/*
 * Copyright 2011 bct electronic GmbH
 * Copyright 2013 Qtechnology/AS
 *
 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
 * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
 *
 * Based on leds-pca955x.c
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62)
 * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.)
 *
 * Note that hardware blinking violates the leds infrastructure driver
 * interface since the hardware only supports blinking all LEDs with the
 * same delay_on/delay_off rates.  That is, only the LEDs that are set to
 * blink will actually blink but all LEDs that are set to blink will blink
 * in identical fashion.  The delay_on/delay_off values of the last LED
 * that is set to blink will be used for all of the blinking LEDs.
 * Hardware blinking is disabled by default but can be enabled by setting
 * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK'
 * or by adding the 'nxp,hw-blink' property to the DTS.
 */

#include <linux/acpi.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/platform_data/leds-pca963x.h>

/* LED select registers determine the source that drives LED outputs */
#define PCA963X_LED_OFF         0x0     /* LED driver off */
#define PCA963X_LED_ON          0x1     /* LED driver on */
#define PCA963X_LED_PWM         0x2     /* Controlled through PWM */
#define PCA963X_LED_GRP_PWM     0x3     /* Controlled through PWM/GRPPWM */

#define PCA963X_MODE2_DMBLNK    0x20    /* Enable blinking */

#define PCA963X_MODE1           0x00
#define PCA963X_MODE2           0x01
#define PCA963X_PWM_BASE        0x02

enum pca963x_type {
        pca9633,
        pca9634,
        pca9635,
};

struct pca963x_chipdef {
        u8                      grppwm;
        u8                      grpfreq;
        u8                      ledout_base;
        int                     n_leds;
        unsigned int            scaling;
};

static struct pca963x_chipdef pca963x_chipdefs[] = {
        [pca9633] = {
                .grppwm         = 0x6,
                .grpfreq        = 0x7,
                .ledout_base    = 0x8,
                .n_leds         = 4,
        },
        [pca9634] = {
                .grppwm         = 0xa,
                .grpfreq        = 0xb,
                .ledout_base    = 0xc,
                .n_leds         = 8,
        },
        [pca9635] = {
                .grppwm         = 0x12,
                .grpfreq        = 0x13,
                .ledout_base    = 0x14,
                .n_leds         = 16,
        },
};

/* Total blink period in milliseconds */
#define PCA963X_BLINK_PERIOD_MIN        42
#define PCA963X_BLINK_PERIOD_MAX        10667

static const struct i2c_device_id pca963x_id[] = {
        { "pca9632", pca9633 },
        { "pca9633", pca9633 },
        { "pca9634", pca9634 },
        { "pca9635", pca9635 },
        { }
};
MODULE_DEVICE_TABLE(i2c, pca963x_id);

static const struct acpi_device_id pca963x_acpi_ids[] = {
        { "PCA9632", pca9633 },
        { "PCA9633", pca9633 },
        { "PCA9634", pca9634 },
        { "PCA9635", pca9635 },
        { }
};
MODULE_DEVICE_TABLE(acpi, pca963x_acpi_ids);

struct pca963x_led;

struct pca963x {
        struct pca963x_chipdef *chipdef;
        struct mutex mutex;
        struct i2c_client *client;
        struct pca963x_led *leds;
        unsigned long leds_on;
};

struct pca963x_led {
        struct pca963x *chip;
        struct led_classdev led_cdev;
        int led_num; /* 0 .. 15 potentially */
        char name[32];
        u8 gdc;
        u8 gfrq;
};

static int pca963x_brightness(struct pca963x_led *pca963x,
                               enum led_brightness brightness)
{
        u8 ledout_addr = pca963x->chip->chipdef->ledout_base
                + (pca963x->led_num / 4);
        u8 ledout;
        int shift = 2 * (pca963x->led_num % 4);
        u8 mask = 0x3 << shift;
        int ret;

        ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
        switch (brightness) {
        case LED_FULL:
                ret = i2c_smbus_write_byte_data(pca963x->chip->client,
                        ledout_addr,
                        (ledout & ~mask) | (PCA963X_LED_ON << shift));
                break;
        case LED_OFF:
                ret = i2c_smbus_write_byte_data(pca963x->chip->client,
                        ledout_addr, ledout & ~mask);
                break;
        default:
                ret = i2c_smbus_write_byte_data(pca963x->chip->client,
                        PCA963X_PWM_BASE + pca963x->led_num,
                        brightness);
                if (ret < 0)
                        return ret;
                ret = i2c_smbus_write_byte_data(pca963x->chip->client,
                        ledout_addr,
                        (ledout & ~mask) | (PCA963X_LED_PWM << shift));
                break;
        }

        return ret;
}

static void pca963x_blink(struct pca963x_led *pca963x)
{
        u8 ledout_addr = pca963x->chip->chipdef->ledout_base +
                (pca963x->led_num / 4);
        u8 ledout;
        u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
                                                        PCA963X_MODE2);
        int shift = 2 * (pca963x->led_num % 4);
        u8 mask = 0x3 << shift;

        i2c_smbus_write_byte_data(pca963x->chip->client,
                        pca963x->chip->chipdef->grppwm, pca963x->gdc);

        i2c_smbus_write_byte_data(pca963x->chip->client,
                        pca963x->chip->chipdef->grpfreq, pca963x->gfrq);

        if (!(mode2 & PCA963X_MODE2_DMBLNK))
                i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
                        mode2 | PCA963X_MODE2_DMBLNK);

        mutex_lock(&pca963x->chip->mutex);
        ledout = i2c_smbus_read_byte_data(pca963x->chip->client, ledout_addr);
        if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift))
                i2c_smbus_write_byte_data(pca963x->chip->client, ledout_addr,
                        (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift));
        mutex_unlock(&pca963x->chip->mutex);
}

static int pca963x_power_state(struct pca963x_led *pca963x)
{
        unsigned long *leds_on = &pca963x->chip->leds_on;
        unsigned long cached_leds = pca963x->chip->leds_on;

        if (pca963x->led_cdev.brightness)
                set_bit(pca963x->led_num, leds_on);
        else
                clear_bit(pca963x->led_num, leds_on);

        if (!(*leds_on) != !cached_leds)
                return i2c_smbus_write_byte_data(pca963x->chip->client,
                        PCA963X_MODE1, *leds_on ? 0 : BIT(4));

        return 0;
}

static int pca963x_led_set(struct led_classdev *led_cdev,
        enum led_brightness value)
{
        struct pca963x_led *pca963x;
        int ret;

        pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

        mutex_lock(&pca963x->chip->mutex);

        ret = pca963x_brightness(pca963x, value);
        if (ret < 0)
                goto unlock;
        ret = pca963x_power_state(pca963x);

unlock:
        mutex_unlock(&pca963x->chip->mutex);
        return ret;
}

static unsigned int pca963x_period_scale(struct pca963x_led *pca963x,
        unsigned int val)
{
        unsigned int scaling = pca963x->chip->chipdef->scaling;

        return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val;
}

static int pca963x_blink_set(struct led_classdev *led_cdev,
                unsigned long *delay_on, unsigned long *delay_off)
{
        struct pca963x_led *pca963x;
        unsigned long time_on, time_off, period;
        u8 gdc, gfrq;

        pca963x = container_of(led_cdev, struct pca963x_led, led_cdev);

        time_on = *delay_on;
        time_off = *delay_off;

        /* If both zero, pick reasonable defaults of 500ms each */
        if (!time_on && !time_off) {
                time_on = 500;
                time_off = 500;
        }

        period = pca963x_period_scale(pca963x, time_on + time_off);

        /* If period not supported by hardware, default to someting sane. */
        if ((period < PCA963X_BLINK_PERIOD_MIN) ||
            (period > PCA963X_BLINK_PERIOD_MAX)) {
                time_on = 500;
                time_off = 500;
                period = pca963x_period_scale(pca963x, 1000);
        }

        /*
         * From manual: duty cycle = (GDC / 256) ->
         *      (time_on / period) = (GDC / 256) ->
         *              GDC = ((time_on * 256) / period)
         */
        gdc = (pca963x_period_scale(pca963x, time_on) * 256) / period;

        /*
         * From manual: period = ((GFRQ + 1) / 24) in seconds.
         * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) ->
         *              GFRQ = ((period * 24 / 1000) - 1)
         */
        gfrq = (period * 24 / 1000) - 1;

        pca963x->gdc = gdc;
        pca963x->gfrq = gfrq;

        pca963x_blink(pca963x);

        *delay_on = time_on;
        *delay_off = time_off;

        return 0;
}

#if IS_ENABLED(CONFIG_OF)
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
        struct device_node *np = client->dev.of_node, *child;
        struct pca963x_platform_data *pdata;
        struct led_info *pca963x_leds;
        int count;

        count = of_get_child_count(np);
        if (!count || count > chip->n_leds)
                return ERR_PTR(-ENODEV);

        pca963x_leds = devm_kzalloc(&client->dev,
                        sizeof(struct led_info) * chip->n_leds, GFP_KERNEL);
        if (!pca963x_leds)
                return ERR_PTR(-ENOMEM);

        for_each_child_of_node(np, child) {
                struct led_info led = {};
                u32 reg;
                int res;

                res = of_property_read_u32(child, "reg", &reg);
                if ((res != 0) || (reg >= chip->n_leds))
                        continue;
                led.name =
                        of_get_property(child, "label", NULL) ? : child->name;
                led.default_trigger =
                        of_get_property(child, "linux,default-trigger", NULL);
                pca963x_leds[reg] = led;
        }
        pdata = devm_kzalloc(&client->dev,
                             sizeof(struct pca963x_platform_data), GFP_KERNEL);
        if (!pdata)
                return ERR_PTR(-ENOMEM);

        pdata->leds.leds = pca963x_leds;
        pdata->leds.num_leds = chip->n_leds;

        /* default to open-drain unless totem pole (push-pull) is specified */
        if (of_property_read_bool(np, "nxp,totem-pole"))
                pdata->outdrv = PCA963X_TOTEM_POLE;
        else
                pdata->outdrv = PCA963X_OPEN_DRAIN;

        /* default to software blinking unless hardware blinking is specified */
        if (of_property_read_bool(np, "nxp,hw-blink"))
                pdata->blink_type = PCA963X_HW_BLINK;
        else
                pdata->blink_type = PCA963X_SW_BLINK;

        if (of_property_read_u32(np, "nxp,period-scale", &chip->scaling))
                chip->scaling = 1000;

        /* default to non-inverted output, unless inverted is specified */
        if (of_property_read_bool(np, "nxp,inverted-out"))
                pdata->dir = PCA963X_INVERTED;
        else
                pdata->dir = PCA963X_NORMAL;

        return pdata;
}

static const struct of_device_id of_pca963x_match[] = {
        { .compatible = "nxp,pca9632", },
        { .compatible = "nxp,pca9633", },
        { .compatible = "nxp,pca9634", },
        { .compatible = "nxp,pca9635", },
        {},
};
MODULE_DEVICE_TABLE(of, of_pca963x_match);
#else
static struct pca963x_platform_data *
pca963x_dt_init(struct i2c_client *client, struct pca963x_chipdef *chip)
{
        return ERR_PTR(-ENODEV);
}
#endif

static int pca963x_probe(struct i2c_client *client,
                                        const struct i2c_device_id *id)
{
        struct pca963x *pca963x_chip;
        struct pca963x_led *pca963x;
        struct pca963x_platform_data *pdata;
        struct pca963x_chipdef *chip;
        int i, err;

        if (id) {
                chip = &pca963x_chipdefs[id->driver_data];
        } else {
                const struct acpi_device_id *acpi_id;

                acpi_id = acpi_match_device(pca963x_acpi_ids, &client->dev);
                if (!acpi_id)
                        return -ENODEV;
                chip = &pca963x_chipdefs[acpi_id->driver_data];
        }
        pdata = dev_get_platdata(&client->dev);

        if (!pdata) {
                pdata = pca963x_dt_init(client, chip);
                if (IS_ERR(pdata)) {
                        dev_warn(&client->dev, "could not parse configuration\n");
                        pdata = NULL;
                }
        }

        if (pdata && (pdata->leds.num_leds < 1 ||
                                 pdata->leds.num_leds > chip->n_leds)) {
                dev_err(&client->dev, "board info must claim 1-%d LEDs",
                                                                chip->n_leds);
                return -EINVAL;
        }

        pca963x_chip = devm_kzalloc(&client->dev, sizeof(*pca963x_chip),
                                                                GFP_KERNEL);
        if (!pca963x_chip)
                return -ENOMEM;
        pca963x = devm_kzalloc(&client->dev, chip->n_leds * sizeof(*pca963x),
                                                                GFP_KERNEL);
        if (!pca963x)
                return -ENOMEM;

        i2c_set_clientdata(client, pca963x_chip);

        mutex_init(&pca963x_chip->mutex);
        pca963x_chip->chipdef = chip;
        pca963x_chip->client = client;
        pca963x_chip->leds = pca963x;

        /* Turn off LEDs by default*/
        for (i = 0; i < chip->n_leds / 4; i++)
                i2c_smbus_write_byte_data(client, chip->ledout_base + i, 0x00);

        for (i = 0; i < chip->n_leds; i++) {
                pca963x[i].led_num = i;
                pca963x[i].chip = pca963x_chip;

                /* Platform data can specify LED names and default triggers */
                if (pdata && i < pdata->leds.num_leds) {
                        if (pdata->leds.leds[i].name)
                                snprintf(pca963x[i].name,
                                         sizeof(pca963x[i].name), "pca963x:%s",
                                         pdata->leds.leds[i].name);
                        if (pdata->leds.leds[i].default_trigger)
                                pca963x[i].led_cdev.default_trigger =
                                        pdata->leds.leds[i].default_trigger;
                }
                if (!pdata || i >= pdata->leds.num_leds ||
                                                !pdata->leds.leds[i].name)
                        snprintf(pca963x[i].name, sizeof(pca963x[i].name),
                                 "pca963x:%d:%.2x:%d", client->adapter->nr,
                                 client->addr, i);

                pca963x[i].led_cdev.name = pca963x[i].name;
                pca963x[i].led_cdev.brightness_set_blocking = pca963x_led_set;

                if (pdata && pdata->blink_type == PCA963X_HW_BLINK)
                        pca963x[i].led_cdev.blink_set = pca963x_blink_set;

                err = led_classdev_register(&client->dev, &pca963x[i].led_cdev);
                if (err < 0)
                        goto exit;
        }

        /* Disable LED all-call address, and power down initially */
        i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4));

        if (pdata) {
                u8 mode2 = i2c_smbus_read_byte_data(pca963x->chip->client,
                                                    PCA963X_MODE2);
                /* Configure output: open-drain or totem pole (push-pull) */
                if (pdata->outdrv == PCA963X_OPEN_DRAIN)
                        mode2 |= 0x01;
                else
                        mode2 |= 0x05;
                /* Configure direction: normal or inverted */
                if (pdata->dir == PCA963X_INVERTED)
                        mode2 |= 0x10;
                i2c_smbus_write_byte_data(pca963x->chip->client, PCA963X_MODE2,
                                          mode2);
        }

        return 0;

exit:
        while (i--)
                led_classdev_unregister(&pca963x[i].led_cdev);

        return err;
}

static int pca963x_remove(struct i2c_client *client)
{
        struct pca963x *pca963x = i2c_get_clientdata(client);
        int i;

        for (i = 0; i < pca963x->chipdef->n_leds; i++)
                led_classdev_unregister(&pca963x->leds[i].led_cdev);

        return 0;
}

static struct i2c_driver pca963x_driver = {
        .driver = {
                .name   = "leds-pca963x",
                .of_match_table = of_match_ptr(of_pca963x_match),
                .acpi_match_table = ACPI_PTR(pca963x_acpi_ids),
        },
        .probe  = pca963x_probe,
        .remove = pca963x_remove,
        .id_table = pca963x_id,
};

module_i2c_driver(pca963x_driver);

MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>");
MODULE_DESCRIPTION("PCA963X LED driver");
MODULE_LICENSE("GPL v2");