = tc3589x;

    tc3589x_gpio->chip = template_chip;
    tc3589x_gpio->chip.ngpio = tc3589x->num_gpio;
    tc3589x_gpio->chip.dev = &pdev->dev;
    tc3589x_gpio->chip.base = (pdata) ? pdata->gpio_base : -1;

#ifdef CONFIG_OF_GPIO
        tc3589x_gpio->chip.of_node = np;
#endif

    tc3589x_gpio->irq_base = tc3589x->irq_base ?
        tc3589x->irq_base + TC3589x_INT_GPIO(0) : 0;

    /* Bring the GPIO module out of reset */
    ret = tc3589x_set_bits(tc3589x, TC3589x_RSTCTRL,
                   TC3589x_RSTCTRL_GPIRST, 0);
    if (ret < 0)
        goto out_free;

    ret = tc3589x_gpio_irq_init(tc3589x_gpio, np);
    if (ret)
        goto out_free;

    ret = request_threaded_irq(irq, NULL, tc3589x_gpio_irq, IRQF_ONESHOT,
                   "tc3589x-gpio", tc3589x_gpio);
    if (ret) {
        dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
        goto out_free;
    }

    ret = gpiochip_add(&tc3589x_gpio->chip);
    if (ret) {
        dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
        goto out_freeirq;
    }

    if (pdata && pdata->setup)
        pdata->setup(tc3589x, tc3589x_gpio->chip.base);

    platform_set_drvdata(pdev, tc3589x_gpio);

    return 0;

out_freeirq:
    free_irq(irq, tc3589x_gpio);
out_free:
    kfree(tc3589x_gpio);
    return ret;
}

static int __devexit tc3589x_gpio_remove(struct platform_device *pdev)
{
    struct tc3589x_gpio *tc3589x_gpio = platform_get_drvdata(pdev);
    struct tc3589x *tc3589x = tc3589x_gpio->tc3589x;
    struct tc3589x_gpio_platform_data *pdata = tc3589x->pdata->gpio;
    int irq = platform_get_irq(pdev, 0);
    int ret;

    if (pdata && pdata->remove)
        pdata->remove(tc3589x, tc3589x_gpio->chip.base);

    ret = gpiochip_remove(&tc3589x_gpio->chip);
    if (ret < 0) {
        dev_err(tc3589x_gpio->dev,
            "unable to remove gpiochip: %d\n", ret);
        return ret;
    }

    free_irq(irq, tc3589x_gpio);

    platform_set_drvdata(pdev, NULL);
    kfree(tc3589x_gpio);

    return 0;
}

static struct platform_driver tc3589x_gpio_driver = {
    .driver.name    = "tc3589x-gpio",
    .driver.owner   = THIS_MODULE,
    .probe      = tc3589x_gpio_probe,
    .remove     = __devexit_p(tc3589x_gpio_remove),
};

static int __init tc3589x_gpio_init(void)
{
    return platform_driver_register(&tc3589x_gpio_driver);
}
subsys_initcall(tc3589x_gpio_init);

static void __exit tc3589x_gpio_exit(void)
{
    platform_driver_unregister(&tc3589x_gpio_driver);
}
module_exit(tc3589x_gpio_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TC3589x GPIO driver");
MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");