gpio-pca953x.c

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/*
 *  PCA953x 4/8/16 bit I/O ports
 *
 *  Copyright (C) 2005 Ben Gardner <[email protected]>
 *  Copyright (C) 2007 Marvell International Ltd.
 *
 *  Derived from drivers/i2c/chips/pca9539.c
 *
 *  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.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/i2c/pca953x.h>
#include <linux/slab.h>
#ifdef CONFIG_OF_GPIO
#include <linux/of_platform.h>
#endif

#define PCA953X_INPUT       0
#define PCA953X_OUTPUT      1
#define PCA953X_INVERT      2
#define PCA953X_DIRECTION   3

#define REG_ADDR_AI     0x80

#define PCA957X_IN      0
#define PCA957X_INVRT       1
#define PCA957X_BKEN        2
#define PCA957X_PUPD        3
#define PCA957X_CFG     4
#define PCA957X_OUT     5
#define PCA957X_MSK     6
#define PCA957X_INTS        7

#define PCA_GPIO_MASK       0x00FF
#define PCA_INT         0x0100
#define PCA953X_TYPE        0x1000
#define PCA957X_TYPE        0x2000

static const struct i2c_device_id pca953x_id[] = {
    { "pca9534", 8  | PCA953X_TYPE | PCA_INT, },
    { "pca9535", 16 | PCA953X_TYPE | PCA_INT, },
    { "pca9536", 4  | PCA953X_TYPE, },
    { "pca9537", 4  | PCA953X_TYPE | PCA_INT, },
    { "pca9538", 8  | PCA953X_TYPE | PCA_INT, },
    { "pca9539", 16 | PCA953X_TYPE | PCA_INT, },
    { "pca9554", 8  | PCA953X_TYPE | PCA_INT, },
    { "pca9555", 16 | PCA953X_TYPE | PCA_INT, },
    { "pca9556", 8  | PCA953X_TYPE, },
    { "pca9557", 8  | PCA953X_TYPE, },
    { "pca9574", 8  | PCA957X_TYPE | PCA_INT, },
    { "pca9575", 16 | PCA957X_TYPE | PCA_INT, },

    { "max7310", 8  | PCA953X_TYPE, },
    { "max7312", 16 | PCA953X_TYPE | PCA_INT, },
    { "max7313", 16 | PCA953X_TYPE | PCA_INT, },
    { "max7315", 8  | PCA953X_TYPE | PCA_INT, },
    { "pca6107", 8  | PCA953X_TYPE | PCA_INT, },
    { "tca6408", 8  | PCA953X_TYPE | PCA_INT, },
    { "tca6416", 16 | PCA953X_TYPE | PCA_INT, },
    { "tca6424", 24 | PCA953X_TYPE | PCA_INT, },
    { }
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);

struct pca953x_chip {
    unsigned gpio_start;
    u32 reg_output;
    u32 reg_direction;
    struct mutex i2c_lock;

#ifdef CONFIG_GPIO_PCA953X_IRQ
    struct mutex irq_lock;
    u32 irq_mask;
    u32 irq_stat;
    u32 irq_trig_raise;
    u32 irq_trig_fall;
    int  irq_base;
#endif

    struct i2c_client *client;
    struct gpio_chip gpio_chip;
    const char *const *names;
    int chip_type;
};

static int pca953x_write_reg(struct pca953x_chip *chip, int reg, u32 val)
{
    int ret = 0;

    if (chip->gpio_chip.ngpio <= 8)
        ret = i2c_smbus_write_byte_data(chip->client, reg, val);
    else if (chip->gpio_chip.ngpio == 24) {
        cpu_to_le32s(&val);
        ret = i2c_smbus_write_i2c_block_data(chip->client,
                        (reg << 2) | REG_ADDR_AI,
                        3,
                        (u8 *) &val);
    }
    else {
        switch (chip->chip_type) {
        case PCA953X_TYPE:
            ret = i2c_smbus_write_word_data(chip->client,
                            reg << 1, val);
            break;
        case PCA957X_TYPE:
            ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
                            val & 0xff);
            if (ret < 0)
                break;
            ret = i2c_smbus_write_byte_data(chip->client,
                            (reg << 1) + 1,
                            (val & 0xff00) >> 8);
            break;
        }
    }

    if (ret < 0) {
        dev_err(&chip->client->dev, "failed writing register\n");
        return ret;
    }

    return 0;
}

static int pca953x_read_reg(struct pca953x_chip *chip, int reg, u32 *val)
{
    int ret;

    if (chip->gpio_chip.ngpio <= 8) {
        ret = i2c_smbus_read_byte_data(chip->client, reg);
        *val = ret;
    }
    else if (chip->gpio_chip.ngpio == 24) {
        *val = 0;
        ret = i2c_smbus_read_i2c_block_data(chip->client,
                        (reg << 2) | REG_ADDR_AI,
                        3,
                        (u8 *) val);
        le32_to_cpus(val);
    } else {
        ret = i2c_smbus_read_word_data(chip->client, reg << 1);
        *val = ret;
    }

    if (ret < 0) {
        dev_err(&chip->client->dev, "failed reading register\n");
        return ret;
    }

    return 0;
}

static int pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
{
    struct pca953x_chip *chip;
    uint reg_val;
    int ret, offset = 0;

    chip = container_of(gc, struct pca953x_chip, gpio_chip);

    mutex_lock(&chip->i2c_lock);
    reg_val = chip->reg_direction | (1u << off);

    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_DIRECTION;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_CFG;
        break;
    }
    ret = pca953x_write_reg(chip, offset, reg_val);
    if (ret)
        goto exit;

    chip->reg_direction = reg_val;
    ret = 0;
exit:
    mutex_unlock(&chip->i2c_lock);
    return ret;
}

static int pca953x_gpio_direction_output(struct gpio_chip *gc,
        unsigned off, int val)
{
    struct pca953x_chip *chip;
    uint reg_val;
    int ret, offset = 0;

    chip = container_of(gc, struct pca953x_chip, gpio_chip);

    mutex_lock(&chip->i2c_lock);
    /* set output level */
    if (val)
        reg_val = chip->reg_output | (1u << off);
    else
        reg_val = chip->reg_output & ~(1u << off);

    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_OUTPUT;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_OUT;
        break;
    }
    ret = pca953x_write_reg(chip, offset, reg_val);
    if (ret)
        goto exit;

    chip->reg_output = reg_val;

    /* then direction */
    reg_val = chip->reg_direction & ~(1u << off);
    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_DIRECTION;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_CFG;
        break;
    }
    ret = pca953x_write_reg(chip, offset, reg_val);
    if (ret)
        goto exit;

    chip->reg_direction = reg_val;
    ret = 0;
exit:
    mutex_unlock(&chip->i2c_lock);
    return ret;
}

static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off)
{
    struct pca953x_chip *chip;
    u32 reg_val;
    int ret, offset = 0;

    chip = container_of(gc, struct pca953x_chip, gpio_chip);

    mutex_lock(&chip->i2c_lock);
    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_INPUT;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_IN;
        break;
    }
    ret = pca953x_read_reg(chip, offset, &reg_val);
    mutex_unlock(&chip->i2c_lock);
    if (ret < 0) {
        /* NOTE:  diagnostic already emitted; that's all we should
         * do unless gpio_*_value_cansleep() calls become different
         * from their nonsleeping siblings (and report faults).
         */
        return 0;
    }

    return (reg_val & (1u << off)) ? 1 : 0;
}

static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
{
    struct pca953x_chip *chip;
    u32 reg_val;
    int ret, offset = 0;

    chip = container_of(gc, struct pca953x_chip, gpio_chip);

    mutex_lock(&chip->i2c_lock);
    if (val)
        reg_val = chip->reg_output | (1u << off);
    else
        reg_val = chip->reg_output & ~(1u << off);

    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_OUTPUT;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_OUT;
        break;
    }
    ret = pca953x_write_reg(chip, offset, reg_val);
    if (ret)
        goto exit;

    chip->reg_output = reg_val;
exit:
    mutex_unlock(&chip->i2c_lock);
}

static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios)
{
    struct gpio_chip *gc;

    gc = &chip->gpio_chip;

    gc->direction_input  = pca953x_gpio_direction_input;
    gc->direction_output = pca953x_gpio_direction_output;
    gc->get = pca953x_gpio_get_value;
    gc->set = pca953x_gpio_set_value;
    gc->can_sleep = 1;

    gc->base = chip->gpio_start;
    gc->ngpio = gpios;
    gc->label = chip->client->name;
    gc->dev = &chip->client->dev;
    gc->owner = THIS_MODULE;
    gc->names = chip->names;
}

#ifdef CONFIG_GPIO_PCA953X_IRQ
static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
{
    struct pca953x_chip *chip;

    chip = container_of(gc, struct pca953x_chip, gpio_chip);
    return chip->irq_base + off;
}

static void pca953x_irq_mask(struct irq_data *d)
{
    struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);

    chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
}

static void pca953x_irq_unmask(struct irq_data *d)
{
    struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);

    chip->irq_mask |= 1 << (d->irq - chip->irq_base);
}

static void pca953x_irq_bus_lock(struct irq_data *d)
{
    struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);

    mutex_lock(&chip->irq_lock);
}

static void pca953x_irq_bus_sync_unlock(struct irq_data *d)
{
    struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
    u32 new_irqs;
    u32 level;

    /* Look for any newly setup interrupt */
    new_irqs = chip->irq_trig_fall | chip->irq_trig_raise;
    new_irqs &= ~chip->reg_direction;

    while (new_irqs) {
        level = __ffs(new_irqs);
        pca953x_gpio_direction_input(&chip->gpio_chip, level);
        new_irqs &= ~(1 << level);
    }

    mutex_unlock(&chip->irq_lock);
}

static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
{
    struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
    u32 level = d->irq - chip->irq_base;
    u32 mask = 1 << level;

    if (!(type & IRQ_TYPE_EDGE_BOTH)) {
        dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
            d->irq, type);
        return -EINVAL;
    }

    if (type & IRQ_TYPE_EDGE_FALLING)
        chip->irq_trig_fall |= mask;
    else
        chip->irq_trig_fall &= ~mask;

    if (type & IRQ_TYPE_EDGE_RISING)
        chip->irq_trig_raise |= mask;
    else
        chip->irq_trig_raise &= ~mask;

    return 0;
}

static struct irq_chip pca953x_irq_chip = {
    .name           = "pca953x",
    .irq_mask       = pca953x_irq_mask,
    .irq_unmask     = pca953x_irq_unmask,
    .irq_bus_lock       = pca953x_irq_bus_lock,
    .irq_bus_sync_unlock    = pca953x_irq_bus_sync_unlock,
    .irq_set_type       = pca953x_irq_set_type,
};

static u32 pca953x_irq_pending(struct pca953x_chip *chip)
{
    u32 cur_stat;
    u32 old_stat;
    u32 pending;
    u32 trigger;
    int ret, offset = 0;

    switch (chip->chip_type) {
    case PCA953X_TYPE:
        offset = PCA953X_INPUT;
        break;
    case PCA957X_TYPE:
        offset = PCA957X_IN;
        break;
    }
    ret = pca953x_read_reg(chip, offset, &cur_stat);
    if (ret)
        return 0;

    /* Remove output pins from the equation */
    cur_stat &= chip->reg_direction;

    old_stat = chip->irq_stat;
    trigger = (cur_stat ^ old_stat) & chip->irq_mask;

    if (!trigger)
        return 0;

    chip->irq_stat = cur_stat;

    pending = (old_stat & chip->irq_trig_fall) |
          (cur_stat & chip->irq_trig_raise);
    pending &= trigger;

    return pending;
}

static irqreturn_t pca953x_irq_handler(int irq, void *devid)
{
    struct pca953x_chip *chip = devid;
    u32 pending;
    u32 level;

    pending = pca953x_irq_pending(chip);

    if (!pending)
        return IRQ_HANDLED;

    do {
        level = __ffs(pending);
        handle_nested_irq(level + chip->irq_base);

        pending &= ~(1 << level);
    } while (pending);

    return IRQ_HANDLED;
}

static int pca953x_irq_setup(struct pca953x_chip *chip,
                 const struct i2c_device_id *id,
                 int irq_base)
{
    struct i2c_client *client = chip->client;
    int ret, offset = 0;
    u32 temporary;

    if (irq_base != -1
            && (id->driver_data & PCA_INT)) {
        int lvl;

        switch (chip->chip_type) {
        case PCA953X_TYPE:
            offset = PCA953X_INPUT;
            break;
        case PCA957X_TYPE:
            offset = PCA957X_IN;
            break;
        }
        ret = pca953x_read_reg(chip, offset, &temporary);
        chip->irq_stat = temporary;
        if (ret)
            goto out_failed;

        /*
         * There is no way to know which GPIO line generated the
         * interrupt.  We have to rely on the previous read for
         * this purpose.
         */
        chip->irq_stat &= chip->reg_direction;
        mutex_init(&chip->irq_lock);

        chip->irq_base = irq_alloc_descs(-1, irq_base, chip->gpio_chip.ngpio, -1);
        if (chip->irq_base < 0)
            goto out_failed;

        for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) {
            int irq = lvl + chip->irq_base;

            irq_clear_status_flags(irq, IRQ_NOREQUEST);
            irq_set_chip_data(irq, chip);
            irq_set_chip(irq, &pca953x_irq_chip);
            irq_set_nested_thread(irq, true);
#ifdef CONFIG_ARM
            set_irq_flags(irq, IRQF_VALID);
#else
            irq_set_noprobe(irq);
#endif
        }

        ret = request_threaded_irq(client->irq,
                       NULL,
                       pca953x_irq_handler,
                       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                       dev_name(&client->dev), chip);
        if (ret) {
            dev_err(&client->dev, "failed to request irq %d\n",
                client->irq);
            goto out_failed;
        }

        chip->gpio_chip.to_irq = pca953x_gpio_to_irq;
    }

    return 0;

out_failed:
    chip->irq_base = -1;
    return ret;
}

static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
    if (chip->irq_base != -1) {
        irq_free_descs(chip->irq_base, chip->gpio_chip.ngpio);
        free_irq(chip->client->irq, chip);
    }
}
#else /* CONFIG_GPIO_PCA953X_IRQ */
static int pca953x_irq_setup(struct pca953x_chip *chip,
                 const struct i2c_device_id *id,
                 int irq_base)
{
    struct i2c_client *client = chip->client;

    if (irq_base != -1 && (id->driver_data & PCA_INT))
        dev_warn(&client->dev, "interrupt support not compiled in\n");

    return 0;
}

static void pca953x_irq_teardown(struct pca953x_chip *chip)
{
}
#endif

/*
 * Handlers for alternative sources of platform_data
 */
#ifdef CONFIG_OF_GPIO
/*
 * Translate OpenFirmware node properties into platform_data
 * WARNING: This is DEPRECATED and will be removed eventually!
 */
static void
pca953x_get_alt_pdata(struct i2c_client *client, int *gpio_base, u32 *invert)
{
    struct device_node *node;
    const __be32 *val;
    int size;

    node = client->dev.of_node;
    if (node == NULL)
        return;

    *gpio_base = -1;
    val = of_get_property(node, "linux,gpio-base", &size);
    WARN(val, "%s: device-tree property 'linux,gpio-base' is deprecated!", __func__);
    if (val) {
        if (size != sizeof(*val))
            dev_warn(&client->dev, "%s: wrong linux,gpio-base\n",
                 node->full_name);
        else
            *gpio_base = be32_to_cpup(val);
    }

    val = of_get_property(node, "polarity", NULL);
    WARN(val, "%s: device-tree property 'polarity' is deprecated!", __func__);
    if (val)
        *invert = *val;
}
#else
static void
pca953x_get_alt_pdata(struct i2c_client *client, int *gpio_base, u32 *invert)
{
    *gpio_base = -1;
}
#endif

static int __devinit device_pca953x_init(struct pca953x_chip *chip, u32 invert)
{
    int ret;

    ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output);
    if (ret)
        goto out;

    ret = pca953x_read_reg(chip, PCA953X_DIRECTION,
                   &chip->reg_direction);
    if (ret)
        goto out;

    /* set platform specific polarity inversion */
    ret = pca953x_write_reg(chip, PCA953X_INVERT, invert);
out:
    return ret;
}

static int __devinit device_pca957x_init(struct pca953x_chip *chip, u32 invert)
{
    int ret;
    u32 val = 0;

    /* Let every port in proper state, that could save power */
    pca953x_write_reg(chip, PCA957X_PUPD, 0x0);
    pca953x_write_reg(chip, PCA957X_CFG, 0xffff);
    pca953x_write_reg(chip, PCA957X_OUT, 0x0);

    ret = pca953x_read_reg(chip, PCA957X_IN, &val);
    if (ret)
        goto out;
    ret = pca953x_read_reg(chip, PCA957X_OUT, &chip->reg_output);
    if (ret)
        goto out;
    ret = pca953x_read_reg(chip, PCA957X_CFG, &chip->reg_direction);
    if (ret)
        goto out;

    /* set platform specific polarity inversion */
    pca953x_write_reg(chip, PCA957X_INVRT, invert);

    /* To enable register 6, 7 to controll pull up and pull down */
    pca953x_write_reg(chip, PCA957X_BKEN, 0x202);

    return 0;
out:
    return ret;
}

static int __devinit pca953x_probe(struct i2c_client *client,
                   const struct i2c_device_id *id)
{
    struct pca953x_platform_data *pdata;
    struct pca953x_chip *chip;
    int irq_base = 0;
    int ret;
    u32 invert = 0;

    chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL);
    if (chip == NULL)
        return -ENOMEM;

    pdata = client->dev.platform_data;
    if (pdata) {
        irq_base = pdata->irq_base;
        chip->gpio_start = pdata->gpio_base;
        invert = pdata->invert;
        chip->names = pdata->names;
    } else {
        pca953x_get_alt_pdata(client, &chip->gpio_start, &invert);
#ifdef CONFIG_OF_GPIO
        /* If I2C node has no interrupts property, disable GPIO interrupts */
        if (of_find_property(client->dev.of_node, "interrupts", NULL) == NULL)
            irq_base = -1;
#endif
    }

    chip->client = client;

    chip->chip_type = id->driver_data & (PCA953X_TYPE | PCA957X_TYPE);

    mutex_init(&chip->i2c_lock);

    /* initialize cached registers from their original values.
     * we can't share this chip with another i2c master.
     */
    pca953x_setup_gpio(chip, id->driver_data & PCA_GPIO_MASK);

    if (chip->chip_type == PCA953X_TYPE)
        ret = device_pca953x_init(chip, invert);
    else
        ret = device_pca957x_init(chip, invert);
    if (ret)
        goto out_failed;

    ret = pca953x_irq_setup(chip, id, irq_base);
    if (ret)
        goto out_failed;

    ret = gpiochip_add(&chip->gpio_chip);
    if (ret)
        goto out_failed_irq;

    if (pdata && pdata->setup) {
        ret = pdata->setup(client, chip->gpio_chip.base,
                chip->gpio_chip.ngpio, pdata->context);
        if (ret < 0)
            dev_warn(&client->dev, "setup failed, %d\n", ret);
    }

    i2c_set_clientdata(client, chip);
    return 0;

out_failed_irq:
    pca953x_irq_teardown(chip);
out_failed:
    kfree(chip);
    return ret;
}

static int pca953x_remove(struct i2c_client *client)
{
    struct pca953x_platform_data *pdata = client->dev.platform_data;
    struct pca953x_chip *chip = i2c_get_clientdata(client);
    int ret = 0;

    if (pdata && pdata->teardown) {
        ret = pdata->teardown(client, chip->gpio_chip.base,
                chip->gpio_chip.ngpio, pdata->context);
        if (ret < 0) {
            dev_err(&client->dev, "%s failed, %d\n",
                    "teardown", ret);
            return ret;
        }
    }

    ret = gpiochip_remove(&chip->gpio_chip);
    if (ret) {
        dev_err(&client->dev, "%s failed, %d\n",
                "gpiochip_remove()", ret);
        return ret;
    }

    pca953x_irq_teardown(chip);
    kfree(chip);
    return 0;
}

static struct i2c_driver pca953x_driver = {
    .driver = {
        .name   = "pca953x",
    },
    .probe      = pca953x_probe,
    .remove     = pca953x_remove,
    .id_table   = pca953x_id,
};

static int __init pca953x_init(void)
{
    return i2c_add_driver(&pca953x_driver);
}
/* register after i2c postcore initcall and before
 * subsys initcalls that may rely on these GPIOs
 */
subsys_initcall(pca953x_init);

static void __exit pca953x_exit(void)
{
    i2c_del_driver(&pca953x_driver);
}
module_exit(pca953x_exit);

MODULE_AUTHOR("eric miao <[email protected]>");
MODULE_DESCRIPTION("GPIO expander driver for PCA953x");
MODULE_LICENSE("GPL");