// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2011 bct electronic GmbH
 * Copyright 2013 Qtechnology/AS
 *
 * Author: Peter Meerwald <p.meerwald@bct-electronic.com>
 * Author: Ricardo Ribalda <ribalda@kernel.org>
 *
 * Based on leds-pca955x.c
 *
 * 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/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/property.h>
#include <linux/slab.h>
#include <linux/of.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_OUTDRV    0x04    /* Open-drain or totem pole */
#define PCA963X_MODE2_INVRT     0x10    /* Normal or inverted direction */
#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);

struct pca963x;

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

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

static int pca963x_brightness(struct pca963x_led *led,
                              enum led_brightness brightness)
{
        struct i2c_client *client = led->chip->client;
        struct pca963x_chipdef *chipdef = led->chip->chipdef;
        u8 ledout_addr, ledout, mask, val;
        int shift;
        int ret;

        ledout_addr = chipdef->ledout_base + (led->led_num / 4);
        shift = 2 * (led->led_num % 4);
        mask = 0x3 << shift;
        ledout = i2c_smbus_read_byte_data(client, ledout_addr);

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

                val = (ledout & ~mask) | (PCA963X_LED_PWM << shift);
                ret = i2c_smbus_write_byte_data(client, ledout_addr, val);
                break;
        }

        return ret;
}

static void pca963x_blink(struct pca963x_led *led)
{
        struct i2c_client *client = led->chip->client;
        struct pca963x_chipdef *chipdef = led->chip->chipdef;
        u8 ledout_addr, ledout, mask, val, mode2;
        int shift;

        ledout_addr = chipdef->ledout_base + (led->led_num / 4);
        shift = 2 * (led->led_num % 4);
        mask = 0x3 << shift;
        mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);

        i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc);

        i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq);

        if (!(mode2 & PCA963X_MODE2_DMBLNK))
                i2c_smbus_write_byte_data(client, PCA963X_MODE2,
                                          mode2 | PCA963X_MODE2_DMBLNK);

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

        ledout = i2c_smbus_read_byte_data(client, ledout_addr);
        if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) {
                val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift);
                i2c_smbus_write_byte_data(client, ledout_addr, val);
        }

        mutex_unlock(&led->chip->mutex);
}

static int pca963x_power_state(struct pca963x_led *led)
{
        struct i2c_client *client = led->chip->client;
        unsigned long *leds_on = &led->chip->leds_on;
        unsigned long cached_leds = *leds_on;

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

        if (!(*leds_on) != !cached_leds)
                return i2c_smbus_write_byte_data(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 *led;
        int ret;

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

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

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

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

static unsigned int pca963x_period_scale(struct pca963x_led *led,
                                         unsigned int val)
{
        unsigned int scaling = led->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)
{
        unsigned long time_on, time_off, period;
        struct pca963x_led *led;
        u8 gdc, gfrq;

        led = 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(led, 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(led, 1000);
        }

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

        led->gdc = gdc;
        led->gfrq = gfrq;

        pca963x_blink(led);

        *delay_on = time_on;
        *delay_off = time_off;

        return 0;
}

static int pca963x_register_leds(struct i2c_client *client,
                                 struct pca963x *chip)
{
        struct pca963x_chipdef *chipdef = chip->chipdef;
        struct pca963x_led *led = chip->leds;
        struct device *dev = &client->dev;
        struct fwnode_handle *child;
        bool hw_blink;
        s32 mode2;
        u32 reg;
        int ret;

        if (device_property_read_u32(dev, "nxp,period-scale",
                                     &chipdef->scaling))
                chipdef->scaling = 1000;

        hw_blink = device_property_read_bool(dev, "nxp,hw-blink");

        mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2);
        if (mode2 < 0)
                return mode2;

        /* default to open-drain unless totem pole (push-pull) is specified */
        if (device_property_read_bool(dev, "nxp,totem-pole"))
                mode2 |= PCA963X_MODE2_OUTDRV;
        else
                mode2 &= ~PCA963X_MODE2_OUTDRV;

        /* default to non-inverted output, unless inverted is specified */
        if (device_property_read_bool(dev, "nxp,inverted-out"))
                mode2 |= PCA963X_MODE2_INVRT;
        else
                mode2 &= ~PCA963X_MODE2_INVRT;

        ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2);
        if (ret < 0)
                return ret;

        device_for_each_child_node(dev, child) {
                struct led_init_data init_data = {};
                char default_label[32];

                ret = fwnode_property_read_u32(child, "reg", &reg);
                if (ret || reg >= chipdef->n_leds) {
                        dev_err(dev, "Invalid 'reg' property for node %pfw\n",
                                child);
                        ret = -EINVAL;
                        goto err;
                }

                led->led_num = reg;
                led->chip = chip;
                led->led_cdev.brightness_set_blocking = pca963x_led_set;
                if (hw_blink)
                        led->led_cdev.blink_set = pca963x_blink_set;

                init_data.fwnode = child;
                /* for backwards compatibility */
                init_data.devicename = "pca963x";
                snprintf(default_label, sizeof(default_label), "%d:%.2x:%u",
                         client->adapter->nr, client->addr, reg);
                init_data.default_label = default_label;

                ret = devm_led_classdev_register_ext(dev, &led->led_cdev,
                                                     &init_data);
                if (ret) {
                        dev_err(dev, "Failed to register LED for node %pfw\n",
                                child);
                        goto err;
                }

                ++led;
        }

        return 0;
err:
        fwnode_handle_put(child);
        return ret;
}

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);

static int pca963x_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
{
        struct device *dev = &client->dev;
        struct pca963x_chipdef *chipdef;
        struct pca963x *chip;
        int i, count;

        chipdef = &pca963x_chipdefs[id->driver_data];

        count = device_get_child_node_count(dev);
        if (!count || count > chipdef->n_leds) {
                dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n",
                        dev_fwnode(dev), chipdef->n_leds);
                return -EINVAL;
        }

        chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        i2c_set_clientdata(client, chip);

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

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

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

        return pca963x_register_leds(client, chip);
}

static struct i2c_driver pca963x_driver = {
        .driver = {
                .name   = "leds-pca963x",
                .of_match_table = of_pca963x_match,
        },
        .probe  = pca963x_probe,
        .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");