leds-pca9532.c

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/*
 * pca9532.c - 16-bit Led dimmer
 *
 * Copyright (C) 2011 Jan Weitzel
 * Copyright (C) 2008 Riku Voipio
 *
 * 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.
 *
 * Datasheet: http://www.nxp.com/documents/data_sheet/PCA9532.pdf
 *
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/input.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/leds-pca9532.h>
#include <linux/gpio.h>

/* m =  num_leds*/
#define PCA9532_REG_INPUT(i)    ((i) >> 3)
#define PCA9532_REG_OFFSET(m)   ((m) >> 4)
#define PCA9532_REG_PSC(m, i)   (PCA9532_REG_OFFSET(m) + 0x1 + (i) * 2)
#define PCA9532_REG_PWM(m, i)   (PCA9532_REG_OFFSET(m) + 0x2 + (i) * 2)
#define LED_REG(m, led)     (PCA9532_REG_OFFSET(m) + 0x5 + (led >> 2))
#define LED_NUM(led)        (led & 0x3)

#define ldev_to_led(c)       container_of(c, struct pca9532_led, ldev)

struct pca9532_chip_info {
    u8  num_leds;
};

struct pca9532_data {
    struct i2c_client *client;
    struct pca9532_led leds[16];
    struct mutex update_lock;
    struct input_dev *idev;
    struct work_struct work;
#ifdef CONFIG_LEDS_PCA9532_GPIO
    struct gpio_chip gpio;
#endif
    const struct pca9532_chip_info *chip_info;
    u8 pwm[2];
    u8 psc[2];
};

static int pca9532_probe(struct i2c_client *client,
    const struct i2c_device_id *id);
static int pca9532_remove(struct i2c_client *client);

enum {
    pca9530,
    pca9531,
    pca9532,
    pca9533,
};

static const struct i2c_device_id pca9532_id[] = {
    { "pca9530", pca9530 },
    { "pca9531", pca9531 },
    { "pca9532", pca9532 },
    { "pca9533", pca9533 },
    { }
};

MODULE_DEVICE_TABLE(i2c, pca9532_id);

static const struct pca9532_chip_info pca9532_chip_info_tbl[] = {
    [pca9530] = {
        .num_leds = 2,
    },
    [pca9531] = {
        .num_leds = 8,
    },
    [pca9532] = {
        .num_leds = 16,
    },
    [pca9533] = {
        .num_leds = 4,
    },
};

static struct i2c_driver pca9532_driver = {
    .driver = {
        .name = "leds-pca953x",
    },
    .probe = pca9532_probe,
    .remove = pca9532_remove,
    .id_table = pca9532_id,
};

/* We have two pwm/blinkers, but 16 possible leds to drive. Additionally,
 * the clever Thecus people are using one pwm to drive the beeper. So,
 * as a compromise we average one pwm to the values requested by all
 * leds that are not ON/OFF.
 * */
static int pca9532_calcpwm(struct i2c_client *client, int pwm, int blink,
    enum led_brightness value)
{
    int a = 0, b = 0, i = 0;
    struct pca9532_data *data = i2c_get_clientdata(client);
    for (i = 0; i < data->chip_info->num_leds; i++) {
        if (data->leds[i].type == PCA9532_TYPE_LED &&
            data->leds[i].state == PCA9532_PWM0+pwm) {
                a++;
                b += data->leds[i].ldev.brightness;
        }
    }
    if (a == 0) {
        dev_err(&client->dev,
        "fear of division by zero %d/%d, wanted %d\n",
            b, a, value);
        return -EINVAL;
    }
    b = b/a;
    if (b > 0xFF)
        return -EINVAL;
    data->pwm[pwm] = b;
    data->psc[pwm] = blink;
    return 0;
}

static int pca9532_setpwm(struct i2c_client *client, int pwm)
{
    struct pca9532_data *data = i2c_get_clientdata(client);
    u8 maxleds = data->chip_info->num_leds;

    mutex_lock(&data->update_lock);
    i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, pwm),
        data->pwm[pwm]);
    i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, pwm),
        data->psc[pwm]);
    mutex_unlock(&data->update_lock);
    return 0;
}

/* Set LED routing */
static void pca9532_setled(struct pca9532_led *led)
{
    struct i2c_client *client = led->client;
    struct pca9532_data *data = i2c_get_clientdata(client);
    u8 maxleds = data->chip_info->num_leds;
    char reg;

    mutex_lock(&data->update_lock);
    reg = i2c_smbus_read_byte_data(client, LED_REG(maxleds, led->id));
    /* zero led bits */
    reg = reg & ~(0x3<<LED_NUM(led->id)*2);
    /* set the new value */
    reg = reg | (led->state << LED_NUM(led->id)*2);
    i2c_smbus_write_byte_data(client, LED_REG(maxleds, led->id), reg);
    mutex_unlock(&data->update_lock);
}

static void pca9532_set_brightness(struct led_classdev *led_cdev,
    enum led_brightness value)
{
    int err = 0;
    struct pca9532_led *led = ldev_to_led(led_cdev);

    if (value == LED_OFF)
        led->state = PCA9532_OFF;
    else if (value == LED_FULL)
        led->state = PCA9532_ON;
    else {
        led->state = PCA9532_PWM0; /* Thecus: hardcode one pwm */
        err = pca9532_calcpwm(led->client, 0, 0, value);
        if (err)
            return; /* XXX: led api doesn't allow error code? */
    }
    schedule_work(&led->work);
}

static int pca9532_set_blink(struct led_classdev *led_cdev,
    unsigned long *delay_on, unsigned long *delay_off)
{
    struct pca9532_led *led = ldev_to_led(led_cdev);
    struct i2c_client *client = led->client;
    int psc;
    int err = 0;

    if (*delay_on == 0 && *delay_off == 0) {
    /* led subsystem ask us for a blink rate */
        *delay_on = 1000;
        *delay_off = 1000;
    }
    if (*delay_on != *delay_off || *delay_on > 1690 || *delay_on < 6)
        return -EINVAL;

    /* Thecus specific: only use PSC/PWM 0 */
    psc = (*delay_on * 152-1)/1000;
    err = pca9532_calcpwm(client, 0, psc, led_cdev->brightness);
    if (err)
        return err;
    schedule_work(&led->work);
    return 0;
}

static int pca9532_event(struct input_dev *dev, unsigned int type,
    unsigned int code, int value)
{
    struct pca9532_data *data = input_get_drvdata(dev);

    if (!(type == EV_SND && (code == SND_BELL || code == SND_TONE)))
        return -1;

    /* XXX: allow different kind of beeps with psc/pwm modifications */
    if (value > 1 && value < 32767)
        data->pwm[1] = 127;
    else
        data->pwm[1] = 0;

    schedule_work(&data->work);

    return 0;
}

static void pca9532_input_work(struct work_struct *work)
{
    struct pca9532_data *data =
        container_of(work, struct pca9532_data, work);
    u8 maxleds = data->chip_info->num_leds;

    mutex_lock(&data->update_lock);
    i2c_smbus_write_byte_data(data->client, PCA9532_REG_PWM(maxleds, 1),
        data->pwm[1]);
    mutex_unlock(&data->update_lock);
}

static void pca9532_led_work(struct work_struct *work)
{
    struct pca9532_led *led;
    led = container_of(work, struct pca9532_led, work);
    if (led->state == PCA9532_PWM0)
        pca9532_setpwm(led->client, 0);
    pca9532_setled(led);
}

#ifdef CONFIG_LEDS_PCA9532_GPIO
static int pca9532_gpio_request_pin(struct gpio_chip *gc, unsigned offset)
{
    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
    struct pca9532_led *led = &data->leds[offset];

    if (led->type == PCA9532_TYPE_GPIO)
        return 0;

    return -EBUSY;
}

static void pca9532_gpio_set_value(struct gpio_chip *gc, unsigned offset, int val)
{
    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
    struct pca9532_led *led = &data->leds[offset];

    if (val)
        led->state = PCA9532_ON;
    else
        led->state = PCA9532_OFF;

    pca9532_setled(led);
}

static int pca9532_gpio_get_value(struct gpio_chip *gc, unsigned offset)
{
    struct pca9532_data *data = container_of(gc, struct pca9532_data, gpio);
    unsigned char reg;

    reg = i2c_smbus_read_byte_data(data->client, PCA9532_REG_INPUT(offset));

    return !!(reg & (1 << (offset % 8)));
}

static int pca9532_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
{
    /* To use as input ensure pin is not driven */
    pca9532_gpio_set_value(gc, offset, 0);

    return 0;
}

static int pca9532_gpio_direction_output(struct gpio_chip *gc, unsigned offset, int val)
{
    pca9532_gpio_set_value(gc, offset, val);

    return 0;
}
#endif /* CONFIG_LEDS_PCA9532_GPIO */

static int pca9532_destroy_devices(struct pca9532_data *data, int n_devs)
{
    int i = n_devs;

    if (!data)
        return -EINVAL;

    while (--i >= 0) {
        switch (data->leds[i].type) {
        case PCA9532_TYPE_NONE:
        case PCA9532_TYPE_GPIO:
            break;
        case PCA9532_TYPE_LED:
            led_classdev_unregister(&data->leds[i].ldev);
            cancel_work_sync(&data->leds[i].work);
            break;
        case PCA9532_TYPE_N2100_BEEP:
            if (data->idev != NULL) {
                input_unregister_device(data->idev);
                cancel_work_sync(&data->work);
                data->idev = NULL;
            }
            break;
        }
    }

#ifdef CONFIG_LEDS_PCA9532_GPIO
    if (data->gpio.dev) {
        int err = gpiochip_remove(&data->gpio);
        if (err) {
            dev_err(&data->client->dev, "%s failed, %d\n",
                        "gpiochip_remove()", err);
            return err;
        }
    }
#endif

    return 0;
}

static int pca9532_configure(struct i2c_client *client,
    struct pca9532_data *data, struct pca9532_platform_data *pdata)
{
    int i, err = 0;
    int gpios = 0;
    u8 maxleds = data->chip_info->num_leds;

    for (i = 0; i < 2; i++) {
        data->pwm[i] = pdata->pwm[i];
        data->psc[i] = pdata->psc[i];
        i2c_smbus_write_byte_data(client, PCA9532_REG_PWM(maxleds, i),
            data->pwm[i]);
        i2c_smbus_write_byte_data(client, PCA9532_REG_PSC(maxleds, i),
            data->psc[i]);
    }

    for (i = 0; i < data->chip_info->num_leds; i++) {
        struct pca9532_led *led = &data->leds[i];
        struct pca9532_led *pled = &pdata->leds[i];
        led->client = client;
        led->id = i;
        led->type = pled->type;
        switch (led->type) {
        case PCA9532_TYPE_NONE:
            break;
        case PCA9532_TYPE_GPIO:
            gpios++;
            break;
        case PCA9532_TYPE_LED:
            led->state = pled->state;
            led->name = pled->name;
            led->ldev.name = led->name;
            led->ldev.brightness = LED_OFF;
            led->ldev.brightness_set = pca9532_set_brightness;
            led->ldev.blink_set = pca9532_set_blink;
            INIT_WORK(&led->work, pca9532_led_work);
            err = led_classdev_register(&client->dev, &led->ldev);
            if (err < 0) {
                dev_err(&client->dev,
                    "couldn't register LED %s\n",
                    led->name);
                goto exit;
            }
            pca9532_setled(led);
            break;
        case PCA9532_TYPE_N2100_BEEP:
            BUG_ON(data->idev);
            led->state = PCA9532_PWM1;
            pca9532_setled(led);
            data->idev = input_allocate_device();
            if (data->idev == NULL) {
                err = -ENOMEM;
                goto exit;
            }
            data->idev->name = pled->name;
            data->idev->phys = "i2c/pca9532";
            data->idev->id.bustype = BUS_HOST;
            data->idev->id.vendor = 0x001f;
            data->idev->id.product = 0x0001;
            data->idev->id.version = 0x0100;
            data->idev->evbit[0] = BIT_MASK(EV_SND);
            data->idev->sndbit[0] = BIT_MASK(SND_BELL) |
                        BIT_MASK(SND_TONE);
            data->idev->event = pca9532_event;
            input_set_drvdata(data->idev, data);
            INIT_WORK(&data->work, pca9532_input_work);
            err = input_register_device(data->idev);
            if (err) {
                input_free_device(data->idev);
                cancel_work_sync(&data->work);
                data->idev = NULL;
                goto exit;
            }
            break;
        }
    }

#ifdef CONFIG_LEDS_PCA9532_GPIO
    if (gpios) {
        data->gpio.label = "gpio-pca9532";
        data->gpio.direction_input = pca9532_gpio_direction_input;
        data->gpio.direction_output = pca9532_gpio_direction_output;
        data->gpio.set = pca9532_gpio_set_value;
        data->gpio.get = pca9532_gpio_get_value;
        data->gpio.request = pca9532_gpio_request_pin;
        data->gpio.can_sleep = 1;
        data->gpio.base = pdata->gpio_base;
        data->gpio.ngpio = data->chip_info->num_leds;
        data->gpio.dev = &client->dev;
        data->gpio.owner = THIS_MODULE;

        err = gpiochip_add(&data->gpio);
        if (err) {
            /* Use data->gpio.dev as a flag for freeing gpiochip */
            data->gpio.dev = NULL;
            dev_warn(&client->dev, "could not add gpiochip\n");
        } else {
            dev_info(&client->dev, "gpios %i...%i\n",
                data->gpio.base, data->gpio.base +
                data->gpio.ngpio - 1);
        }
    }
#endif

    return 0;

exit:
    pca9532_destroy_devices(data, i);
    return err;
}

static int pca9532_probe(struct i2c_client *client,
    const struct i2c_device_id *id)
{
    struct pca9532_data *data = i2c_get_clientdata(client);
    struct pca9532_platform_data *pca9532_pdata = client->dev.platform_data;

    if (!pca9532_pdata)
        return -EIO;

    if (!i2c_check_functionality(client->adapter,
        I2C_FUNC_SMBUS_BYTE_DATA))
        return -EIO;

    data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    data->chip_info = &pca9532_chip_info_tbl[id->driver_data];

    dev_info(&client->dev, "setting platform data\n");
    i2c_set_clientdata(client, data);
    data->client = client;
    mutex_init(&data->update_lock);

    return pca9532_configure(client, data, pca9532_pdata);
}

static int pca9532_remove(struct i2c_client *client)
{
    struct pca9532_data *data = i2c_get_clientdata(client);
    int err;

    err = pca9532_destroy_devices(data, data->chip_info->num_leds);
    if (err)
        return err;

    return 0;
}

module_i2c_driver(pca9532_driver);

MODULE_AUTHOR("Riku Voipio");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PCA 9532 LED dimmer");