root/drivers/video/backlight/ams369fg06.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * ams369fg06 AMOLED LCD panel driver.
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 * Author: Jingoo Han  <jg1.han@samsung.com>
 *
 * Derived from drivers/video/s6e63m0.c
 */

#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/lcd.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/wait.h>

#define SLEEPMSEC               0x1000
#define ENDDEF                  0x2000
#define DEFMASK                 0xFF00
#define COMMAND_ONLY            0xFE
#define DATA_ONLY               0xFF

#define MAX_GAMMA_LEVEL         5
#define GAMMA_TABLE_COUNT       21

#define MIN_BRIGHTNESS          0
#define MAX_BRIGHTNESS          255
#define DEFAULT_BRIGHTNESS      150

struct ams369fg06 {
        struct device                   *dev;
        struct spi_device               *spi;
        unsigned int                    power;
        struct lcd_device               *ld;
        struct backlight_device         *bd;
        struct lcd_platform_data        *lcd_pd;
};

static const unsigned short seq_display_on[] = {
        0x14, 0x03,
        ENDDEF, 0x0000
};

static const unsigned short seq_display_off[] = {
        0x14, 0x00,
        ENDDEF, 0x0000
};

static const unsigned short seq_stand_by_on[] = {
        0x1D, 0xA1,
        SLEEPMSEC, 200,
        ENDDEF, 0x0000
};

static const unsigned short seq_stand_by_off[] = {
        0x1D, 0xA0,
        SLEEPMSEC, 250,
        ENDDEF, 0x0000
};

static const unsigned short seq_setting[] = {
        0x31, 0x08,
        0x32, 0x14,
        0x30, 0x02,
        0x27, 0x01,
        0x12, 0x08,
        0x13, 0x08,
        0x15, 0x00,
        0x16, 0x00,

        0xef, 0xd0,
        DATA_ONLY, 0xe8,

        0x39, 0x44,
        0x40, 0x00,
        0x41, 0x3f,
        0x42, 0x2a,
        0x43, 0x27,
        0x44, 0x27,
        0x45, 0x1f,
        0x46, 0x44,
        0x50, 0x00,
        0x51, 0x00,
        0x52, 0x17,
        0x53, 0x24,
        0x54, 0x26,
        0x55, 0x1f,
        0x56, 0x43,
        0x60, 0x00,
        0x61, 0x3f,
        0x62, 0x2a,
        0x63, 0x25,
        0x64, 0x24,
        0x65, 0x1b,
        0x66, 0x5c,

        0x17, 0x22,
        0x18, 0x33,
        0x19, 0x03,
        0x1a, 0x01,
        0x22, 0xa4,
        0x23, 0x00,
        0x26, 0xa0,

        0x1d, 0xa0,
        SLEEPMSEC, 300,

        0x14, 0x03,

        ENDDEF, 0x0000
};

/* gamma value: 2.2 */
static const unsigned int ams369fg06_22_250[] = {
        0x00, 0x3f, 0x2a, 0x27, 0x27, 0x1f, 0x44,
        0x00, 0x00, 0x17, 0x24, 0x26, 0x1f, 0x43,
        0x00, 0x3f, 0x2a, 0x25, 0x24, 0x1b, 0x5c,
};

static const unsigned int ams369fg06_22_200[] = {
        0x00, 0x3f, 0x28, 0x29, 0x27, 0x21, 0x3e,
        0x00, 0x00, 0x10, 0x25, 0x27, 0x20, 0x3d,
        0x00, 0x3f, 0x28, 0x27, 0x25, 0x1d, 0x53,
};

static const unsigned int ams369fg06_22_150[] = {
        0x00, 0x3f, 0x2d, 0x29, 0x28, 0x23, 0x37,
        0x00, 0x00, 0x0b, 0x25, 0x28, 0x22, 0x36,
        0x00, 0x3f, 0x2b, 0x28, 0x26, 0x1f, 0x4a,
};

static const unsigned int ams369fg06_22_100[] = {
        0x00, 0x3f, 0x30, 0x2a, 0x2b, 0x24, 0x2f,
        0x00, 0x00, 0x00, 0x25, 0x29, 0x24, 0x2e,
        0x00, 0x3f, 0x2f, 0x29, 0x29, 0x21, 0x3f,
};

static const unsigned int ams369fg06_22_50[] = {
        0x00, 0x3f, 0x3c, 0x2c, 0x2d, 0x27, 0x24,
        0x00, 0x00, 0x00, 0x22, 0x2a, 0x27, 0x23,
        0x00, 0x3f, 0x3b, 0x2c, 0x2b, 0x24, 0x31,
};

struct ams369fg06_gamma {
        unsigned int *gamma_22_table[MAX_GAMMA_LEVEL];
};

static struct ams369fg06_gamma gamma_table = {
        .gamma_22_table[0] = (unsigned int *)&ams369fg06_22_50,
        .gamma_22_table[1] = (unsigned int *)&ams369fg06_22_100,
        .gamma_22_table[2] = (unsigned int *)&ams369fg06_22_150,
        .gamma_22_table[3] = (unsigned int *)&ams369fg06_22_200,
        .gamma_22_table[4] = (unsigned int *)&ams369fg06_22_250,
};

static int ams369fg06_spi_write_byte(struct ams369fg06 *lcd, int addr, int data)
{
        u16 buf[1];
        struct spi_message msg;

        struct spi_transfer xfer = {
                .len            = 2,
                .tx_buf         = buf,
        };

        buf[0] = (addr << 8) | data;

        spi_message_init(&msg);
        spi_message_add_tail(&xfer, &msg);

        return spi_sync(lcd->spi, &msg);
}

static int ams369fg06_spi_write(struct ams369fg06 *lcd, unsigned char address,
        unsigned char command)
{
        int ret = 0;

        if (address != DATA_ONLY)
                ret = ams369fg06_spi_write_byte(lcd, 0x70, address);
        if (command != COMMAND_ONLY)
                ret = ams369fg06_spi_write_byte(lcd, 0x72, command);

        return ret;
}

static int ams369fg06_panel_send_sequence(struct ams369fg06 *lcd,
        const unsigned short *wbuf)
{
        int ret = 0, i = 0;

        while ((wbuf[i] & DEFMASK) != ENDDEF) {
                if ((wbuf[i] & DEFMASK) != SLEEPMSEC) {
                        ret = ams369fg06_spi_write(lcd, wbuf[i], wbuf[i+1]);
                        if (ret)
                                break;
                } else {
                        msleep(wbuf[i+1]);
                }
                i += 2;
        }

        return ret;
}

static int _ams369fg06_gamma_ctl(struct ams369fg06 *lcd,
        const unsigned int *gamma)
{
        unsigned int i = 0;
        int ret = 0;

        for (i = 0 ; i < GAMMA_TABLE_COUNT / 3; i++) {
                ret = ams369fg06_spi_write(lcd, 0x40 + i, gamma[i]);
                ret = ams369fg06_spi_write(lcd, 0x50 + i, gamma[i+7*1]);
                ret = ams369fg06_spi_write(lcd, 0x60 + i, gamma[i+7*2]);
                if (ret) {
                        dev_err(lcd->dev, "failed to set gamma table.\n");
                        goto gamma_err;
                }
        }

gamma_err:
        return ret;
}

static int ams369fg06_gamma_ctl(struct ams369fg06 *lcd, int brightness)
{
        int ret = 0;
        int gamma = 0;

        if ((brightness >= 0) && (brightness <= 50))
                gamma = 0;
        else if ((brightness > 50) && (brightness <= 100))
                gamma = 1;
        else if ((brightness > 100) && (brightness <= 150))
                gamma = 2;
        else if ((brightness > 150) && (brightness <= 200))
                gamma = 3;
        else if ((brightness > 200) && (brightness <= 255))
                gamma = 4;

        ret = _ams369fg06_gamma_ctl(lcd, gamma_table.gamma_22_table[gamma]);

        return ret;
}

static int ams369fg06_ldi_init(struct ams369fg06 *lcd)
{
        int ret, i;
        static const unsigned short *init_seq[] = {
                seq_setting,
                seq_stand_by_off,
        };

        for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
                ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
                if (ret)
                        break;
        }

        return ret;
}

static int ams369fg06_ldi_enable(struct ams369fg06 *lcd)
{
        int ret, i;
        static const unsigned short *init_seq[] = {
                seq_stand_by_off,
                seq_display_on,
        };

        for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
                ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
                if (ret)
                        break;
        }

        return ret;
}

static int ams369fg06_ldi_disable(struct ams369fg06 *lcd)
{
        int ret, i;

        static const unsigned short *init_seq[] = {
                seq_display_off,
                seq_stand_by_on,
        };

        for (i = 0; i < ARRAY_SIZE(init_seq); i++) {
                ret = ams369fg06_panel_send_sequence(lcd, init_seq[i]);
                if (ret)
                        break;
        }

        return ret;
}

static int ams369fg06_power_is_on(int power)
{
        return power <= BACKLIGHT_POWER_REDUCED;
}

static int ams369fg06_power_on(struct ams369fg06 *lcd)
{
        int ret = 0;
        struct lcd_platform_data *pd;
        struct backlight_device *bd;

        pd = lcd->lcd_pd;
        bd = lcd->bd;

        if (pd->power_on) {
                pd->power_on(lcd->ld, 1);
                msleep(pd->power_on_delay);
        }

        if (!pd->reset) {
                dev_err(lcd->dev, "reset is NULL.\n");
                return -EINVAL;
        }

        pd->reset(lcd->ld);
        msleep(pd->reset_delay);

        ret = ams369fg06_ldi_init(lcd);
        if (ret) {
                dev_err(lcd->dev, "failed to initialize ldi.\n");
                return ret;
        }

        ret = ams369fg06_ldi_enable(lcd);
        if (ret) {
                dev_err(lcd->dev, "failed to enable ldi.\n");
                return ret;
        }

        /* set brightness to current value after power on or resume. */
        ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
        if (ret) {
                dev_err(lcd->dev, "lcd gamma setting failed.\n");
                return ret;
        }

        return 0;
}

static int ams369fg06_power_off(struct ams369fg06 *lcd)
{
        int ret;
        struct lcd_platform_data *pd;

        pd = lcd->lcd_pd;

        ret = ams369fg06_ldi_disable(lcd);
        if (ret) {
                dev_err(lcd->dev, "lcd setting failed.\n");
                return -EIO;
        }

        msleep(pd->power_off_delay);

        if (pd->power_on)
                pd->power_on(lcd->ld, 0);

        return 0;
}

static int ams369fg06_power(struct ams369fg06 *lcd, int power)
{
        int ret = 0;

        if (ams369fg06_power_is_on(power) &&
                !ams369fg06_power_is_on(lcd->power))
                ret = ams369fg06_power_on(lcd);
        else if (!ams369fg06_power_is_on(power) &&
                ams369fg06_power_is_on(lcd->power))
                ret = ams369fg06_power_off(lcd);

        if (!ret)
                lcd->power = power;

        return ret;
}

static int ams369fg06_get_power(struct lcd_device *ld)
{
        struct ams369fg06 *lcd = lcd_get_data(ld);

        return lcd->power;
}

static int ams369fg06_set_power(struct lcd_device *ld, int power)
{
        struct ams369fg06 *lcd = lcd_get_data(ld);

        if (power != BACKLIGHT_POWER_ON && power != BACKLIGHT_POWER_OFF &&
                power != BACKLIGHT_POWER_REDUCED) {
                dev_err(lcd->dev, "power value should be 0, 1 or 4.\n");
                return -EINVAL;
        }

        return ams369fg06_power(lcd, power);
}

static int ams369fg06_set_brightness(struct backlight_device *bd)
{
        int ret = 0;
        int brightness = bd->props.brightness;
        struct ams369fg06 *lcd = bl_get_data(bd);

        if (brightness < MIN_BRIGHTNESS ||
                brightness > bd->props.max_brightness) {
                dev_err(&bd->dev, "lcd brightness should be %d to %d.\n",
                        MIN_BRIGHTNESS, MAX_BRIGHTNESS);
                return -EINVAL;
        }

        ret = ams369fg06_gamma_ctl(lcd, bd->props.brightness);
        if (ret) {
                dev_err(&bd->dev, "lcd brightness setting failed.\n");
                return -EIO;
        }

        return ret;
}

static const struct lcd_ops ams369fg06_lcd_ops = {
        .get_power = ams369fg06_get_power,
        .set_power = ams369fg06_set_power,
};

static const struct backlight_ops ams369fg06_backlight_ops = {
        .update_status = ams369fg06_set_brightness,
};

static int ams369fg06_probe(struct spi_device *spi)
{
        int ret = 0;
        struct ams369fg06 *lcd = NULL;
        struct lcd_device *ld = NULL;
        struct backlight_device *bd = NULL;
        struct backlight_properties props;

        lcd = devm_kzalloc(&spi->dev, sizeof(struct ams369fg06), GFP_KERNEL);
        if (!lcd)
                return -ENOMEM;

        /* ams369fg06 lcd panel uses 3-wire 16bits SPI Mode. */
        spi->bits_per_word = 16;

        ret = spi_setup(spi);
        if (ret < 0) {
                dev_err(&spi->dev, "spi setup failed.\n");
                return ret;
        }

        lcd->spi = spi;
        lcd->dev = &spi->dev;

        lcd->lcd_pd = dev_get_platdata(&spi->dev);
        if (!lcd->lcd_pd) {
                dev_err(&spi->dev, "platform data is NULL\n");
                return -EINVAL;
        }

        ld = devm_lcd_device_register(&spi->dev, "ams369fg06", &spi->dev, lcd,
                                        &ams369fg06_lcd_ops);
        if (IS_ERR(ld))
                return PTR_ERR(ld);

        lcd->ld = ld;

        memset(&props, 0, sizeof(struct backlight_properties));
        props.type = BACKLIGHT_RAW;
        props.max_brightness = MAX_BRIGHTNESS;

        bd = devm_backlight_device_register(&spi->dev, "ams369fg06-bl",
                                        &spi->dev, lcd,
                                        &ams369fg06_backlight_ops, &props);
        if (IS_ERR(bd))
                return PTR_ERR(bd);

        bd->props.brightness = DEFAULT_BRIGHTNESS;
        lcd->bd = bd;

        if (!lcd->lcd_pd->lcd_enabled) {
                /*
                 * if lcd panel was off from bootloader then
                 * current lcd status is powerdown and then
                 * it enables lcd panel.
                 */
                lcd->power = BACKLIGHT_POWER_OFF;

                ams369fg06_power(lcd, BACKLIGHT_POWER_ON);
        } else {
                lcd->power = BACKLIGHT_POWER_ON;
        }

        spi_set_drvdata(spi, lcd);

        dev_info(&spi->dev, "ams369fg06 panel driver has been probed.\n");

        return 0;
}

static void ams369fg06_remove(struct spi_device *spi)
{
        struct ams369fg06 *lcd = spi_get_drvdata(spi);

        ams369fg06_power(lcd, BACKLIGHT_POWER_OFF);
}

#ifdef CONFIG_PM_SLEEP
static int ams369fg06_suspend(struct device *dev)
{
        struct ams369fg06 *lcd = dev_get_drvdata(dev);

        dev_dbg(dev, "lcd->power = %d\n", lcd->power);

        /*
         * when lcd panel is suspend, lcd panel becomes off
         * regardless of status.
         */
        return ams369fg06_power(lcd, BACKLIGHT_POWER_OFF);
}

static int ams369fg06_resume(struct device *dev)
{
        struct ams369fg06 *lcd = dev_get_drvdata(dev);

        lcd->power = BACKLIGHT_POWER_OFF;

        return ams369fg06_power(lcd, BACKLIGHT_POWER_ON);
}
#endif

static SIMPLE_DEV_PM_OPS(ams369fg06_pm_ops, ams369fg06_suspend,
                        ams369fg06_resume);

static void ams369fg06_shutdown(struct spi_device *spi)
{
        struct ams369fg06 *lcd = spi_get_drvdata(spi);

        ams369fg06_power(lcd, BACKLIGHT_POWER_OFF);
}

static struct spi_driver ams369fg06_driver = {
        .driver = {
                .name   = "ams369fg06",
                .pm     = &ams369fg06_pm_ops,
        },
        .probe          = ams369fg06_probe,
        .remove         = ams369fg06_remove,
        .shutdown       = ams369fg06_shutdown,
};

module_spi_driver(ams369fg06_driver);

MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
MODULE_DESCRIPTION("ams369fg06 LCD Driver");
MODULE_LICENSE("GPL");