root/drivers/gpu/drm/sprd/sprd_dsi.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 Unisoc Inc.
 */

#include <linux/component.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <video/mipi_display.h>

#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_of.h>
#include <drm/drm_probe_helper.h>

#include "sprd_drm.h"
#include "sprd_dpu.h"
#include "sprd_dsi.h"

#define SOFT_RESET 0x04
#define MASK_PROTOCOL_INT 0x0C
#define MASK_INTERNAL_INT 0x14
#define DSI_MODE_CFG 0x18

#define VIRTUAL_CHANNEL_ID 0x1C
#define GEN_RX_VCID GENMASK(1, 0)
#define VIDEO_PKT_VCID GENMASK(3, 2)

#define DPI_VIDEO_FORMAT 0x20
#define DPI_VIDEO_MODE_FORMAT GENMASK(5, 0)
#define LOOSELY18_EN BIT(6)

#define VIDEO_PKT_CONFIG 0x24
#define VIDEO_PKT_SIZE GENMASK(15, 0)
#define VIDEO_LINE_CHUNK_NUM GENMASK(31, 16)

#define VIDEO_LINE_HBLK_TIME 0x28
#define VIDEO_LINE_HBP_TIME GENMASK(15, 0)
#define VIDEO_LINE_HSA_TIME GENMASK(31, 16)

#define VIDEO_LINE_TIME 0x2C

#define VIDEO_VBLK_LINES 0x30
#define VFP_LINES GENMASK(9, 0)
#define VBP_LINES GENMASK(19, 10)
#define VSA_LINES GENMASK(29, 20)

#define VIDEO_VACTIVE_LINES 0x34

#define VID_MODE_CFG 0x38
#define VID_MODE_TYPE GENMASK(1, 0)
#define LP_VSA_EN BIT(8)
#define LP_VBP_EN BIT(9)
#define LP_VFP_EN BIT(10)
#define LP_VACT_EN BIT(11)
#define LP_HBP_EN BIT(12)
#define LP_HFP_EN BIT(13)
#define FRAME_BTA_ACK_EN BIT(14)

#define TIMEOUT_CNT_CLK_CONFIG 0x40
#define HTX_TO_CONFIG 0x44
#define LRX_H_TO_CONFIG 0x48

#define TX_ESC_CLK_CONFIG 0x5C

#define CMD_MODE_CFG 0x68
#define TEAR_FX_EN BIT(0)

#define GEN_HDR 0x6C
#define GEN_DT GENMASK(5, 0)
#define GEN_VC GENMASK(7, 6)

#define GEN_PLD_DATA 0x70

#define PHY_CLK_LANE_LP_CTRL 0x74
#define PHY_CLKLANE_TX_REQ_HS BIT(0)
#define AUTO_CLKLANE_CTRL_EN BIT(1)

#define PHY_INTERFACE_CTRL 0x78
#define RF_PHY_SHUTDOWN BIT(0)
#define RF_PHY_RESET_N BIT(1)
#define RF_PHY_CLK_EN BIT(2)

#define CMD_MODE_STATUS 0x98
#define GEN_CMD_RDATA_FIFO_EMPTY BIT(1)
#define GEN_CMD_WDATA_FIFO_EMPTY BIT(3)
#define GEN_CMD_CMD_FIFO_EMPTY BIT(5)
#define GEN_CMD_RDCMD_DONE BIT(7)

#define PHY_STATUS 0x9C
#define PHY_LOCK BIT(1)

#define PHY_MIN_STOP_TIME 0xA0
#define PHY_LANE_NUM_CONFIG 0xA4

#define PHY_CLKLANE_TIME_CONFIG 0xA8
#define PHY_CLKLANE_LP_TO_HS_TIME GENMASK(15, 0)
#define PHY_CLKLANE_HS_TO_LP_TIME GENMASK(31, 16)

#define PHY_DATALANE_TIME_CONFIG 0xAC
#define PHY_DATALANE_LP_TO_HS_TIME GENMASK(15, 0)
#define PHY_DATALANE_HS_TO_LP_TIME GENMASK(31, 16)

#define MAX_READ_TIME 0xB0

#define RX_PKT_CHECK_CONFIG 0xB4
#define RX_PKT_ECC_EN BIT(0)
#define RX_PKT_CRC_EN BIT(1)

#define TA_EN 0xB8

#define EOTP_EN 0xBC
#define TX_EOTP_EN BIT(0)
#define RX_EOTP_EN BIT(1)

#define VIDEO_NULLPKT_SIZE 0xC0
#define DCS_WM_PKT_SIZE 0xC4

#define VIDEO_SIG_DELAY_CONFIG 0xD0
#define VIDEO_SIG_DELAY GENMASK(23, 0)

#define PHY_TST_CTRL0 0xF0
#define PHY_TESTCLR BIT(0)
#define PHY_TESTCLK BIT(1)

#define PHY_TST_CTRL1 0xF4
#define PHY_TESTDIN GENMASK(7, 0)
#define PHY_TESTDOUT GENMASK(15, 8)
#define PHY_TESTEN BIT(16)

#define host_to_dsi(host) \
        container_of(host, struct sprd_dsi, host)

static inline u32
dsi_reg_rd(struct dsi_context *ctx, u32 offset, u32 mask,
           u32 shift)
{
        return (readl(ctx->base + offset) & mask) >> shift;
}

static inline void
dsi_reg_wr(struct dsi_context *ctx, u32 offset, u32 mask,
           u32 shift, u32 val)
{
        u32 ret;

        ret = readl(ctx->base + offset);
        ret &= ~mask;
        ret |= (val << shift) & mask;
        writel(ret, ctx->base + offset);
}

static inline void
dsi_reg_up(struct dsi_context *ctx, u32 offset, u32 mask,
           u32 val)
{
        u32 ret = readl(ctx->base + offset);

        writel((ret & ~mask) | (val & mask), ctx->base + offset);
}

static int regmap_tst_io_write(void *context, u32 reg, u32 val)
{
        struct sprd_dsi *dsi = context;
        struct dsi_context *ctx = &dsi->ctx;

        if (val > 0xff || reg > 0xff)
                return -EINVAL;

        drm_dbg(dsi->drm, "reg = 0x%02x, val = 0x%02x\n", reg, val);

        dsi_reg_up(ctx, PHY_TST_CTRL1, PHY_TESTEN, PHY_TESTEN);
        dsi_reg_wr(ctx, PHY_TST_CTRL1, PHY_TESTDIN, 0, reg);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, PHY_TESTCLK);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, 0);
        dsi_reg_up(ctx, PHY_TST_CTRL1, PHY_TESTEN, 0);
        dsi_reg_wr(ctx, PHY_TST_CTRL1, PHY_TESTDIN, 0, val);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, PHY_TESTCLK);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, 0);

        return 0;
}

static int regmap_tst_io_read(void *context, u32 reg, u32 *val)
{
        struct sprd_dsi *dsi = context;
        struct dsi_context *ctx = &dsi->ctx;
        int ret;

        if (reg > 0xff)
                return -EINVAL;

        dsi_reg_up(ctx, PHY_TST_CTRL1, PHY_TESTEN, PHY_TESTEN);
        dsi_reg_wr(ctx, PHY_TST_CTRL1, PHY_TESTDIN, 0, reg);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, PHY_TESTCLK);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLK, 0);
        dsi_reg_up(ctx, PHY_TST_CTRL1, PHY_TESTEN, 0);

        udelay(1);

        ret = dsi_reg_rd(ctx, PHY_TST_CTRL1, PHY_TESTDOUT, 8);
        if (ret < 0)
                return ret;

        *val = ret;

        drm_dbg(dsi->drm, "reg = 0x%02x, val = 0x%02x\n", reg, *val);
        return 0;
}

static const struct regmap_bus regmap_tst_io = {
        .reg_write = regmap_tst_io_write,
        .reg_read = regmap_tst_io_read,
};

static const struct regmap_config byte_config = {
        .reg_bits = 8,
        .val_bits = 8,
};

static int dphy_wait_pll_locked(struct dsi_context *ctx)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        int i;

        for (i = 0; i < 50000; i++) {
                if (dsi_reg_rd(ctx, PHY_STATUS, PHY_LOCK, 1))
                        return 0;
                udelay(3);
        }

        drm_err(dsi->drm, "dphy pll can not be locked\n");
        return -ETIMEDOUT;
}

static int dsi_wait_tx_payload_fifo_empty(struct dsi_context *ctx)
{
        int i;

        for (i = 0; i < 5000; i++) {
                if (dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_WDATA_FIFO_EMPTY, 3))
                        return 0;
                udelay(1);
        }

        return -ETIMEDOUT;
}

static int dsi_wait_tx_cmd_fifo_empty(struct dsi_context *ctx)
{
        int i;

        for (i = 0; i < 5000; i++) {
                if (dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_CMD_FIFO_EMPTY, 5))
                        return 0;
                udelay(1);
        }

        return -ETIMEDOUT;
}

static int dsi_wait_rd_resp_completed(struct dsi_context *ctx)
{
        int i;

        for (i = 0; i < 10000; i++) {
                if (dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_RDCMD_DONE, 7))
                        return 0;
                udelay(10);
        }

        return -ETIMEDOUT;
}

static u16 calc_bytes_per_pixel_x100(int coding)
{
        u16 bpp_x100;

        switch (coding) {
        case COLOR_CODE_16BIT_CONFIG1:
        case COLOR_CODE_16BIT_CONFIG2:
        case COLOR_CODE_16BIT_CONFIG3:
                bpp_x100 = 200;
                break;
        case COLOR_CODE_18BIT_CONFIG1:
        case COLOR_CODE_18BIT_CONFIG2:
                bpp_x100 = 225;
                break;
        case COLOR_CODE_24BIT:
                bpp_x100 = 300;
                break;
        case COLOR_CODE_COMPRESSTION:
                bpp_x100 = 100;
                break;
        case COLOR_CODE_20BIT_YCC422_LOOSELY:
                bpp_x100 = 250;
                break;
        case COLOR_CODE_24BIT_YCC422:
                bpp_x100 = 300;
                break;
        case COLOR_CODE_16BIT_YCC422:
                bpp_x100 = 200;
                break;
        case COLOR_CODE_30BIT:
                bpp_x100 = 375;
                break;
        case COLOR_CODE_36BIT:
                bpp_x100 = 450;
                break;
        case COLOR_CODE_12BIT_YCC420:
                bpp_x100 = 150;
                break;
        default:
                DRM_ERROR("invalid color coding");
                bpp_x100 = 0;
                break;
        }

        return bpp_x100;
}

static u8 calc_video_size_step(int coding)
{
        u8 video_size_step;

        switch (coding) {
        case COLOR_CODE_16BIT_CONFIG1:
        case COLOR_CODE_16BIT_CONFIG2:
        case COLOR_CODE_16BIT_CONFIG3:
        case COLOR_CODE_18BIT_CONFIG1:
        case COLOR_CODE_18BIT_CONFIG2:
        case COLOR_CODE_24BIT:
        case COLOR_CODE_COMPRESSTION:
                return video_size_step = 1;
        case COLOR_CODE_20BIT_YCC422_LOOSELY:
        case COLOR_CODE_24BIT_YCC422:
        case COLOR_CODE_16BIT_YCC422:
        case COLOR_CODE_30BIT:
        case COLOR_CODE_36BIT:
        case COLOR_CODE_12BIT_YCC420:
                return video_size_step = 2;
        default:
                DRM_ERROR("invalid color coding");
                return 0;
        }
}

static u16 round_video_size(int coding, u16 video_size)
{
        switch (coding) {
        case COLOR_CODE_16BIT_YCC422:
        case COLOR_CODE_24BIT_YCC422:
        case COLOR_CODE_20BIT_YCC422_LOOSELY:
        case COLOR_CODE_12BIT_YCC420:
                /* round up active H pixels to a multiple of 2 */
                if ((video_size % 2) != 0)
                        video_size += 1;
                break;
        default:
                break;
        }

        return video_size;
}

#define SPRD_MIPI_DSI_FMT_DSC 0xff
static u32 fmt_to_coding(u32 fmt)
{
        switch (fmt) {
        case MIPI_DSI_FMT_RGB565:
                return COLOR_CODE_16BIT_CONFIG1;
        case MIPI_DSI_FMT_RGB666:
        case MIPI_DSI_FMT_RGB666_PACKED:
                return COLOR_CODE_18BIT_CONFIG1;
        case MIPI_DSI_FMT_RGB888:
                return COLOR_CODE_24BIT;
        case SPRD_MIPI_DSI_FMT_DSC:
                return COLOR_CODE_COMPRESSTION;
        default:
                DRM_ERROR("Unsupported format (%d)\n", fmt);
                return COLOR_CODE_24BIT;
        }
}

#define ns_to_cycle(ns, byte_clk) \
        DIV_ROUND_UP((ns) * (byte_clk), 1000000)

static void sprd_dsi_init(struct dsi_context *ctx)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        u32 byte_clk = dsi->slave->hs_rate / 8;
        u16 data_hs2lp, data_lp2hs, clk_hs2lp, clk_lp2hs;
        u16 max_rd_time;
        int div;

        writel(0, ctx->base + SOFT_RESET);
        writel(0xffffffff, ctx->base + MASK_PROTOCOL_INT);
        writel(0xffffffff, ctx->base + MASK_INTERNAL_INT);
        writel(1, ctx->base + DSI_MODE_CFG);
        dsi_reg_up(ctx, EOTP_EN, RX_EOTP_EN, 0);
        dsi_reg_up(ctx, EOTP_EN, TX_EOTP_EN, 0);
        dsi_reg_up(ctx, RX_PKT_CHECK_CONFIG, RX_PKT_ECC_EN, RX_PKT_ECC_EN);
        dsi_reg_up(ctx, RX_PKT_CHECK_CONFIG, RX_PKT_CRC_EN, RX_PKT_CRC_EN);
        writel(1, ctx->base + TA_EN);
        dsi_reg_up(ctx, VIRTUAL_CHANNEL_ID, VIDEO_PKT_VCID, 0);
        dsi_reg_up(ctx, VIRTUAL_CHANNEL_ID, GEN_RX_VCID, 0);

        div = DIV_ROUND_UP(byte_clk, dsi->slave->lp_rate);
        writel(div, ctx->base + TX_ESC_CLK_CONFIG);

        max_rd_time = ns_to_cycle(ctx->max_rd_time, byte_clk);
        writel(max_rd_time, ctx->base + MAX_READ_TIME);

        data_hs2lp = ns_to_cycle(ctx->data_hs2lp, byte_clk);
        data_lp2hs = ns_to_cycle(ctx->data_lp2hs, byte_clk);
        clk_hs2lp = ns_to_cycle(ctx->clk_hs2lp, byte_clk);
        clk_lp2hs = ns_to_cycle(ctx->clk_lp2hs, byte_clk);
        dsi_reg_wr(ctx, PHY_DATALANE_TIME_CONFIG,
                   PHY_DATALANE_HS_TO_LP_TIME, 16, data_hs2lp);
        dsi_reg_wr(ctx, PHY_DATALANE_TIME_CONFIG,
                   PHY_DATALANE_LP_TO_HS_TIME, 0, data_lp2hs);
        dsi_reg_wr(ctx, PHY_CLKLANE_TIME_CONFIG,
                   PHY_CLKLANE_HS_TO_LP_TIME, 16, clk_hs2lp);
        dsi_reg_wr(ctx, PHY_CLKLANE_TIME_CONFIG,
                   PHY_CLKLANE_LP_TO_HS_TIME, 0, clk_lp2hs);

        writel(1, ctx->base + SOFT_RESET);
}

/*
 * Free up resources and shutdown host controller and PHY
 */
static void sprd_dsi_fini(struct dsi_context *ctx)
{
        writel(0xffffffff, ctx->base + MASK_PROTOCOL_INT);
        writel(0xffffffff, ctx->base + MASK_INTERNAL_INT);
        writel(0, ctx->base + SOFT_RESET);
}

/*
 * If not in burst mode, it will compute the video and null packet sizes
 * according to necessity.
 * Configure timers for data lanes and/or clock lane to return to LP when
 * bandwidth is not filled by data.
 */
static int sprd_dsi_dpi_video(struct dsi_context *ctx)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        struct videomode *vm = &ctx->vm;
        u32 byte_clk = dsi->slave->hs_rate / 8;
        u16 bpp_x100;
        u16 video_size;
        u32 ratio_x1000;
        u16 null_pkt_size = 0;
        u8 video_size_step;
        u32 hs_to;
        u32 total_bytes;
        u32 bytes_per_chunk;
        u32 chunks = 0;
        u32 bytes_left = 0;
        u32 chunk_overhead;
        const u8 pkt_header = 6;
        u8 coding;
        int div;
        u16 hline;
        u16 byte_cycle;

        coding = fmt_to_coding(dsi->slave->format);
        video_size = round_video_size(coding, vm->hactive);
        bpp_x100 = calc_bytes_per_pixel_x100(coding);
        video_size_step = calc_video_size_step(coding);
        ratio_x1000 = byte_clk * 1000 / (vm->pixelclock / 1000);
        hline = vm->hactive + vm->hsync_len + vm->hfront_porch +
                vm->hback_porch;

        writel(0, ctx->base + SOFT_RESET);
        dsi_reg_wr(ctx, VID_MODE_CFG, FRAME_BTA_ACK_EN, 15, ctx->frame_ack_en);
        dsi_reg_wr(ctx, DPI_VIDEO_FORMAT, DPI_VIDEO_MODE_FORMAT, 0, coding);
        dsi_reg_wr(ctx, VID_MODE_CFG, VID_MODE_TYPE, 0, ctx->burst_mode);
        byte_cycle = 95 * hline * ratio_x1000 / 100000;
        dsi_reg_wr(ctx, VIDEO_SIG_DELAY_CONFIG, VIDEO_SIG_DELAY, 0, byte_cycle);
        byte_cycle = hline * ratio_x1000 / 1000;
        writel(byte_cycle, ctx->base + VIDEO_LINE_TIME);
        byte_cycle = vm->hsync_len * ratio_x1000 / 1000;
        dsi_reg_wr(ctx, VIDEO_LINE_HBLK_TIME, VIDEO_LINE_HSA_TIME, 16, byte_cycle);
        byte_cycle = vm->hback_porch * ratio_x1000 / 1000;
        dsi_reg_wr(ctx, VIDEO_LINE_HBLK_TIME, VIDEO_LINE_HBP_TIME, 0, byte_cycle);
        writel(vm->vactive, ctx->base + VIDEO_VACTIVE_LINES);
        dsi_reg_wr(ctx, VIDEO_VBLK_LINES, VFP_LINES, 0, vm->vfront_porch);
        dsi_reg_wr(ctx, VIDEO_VBLK_LINES, VBP_LINES, 10, vm->vback_porch);
        dsi_reg_wr(ctx, VIDEO_VBLK_LINES, VSA_LINES, 20, vm->vsync_len);
        dsi_reg_up(ctx, VID_MODE_CFG, LP_HBP_EN | LP_HFP_EN | LP_VACT_EN |
                        LP_VFP_EN | LP_VBP_EN | LP_VSA_EN, LP_HBP_EN | LP_HFP_EN |
                        LP_VACT_EN | LP_VFP_EN | LP_VBP_EN | LP_VSA_EN);

        hs_to = (hline * vm->vactive) + (2 * bpp_x100) / 100;
        for (div = 0x80; (div < hs_to) && (div > 2); div--) {
                if ((hs_to % div) == 0) {
                        writel(div, ctx->base + TIMEOUT_CNT_CLK_CONFIG);
                        writel(hs_to / div, ctx->base + LRX_H_TO_CONFIG);
                        writel(hs_to / div, ctx->base + HTX_TO_CONFIG);
                        break;
                }
        }

        if (ctx->burst_mode == VIDEO_BURST_WITH_SYNC_PULSES) {
                dsi_reg_wr(ctx, VIDEO_PKT_CONFIG, VIDEO_PKT_SIZE, 0, video_size);
                writel(0, ctx->base + VIDEO_NULLPKT_SIZE);
                dsi_reg_up(ctx, VIDEO_PKT_CONFIG, VIDEO_LINE_CHUNK_NUM, 0);
        } else {
                /* non burst transmission */
                null_pkt_size = 0;

                /* bytes to be sent - first as one chunk */
                bytes_per_chunk = vm->hactive * bpp_x100 / 100 + pkt_header;

                /* hline total bytes from the DPI interface */
                total_bytes = (vm->hactive + vm->hfront_porch) *
                                ratio_x1000 / dsi->slave->lanes / 1000;

                /* check if the pixels actually fit on the DSI link */
                if (total_bytes < bytes_per_chunk) {
                        drm_err(dsi->drm, "current resolution can not be set\n");
                        return -EINVAL;
                }

                chunk_overhead = total_bytes - bytes_per_chunk;

                /* overhead higher than 1 -> enable multi packets */
                if (chunk_overhead > 1) {
                        /* multi packets */
                        for (video_size = video_size_step;
                             video_size < vm->hactive;
                             video_size += video_size_step) {
                                if (vm->hactive * 1000 / video_size % 1000)
                                        continue;

                                chunks = vm->hactive / video_size;
                                bytes_per_chunk = bpp_x100 * video_size / 100
                                                  + pkt_header;
                                if (total_bytes >= (bytes_per_chunk * chunks)) {
                                        bytes_left = total_bytes -
                                                     bytes_per_chunk * chunks;
                                        break;
                                }
                        }

                        /* prevent overflow (unsigned - unsigned) */
                        if (bytes_left > (pkt_header * chunks)) {
                                null_pkt_size = (bytes_left -
                                                pkt_header * chunks) / chunks;
                                /* avoid register overflow */
                                if (null_pkt_size > 1023)
                                        null_pkt_size = 1023;
                        }

                } else {
                        /* single packet */
                        chunks = 1;

                        /* must be a multiple of 4 except 18 loosely */
                        for (video_size = vm->hactive;
                            (video_size % video_size_step) != 0;
                             video_size++)
                                ;
                }

                dsi_reg_wr(ctx, VIDEO_PKT_CONFIG, VIDEO_PKT_SIZE, 0, video_size);
                writel(null_pkt_size, ctx->base + VIDEO_NULLPKT_SIZE);
                dsi_reg_wr(ctx, VIDEO_PKT_CONFIG, VIDEO_LINE_CHUNK_NUM, 16, chunks);
        }

        writel(ctx->int0_mask, ctx->base + MASK_PROTOCOL_INT);
        writel(ctx->int1_mask, ctx->base + MASK_INTERNAL_INT);
        writel(1, ctx->base + SOFT_RESET);

        return 0;
}

static void sprd_dsi_edpi_video(struct dsi_context *ctx)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        const u32 fifo_depth = 1096;
        const u32 word_length = 4;
        u32 hactive = ctx->vm.hactive;
        u32 bpp_x100;
        u32 max_fifo_len;
        u8 coding;

        coding = fmt_to_coding(dsi->slave->format);
        bpp_x100 = calc_bytes_per_pixel_x100(coding);
        max_fifo_len = word_length * fifo_depth * 100 / bpp_x100;

        writel(0, ctx->base + SOFT_RESET);
        dsi_reg_wr(ctx, DPI_VIDEO_FORMAT, DPI_VIDEO_MODE_FORMAT, 0, coding);
        dsi_reg_wr(ctx, CMD_MODE_CFG, TEAR_FX_EN, 0, ctx->te_ack_en);

        if (max_fifo_len > hactive)
                writel(hactive, ctx->base + DCS_WM_PKT_SIZE);
        else
                writel(max_fifo_len, ctx->base + DCS_WM_PKT_SIZE);

        writel(ctx->int0_mask, ctx->base + MASK_PROTOCOL_INT);
        writel(ctx->int1_mask, ctx->base + MASK_INTERNAL_INT);
        writel(1, ctx->base + SOFT_RESET);
}

/*
 * Send a packet on the generic interface,
 * this function has an active delay to wait for the buffer to clear.
 * The delay is limited to:
 * (param_length / 4) x DSIH_FIFO_ACTIVE_WAIT x register access time
 * the controller restricts the sending of.
 *
 * This function will not be able to send Null and Blanking packets due to
 * controller restriction
 */
static int sprd_dsi_wr_pkt(struct dsi_context *ctx, u8 vc, u8 type,
                           const u8 *param, u16 len)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        u8 wc_lsbyte, wc_msbyte;
        u32 payload;
        int i, j, ret;

        if (vc > 3)
                return -EINVAL;

        /* 1st: for long packet, must config payload first */
        ret = dsi_wait_tx_payload_fifo_empty(ctx);
        if (ret) {
                drm_err(dsi->drm, "tx payload fifo is not empty\n");
                return ret;
        }

        if (len > 2) {
                for (i = 0, j = 0; i < len; i += j) {
                        payload = 0;
                        for (j = 0; (j < 4) && ((j + i) < (len)); j++)
                                payload |= param[i + j] << (j * 8);

                        writel(payload, ctx->base + GEN_PLD_DATA);
                }
                wc_lsbyte = len & 0xff;
                wc_msbyte = len >> 8;
        } else {
                wc_lsbyte = (len > 0) ? param[0] : 0;
                wc_msbyte = (len > 1) ? param[1] : 0;
        }

        /* 2nd: then set packet header */
        ret = dsi_wait_tx_cmd_fifo_empty(ctx);
        if (ret) {
                drm_err(dsi->drm, "tx cmd fifo is not empty\n");
                return ret;
        }

        writel(type | (vc << 6) | (wc_lsbyte << 8) | (wc_msbyte << 16),
               ctx->base + GEN_HDR);

        return 0;
}

/*
 * Send READ packet to peripheral using the generic interface,
 * this will force command mode and stop video mode (because of BTA).
 *
 * This function has an active delay to wait for the buffer to clear,
 * the delay is limited to 2 x DSIH_FIFO_ACTIVE_WAIT
 * (waiting for command buffer, and waiting for receiving)
 * @note this function will enable BTA
 */
static int sprd_dsi_rd_pkt(struct dsi_context *ctx, u8 vc, u8 type,
                           u8 msb_byte, u8 lsb_byte,
                           u8 *buffer, u8 bytes_to_read)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        int i, ret;
        int count = 0;
        u32 temp;

        if (vc > 3)
                return -EINVAL;

        /* 1st: send read command to peripheral */
        ret = dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_CMD_FIFO_EMPTY, 5);
        if (!ret)
                return -EIO;

        writel(type | (vc << 6) | (lsb_byte << 8) | (msb_byte << 16),
               ctx->base + GEN_HDR);

        /* 2nd: wait peripheral response completed */
        ret = dsi_wait_rd_resp_completed(ctx);
        if (ret) {
                drm_err(dsi->drm, "wait read response time out\n");
                return ret;
        }

        /* 3rd: get data from rx payload fifo */
        ret = dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_RDATA_FIFO_EMPTY, 1);
        if (ret) {
                drm_err(dsi->drm, "rx payload fifo empty\n");
                return -EIO;
        }

        for (i = 0; i < 100; i++) {
                temp = readl(ctx->base + GEN_PLD_DATA);

                if (count < bytes_to_read)
                        buffer[count++] = temp & 0xff;
                if (count < bytes_to_read)
                        buffer[count++] = (temp >> 8) & 0xff;
                if (count < bytes_to_read)
                        buffer[count++] = (temp >> 16) & 0xff;
                if (count < bytes_to_read)
                        buffer[count++] = (temp >> 24) & 0xff;

                ret = dsi_reg_rd(ctx, CMD_MODE_STATUS, GEN_CMD_RDATA_FIFO_EMPTY, 1);
                if (ret)
                        return count;
        }

        return 0;
}

static void sprd_dsi_set_work_mode(struct dsi_context *ctx, u8 mode)
{
        if (mode == DSI_MODE_CMD)
                writel(1, ctx->base + DSI_MODE_CFG);
        else
                writel(0, ctx->base + DSI_MODE_CFG);
}

static void sprd_dsi_state_reset(struct dsi_context *ctx)
{
        writel(0, ctx->base + SOFT_RESET);
        udelay(100);
        writel(1, ctx->base + SOFT_RESET);
}

static int sprd_dphy_init(struct dsi_context *ctx)
{
        struct sprd_dsi *dsi = container_of(ctx, struct sprd_dsi, ctx);
        int ret;

        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_RESET_N, 0);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_SHUTDOWN, 0);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_CLK_EN, 0);

        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLR, 0);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLR, PHY_TESTCLR);
        dsi_reg_up(ctx, PHY_TST_CTRL0, PHY_TESTCLR, 0);

        dphy_pll_config(ctx);
        dphy_timing_config(ctx);

        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_SHUTDOWN, RF_PHY_SHUTDOWN);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_RESET_N, RF_PHY_RESET_N);
        writel(0x1C, ctx->base + PHY_MIN_STOP_TIME);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_CLK_EN, RF_PHY_CLK_EN);
        writel(dsi->slave->lanes - 1, ctx->base + PHY_LANE_NUM_CONFIG);

        ret = dphy_wait_pll_locked(ctx);
        if (ret) {
                drm_err(dsi->drm, "dphy initial failed\n");
                return ret;
        }

        return 0;
}

static void sprd_dphy_fini(struct dsi_context *ctx)
{
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_RESET_N, 0);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_SHUTDOWN, 0);
        dsi_reg_up(ctx, PHY_INTERFACE_CTRL, RF_PHY_RESET_N, RF_PHY_RESET_N);
}

static void sprd_dsi_encoder_mode_set(struct drm_encoder *encoder,
                                      struct drm_display_mode *mode,
                                 struct drm_display_mode *adj_mode)
{
        struct sprd_dsi *dsi = encoder_to_dsi(encoder);

        drm_display_mode_to_videomode(adj_mode, &dsi->ctx.vm);
}

static void sprd_dsi_encoder_enable(struct drm_encoder *encoder)
{
        struct sprd_dsi *dsi = encoder_to_dsi(encoder);
        struct sprd_dpu *dpu = to_sprd_crtc(encoder->crtc);
        struct dsi_context *ctx = &dsi->ctx;

        if (ctx->enabled) {
                drm_warn(dsi->drm, "dsi is initialized\n");
                return;
        }

        sprd_dsi_init(ctx);
        if (ctx->work_mode == DSI_MODE_VIDEO)
                sprd_dsi_dpi_video(ctx);
        else
                sprd_dsi_edpi_video(ctx);

        sprd_dphy_init(ctx);

        sprd_dsi_set_work_mode(ctx, ctx->work_mode);
        sprd_dsi_state_reset(ctx);

        if (dsi->slave->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
                dsi_reg_up(ctx, PHY_CLK_LANE_LP_CTRL, AUTO_CLKLANE_CTRL_EN,
                           AUTO_CLKLANE_CTRL_EN);
        } else {
                dsi_reg_up(ctx, PHY_CLK_LANE_LP_CTRL, RF_PHY_CLK_EN, RF_PHY_CLK_EN);
                dsi_reg_up(ctx, PHY_CLK_LANE_LP_CTRL, PHY_CLKLANE_TX_REQ_HS,
                           PHY_CLKLANE_TX_REQ_HS);
                dphy_wait_pll_locked(ctx);
        }

        sprd_dpu_run(dpu);

        ctx->enabled = true;
}

static void sprd_dsi_encoder_disable(struct drm_encoder *encoder)
{
        struct sprd_dsi *dsi = encoder_to_dsi(encoder);
        struct sprd_dpu *dpu = to_sprd_crtc(encoder->crtc);
        struct dsi_context *ctx = &dsi->ctx;

        if (!ctx->enabled) {
                drm_warn(dsi->drm, "dsi isn't initialized\n");
                return;
        }

        sprd_dpu_stop(dpu);
        sprd_dphy_fini(ctx);
        sprd_dsi_fini(ctx);

        ctx->enabled = false;
}

static const struct drm_encoder_helper_funcs sprd_encoder_helper_funcs = {
        .mode_set       = sprd_dsi_encoder_mode_set,
        .enable         = sprd_dsi_encoder_enable,
        .disable        = sprd_dsi_encoder_disable
};

static const struct drm_encoder_funcs sprd_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
};

static int sprd_dsi_encoder_init(struct sprd_dsi *dsi,
                                 struct device *dev)
{
        struct drm_encoder *encoder = &dsi->encoder;
        u32 crtc_mask;
        int ret;

        crtc_mask = drm_of_find_possible_crtcs(dsi->drm, dev->of_node);
        if (!crtc_mask) {
                drm_err(dsi->drm, "failed to find crtc mask\n");
                return -EINVAL;
        }

        drm_dbg(dsi->drm, "find possible crtcs: 0x%08x\n", crtc_mask);

        encoder->possible_crtcs = crtc_mask;
        ret = drm_encoder_init(dsi->drm, encoder, &sprd_encoder_funcs,
                               DRM_MODE_ENCODER_DSI, NULL);
        if (ret) {
                drm_err(dsi->drm, "failed to init dsi encoder\n");
                return ret;
        }

        drm_encoder_helper_add(encoder, &sprd_encoder_helper_funcs);

        return 0;
}

static int sprd_dsi_bridge_init(struct sprd_dsi *dsi,
                                struct device *dev)
{
        int ret;

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

        ret = drm_bridge_attach(&dsi->encoder, dsi->panel_bridge, NULL, 0);
        if (ret)
                return ret;

        return 0;
}

static int sprd_dsi_context_init(struct sprd_dsi *dsi,
                                 struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct dsi_context *ctx = &dsi->ctx;

        ctx->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(ctx->base)) {
                drm_err(dsi->drm, "failed to map dsi host registers\n");
                return PTR_ERR(ctx->base);
        }

        ctx->regmap = devm_regmap_init(dev, &regmap_tst_io, dsi, &byte_config);
        if (IS_ERR(ctx->regmap)) {
                drm_err(dsi->drm, "dphy regmap init failed\n");
                return PTR_ERR(ctx->regmap);
        }

        ctx->data_hs2lp = 120;
        ctx->data_lp2hs = 500;
        ctx->clk_hs2lp = 4;
        ctx->clk_lp2hs = 15;
        ctx->max_rd_time = 6000;
        ctx->int0_mask = 0xffffffff;
        ctx->int1_mask = 0xffffffff;
        ctx->enabled = true;

        return 0;
}

static int sprd_dsi_bind(struct device *dev, struct device *master, void *data)
{
        struct drm_device *drm = data;
        struct sprd_dsi *dsi = dev_get_drvdata(dev);
        int ret;

        dsi->drm = drm;

        ret = sprd_dsi_encoder_init(dsi, dev);
        if (ret)
                return ret;

        ret = sprd_dsi_bridge_init(dsi, dev);
        if (ret)
                return ret;

        ret = sprd_dsi_context_init(dsi, dev);
        if (ret)
                return ret;

        return 0;
}

static void sprd_dsi_unbind(struct device *dev,
                            struct device *master, void *data)
{
        struct sprd_dsi *dsi = dev_get_drvdata(dev);

        drm_of_panel_bridge_remove(dev->of_node, 1, 0);

        drm_encoder_cleanup(&dsi->encoder);
}

static const struct component_ops dsi_component_ops = {
        .bind   = sprd_dsi_bind,
        .unbind = sprd_dsi_unbind,
};

static int sprd_dsi_host_attach(struct mipi_dsi_host *host,
                                struct mipi_dsi_device *slave)
{
        struct sprd_dsi *dsi = host_to_dsi(host);
        struct dsi_context *ctx = &dsi->ctx;

        dsi->slave = slave;

        if (slave->mode_flags & MIPI_DSI_MODE_VIDEO)
                ctx->work_mode = DSI_MODE_VIDEO;
        else
                ctx->work_mode = DSI_MODE_CMD;

        if (slave->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
                ctx->burst_mode = VIDEO_BURST_WITH_SYNC_PULSES;
        else if (slave->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
                ctx->burst_mode = VIDEO_NON_BURST_WITH_SYNC_PULSES;
        else
                ctx->burst_mode = VIDEO_NON_BURST_WITH_SYNC_EVENTS;

        return component_add(host->dev, &dsi_component_ops);
}

static int sprd_dsi_host_detach(struct mipi_dsi_host *host,
                                struct mipi_dsi_device *slave)
{
        component_del(host->dev, &dsi_component_ops);

        return 0;
}

static ssize_t sprd_dsi_host_transfer(struct mipi_dsi_host *host,
                                      const struct mipi_dsi_msg *msg)
{
        struct sprd_dsi *dsi = host_to_dsi(host);
        const u8 *tx_buf = msg->tx_buf;

        if (msg->rx_buf && msg->rx_len) {
                u8 lsb = (msg->tx_len > 0) ? tx_buf[0] : 0;
                u8 msb = (msg->tx_len > 1) ? tx_buf[1] : 0;

                return sprd_dsi_rd_pkt(&dsi->ctx, msg->channel, msg->type,
                                msb, lsb, msg->rx_buf, msg->rx_len);
        }

        if (msg->tx_buf && msg->tx_len)
                return sprd_dsi_wr_pkt(&dsi->ctx, msg->channel, msg->type,
                                        tx_buf, msg->tx_len);

        return 0;
}

static const struct mipi_dsi_host_ops sprd_dsi_host_ops = {
        .attach = sprd_dsi_host_attach,
        .detach = sprd_dsi_host_detach,
        .transfer = sprd_dsi_host_transfer,
};

static const struct of_device_id dsi_match_table[] = {
        { .compatible = "sprd,sharkl3-dsi-host" },
        { /* sentinel */ },
};

static int sprd_dsi_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct sprd_dsi *dsi;

        dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
        if (!dsi)
                return -ENOMEM;

        dev_set_drvdata(dev, dsi);

        dsi->host.ops = &sprd_dsi_host_ops;
        dsi->host.dev = dev;

        return mipi_dsi_host_register(&dsi->host);
}

static void sprd_dsi_remove(struct platform_device *pdev)
{
        struct sprd_dsi *dsi = dev_get_drvdata(&pdev->dev);

        mipi_dsi_host_unregister(&dsi->host);
}

struct platform_driver sprd_dsi_driver = {
        .probe = sprd_dsi_probe,
        .remove = sprd_dsi_remove,
        .driver = {
                .name = "sprd-dsi-drv",
                .of_match_table = dsi_match_table,
        },
};

MODULE_AUTHOR("Leon He <leon.he@unisoc.com>");
MODULE_AUTHOR("Kevin Tang <kevin.tang@unisoc.com>");
MODULE_DESCRIPTION("Unisoc MIPI DSI HOST Controller Driver");
MODULE_LICENSE("GPL v2");