// SPDX-License-Identifier: GPL-2.0-only
/*
 * LP5562 LED driver
 *
 * Copyright (C) 2013 Texas Instruments
 *
 * Author: Milo(Woogyom) Kim <milo.kim@ti.com>
 */

#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_data/leds-lp55xx.h>
#include <linux/slab.h>

#include "leds-lp55xx-common.h"

#define LP5562_PROGRAM_LENGTH           32
#define LP5562_MAX_LEDS                 4

/* ENABLE Register 00h */
#define LP5562_REG_ENABLE               0x00
#define LP5562_EXEC_ENG1_M              0x30
#define LP5562_EXEC_ENG2_M              0x0C
#define LP5562_EXEC_ENG3_M              0x03
#define LP5562_EXEC_M                   0x3F
#define LP5562_MASTER_ENABLE            0x40    /* Chip master enable */
#define LP5562_LOGARITHMIC_PWM          0x80    /* Logarithmic PWM adjustment */
#define LP5562_EXEC_RUN                 0x2A
#define LP5562_ENABLE_DEFAULT   \
        (LP5562_MASTER_ENABLE | LP5562_LOGARITHMIC_PWM)
#define LP5562_ENABLE_RUN_PROGRAM       \
        (LP5562_ENABLE_DEFAULT | LP5562_EXEC_RUN)

/* OPMODE Register 01h */
#define LP5562_REG_OP_MODE              0x01
#define LP5562_MODE_ENG1_M              0x30
#define LP5562_MODE_ENG2_M              0x0C
#define LP5562_MODE_ENG3_M              0x03
#define LP5562_LOAD_ENG1                0x10
#define LP5562_LOAD_ENG2                0x04
#define LP5562_LOAD_ENG3                0x01
#define LP5562_RUN_ENG1                 0x20
#define LP5562_RUN_ENG2                 0x08
#define LP5562_RUN_ENG3                 0x02
#define LP5562_ENG1_IS_LOADING(mode)    \
        ((mode & LP5562_MODE_ENG1_M) == LP5562_LOAD_ENG1)
#define LP5562_ENG2_IS_LOADING(mode)    \
        ((mode & LP5562_MODE_ENG2_M) == LP5562_LOAD_ENG2)
#define LP5562_ENG3_IS_LOADING(mode)    \
        ((mode & LP5562_MODE_ENG3_M) == LP5562_LOAD_ENG3)

/* BRIGHTNESS Registers */
#define LP5562_REG_R_PWM                0x04
#define LP5562_REG_G_PWM                0x03
#define LP5562_REG_B_PWM                0x02
#define LP5562_REG_W_PWM                0x0E

/* CURRENT Registers */
#define LP5562_REG_R_CURRENT            0x07
#define LP5562_REG_G_CURRENT            0x06
#define LP5562_REG_B_CURRENT            0x05
#define LP5562_REG_W_CURRENT            0x0F

/* CONFIG Register 08h */
#define LP5562_REG_CONFIG               0x08
#define LP5562_PWM_HF                   0x40
#define LP5562_PWRSAVE_EN               0x20
#define LP5562_CLK_INT                  0x01    /* Internal clock */
#define LP5562_DEFAULT_CFG              (LP5562_PWM_HF | LP5562_PWRSAVE_EN)

/* RESET Register 0Dh */
#define LP5562_REG_RESET                0x0D
#define LP5562_RESET                    0xFF

/* PROGRAM ENGINE Registers */
#define LP5562_REG_PROG_MEM_ENG1        0x10
#define LP5562_REG_PROG_MEM_ENG2        0x30
#define LP5562_REG_PROG_MEM_ENG3        0x50

/* LEDMAP Register 70h */
#define LP5562_REG_ENG_SEL              0x70
#define LP5562_ENG_SEL_PWM              0
#define LP5562_ENG_FOR_RGB_M            0x3F
#define LP5562_ENG_SEL_RGB              0x1B    /* R:ENG1, G:ENG2, B:ENG3 */
#define LP5562_ENG_FOR_W_M              0xC0
#define LP5562_ENG1_FOR_W               0x40    /* W:ENG1 */
#define LP5562_ENG2_FOR_W               0x80    /* W:ENG2 */
#define LP5562_ENG3_FOR_W               0xC0    /* W:ENG3 */

/* Program Commands */
#define LP5562_CMD_DISABLE              0x00
#define LP5562_CMD_LOAD                 0x15
#define LP5562_CMD_RUN                  0x2A
#define LP5562_CMD_DIRECT               0x3F
#define LP5562_PATTERN_OFF              0

static inline void lp5562_wait_opmode_done(void)
{
        /* operation mode change needs to be longer than 153 us */
        usleep_range(200, 300);
}

static inline void lp5562_wait_enable_done(void)
{
        /* it takes more 488 us to update ENABLE register */
        usleep_range(500, 600);
}

static void lp5562_set_led_current(struct lp55xx_led *led, u8 led_current)
{
        static const u8 addr[] = {
                LP5562_REG_R_CURRENT,
                LP5562_REG_G_CURRENT,
                LP5562_REG_B_CURRENT,
                LP5562_REG_W_CURRENT,
        };

        led->led_current = led_current;
        lp55xx_write(led->chip, addr[led->chan_nr], led_current);
}

static void lp5562_load_engine(struct lp55xx_chip *chip)
{
        enum lp55xx_engine_index idx = chip->engine_idx;
        static const u8 mask[] = {
                [LP55XX_ENGINE_1] = LP5562_MODE_ENG1_M,
                [LP55XX_ENGINE_2] = LP5562_MODE_ENG2_M,
                [LP55XX_ENGINE_3] = LP5562_MODE_ENG3_M,
        };

        static const u8 val[] = {
                [LP55XX_ENGINE_1] = LP5562_LOAD_ENG1,
                [LP55XX_ENGINE_2] = LP5562_LOAD_ENG2,
                [LP55XX_ENGINE_3] = LP5562_LOAD_ENG3,
        };

        lp55xx_update_bits(chip, LP5562_REG_OP_MODE, mask[idx], val[idx]);

        lp5562_wait_opmode_done();
}

static void lp5562_stop_engine(struct lp55xx_chip *chip)
{
        lp55xx_write(chip, LP5562_REG_OP_MODE, LP5562_CMD_DISABLE);
        lp5562_wait_opmode_done();
}

static void lp5562_run_engine(struct lp55xx_chip *chip, bool start)
{
        int ret;
        u8 mode;
        u8 exec;

        /* stop engine */
        if (!start) {
                lp55xx_write(chip, LP5562_REG_ENABLE, LP5562_ENABLE_DEFAULT);
                lp5562_wait_enable_done();
                lp5562_stop_engine(chip);
                lp55xx_write(chip, LP5562_REG_ENG_SEL, LP5562_ENG_SEL_PWM);
                lp55xx_write(chip, LP5562_REG_OP_MODE, LP5562_CMD_DIRECT);
                lp5562_wait_opmode_done();
                return;
        }

        /*
         * To run the engine,
         * operation mode and enable register should updated at the same time
         */

        ret = lp55xx_read(chip, LP5562_REG_OP_MODE, &mode);
        if (ret)
                return;

        ret = lp55xx_read(chip, LP5562_REG_ENABLE, &exec);
        if (ret)
                return;

        /* change operation mode to RUN only when each engine is loading */
        if (LP5562_ENG1_IS_LOADING(mode)) {
                mode = (mode & ~LP5562_MODE_ENG1_M) | LP5562_RUN_ENG1;
                exec = (exec & ~LP5562_EXEC_ENG1_M) | LP5562_RUN_ENG1;
        }

        if (LP5562_ENG2_IS_LOADING(mode)) {
                mode = (mode & ~LP5562_MODE_ENG2_M) | LP5562_RUN_ENG2;
                exec = (exec & ~LP5562_EXEC_ENG2_M) | LP5562_RUN_ENG2;
        }

        if (LP5562_ENG3_IS_LOADING(mode)) {
                mode = (mode & ~LP5562_MODE_ENG3_M) | LP5562_RUN_ENG3;
                exec = (exec & ~LP5562_EXEC_ENG3_M) | LP5562_RUN_ENG3;
        }

        lp55xx_write(chip, LP5562_REG_OP_MODE, mode);
        lp5562_wait_opmode_done();

        lp55xx_update_bits(chip, LP5562_REG_ENABLE, LP5562_EXEC_M, exec);
        lp5562_wait_enable_done();
}

static int lp5562_update_firmware(struct lp55xx_chip *chip,
                                        const u8 *data, size_t size)
{
        enum lp55xx_engine_index idx = chip->engine_idx;
        u8 pattern[LP5562_PROGRAM_LENGTH] = {0};
        static const u8 addr[] = {
                [LP55XX_ENGINE_1] = LP5562_REG_PROG_MEM_ENG1,
                [LP55XX_ENGINE_2] = LP5562_REG_PROG_MEM_ENG2,
                [LP55XX_ENGINE_3] = LP5562_REG_PROG_MEM_ENG3,
        };
        unsigned cmd;
        char c[3];
        int program_size;
        int nrchars;
        int offset = 0;
        int ret;
        int i;

        /* clear program memory before updating */
        for (i = 0; i < LP5562_PROGRAM_LENGTH; i++)
                lp55xx_write(chip, addr[idx] + i, 0);

        i = 0;
        while ((offset < size - 1) && (i < LP5562_PROGRAM_LENGTH)) {
                /* separate sscanfs because length is working only for %s */
                ret = sscanf(data + offset, "%2s%n ", c, &nrchars);
                if (ret != 1)
                        goto err;

                ret = sscanf(c, "%2x", &cmd);
                if (ret != 1)
                        goto err;

                pattern[i] = (u8)cmd;
                offset += nrchars;
                i++;
        }

        /* Each instruction is 16bit long. Check that length is even */
        if (i % 2)
                goto err;

        program_size = i;
        for (i = 0; i < program_size; i++)
                lp55xx_write(chip, addr[idx] + i, pattern[i]);

        return 0;

err:
        dev_err(&chip->cl->dev, "wrong pattern format\n");
        return -EINVAL;
}

static void lp5562_firmware_loaded(struct lp55xx_chip *chip)
{
        const struct firmware *fw = chip->fw;

        /*
         * the firmware is encoded in ascii hex character, with 2 chars
         * per byte
         */
        if (fw->size > (LP5562_PROGRAM_LENGTH * 2)) {
                dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
                        fw->size);
                return;
        }

        /*
         * Program memory sequence
         *  1) set engine mode to "LOAD"
         *  2) write firmware data into program memory
         */

        lp5562_load_engine(chip);
        lp5562_update_firmware(chip, fw->data, fw->size);
}

static int lp5562_post_init_device(struct lp55xx_chip *chip)
{
        int ret;
        u8 cfg = LP5562_DEFAULT_CFG;

        /* Set all PWMs to direct control mode */
        ret = lp55xx_write(chip, LP5562_REG_OP_MODE, LP5562_CMD_DIRECT);
        if (ret)
                return ret;

        lp5562_wait_opmode_done();

        /* Update configuration for the clock setting */
        if (!lp55xx_is_extclk_used(chip))
                cfg |= LP5562_CLK_INT;

        ret = lp55xx_write(chip, LP5562_REG_CONFIG, cfg);
        if (ret)
                return ret;

        /* Initialize all channels PWM to zero -> leds off */
        lp55xx_write(chip, LP5562_REG_R_PWM, 0);
        lp55xx_write(chip, LP5562_REG_G_PWM, 0);
        lp55xx_write(chip, LP5562_REG_B_PWM, 0);
        lp55xx_write(chip, LP5562_REG_W_PWM, 0);

        /* Set LED map as register PWM by default */
        lp55xx_write(chip, LP5562_REG_ENG_SEL, LP5562_ENG_SEL_PWM);

        return 0;
}

static int lp5562_led_brightness(struct lp55xx_led *led)
{
        struct lp55xx_chip *chip = led->chip;
        static const u8 addr[] = {
                LP5562_REG_R_PWM,
                LP5562_REG_G_PWM,
                LP5562_REG_B_PWM,
                LP5562_REG_W_PWM,
        };
        int ret;

        mutex_lock(&chip->lock);
        ret = lp55xx_write(chip, addr[led->chan_nr], led->brightness);
        mutex_unlock(&chip->lock);

        return ret;
}

static void lp5562_write_program_memory(struct lp55xx_chip *chip,
                                        u8 base, const u8 *rgb, int size)
{
        int i;

        if (!rgb || size <= 0)
                return;

        for (i = 0; i < size; i++)
                lp55xx_write(chip, base + i, *(rgb + i));

        lp55xx_write(chip, base + i, 0);
        lp55xx_write(chip, base + i + 1, 0);
}

/* check the size of program count */
static inline bool _is_pc_overflow(struct lp55xx_predef_pattern *ptn)
{
        return ptn->size_r >= LP5562_PROGRAM_LENGTH ||
               ptn->size_g >= LP5562_PROGRAM_LENGTH ||
               ptn->size_b >= LP5562_PROGRAM_LENGTH;
}

static int lp5562_run_predef_led_pattern(struct lp55xx_chip *chip, int mode)
{
        struct lp55xx_predef_pattern *ptn;
        int i;

        if (mode == LP5562_PATTERN_OFF) {
                lp5562_run_engine(chip, false);
                return 0;
        }

        ptn = chip->pdata->patterns + (mode - 1);
        if (!ptn || _is_pc_overflow(ptn)) {
                dev_err(&chip->cl->dev, "invalid pattern data\n");
                return -EINVAL;
        }

        lp5562_stop_engine(chip);

        /* Set LED map as RGB */
        lp55xx_write(chip, LP5562_REG_ENG_SEL, LP5562_ENG_SEL_RGB);

        /* Load engines */
        for (i = LP55XX_ENGINE_1; i <= LP55XX_ENGINE_3; i++) {
                chip->engine_idx = i;
                lp5562_load_engine(chip);
        }

        /* Clear program registers */
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG1, 0);
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG1 + 1, 0);
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG2, 0);
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG2 + 1, 0);
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG3, 0);
        lp55xx_write(chip, LP5562_REG_PROG_MEM_ENG3 + 1, 0);

        /* Program engines */
        lp5562_write_program_memory(chip, LP5562_REG_PROG_MEM_ENG1,
                                ptn->r, ptn->size_r);
        lp5562_write_program_memory(chip, LP5562_REG_PROG_MEM_ENG2,
                                ptn->g, ptn->size_g);
        lp5562_write_program_memory(chip, LP5562_REG_PROG_MEM_ENG3,
                                ptn->b, ptn->size_b);

        /* Run engines */
        lp5562_run_engine(chip, true);

        return 0;
}

static ssize_t lp5562_store_pattern(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t len)
{
        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
        struct lp55xx_chip *chip = led->chip;
        struct lp55xx_predef_pattern *ptn = chip->pdata->patterns;
        int num_patterns = chip->pdata->num_patterns;
        unsigned long mode;
        int ret;

        ret = kstrtoul(buf, 0, &mode);
        if (ret)
                return ret;

        if (mode > num_patterns || !ptn)
                return -EINVAL;

        mutex_lock(&chip->lock);
        ret = lp5562_run_predef_led_pattern(chip, mode);
        mutex_unlock(&chip->lock);

        if (ret)
                return ret;

        return len;
}

static ssize_t lp5562_store_engine_mux(struct device *dev,
                                     struct device_attribute *attr,
                                     const char *buf, size_t len)
{
        struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
        struct lp55xx_chip *chip = led->chip;
        u8 mask;
        u8 val;

        /* LED map
         * R ... Engine 1 (fixed)
         * G ... Engine 2 (fixed)
         * B ... Engine 3 (fixed)
         * W ... Engine 1 or 2 or 3
         */

        if (sysfs_streq(buf, "RGB")) {
                mask = LP5562_ENG_FOR_RGB_M;
                val = LP5562_ENG_SEL_RGB;
        } else if (sysfs_streq(buf, "W")) {
                enum lp55xx_engine_index idx = chip->engine_idx;

                mask = LP5562_ENG_FOR_W_M;
                switch (idx) {
                case LP55XX_ENGINE_1:
                        val = LP5562_ENG1_FOR_W;
                        break;
                case LP55XX_ENGINE_2:
                        val = LP5562_ENG2_FOR_W;
                        break;
                case LP55XX_ENGINE_3:
                        val = LP5562_ENG3_FOR_W;
                        break;
                default:
                        return -EINVAL;
                }

        } else {
                dev_err(dev, "choose RGB or W\n");
                return -EINVAL;
        }

        mutex_lock(&chip->lock);
        lp55xx_update_bits(chip, LP5562_REG_ENG_SEL, mask, val);
        mutex_unlock(&chip->lock);

        return len;
}

static LP55XX_DEV_ATTR_WO(led_pattern, lp5562_store_pattern);
static LP55XX_DEV_ATTR_WO(engine_mux, lp5562_store_engine_mux);

static struct attribute *lp5562_attributes[] = {
        &dev_attr_led_pattern.attr,
        &dev_attr_engine_mux.attr,
        NULL,
};

static const struct attribute_group lp5562_group = {
        .attrs = lp5562_attributes,
};

/* Chip specific configurations */
static struct lp55xx_device_config lp5562_cfg = {
        .max_channel  = LP5562_MAX_LEDS,
        .reset = {
                .addr = LP5562_REG_RESET,
                .val  = LP5562_RESET,
        },
        .enable = {
                .addr = LP5562_REG_ENABLE,
                .val  = LP5562_ENABLE_DEFAULT,
        },
        .post_init_device   = lp5562_post_init_device,
        .set_led_current    = lp5562_set_led_current,
        .brightness_fn      = lp5562_led_brightness,
        .run_engine         = lp5562_run_engine,
        .firmware_cb        = lp5562_firmware_loaded,
        .dev_attr_group     = &lp5562_group,
};

static int lp5562_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
{
        int ret;
        struct lp55xx_chip *chip;
        struct lp55xx_led *led;
        struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
        struct device_node *np = dev_of_node(&client->dev);

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

        chip->cfg = &lp5562_cfg;

        if (!pdata) {
                if (np) {
                        pdata = lp55xx_of_populate_pdata(&client->dev, np,
                                                         chip);
                        if (IS_ERR(pdata))
                                return PTR_ERR(pdata);
                } else {
                        dev_err(&client->dev, "no platform data\n");
                        return -EINVAL;
                }
        }


        led = devm_kcalloc(&client->dev,
                        pdata->num_channels, sizeof(*led), GFP_KERNEL);
        if (!led)
                return -ENOMEM;

        chip->cl = client;
        chip->pdata = pdata;

        mutex_init(&chip->lock);

        i2c_set_clientdata(client, led);

        ret = lp55xx_init_device(chip);
        if (ret)
                goto err_init;

        ret = lp55xx_register_leds(led, chip);
        if (ret)
                goto err_out;

        ret = lp55xx_register_sysfs(chip);
        if (ret) {
                dev_err(&client->dev, "registering sysfs failed\n");
                goto err_out;
        }

        return 0;

err_out:
        lp55xx_deinit_device(chip);
err_init:
        return ret;
}

static int lp5562_remove(struct i2c_client *client)
{
        struct lp55xx_led *led = i2c_get_clientdata(client);
        struct lp55xx_chip *chip = led->chip;

        lp5562_stop_engine(chip);

        lp55xx_unregister_sysfs(chip);
        lp55xx_deinit_device(chip);

        return 0;
}

static const struct i2c_device_id lp5562_id[] = {
        { "lp5562", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, lp5562_id);

#ifdef CONFIG_OF
static const struct of_device_id of_lp5562_leds_match[] = {
        { .compatible = "ti,lp5562", },
        {},
};

MODULE_DEVICE_TABLE(of, of_lp5562_leds_match);
#endif

static struct i2c_driver lp5562_driver = {
        .driver = {
                .name   = "lp5562",
                .of_match_table = of_match_ptr(of_lp5562_leds_match),
        },
        .probe          = lp5562_probe,
        .remove         = lp5562_remove,
        .id_table       = lp5562_id,
};

module_i2c_driver(lp5562_driver);

MODULE_DESCRIPTION("Texas Instruments LP5562 LED Driver");
MODULE_AUTHOR("Milo Kim");
MODULE_LICENSE("GPL");