// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2021 RenewOutReach
 * Copyright (C) 2021 Amarula Solutions(India)
 *
 * Author:
 * Jagan Teki <jagan@amarulasolutions.com>
 * Christopher Vollo <chris@renewoutreach.org>
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_of.h>
#include <drm/drm_print.h>
#include <drm/drm_mipi_dsi.h>

#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/media-bus-format.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>

enum cmd_registers {
        WR_INPUT_SOURCE         = 0x05, /* Write Input Source Select */
        WR_EXT_SOURCE_FMT       = 0x07, /* Write External Video Source Format */
        WR_IMAGE_CROP           = 0x10, /* Write Image Crop */
        WR_DISPLAY_SIZE         = 0x12, /* Write Display Size */
        WR_IMAGE_FREEZE         = 0x1A, /* Write Image Freeze */
        WR_INPUT_IMAGE_SIZE     = 0x2E, /* Write External Input Image Size */
        WR_RGB_LED_EN           = 0x52, /* Write RGB LED Enable */
        WR_RGB_LED_CURRENT      = 0x54, /* Write RGB LED Current */
        WR_RGB_LED_MAX_CURRENT  = 0x5C, /* Write RGB LED Max Current */
        WR_DSI_HS_CLK           = 0xBD, /* Write DSI HS Clock */
        RD_DEVICE_ID            = 0xD4, /* Read Controller Device ID */
        WR_DSI_PORT_EN          = 0xD7, /* Write DSI Port Enable */
};

enum input_source {
        INPUT_EXTERNAL_VIDEO    = 0,
        INPUT_TEST_PATTERN,
        INPUT_SPLASH_SCREEN,
};

#define DEV_ID_MASK             GENMASK(3, 0)
#define IMAGE_FREESE_EN         BIT(0)
#define DSI_PORT_EN             0
#define EXT_SOURCE_FMT_DSI      0
#define RED_LED_EN              BIT(0)
#define GREEN_LED_EN            BIT(1)
#define BLUE_LED_EN             BIT(2)
#define LED_MASK                GENMASK(2, 0)
#define MAX_BYTE_SIZE           8

struct dlpc {
        struct device           *dev;
        struct drm_bridge       bridge;
        struct drm_bridge       *next_bridge;
        struct device_node      *host_node;
        struct mipi_dsi_device  *dsi;
        struct drm_display_mode mode;

        struct gpio_desc        *enable_gpio;
        struct regulator        *vcc_intf;
        struct regulator        *vcc_flsh;
        struct regmap           *regmap;
        unsigned int            dsi_lanes;
};

static inline struct dlpc *bridge_to_dlpc(struct drm_bridge *bridge)
{
        return container_of(bridge, struct dlpc, bridge);
}

static bool dlpc_writeable_noinc_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case WR_IMAGE_CROP:
        case WR_DISPLAY_SIZE:
        case WR_INPUT_IMAGE_SIZE:
        case WR_DSI_HS_CLK:
                return true;
        default:
                return false;
        }
}

static const struct regmap_range dlpc_volatile_ranges[] = {
        { .range_min = 0x10, .range_max = 0xBF },
};

static const struct regmap_access_table dlpc_volatile_table = {
        .yes_ranges = dlpc_volatile_ranges,
        .n_yes_ranges = ARRAY_SIZE(dlpc_volatile_ranges),
};

static const struct regmap_config dlpc_regmap_config = {
        .reg_bits               = 8,
        .val_bits               = 8,
        .max_register           = WR_DSI_PORT_EN,
        .writeable_noinc_reg    = dlpc_writeable_noinc_reg,
        .volatile_table         = &dlpc_volatile_table,
        .cache_type             = REGCACHE_MAPLE,
        .name                   = "dlpc3433",
};

static void dlpc_atomic_enable(struct drm_bridge *bridge,
                               struct drm_atomic_commit *state)
{
        struct dlpc *dlpc = bridge_to_dlpc(bridge);
        struct device *dev = dlpc->dev;
        struct drm_display_mode *mode = &dlpc->mode;
        struct regmap *regmap = dlpc->regmap;
        char buf[MAX_BYTE_SIZE];
        unsigned int devid;

        regmap_read(regmap, RD_DEVICE_ID, &devid);
        devid &= DEV_ID_MASK;

        DRM_DEV_DEBUG(dev, "DLPC3433 device id: 0x%02x\n", devid);

        if (devid != 0x01) {
                DRM_DEV_ERROR(dev, "Unsupported DLPC device id: 0x%02x\n", devid);
                return;
        }

        /* disable image freeze */
        regmap_write(regmap, WR_IMAGE_FREEZE, IMAGE_FREESE_EN);

        /* enable DSI port */
        regmap_write(regmap, WR_DSI_PORT_EN, DSI_PORT_EN);

        memset(buf, 0, MAX_BYTE_SIZE);

        /* set image crop */
        buf[4] = mode->hdisplay & 0xff;
        buf[5] = (mode->hdisplay & 0xff00) >> 8;
        buf[6] = mode->vdisplay & 0xff;
        buf[7] = (mode->vdisplay & 0xff00) >> 8;
        regmap_noinc_write(regmap, WR_IMAGE_CROP, buf, MAX_BYTE_SIZE);

        /* set display size */
        buf[4] = mode->hdisplay & 0xff;
        buf[5] = (mode->hdisplay & 0xff00) >> 8;
        buf[6] = mode->vdisplay & 0xff;
        buf[7] = (mode->vdisplay & 0xff00) >> 8;
        regmap_noinc_write(regmap, WR_DISPLAY_SIZE, buf, MAX_BYTE_SIZE);

        /* set input image size */
        buf[0] = mode->hdisplay & 0xff;
        buf[1] = (mode->hdisplay & 0xff00) >> 8;
        buf[2] = mode->vdisplay & 0xff;
        buf[3] = (mode->vdisplay & 0xff00) >> 8;
        regmap_noinc_write(regmap, WR_INPUT_IMAGE_SIZE, buf, 4);

        /* set external video port */
        regmap_write(regmap, WR_INPUT_SOURCE, INPUT_EXTERNAL_VIDEO);

        /* set external video format select as DSI */
        regmap_write(regmap, WR_EXT_SOURCE_FMT, EXT_SOURCE_FMT_DSI);

        /* disable image freeze */
        regmap_write(regmap, WR_IMAGE_FREEZE, 0x00);

        /* enable RGB led */
        regmap_update_bits(regmap, WR_RGB_LED_EN, LED_MASK,
                           RED_LED_EN | GREEN_LED_EN | BLUE_LED_EN);

        msleep(10);
}

static void dlpc_atomic_pre_enable(struct drm_bridge *bridge,
                                   struct drm_atomic_commit *state)
{
        struct dlpc *dlpc = bridge_to_dlpc(bridge);
        int ret;

        gpiod_set_value(dlpc->enable_gpio, 1);

        msleep(500);

        ret = regulator_enable(dlpc->vcc_intf);
        if (ret)
                DRM_DEV_ERROR(dlpc->dev,
                              "failed to enable VCC_INTF regulator: %d\n", ret);

        ret = regulator_enable(dlpc->vcc_flsh);
        if (ret)
                DRM_DEV_ERROR(dlpc->dev,
                              "failed to enable VCC_FLSH regulator: %d\n", ret);

        msleep(10);
}

static void dlpc_atomic_post_disable(struct drm_bridge *bridge,
                                     struct drm_atomic_commit *state)
{
        struct dlpc *dlpc = bridge_to_dlpc(bridge);

        regulator_disable(dlpc->vcc_flsh);
        regulator_disable(dlpc->vcc_intf);

        msleep(10);

        gpiod_set_value(dlpc->enable_gpio, 0);

        msleep(500);
}

#define MAX_INPUT_SEL_FORMATS   1

static u32 *
dlpc_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
                               struct drm_bridge_state *bridge_state,
                               struct drm_crtc_state *crtc_state,
                               struct drm_connector_state *conn_state,
                               u32 output_fmt,
                               unsigned int *num_input_fmts)
{
        u32 *input_fmts;

        *num_input_fmts = 0;

        input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
                             GFP_KERNEL);
        if (!input_fmts)
                return NULL;

        /* This is the DSI-end bus format */
        input_fmts[0] = MEDIA_BUS_FMT_RGB888_1X24;
        *num_input_fmts = 1;

        return input_fmts;
}

static void dlpc_mode_set(struct drm_bridge *bridge,
                          const struct drm_display_mode *mode,
                          const struct drm_display_mode *adjusted_mode)
{
        struct dlpc *dlpc = bridge_to_dlpc(bridge);

        drm_mode_copy(&dlpc->mode, adjusted_mode);
}

static int dlpc_attach(struct drm_bridge *bridge, struct drm_encoder *encoder,
                       enum drm_bridge_attach_flags flags)
{
        struct dlpc *dlpc = bridge_to_dlpc(bridge);

        return drm_bridge_attach(encoder, dlpc->next_bridge, bridge, flags);
}

static const struct drm_bridge_funcs dlpc_bridge_funcs = {
        .atomic_duplicate_state         = drm_atomic_helper_bridge_duplicate_state,
        .atomic_destroy_state           = drm_atomic_helper_bridge_destroy_state,
        .atomic_get_input_bus_fmts      = dlpc_atomic_get_input_bus_fmts,
        .atomic_reset                   = drm_atomic_helper_bridge_reset,
        .atomic_pre_enable              = dlpc_atomic_pre_enable,
        .atomic_enable                  = dlpc_atomic_enable,
        .atomic_post_disable            = dlpc_atomic_post_disable,
        .mode_set                       = dlpc_mode_set,
        .attach                         = dlpc_attach,
};

static int dlpc3433_parse_dt(struct dlpc *dlpc)
{
        struct device *dev = dlpc->dev;
        struct device_node *endpoint;
        int ret;

        dlpc->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
        if (IS_ERR(dlpc->enable_gpio))
                return PTR_ERR(dlpc->enable_gpio);

        dlpc->vcc_intf = devm_regulator_get(dlpc->dev, "vcc_intf");
        if (IS_ERR(dlpc->vcc_intf))
                return dev_err_probe(dev, PTR_ERR(dlpc->vcc_intf),
                                     "failed to get VCC_INTF supply\n");

        dlpc->vcc_flsh = devm_regulator_get(dlpc->dev, "vcc_flsh");
        if (IS_ERR(dlpc->vcc_flsh))
                return dev_err_probe(dev, PTR_ERR(dlpc->vcc_flsh),
                                     "failed to get VCC_FLSH supply\n");

        dlpc->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
        if (IS_ERR(dlpc->next_bridge))
                return PTR_ERR(dlpc->next_bridge);

        endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);
        dlpc->dsi_lanes = of_property_count_u32_elems(endpoint, "data-lanes");
        if (dlpc->dsi_lanes < 0 || dlpc->dsi_lanes > 4) {
                ret = -EINVAL;
                goto err_put_endpoint;
        }

        dlpc->host_node = of_graph_get_remote_port_parent(endpoint);
        if (!dlpc->host_node) {
                ret = -ENODEV;
                goto err_put_host;
        }

        of_node_put(endpoint);

        return 0;

err_put_host:
        of_node_put(dlpc->host_node);
err_put_endpoint:
        of_node_put(endpoint);
        return ret;
}

static int dlpc_host_attach(struct dlpc *dlpc)
{
        struct device *dev = dlpc->dev;
        struct mipi_dsi_host *host;
        struct mipi_dsi_device_info info = {
                .type = "dlpc3433",
                .channel = 0,
                .node = NULL,
        };
        int ret;

        host = of_find_mipi_dsi_host_by_node(dlpc->host_node);
        if (!host)
                return dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n");

        dlpc->dsi = mipi_dsi_device_register_full(host, &info);
        if (IS_ERR(dlpc->dsi)) {
                DRM_DEV_ERROR(dev, "failed to create dsi device\n");
                return PTR_ERR(dlpc->dsi);
        }

        dlpc->dsi->mode_flags = MIPI_DSI_MODE_VIDEO_BURST;
        dlpc->dsi->format = MIPI_DSI_FMT_RGB565;
        dlpc->dsi->lanes = dlpc->dsi_lanes;

        ret = devm_mipi_dsi_attach(dev, dlpc->dsi);
        if (ret)
                DRM_DEV_ERROR(dev, "failed to attach dsi host\n");

        return ret;
}

static int dlpc3433_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct dlpc *dlpc;
        int ret;

        dlpc = devm_drm_bridge_alloc(dev, struct dlpc, bridge,
                                     &dlpc_bridge_funcs);
        if (IS_ERR(dlpc))
                return PTR_ERR(dlpc);

        dlpc->dev = dev;

        dlpc->regmap = devm_regmap_init_i2c(client, &dlpc_regmap_config);
        if (IS_ERR(dlpc->regmap))
                return PTR_ERR(dlpc->regmap);

        ret = dlpc3433_parse_dt(dlpc);
        if (ret)
                return ret;

        dev_set_drvdata(dev, dlpc);
        i2c_set_clientdata(client, dlpc);

        dlpc->bridge.of_node = dev->of_node;
        drm_bridge_add(&dlpc->bridge);

        ret = dlpc_host_attach(dlpc);
        if (ret)
                goto err_remove_bridge;

        return 0;

err_remove_bridge:
        drm_bridge_remove(&dlpc->bridge);
        return ret;
}

static void dlpc3433_remove(struct i2c_client *client)
{
        struct dlpc *dlpc = i2c_get_clientdata(client);

        drm_bridge_remove(&dlpc->bridge);
        of_node_put(dlpc->host_node);
}

static const struct i2c_device_id dlpc3433_id[] = {
        { "ti,dlpc3433" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(i2c, dlpc3433_id);

static const struct of_device_id dlpc3433_match_table[] = {
        { .compatible = "ti,dlpc3433" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, dlpc3433_match_table);

static struct i2c_driver dlpc3433_driver = {
        .probe = dlpc3433_probe,
        .remove = dlpc3433_remove,
        .id_table = dlpc3433_id,
        .driver = {
                .name = "ti-dlpc3433",
                .of_match_table = dlpc3433_match_table,
        },
};
module_i2c_driver(dlpc3433_driver);

MODULE_AUTHOR("Jagan Teki <jagan@amarulasolutions.com>");
MODULE_AUTHOR("Christopher Vollo <chris@renewoutreach.org>");
MODULE_DESCRIPTION("TI DLPC3433 MIPI DSI Display Controller Bridge");
MODULE_LICENSE("GPL");