// SPDX-License-Identifier: GPL-2.0+
/*
 * MIPI-DSI Novatek NT35560-based panel controller.
 *
 * Supported panels include:
 * Sony ACX424AKM - a 480x854 AMOLED DSI panel
 * Sony ACX424AKP - a 480x864 AMOLED DSI panel
 *
 * Copyright (C) Linaro Ltd. 2019-2021
 * Author: Linus Walleij
 * Based on code and know-how from Marcus Lorentzon
 * Copyright (C) ST-Ericsson SA 2010
 * Based on code and know-how from Johan Olson and Joakim Wesslen
 * Copyright (C) Sony Ericsson Mobile Communications 2010
 */
#include <linux/backlight.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regulator/consumer.h>

#include <video/mipi_display.h>

#include <drm/drm_mipi_dsi.h>
#include <drm/drm_modes.h>
#include <drm/drm_panel.h>

#define NT35560_DCS_READ_ID1            0xDA
#define NT35560_DCS_READ_ID2            0xDB
#define NT35560_DCS_READ_ID3            0xDC
#define NT35560_DCS_SET_MDDI            0xAE

/*
 * Sony seems to use vendor ID 0x81
 */
#define DISPLAY_SONY_ACX424AKP_ID1      0x8103
#define DISPLAY_SONY_ACX424AKP_ID2      0x811a
#define DISPLAY_SONY_ACX424AKP_ID3      0x811b
/*
 * The fourth ID looks like a bug, vendor IDs begin at 0x80
 * and panel 00 ... seems like default values.
 */
#define DISPLAY_SONY_ACX424AKP_ID4      0x8000

struct nt35560_config {
        const struct drm_display_mode *vid_mode;
        const struct drm_display_mode *cmd_mode;
};

struct nt35560 {
        const struct nt35560_config *conf;
        struct drm_panel panel;
        struct device *dev;
        struct regulator *supply;
        struct gpio_desc *reset_gpio;
        bool video_mode;
};

static const struct drm_display_mode sony_acx424akp_vid_mode = {
        .clock = 27234,
        .hdisplay = 480,
        .hsync_start = 480 + 15,
        .hsync_end = 480 + 15 + 0,
        .htotal = 480 + 15 + 0 + 15,
        .vdisplay = 864,
        .vsync_start = 864 + 14,
        .vsync_end = 864 + 14 + 1,
        .vtotal = 864 + 14 + 1 + 11,
        .width_mm = 48,
        .height_mm = 84,
        .flags = DRM_MODE_FLAG_PVSYNC,
};

/*
 * The timings are not very helpful as the display is used in
 * command mode using the maximum HS frequency.
 */
static const struct drm_display_mode sony_acx424akp_cmd_mode = {
        .clock = 35478,
        .hdisplay = 480,
        .hsync_start = 480 + 154,
        .hsync_end = 480 + 154 + 16,
        .htotal = 480 + 154 + 16 + 32,
        .vdisplay = 864,
        .vsync_start = 864 + 1,
        .vsync_end = 864 + 1 + 1,
        .vtotal = 864 + 1 + 1 + 1,
        /*
         * Some desired refresh rate, experiments at the maximum "pixel"
         * clock speed (HS clock 420 MHz) yields around 117Hz.
         */
        .width_mm = 48,
        .height_mm = 84,
};

static const struct nt35560_config sony_acx424akp_data = {
        .vid_mode = &sony_acx424akp_vid_mode,
        .cmd_mode = &sony_acx424akp_cmd_mode,
};

static const struct drm_display_mode sony_acx424akm_vid_mode = {
        .clock = 27234,
        .hdisplay = 480,
        .hsync_start = 480 + 15,
        .hsync_end = 480 + 15 + 0,
        .htotal = 480 + 15 + 0 + 15,
        .vdisplay = 854,
        .vsync_start = 854 + 14,
        .vsync_end = 854 + 14 + 1,
        .vtotal = 854 + 14 + 1 + 11,
        .width_mm = 46,
        .height_mm = 82,
        .flags = DRM_MODE_FLAG_PVSYNC,
};

/*
 * The timings are not very helpful as the display is used in
 * command mode using the maximum HS frequency.
 */
static const struct drm_display_mode sony_acx424akm_cmd_mode = {
        .clock = 35478,
        .hdisplay = 480,
        .hsync_start = 480 + 154,
        .hsync_end = 480 + 154 + 16,
        .htotal = 480 + 154 + 16 + 32,
        .vdisplay = 854,
        .vsync_start = 854 + 1,
        .vsync_end = 854 + 1 + 1,
        .vtotal = 854 + 1 + 1 + 1,
        .width_mm = 46,
        .height_mm = 82,
};

static const struct nt35560_config sony_acx424akm_data = {
        .vid_mode = &sony_acx424akm_vid_mode,
        .cmd_mode = &sony_acx424akm_cmd_mode,
};

static inline struct nt35560 *panel_to_nt35560(struct drm_panel *panel)
{
        return container_of(panel, struct nt35560, panel);
}

#define FOSC                    20 /* 20Mhz */
#define SCALE_FACTOR_NS_DIV_MHZ 1000

static int nt35560_set_brightness(struct backlight_device *bl)
{
        struct nt35560 *nt = bl_get_data(bl);
        struct mipi_dsi_multi_context dsi_ctx = {
                .dsi = to_mipi_dsi_device(nt->dev)
        };
        int duty_ns = bl->props.brightness;
        int period_ns = 1023;
        u8 pwm_ratio;
        u8 pwm_div;

        if (backlight_is_blank(bl)) {
                /* Disable backlight */
                mipi_dsi_dcs_write_seq_multi(&dsi_ctx,
                                             MIPI_DCS_WRITE_CONTROL_DISPLAY,
                                             0x00);
                return dsi_ctx.accum_err;
        }

        /* Calculate the PWM duty cycle in n/256's */
        pwm_ratio = max(((duty_ns * 256) / period_ns) - 1, 1);
        pwm_div = max(1,
                      ((FOSC * period_ns) / 256) /
                      SCALE_FACTOR_NS_DIV_MHZ);

        /* Set up PWM dutycycle ONE byte (differs from the standard) */
        dev_dbg(nt->dev, "calculated duty cycle %02x\n", pwm_ratio);

        /*
         * Sequence to write PWMDIV:
         *      address         data
         *      0xF3            0xAA   CMD2 Unlock
         *      0x00            0x01   Enter CMD2 page 0
         *      0X7D            0x01   No reload MTP of CMD2 P1
         *      0x22            PWMDIV
         *      0x7F            0xAA   CMD2 page 1 lock
         */
        mipi_dsi_dcs_write_var_seq_multi(&dsi_ctx,
                                         MIPI_DCS_SET_DISPLAY_BRIGHTNESS,
                                         pwm_ratio);

        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf3, 0xaa);
        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x00, 0x01);
        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x7d, 0x01);

        mipi_dsi_dcs_write_var_seq_multi(&dsi_ctx, 0x22, pwm_div);

        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x7f, 0xaa);

        /* Enable backlight */
        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,
                                     0x24);

        return dsi_ctx.accum_err;
}

static const struct backlight_ops nt35560_bl_ops = {
        .update_status = nt35560_set_brightness,
};

static const struct backlight_properties nt35560_bl_props = {
        .type = BACKLIGHT_RAW,
        .brightness = 512,
        .max_brightness = 1023,
};

static void nt35560_read_id(struct mipi_dsi_multi_context *dsi_ctx)
{
        struct device *dev = &dsi_ctx->dsi->dev;
        u8 vendor, version, panel;
        u16 val;

        mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID1, &vendor, 1);
        mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID2, &version, 1);
        mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID3, &panel, 1);

        if (dsi_ctx->accum_err < 0)
                return;

        if (vendor == 0x00) {
                dev_err(dev, "device vendor ID is zero\n");
                dsi_ctx->accum_err = -ENODEV;
                return;
        }

        val = (vendor << 8) | panel;
        switch (val) {
        case DISPLAY_SONY_ACX424AKP_ID1:
        case DISPLAY_SONY_ACX424AKP_ID2:
        case DISPLAY_SONY_ACX424AKP_ID3:
        case DISPLAY_SONY_ACX424AKP_ID4:
                dev_info(dev,
                         "MTP vendor: %02x, version: %02x, panel: %02x\n",
                         vendor, version, panel);
                break;
        default:
                dev_info(dev,
                         "unknown vendor: %02x, version: %02x, panel: %02x\n",
                         vendor, version, panel);
                break;
        }
}

static int nt35560_power_on(struct nt35560 *nt)
{
        int ret;

        ret = regulator_enable(nt->supply);
        if (ret) {
                dev_err(nt->dev, "failed to enable supply (%d)\n", ret);
                return ret;
        }

        /* Assert RESET */
        gpiod_set_value_cansleep(nt->reset_gpio, 1);
        udelay(20);
        /* De-assert RESET */
        gpiod_set_value_cansleep(nt->reset_gpio, 0);
        usleep_range(11000, 20000);

        return 0;
}

static void nt35560_power_off(struct nt35560 *nt)
{
        /* Assert RESET */
        gpiod_set_value_cansleep(nt->reset_gpio, 1);
        usleep_range(11000, 20000);

        regulator_disable(nt->supply);
}

static int nt35560_prepare(struct drm_panel *panel)
{
        struct nt35560 *nt = panel_to_nt35560(panel);
        struct mipi_dsi_multi_context dsi_ctx = {
                .dsi = to_mipi_dsi_device(nt->dev)
        };
        int ret;

        ret = nt35560_power_on(nt);
        if (ret)
                return ret;

        nt35560_read_id(&dsi_ctx);

        /* Enable tearing mode: send TE (tearing effect) at VBLANK */
        mipi_dsi_dcs_set_tear_on_multi(&dsi_ctx,
                                       MIPI_DSI_DCS_TEAR_MODE_VBLANK);

        /*
         * Set MDDI
         *
         * This presumably deactivates the Qualcomm MDDI interface and
         * selects DSI, similar code is found in other drivers such as the
         * Sharp LS043T1LE01.
         */
        mipi_dsi_dcs_write_seq_multi(&dsi_ctx, NT35560_DCS_SET_MDDI, 3);

        mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
        mipi_dsi_msleep(&dsi_ctx, 140);

        mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
        if (nt->video_mode) {
                mipi_dsi_turn_on_peripheral_multi(&dsi_ctx);
        }

        if (dsi_ctx.accum_err < 0)
                nt35560_power_off(nt);
        return dsi_ctx.accum_err;
}

static int nt35560_unprepare(struct drm_panel *panel)
{
        struct nt35560 *nt = panel_to_nt35560(panel);
        struct mipi_dsi_multi_context dsi_ctx = {
                .dsi = to_mipi_dsi_device(nt->dev)
        };

        mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
        mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);

        if (dsi_ctx.accum_err < 0)
                return dsi_ctx.accum_err;

        msleep(85);

        nt35560_power_off(nt);

        return 0;
}


static int nt35560_get_modes(struct drm_panel *panel,
                             struct drm_connector *connector)
{
        struct nt35560 *nt = panel_to_nt35560(panel);
        const struct nt35560_config *conf = nt->conf;
        struct drm_display_mode *mode;

        if (nt->video_mode)
                mode = drm_mode_duplicate(connector->dev,
                                          conf->vid_mode);
        else
                mode = drm_mode_duplicate(connector->dev,
                                          conf->cmd_mode);
        if (!mode) {
                dev_err(panel->dev, "bad mode or failed to add mode\n");
                return -EINVAL;
        }
        drm_mode_set_name(mode);
        mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;

        connector->display_info.width_mm = mode->width_mm;
        connector->display_info.height_mm = mode->height_mm;

        drm_mode_probed_add(connector, mode);

        return 1; /* Number of modes */
}

static const struct drm_panel_funcs nt35560_drm_funcs = {
        .unprepare = nt35560_unprepare,
        .prepare = nt35560_prepare,
        .get_modes = nt35560_get_modes,
};

static int nt35560_probe(struct mipi_dsi_device *dsi)
{
        struct device *dev = &dsi->dev;
        struct nt35560 *nt;
        int ret;

        nt = devm_drm_panel_alloc(dev, struct nt35560, panel,
                                  &nt35560_drm_funcs,
                                  DRM_MODE_CONNECTOR_DSI);
        if (IS_ERR(nt))
                return PTR_ERR(nt);

        nt->video_mode = of_property_read_bool(dev->of_node,
                                                "enforce-video-mode");

        mipi_dsi_set_drvdata(dsi, nt);
        nt->dev = dev;

        nt->conf = of_device_get_match_data(dev);
        if (!nt->conf) {
                dev_err(dev, "missing device configuration\n");
                return -ENODEV;
        }

        dsi->lanes = 2;
        dsi->format = MIPI_DSI_FMT_RGB888;
        /*
         * FIXME: these come from the ST-Ericsson vendor driver for the
         * HREF520 and seems to reflect limitations in the PLLs on that
         * platform, if you have the datasheet, please cross-check the
         * actual max rates.
         */
        dsi->lp_rate = 19200000;
        dsi->hs_rate = 420160000;

        if (nt->video_mode)
                /* Burst mode using event for sync */
                dsi->mode_flags =
                        MIPI_DSI_MODE_VIDEO |
                        MIPI_DSI_MODE_VIDEO_BURST;
        else
                dsi->mode_flags =
                        MIPI_DSI_CLOCK_NON_CONTINUOUS;

        nt->supply = devm_regulator_get(dev, "vddi");
        if (IS_ERR(nt->supply))
                return PTR_ERR(nt->supply);

        /* This asserts RESET by default */
        nt->reset_gpio = devm_gpiod_get_optional(dev, "reset",
                                                 GPIOD_OUT_HIGH);
        if (IS_ERR(nt->reset_gpio))
                return dev_err_probe(dev, PTR_ERR(nt->reset_gpio),
                                     "failed to request GPIO\n");

        nt->panel.backlight = devm_backlight_device_register(dev, "nt35560", dev, nt,
                                        &nt35560_bl_ops, &nt35560_bl_props);
        if (IS_ERR(nt->panel.backlight))
                return dev_err_probe(dev, PTR_ERR(nt->panel.backlight),
                                     "failed to register backlight device\n");

        drm_panel_add(&nt->panel);

        ret = mipi_dsi_attach(dsi);
        if (ret < 0) {
                drm_panel_remove(&nt->panel);
                return ret;
        }

        return 0;
}

static void nt35560_remove(struct mipi_dsi_device *dsi)
{
        struct nt35560 *nt = mipi_dsi_get_drvdata(dsi);

        mipi_dsi_detach(dsi);
        drm_panel_remove(&nt->panel);
}

static const struct of_device_id nt35560_of_match[] = {
        {
                .compatible = "sony,acx424akp",
                .data = &sony_acx424akp_data,
        },
        {
                .compatible = "sony,acx424akm",
                .data = &sony_acx424akm_data,
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, nt35560_of_match);

static struct mipi_dsi_driver nt35560_driver = {
        .probe = nt35560_probe,
        .remove = nt35560_remove,
        .driver = {
                .name = "panel-novatek-nt35560",
                .of_match_table = nt35560_of_match,
        },
};
module_mipi_dsi_driver(nt35560_driver);

MODULE_AUTHOR("Linus Wallei <linus.walleij@linaro.org>");
MODULE_DESCRIPTION("MIPI-DSI Novatek NT35560 Panel Driver");
MODULE_LICENSE("GPL v2");