drm/rockchip: dw-mipi-dsi: fix escape clock rate

[mirror_ubuntu-artful-kernel.git] / drivers / gpu / drm / rockchip / dw-mipi-dsi.c

/*
 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */
#include <linux/clk.h>
#include <linux/component.h>
#include <linux/iopoll.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drmP.h>
#include <video/mipi_display.h>

#include "rockchip_drm_drv.h"
#include "rockchip_drm_vop.h"

#define DRIVER_NAME    "dw-mipi-dsi"

#define GRF_SOC_CON6                    0x025c
#define DSI0_SEL_VOP_LIT                (1 << 6)
#define DSI1_SEL_VOP_LIT                (1 << 9)

#define DSI_VERSION                     0x00
#define DSI_PWR_UP                      0x04
#define RESET                           0
#define POWERUP                         BIT(0)

#define DSI_CLKMGR_CFG                  0x08
#define TO_CLK_DIVIDSION(div)           (((div) & 0xff) << 8)
#define TX_ESC_CLK_DIVIDSION(div)       (((div) & 0xff) << 0)

#define DSI_DPI_VCID                    0x0c
#define DPI_VID(vid)                    (((vid) & 0x3) << 0)

#define DSI_DPI_COLOR_CODING            0x10
#define EN18_LOOSELY                    BIT(8)
#define DPI_COLOR_CODING_16BIT_1        0x0
#define DPI_COLOR_CODING_16BIT_2        0x1
#define DPI_COLOR_CODING_16BIT_3        0x2
#define DPI_COLOR_CODING_18BIT_1        0x3
#define DPI_COLOR_CODING_18BIT_2        0x4
#define DPI_COLOR_CODING_24BIT          0x5

#define DSI_DPI_CFG_POL                 0x14
#define COLORM_ACTIVE_LOW               BIT(4)
#define SHUTD_ACTIVE_LOW                BIT(3)
#define HSYNC_ACTIVE_LOW                BIT(2)
#define VSYNC_ACTIVE_LOW                BIT(1)
#define DATAEN_ACTIVE_LOW               BIT(0)

#define DSI_DPI_LP_CMD_TIM              0x18
#define OUTVACT_LPCMD_TIME(p)           (((p) & 0xff) << 16)
#define INVACT_LPCMD_TIME(p)            ((p) & 0xff)

#define DSI_DBI_CFG                     0x20
#define DSI_DBI_CMDSIZE                 0x28

#define DSI_PCKHDL_CFG                  0x2c
#define EN_CRC_RX                       BIT(4)
#define EN_ECC_RX                       BIT(3)
#define EN_BTA                          BIT(2)
#define EN_EOTP_RX                      BIT(1)
#define EN_EOTP_TX                      BIT(0)

#define DSI_MODE_CFG                    0x34
#define ENABLE_VIDEO_MODE               0
#define ENABLE_CMD_MODE                 BIT(0)

#define DSI_VID_MODE_CFG                0x38
#define FRAME_BTA_ACK                   BIT(14)
#define ENABLE_LOW_POWER                (0x3f << 8)
#define ENABLE_LOW_POWER_MASK           (0x3f << 8)
#define VID_MODE_TYPE_BURST_SYNC_PULSES         0x2
#define VID_MODE_TYPE_MASK                      0x3

#define DSI_VID_PKT_SIZE                0x3c
#define VID_PKT_SIZE(p)                 (((p) & 0x3fff) << 0)
#define VID_PKT_MAX_SIZE                0x3fff

#define DSI_VID_HSA_TIME                0x48
#define DSI_VID_HBP_TIME                0x4c
#define DSI_VID_HLINE_TIME              0x50
#define DSI_VID_VSA_LINES               0x54
#define DSI_VID_VBP_LINES               0x58
#define DSI_VID_VFP_LINES               0x5c
#define DSI_VID_VACTIVE_LINES           0x60
#define DSI_CMD_MODE_CFG                0x68
#define MAX_RD_PKT_SIZE_LP              BIT(24)
#define DCS_LW_TX_LP                    BIT(19)
#define DCS_SR_0P_TX_LP                 BIT(18)
#define DCS_SW_1P_TX_LP                 BIT(17)
#define DCS_SW_0P_TX_LP                 BIT(16)
#define GEN_LW_TX_LP                    BIT(14)
#define GEN_SR_2P_TX_LP                 BIT(13)
#define GEN_SR_1P_TX_LP                 BIT(12)
#define GEN_SR_0P_TX_LP                 BIT(11)
#define GEN_SW_2P_TX_LP                 BIT(10)
#define GEN_SW_1P_TX_LP                 BIT(9)
#define GEN_SW_0P_TX_LP                 BIT(8)
#define EN_ACK_RQST                     BIT(1)
#define EN_TEAR_FX                      BIT(0)

#define CMD_MODE_ALL_LP                 (MAX_RD_PKT_SIZE_LP | \
                                         DCS_LW_TX_LP | \
                                         DCS_SR_0P_TX_LP | \
                                         DCS_SW_1P_TX_LP | \
                                         DCS_SW_0P_TX_LP | \
                                         GEN_LW_TX_LP | \
                                         GEN_SR_2P_TX_LP | \
                                         GEN_SR_1P_TX_LP | \
                                         GEN_SR_0P_TX_LP | \
                                         GEN_SW_2P_TX_LP | \
                                         GEN_SW_1P_TX_LP | \
                                         GEN_SW_0P_TX_LP)

#define DSI_GEN_HDR                     0x6c
#define GEN_HDATA(data)                 (((data) & 0xffff) << 8)
#define GEN_HDATA_MASK                  (0xffff << 8)
#define GEN_HTYPE(type)                 (((type) & 0xff) << 0)
#define GEN_HTYPE_MASK                  0xff

#define DSI_GEN_PLD_DATA                0x70

#define DSI_CMD_PKT_STATUS              0x74
#define GEN_CMD_EMPTY                   BIT(0)
#define GEN_CMD_FULL                    BIT(1)
#define GEN_PLD_W_EMPTY                 BIT(2)
#define GEN_PLD_W_FULL                  BIT(3)
#define GEN_PLD_R_EMPTY                 BIT(4)
#define GEN_PLD_R_FULL                  BIT(5)
#define GEN_RD_CMD_BUSY                 BIT(6)

#define DSI_TO_CNT_CFG                  0x78
#define HSTX_TO_CNT(p)                  (((p) & 0xffff) << 16)
#define LPRX_TO_CNT(p)                  ((p) & 0xffff)

#define DSI_BTA_TO_CNT                  0x8c

#define DSI_LPCLK_CTRL                  0x94
#define AUTO_CLKLANE_CTRL               BIT(1)
#define PHY_TXREQUESTCLKHS              BIT(0)

#define DSI_PHY_TMR_LPCLK_CFG           0x98
#define PHY_CLKHS2LP_TIME(lbcc)         (((lbcc) & 0x3ff) << 16)
#define PHY_CLKLP2HS_TIME(lbcc)         ((lbcc) & 0x3ff)

#define DSI_PHY_TMR_CFG                 0x9c
#define PHY_HS2LP_TIME(lbcc)            (((lbcc) & 0xff) << 24)
#define PHY_LP2HS_TIME(lbcc)            (((lbcc) & 0xff) << 16)
#define MAX_RD_TIME(lbcc)               ((lbcc) & 0x7fff)

#define DSI_PHY_RSTZ                    0xa0
#define PHY_DISFORCEPLL                 0
#define PHY_ENFORCEPLL                  BIT(3)
#define PHY_DISABLECLK                  0
#define PHY_ENABLECLK                   BIT(2)
#define PHY_RSTZ                        0
#define PHY_UNRSTZ                      BIT(1)
#define PHY_SHUTDOWNZ                   0
#define PHY_UNSHUTDOWNZ                 BIT(0)

#define DSI_PHY_IF_CFG                  0xa4
#define N_LANES(n)                      ((((n) - 1) & 0x3) << 0)
#define PHY_STOP_WAIT_TIME(cycle)       (((cycle) & 0xff) << 8)

#define DSI_PHY_STATUS                  0xb0
#define LOCK                            BIT(0)
#define STOP_STATE_CLK_LANE             BIT(2)

#define DSI_PHY_TST_CTRL0               0xb4
#define PHY_TESTCLK                     BIT(1)
#define PHY_UNTESTCLK                   0
#define PHY_TESTCLR                     BIT(0)
#define PHY_UNTESTCLR                   0

#define DSI_PHY_TST_CTRL1               0xb8
#define PHY_TESTEN                      BIT(16)
#define PHY_UNTESTEN                    0
#define PHY_TESTDOUT(n)                 (((n) & 0xff) << 8)
#define PHY_TESTDIN(n)                  (((n) & 0xff) << 0)

#define DSI_INT_ST0                     0xbc
#define DSI_INT_ST1                     0xc0
#define DSI_INT_MSK0                    0xc4
#define DSI_INT_MSK1                    0xc8

#define PHY_STATUS_TIMEOUT_US           10000
#define CMD_PKT_STATUS_TIMEOUT_US       20000

#define BYPASS_VCO_RANGE        BIT(7)
#define VCO_RANGE_CON_SEL(val)  (((val) & 0x7) << 3)
#define VCO_IN_CAP_CON_DEFAULT  (0x0 << 1)
#define VCO_IN_CAP_CON_LOW      (0x1 << 1)
#define VCO_IN_CAP_CON_HIGH     (0x2 << 1)
#define REF_BIAS_CUR_SEL        BIT(0)

#define CP_CURRENT_3MA          BIT(3)
#define CP_PROGRAM_EN           BIT(7)
#define LPF_PROGRAM_EN          BIT(6)
#define LPF_RESISTORS_20_KOHM   0

#define HSFREQRANGE_SEL(val)    (((val) & 0x3f) << 1)

#define INPUT_DIVIDER(val)      ((val - 1) & 0x7f)
#define LOW_PROGRAM_EN          0
#define HIGH_PROGRAM_EN         BIT(7)
#define LOOP_DIV_LOW_SEL(val)   ((val - 1) & 0x1f)
#define LOOP_DIV_HIGH_SEL(val)  (((val - 1) >> 5) & 0x1f)
#define PLL_LOOP_DIV_EN         BIT(5)
#define PLL_INPUT_DIV_EN        BIT(4)

#define POWER_CONTROL           BIT(6)
#define INTERNAL_REG_CURRENT    BIT(3)
#define BIAS_BLOCK_ON           BIT(2)
#define BANDGAP_ON              BIT(0)

#define TER_RESISTOR_HIGH       BIT(7)
#define TER_RESISTOR_LOW        0
#define LEVEL_SHIFTERS_ON       BIT(6)
#define TER_CAL_DONE            BIT(5)
#define SETRD_MAX               (0x7 << 2)
#define POWER_MANAGE            BIT(1)
#define TER_RESISTORS_ON        BIT(0)

#define BIASEXTR_SEL(val)       ((val) & 0x7)
#define BANDGAP_SEL(val)        ((val) & 0x7)
#define TLP_PROGRAM_EN          BIT(7)
#define THS_PRE_PROGRAM_EN      BIT(7)
#define THS_ZERO_PROGRAM_EN     BIT(6)

enum {
        BANDGAP_97_07,
        BANDGAP_98_05,
        BANDGAP_99_02,
        BANDGAP_100_00,
        BANDGAP_93_17,
        BANDGAP_94_15,
        BANDGAP_95_12,
        BANDGAP_96_10,
};

enum {
        BIASEXTR_87_1,
        BIASEXTR_91_5,
        BIASEXTR_95_9,
        BIASEXTR_100,
        BIASEXTR_105_94,
        BIASEXTR_111_88,
        BIASEXTR_118_8,
        BIASEXTR_127_7,
};

struct dw_mipi_dsi_plat_data {
        unsigned int max_data_lanes;
        enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
                                           struct drm_display_mode *mode);
};

struct dw_mipi_dsi {
        struct drm_encoder encoder;
        struct drm_connector connector;
        struct mipi_dsi_host dsi_host;
        struct drm_panel *panel;
        struct device *dev;
        struct regmap *grf_regmap;
        void __iomem *base;

        struct clk *pllref_clk;
        struct clk *pclk;

        unsigned int lane_mbps; /* per lane */
        u32 channel;
        u32 lanes;
        u32 format;
        u16 input_div;
        u16 feedback_div;

        const struct dw_mipi_dsi_plat_data *pdata;
};

enum dw_mipi_dsi_mode {
        DW_MIPI_DSI_CMD_MODE,
        DW_MIPI_DSI_VID_MODE,
};

struct dphy_pll_testdin_map {
        unsigned int max_mbps;
        u8 testdin;
};

/* The table is based on 27MHz DPHY pll reference clock. */
static const struct dphy_pll_testdin_map dptdin_map[] = {
        {  90, 0x00}, { 100, 0x10}, { 110, 0x20}, { 130, 0x01},
        { 140, 0x11}, { 150, 0x21}, { 170, 0x02}, { 180, 0x12},
        { 200, 0x22}, { 220, 0x03}, { 240, 0x13}, { 250, 0x23},
        { 270, 0x04}, { 300, 0x14}, { 330, 0x05}, { 360, 0x15},
        { 400, 0x25}, { 450, 0x06}, { 500, 0x16}, { 550, 0x07},
        { 600, 0x17}, { 650, 0x08}, { 700, 0x18}, { 750, 0x09},
        { 800, 0x19}, { 850, 0x29}, { 900, 0x39}, { 950, 0x0a},
        {1000, 0x1a}, {1050, 0x2a}, {1100, 0x3a}, {1150, 0x0b},
        {1200, 0x1b}, {1250, 0x2b}, {1300, 0x3b}, {1350, 0x0c},
        {1400, 0x1c}, {1450, 0x2c}, {1500, 0x3c}
};

static int max_mbps_to_testdin(unsigned int max_mbps)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(dptdin_map); i++)
                if (dptdin_map[i].max_mbps > max_mbps)
                        return dptdin_map[i].testdin;

        return -EINVAL;
}

/*
 * The controller should generate 2 frames before
 * preparing the peripheral.
 */
static void dw_mipi_dsi_wait_for_two_frames(struct drm_display_mode *mode)
{
        int refresh, two_frames;

        refresh = drm_mode_vrefresh(mode);
        two_frames = DIV_ROUND_UP(MSEC_PER_SEC, refresh) * 2;
        msleep(two_frames);
}

static inline struct dw_mipi_dsi *host_to_dsi(struct mipi_dsi_host *host)
{
        return container_of(host, struct dw_mipi_dsi, dsi_host);
}

static inline struct dw_mipi_dsi *con_to_dsi(struct drm_connector *con)
{
        return container_of(con, struct dw_mipi_dsi, connector);
}

static inline struct dw_mipi_dsi *encoder_to_dsi(struct drm_encoder *encoder)
{
        return container_of(encoder, struct dw_mipi_dsi, encoder);
}
static inline void dsi_write(struct dw_mipi_dsi *dsi, u32 reg, u32 val)
{
        writel(val, dsi->base + reg);
}

static inline u32 dsi_read(struct dw_mipi_dsi *dsi, u32 reg)
{
        return readl(dsi->base + reg);
}

static void dw_mipi_dsi_phy_write(struct dw_mipi_dsi *dsi, u8 test_code,
                                 u8 test_data)
{
        /*
         * With the falling edge on TESTCLK, the TESTDIN[7:0] signal content
         * is latched internally as the current test code. Test data is
         * programmed internally by rising edge on TESTCLK.
         */
        dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLK | PHY_UNTESTCLR);

        dsi_write(dsi, DSI_PHY_TST_CTRL1, PHY_TESTEN | PHY_TESTDOUT(0) |
                                          PHY_TESTDIN(test_code));

        dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLK | PHY_UNTESTCLR);

        dsi_write(dsi, DSI_PHY_TST_CTRL1, PHY_UNTESTEN | PHY_TESTDOUT(0) |
                                          PHY_TESTDIN(test_data));

        dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLK | PHY_UNTESTCLR);
}

static int dw_mipi_dsi_phy_init(struct dw_mipi_dsi *dsi)
{
        int ret, testdin, vco, val;

        vco = (dsi->lane_mbps < 200) ? 0 : (dsi->lane_mbps + 100) / 200;

        testdin = max_mbps_to_testdin(dsi->lane_mbps);
        if (testdin < 0) {
                dev_err(dsi->dev,
                        "failed to get testdin for %dmbps lane clock\n",
                        dsi->lane_mbps);
                return testdin;
        }

        dsi_write(dsi, DSI_PWR_UP, POWERUP);

        dw_mipi_dsi_phy_write(dsi, 0x10, BYPASS_VCO_RANGE |
                                         VCO_RANGE_CON_SEL(vco) |
                                         VCO_IN_CAP_CON_LOW |
                                         REF_BIAS_CUR_SEL);

        dw_mipi_dsi_phy_write(dsi, 0x11, CP_CURRENT_3MA);
        dw_mipi_dsi_phy_write(dsi, 0x12, CP_PROGRAM_EN | LPF_PROGRAM_EN |
                                         LPF_RESISTORS_20_KOHM);

        dw_mipi_dsi_phy_write(dsi, 0x44, HSFREQRANGE_SEL(testdin));

        dw_mipi_dsi_phy_write(dsi, 0x19, PLL_LOOP_DIV_EN | PLL_INPUT_DIV_EN);
        dw_mipi_dsi_phy_write(dsi, 0x17, INPUT_DIVIDER(dsi->input_div));
        dw_mipi_dsi_phy_write(dsi, 0x18, LOOP_DIV_LOW_SEL(dsi->feedback_div) |
                                         LOW_PROGRAM_EN);
        dw_mipi_dsi_phy_write(dsi, 0x18, LOOP_DIV_HIGH_SEL(dsi->feedback_div) |
                                         HIGH_PROGRAM_EN);

        dw_mipi_dsi_phy_write(dsi, 0x20, POWER_CONTROL | INTERNAL_REG_CURRENT |
                                         BIAS_BLOCK_ON | BANDGAP_ON);

        dw_mipi_dsi_phy_write(dsi, 0x21, TER_RESISTOR_LOW | TER_CAL_DONE |
                                         SETRD_MAX | TER_RESISTORS_ON);
        dw_mipi_dsi_phy_write(dsi, 0x21, TER_RESISTOR_HIGH | LEVEL_SHIFTERS_ON |
                                         SETRD_MAX | POWER_MANAGE |
                                         TER_RESISTORS_ON);

        dw_mipi_dsi_phy_write(dsi, 0x22, LOW_PROGRAM_EN |
                                         BIASEXTR_SEL(BIASEXTR_127_7));
        dw_mipi_dsi_phy_write(dsi, 0x22, HIGH_PROGRAM_EN |
                                         BANDGAP_SEL(BANDGAP_96_10));

        dw_mipi_dsi_phy_write(dsi, 0x70, TLP_PROGRAM_EN | 0xf);
        dw_mipi_dsi_phy_write(dsi, 0x71, THS_PRE_PROGRAM_EN | 0x55);
        dw_mipi_dsi_phy_write(dsi, 0x72, THS_ZERO_PROGRAM_EN | 0xa);

        dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
                                     PHY_UNRSTZ | PHY_UNSHUTDOWNZ);


        ret = readx_poll_timeout(readl, dsi->base + DSI_PHY_STATUS,
                                 val, val & LOCK, 1000, PHY_STATUS_TIMEOUT_US);
        if (ret < 0) {
                dev_err(dsi->dev, "failed to wait for phy lock state\n");
                return ret;
        }

        ret = readx_poll_timeout(readl, dsi->base + DSI_PHY_STATUS,
                                 val, val & STOP_STATE_CLK_LANE, 1000,
                                 PHY_STATUS_TIMEOUT_US);
        if (ret < 0) {
                dev_err(dsi->dev,
                        "failed to wait for phy clk lane stop state\n");
                return ret;
        }

        return ret;
}

static int dw_mipi_dsi_get_lane_bps(struct dw_mipi_dsi *dsi,
                                    struct drm_display_mode *mode)
{
        unsigned int i, pre;
        unsigned long mpclk, pllref, tmp;
        unsigned int m = 1, n = 1, target_mbps = 1000;
        unsigned int max_mbps = dptdin_map[ARRAY_SIZE(dptdin_map) - 1].max_mbps;
        int bpp;

        bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);
        if (bpp < 0) {
                dev_err(dsi->dev, "failed to get bpp for pixel format %d\n",
                        dsi->format);
                return bpp;
        }

        mpclk = DIV_ROUND_UP(mode->clock, MSEC_PER_SEC);
        if (mpclk) {
                /* take 1 / 0.9, since mbps must big than bandwidth of RGB */
                tmp = mpclk * (bpp / dsi->lanes) * 10 / 9;
                if (tmp < max_mbps)
                        target_mbps = tmp;
                else
                        dev_err(dsi->dev, "DPHY clock frequency is out of range\n");
        }

        pllref = DIV_ROUND_UP(clk_get_rate(dsi->pllref_clk), USEC_PER_SEC);
        tmp = pllref;

        for (i = 1; i < 6; i++) {
                pre = pllref / i;
                if ((tmp > (target_mbps % pre)) && (target_mbps / pre < 512)) {
                        tmp = target_mbps % pre;
                        n = i;
                        m = target_mbps / pre;
                }
                if (tmp == 0)
                        break;
        }

        dsi->lane_mbps = pllref / n * m;
        dsi->input_div = n;
        dsi->feedback_div = m;

        return 0;
}

static int dw_mipi_dsi_host_attach(struct mipi_dsi_host *host,
                                   struct mipi_dsi_device *device)
{
        struct dw_mipi_dsi *dsi = host_to_dsi(host);

        if (device->lanes > dsi->pdata->max_data_lanes) {
                dev_err(dsi->dev, "the number of data lanes(%u) is too many\n",
                                device->lanes);
                return -EINVAL;
        }

        if (!(device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) ||
            !(device->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)) {
                dev_err(dsi->dev, "device mode is unsupported\n");
                return -EINVAL;
        }

        dsi->lanes = device->lanes;
        dsi->channel = device->channel;
        dsi->format = device->format;
        dsi->panel = of_drm_find_panel(device->dev.of_node);
        if (dsi->panel)
                return drm_panel_attach(dsi->panel, &dsi->connector);

        return -EINVAL;
}

static int dw_mipi_dsi_host_detach(struct mipi_dsi_host *host,
                                   struct mipi_dsi_device *device)
{
        struct dw_mipi_dsi *dsi = host_to_dsi(host);

        drm_panel_detach(dsi->panel);

        return 0;
}

static void dw_mipi_message_config(struct dw_mipi_dsi *dsi,
                                   const struct mipi_dsi_msg *msg)
{
        bool lpm = msg->flags & MIPI_DSI_MSG_USE_LPM;
        u32 val = 0;

        if (msg->flags & MIPI_DSI_MSG_REQ_ACK)
                val |= EN_ACK_RQST;
        if (lpm)
                val |= CMD_MODE_ALL_LP;

        dsi_write(dsi, DSI_LPCLK_CTRL, lpm ? 0 : PHY_TXREQUESTCLKHS);
        dsi_write(dsi, DSI_CMD_MODE_CFG, val);
}

static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
{
        int ret;
        u32 val, mask;

        ret = readx_poll_timeout(readl, dsi->base + DSI_CMD_PKT_STATUS,
                                 val, !(val & GEN_CMD_FULL), 1000,
                                 CMD_PKT_STATUS_TIMEOUT_US);
        if (ret < 0) {
                dev_err(dsi->dev, "failed to get available command FIFO\n");
                return ret;
        }

        dsi_write(dsi, DSI_GEN_HDR, hdr_val);

        mask = GEN_CMD_EMPTY | GEN_PLD_W_EMPTY;
        ret = readx_poll_timeout(readl, dsi->base + DSI_CMD_PKT_STATUS,
                                 val, (val & mask) == mask,
                                 1000, CMD_PKT_STATUS_TIMEOUT_US);
        if (ret < 0) {
                dev_err(dsi->dev, "failed to write command FIFO\n");
                return ret;
        }

        return 0;
}

static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi,
                                       const struct mipi_dsi_msg *msg)
{
        const u8 *tx_buf = msg->tx_buf;
        u16 data = 0;
        u32 val;

        if (msg->tx_len > 0)
                data |= tx_buf[0];
        if (msg->tx_len > 1)
                data |= tx_buf[1] << 8;

        if (msg->tx_len > 2) {
                dev_err(dsi->dev, "too long tx buf length %zu for short write\n",
                        msg->tx_len);
                return -EINVAL;
        }

        val = GEN_HDATA(data) | GEN_HTYPE(msg->type);
        return dw_mipi_dsi_gen_pkt_hdr_write(dsi, val);
}

static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
                                      const struct mipi_dsi_msg *msg)
{
        const u8 *tx_buf = msg->tx_buf;
        int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret;
        u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type);
        u32 remainder;
        u32 val;

        if (msg->tx_len < 3) {
                dev_err(dsi->dev, "wrong tx buf length %zu for long write\n",
                        msg->tx_len);
                return -EINVAL;
        }

        while (DIV_ROUND_UP(len, pld_data_bytes)) {
                if (len < pld_data_bytes) {
                        remainder = 0;
                        memcpy(&remainder, tx_buf, len);
                        dsi_write(dsi, DSI_GEN_PLD_DATA, remainder);
                        len = 0;
                } else {
                        memcpy(&remainder, tx_buf, pld_data_bytes);
                        dsi_write(dsi, DSI_GEN_PLD_DATA, remainder);
                        tx_buf += pld_data_bytes;
                        len -= pld_data_bytes;
                }

                ret = readx_poll_timeout(readl, dsi->base + DSI_CMD_PKT_STATUS,
                                         val, !(val & GEN_PLD_W_FULL), 1000,
                                         CMD_PKT_STATUS_TIMEOUT_US);
                if (ret < 0) {
                        dev_err(dsi->dev,
                                "failed to get available write payload FIFO\n");
                        return ret;
                }
        }

        return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val);
}

static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host,
                                         const struct mipi_dsi_msg *msg)
{
        struct dw_mipi_dsi *dsi = host_to_dsi(host);
        int ret;

        dw_mipi_message_config(dsi, msg);

        switch (msg->type) {
        case MIPI_DSI_DCS_SHORT_WRITE:
        case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
        case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
                ret = dw_mipi_dsi_dcs_short_write(dsi, msg);
                break;
        case MIPI_DSI_DCS_LONG_WRITE:
                ret = dw_mipi_dsi_dcs_long_write(dsi, msg);
                break;
        default:
                dev_err(dsi->dev, "unsupported message type 0x%02x\n",
                        msg->type);
                ret = -EINVAL;
        }

        return ret;
}

static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {
        .attach = dw_mipi_dsi_host_attach,
        .detach = dw_mipi_dsi_host_detach,
        .transfer = dw_mipi_dsi_host_transfer,
};

static void dw_mipi_dsi_video_mode_config(struct dw_mipi_dsi *dsi)
{
        u32 val;

        val = VID_MODE_TYPE_BURST_SYNC_PULSES | ENABLE_LOW_POWER;

        dsi_write(dsi, DSI_VID_MODE_CFG, val);
}

static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
                                 enum dw_mipi_dsi_mode mode)
{
        if (mode == DW_MIPI_DSI_CMD_MODE) {
                dsi_write(dsi, DSI_PWR_UP, RESET);
                dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
                dsi_write(dsi, DSI_PWR_UP, POWERUP);
        } else {
                dsi_write(dsi, DSI_PWR_UP, RESET);
                dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
                dw_mipi_dsi_video_mode_config(dsi);
                dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
                dsi_write(dsi, DSI_PWR_UP, POWERUP);
        }
}

static void dw_mipi_dsi_disable(struct dw_mipi_dsi *dsi)
{
        dsi_write(dsi, DSI_PWR_UP, RESET);
        dsi_write(dsi, DSI_PHY_RSTZ, PHY_RSTZ);
}

static void dw_mipi_dsi_init(struct dw_mipi_dsi *dsi)
{
        /*
         * The maximum permitted escape clock is 20MHz and it is derived from
         * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
         *
         *     (lane_mbps >> 3) / esc_clk_division < 20
         * which is:
         *     (lane_mbps >> 3) / 20 > esc_clk_division
         */
        u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;

        dsi_write(dsi, DSI_PWR_UP, RESET);
        dsi_write(dsi, DSI_PHY_RSTZ, PHY_DISFORCEPLL | PHY_DISABLECLK
                  | PHY_RSTZ | PHY_SHUTDOWNZ);
        dsi_write(dsi, DSI_CLKMGR_CFG, TO_CLK_DIVIDSION(10) |
                  TX_ESC_CLK_DIVIDSION(esc_clk_division));
}

static void dw_mipi_dsi_dpi_config(struct dw_mipi_dsi *dsi,
                                   struct drm_display_mode *mode)
{
        u32 val = 0, color = 0;

        switch (dsi->format) {
        case MIPI_DSI_FMT_RGB888:
                color = DPI_COLOR_CODING_24BIT;
                break;
        case MIPI_DSI_FMT_RGB666:
                color = DPI_COLOR_CODING_18BIT_2 | EN18_LOOSELY;
                break;
        case MIPI_DSI_FMT_RGB666_PACKED:
                color = DPI_COLOR_CODING_18BIT_1;
                break;
        case MIPI_DSI_FMT_RGB565:
                color = DPI_COLOR_CODING_16BIT_1;
                break;
        }

        if (!(mode->flags & DRM_MODE_FLAG_PVSYNC))
                val |= VSYNC_ACTIVE_LOW;
        if (!(mode->flags & DRM_MODE_FLAG_PHSYNC))
                val |= HSYNC_ACTIVE_LOW;

        dsi_write(dsi, DSI_DPI_VCID, DPI_VID(dsi->channel));
        dsi_write(dsi, DSI_DPI_COLOR_CODING, color);
        dsi_write(dsi, DSI_DPI_CFG_POL, val);
        dsi_write(dsi, DSI_DPI_LP_CMD_TIM, OUTVACT_LPCMD_TIME(4)
                  | INVACT_LPCMD_TIME(4));
}

static void dw_mipi_dsi_packet_handler_config(struct dw_mipi_dsi *dsi)
{
        dsi_write(dsi, DSI_PCKHDL_CFG, EN_CRC_RX | EN_ECC_RX | EN_BTA);
}

static void dw_mipi_dsi_video_packet_config(struct dw_mipi_dsi *dsi,
                                            struct drm_display_mode *mode)
{
        dsi_write(dsi, DSI_VID_PKT_SIZE, VID_PKT_SIZE(mode->hdisplay));
}

static void dw_mipi_dsi_command_mode_config(struct dw_mipi_dsi *dsi)
{
        dsi_write(dsi, DSI_TO_CNT_CFG, HSTX_TO_CNT(1000) | LPRX_TO_CNT(1000));
        dsi_write(dsi, DSI_BTA_TO_CNT, 0xd00);
        dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
}

/* Get lane byte clock cycles. */
static u32 dw_mipi_dsi_get_hcomponent_lbcc(struct dw_mipi_dsi *dsi,
                                           struct drm_display_mode *mode,
                                           u32 hcomponent)
{
        u32 frac, lbcc;

        lbcc = hcomponent * dsi->lane_mbps * MSEC_PER_SEC / 8;

        frac = lbcc % mode->clock;
        lbcc = lbcc / mode->clock;
        if (frac)
                lbcc++;

        return lbcc;
}

static void dw_mipi_dsi_line_timer_config(struct dw_mipi_dsi *dsi,
                                          struct drm_display_mode *mode)
{
        u32 htotal, hsa, hbp, lbcc;

        htotal = mode->htotal;
        hsa = mode->hsync_end - mode->hsync_start;
        hbp = mode->htotal - mode->hsync_end;

        lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, htotal);
        dsi_write(dsi, DSI_VID_HLINE_TIME, lbcc);

        lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hsa);
        dsi_write(dsi, DSI_VID_HSA_TIME, lbcc);

        lbcc = dw_mipi_dsi_get_hcomponent_lbcc(dsi, mode, hbp);
        dsi_write(dsi, DSI_VID_HBP_TIME, lbcc);
}

static void dw_mipi_dsi_vertical_timing_config(struct dw_mipi_dsi *dsi,
                                               struct drm_display_mode *mode)
{
        u32 vactive, vsa, vfp, vbp;

        vactive = mode->vdisplay;
        vsa = mode->vsync_end - mode->vsync_start;
        vfp = mode->vsync_start - mode->vdisplay;
        vbp = mode->vtotal - mode->vsync_end;

        dsi_write(dsi, DSI_VID_VACTIVE_LINES, vactive);
        dsi_write(dsi, DSI_VID_VSA_LINES, vsa);
        dsi_write(dsi, DSI_VID_VFP_LINES, vfp);
        dsi_write(dsi, DSI_VID_VBP_LINES, vbp);
}

static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
{
        dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME(0x40)
                  | PHY_LP2HS_TIME(0x40) | MAX_RD_TIME(10000));

        dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(0x40)
                  | PHY_CLKLP2HS_TIME(0x40));
}

static void dw_mipi_dsi_dphy_interface_config(struct dw_mipi_dsi *dsi)
{
        dsi_write(dsi, DSI_PHY_IF_CFG, PHY_STOP_WAIT_TIME(0x20) |
                  N_LANES(dsi->lanes));
}

static void dw_mipi_dsi_clear_err(struct dw_mipi_dsi *dsi)
{
        dsi_read(dsi, DSI_INT_ST0);
        dsi_read(dsi, DSI_INT_ST1);
        dsi_write(dsi, DSI_INT_MSK0, 0);
        dsi_write(dsi, DSI_INT_MSK1, 0);
}

static void dw_mipi_dsi_encoder_disable(struct drm_encoder *encoder)
{
        struct dw_mipi_dsi *dsi = encoder_to_dsi(encoder);

        if (clk_prepare_enable(dsi->pclk)) {
                dev_err(dsi->dev, "%s: Failed to enable pclk\n", __func__);
                return;
        }

        drm_panel_disable(dsi->panel);

        dw_mipi_dsi_set_mode(dsi, DW_MIPI_DSI_CMD_MODE);
        drm_panel_unprepare(dsi->panel);

        dw_mipi_dsi_disable(dsi);
        clk_disable_unprepare(dsi->pclk);
}

static void dw_mipi_dsi_encoder_enable(struct drm_encoder *encoder)
{
        struct dw_mipi_dsi *dsi = encoder_to_dsi(encoder);
        struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
        int mux = drm_of_encoder_active_endpoint_id(dsi->dev->of_node, encoder);
        u32 val;
        int ret;

        ret = dw_mipi_dsi_get_lane_bps(dsi, mode);
        if (ret < 0)
                return;

        if (clk_prepare_enable(dsi->pclk)) {
                dev_err(dsi->dev, "%s: Failed to enable pclk\n", __func__);
                return;
        }

        dw_mipi_dsi_init(dsi);
        dw_mipi_dsi_dpi_config(dsi, mode);
        dw_mipi_dsi_packet_handler_config(dsi);
        dw_mipi_dsi_video_mode_config(dsi);
        dw_mipi_dsi_video_packet_config(dsi, mode);
        dw_mipi_dsi_command_mode_config(dsi);
        dw_mipi_dsi_line_timer_config(dsi, mode);
        dw_mipi_dsi_vertical_timing_config(dsi, mode);
        dw_mipi_dsi_dphy_timing_config(dsi);
        dw_mipi_dsi_dphy_interface_config(dsi);
        dw_mipi_dsi_clear_err(dsi);

        dw_mipi_dsi_phy_init(dsi);
        dw_mipi_dsi_wait_for_two_frames(mode);

        dw_mipi_dsi_set_mode(dsi, DW_MIPI_DSI_CMD_MODE);
        if (drm_panel_prepare(dsi->panel))
                dev_err(dsi->dev, "failed to prepare panel\n");

        dw_mipi_dsi_set_mode(dsi, DW_MIPI_DSI_VID_MODE);
        drm_panel_enable(dsi->panel);

        clk_disable_unprepare(dsi->pclk);

        if (mux)
                val = DSI0_SEL_VOP_LIT | (DSI0_SEL_VOP_LIT << 16);
        else
                val = DSI0_SEL_VOP_LIT << 16;

        regmap_write(dsi->grf_regmap, GRF_SOC_CON6, val);
        dev_dbg(dsi->dev, "vop %s output to dsi0\n", (mux) ? "LIT" : "BIG");
}

static int
dw_mipi_dsi_encoder_atomic_check(struct drm_encoder *encoder,
                                 struct drm_crtc_state *crtc_state,
                                 struct drm_connector_state *conn_state)
{
        struct rockchip_crtc_state *s = to_rockchip_crtc_state(crtc_state);
        struct dw_mipi_dsi *dsi = encoder_to_dsi(encoder);

        switch (dsi->format) {
        case MIPI_DSI_FMT_RGB888:
                s->output_mode = ROCKCHIP_OUT_MODE_P888;
                break;
        case MIPI_DSI_FMT_RGB666:
                s->output_mode = ROCKCHIP_OUT_MODE_P666;
                break;
        case MIPI_DSI_FMT_RGB565:
                s->output_mode = ROCKCHIP_OUT_MODE_P565;
                break;
        default:
                WARN_ON(1);
                return -EINVAL;
        }

        s->output_type = DRM_MODE_CONNECTOR_DSI;

        return 0;
}

static struct drm_encoder_helper_funcs
dw_mipi_dsi_encoder_helper_funcs = {
        .enable = dw_mipi_dsi_encoder_enable,
        .disable = dw_mipi_dsi_encoder_disable,
        .atomic_check = dw_mipi_dsi_encoder_atomic_check,
};

static struct drm_encoder_funcs dw_mipi_dsi_encoder_funcs = {
        .destroy = drm_encoder_cleanup,
};

static int dw_mipi_dsi_connector_get_modes(struct drm_connector *connector)
{
        struct dw_mipi_dsi *dsi = con_to_dsi(connector);

        return drm_panel_get_modes(dsi->panel);
}

static enum drm_mode_status dw_mipi_dsi_mode_valid(
                                        struct drm_connector *connector,
                                        struct drm_display_mode *mode)
{
        struct dw_mipi_dsi *dsi = con_to_dsi(connector);

        enum drm_mode_status mode_status = MODE_OK;

        if (dsi->pdata->mode_valid)
                mode_status = dsi->pdata->mode_valid(connector, mode);

        return mode_status;
}

static struct drm_connector_helper_funcs dw_mipi_dsi_connector_helper_funcs = {
        .get_modes = dw_mipi_dsi_connector_get_modes,
        .mode_valid = dw_mipi_dsi_mode_valid,
};

static void dw_mipi_dsi_drm_connector_destroy(struct drm_connector *connector)
{
        drm_connector_unregister(connector);
        drm_connector_cleanup(connector);
}

static struct drm_connector_funcs dw_mipi_dsi_atomic_connector_funcs = {
        .dpms = drm_atomic_helper_connector_dpms,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = dw_mipi_dsi_drm_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int dw_mipi_dsi_register(struct drm_device *drm,
                                      struct dw_mipi_dsi *dsi)
{
        struct drm_encoder *encoder = &dsi->encoder;
        struct drm_connector *connector = &dsi->connector;
        struct device *dev = dsi->dev;
        int ret;

        encoder->possible_crtcs = drm_of_find_possible_crtcs(drm,
                                                             dev->of_node);
        /*
         * If we failed to find the CRTC(s) which this encoder is
         * supposed to be connected to, it's because the CRTC has
         * not been registered yet.  Defer probing, and hope that
         * the required CRTC is added later.
         */
        if (encoder->possible_crtcs == 0)
                return -EPROBE_DEFER;

        drm_encoder_helper_add(&dsi->encoder,
                               &dw_mipi_dsi_encoder_helper_funcs);
        ret = drm_encoder_init(drm, &dsi->encoder, &dw_mipi_dsi_encoder_funcs,
                         DRM_MODE_ENCODER_DSI, NULL);
        if (ret) {
                dev_err(dev, "Failed to initialize encoder with drm\n");
                return ret;
        }

        drm_connector_helper_add(connector,
                        &dw_mipi_dsi_connector_helper_funcs);

        drm_connector_init(drm, &dsi->connector,
                           &dw_mipi_dsi_atomic_connector_funcs,
                           DRM_MODE_CONNECTOR_DSI);

        drm_mode_connector_attach_encoder(connector, encoder);

        return 0;
}

static int rockchip_mipi_parse_dt(struct dw_mipi_dsi *dsi)
{
        struct device_node *np = dsi->dev->of_node;

        dsi->grf_regmap = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
        if (IS_ERR(dsi->grf_regmap)) {
                dev_err(dsi->dev, "Unable to get rockchip,grf\n");
                return PTR_ERR(dsi->grf_regmap);
        }

        return 0;
}

static enum drm_mode_status rk3288_mipi_dsi_mode_valid(
                                        struct drm_connector *connector,
                                        struct drm_display_mode *mode)
{
        /*
         * The VID_PKT_SIZE field in the DSI_VID_PKT_CFG
         * register is 11-bit.
         */
        if (mode->hdisplay > 0x7ff)
                return MODE_BAD_HVALUE;

        /*
         * The V_ACTIVE_LINES field in the DSI_VTIMING_CFG
         * register is 11-bit.
         */
        if (mode->vdisplay > 0x7ff)
                return MODE_BAD_VVALUE;

        return MODE_OK;
}

static struct dw_mipi_dsi_plat_data rk3288_mipi_dsi_drv_data = {
        .max_data_lanes = 4,
        .mode_valid = rk3288_mipi_dsi_mode_valid,
};

static const struct of_device_id dw_mipi_dsi_dt_ids[] = {
        {
         .compatible = "rockchip,rk3288-mipi-dsi",
         .data = &rk3288_mipi_dsi_drv_data,
        },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, dw_mipi_dsi_dt_ids);

static int dw_mipi_dsi_bind(struct device *dev, struct device *master,
                             void *data)
{
        const struct of_device_id *of_id =
                        of_match_device(dw_mipi_dsi_dt_ids, dev);
        const struct dw_mipi_dsi_plat_data *pdata = of_id->data;
        struct platform_device *pdev = to_platform_device(dev);
        struct drm_device *drm = data;
        struct dw_mipi_dsi *dsi;
        struct resource *res;
        int ret;

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

        dsi->dev = dev;
        dsi->pdata = pdata;

        ret = rockchip_mipi_parse_dt(dsi);
        if (ret)
                return ret;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;

        dsi->base = devm_ioremap_resource(dev, res);
        if (IS_ERR(dsi->base))
                return PTR_ERR(dsi->base);

        dsi->pllref_clk = devm_clk_get(dev, "ref");
        if (IS_ERR(dsi->pllref_clk)) {
                ret = PTR_ERR(dsi->pllref_clk);
                dev_err(dev, "Unable to get pll reference clock: %d\n", ret);
                return ret;
        }

        dsi->pclk = devm_clk_get(dev, "pclk");
        if (IS_ERR(dsi->pclk)) {
                ret = PTR_ERR(dsi->pclk);
                dev_err(dev, "Unable to get pclk: %d\n", ret);
                return ret;
        }

        ret = clk_prepare_enable(dsi->pllref_clk);
        if (ret) {
                dev_err(dev, "%s: Failed to enable pllref_clk\n", __func__);
                return ret;
        }

        ret = dw_mipi_dsi_register(drm, dsi);
        if (ret) {
                dev_err(dev, "Failed to register mipi_dsi: %d\n", ret);
                goto err_pllref;
        }

        dev_set_drvdata(dev, dsi);

        dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
        dsi->dsi_host.dev = dev;
        return mipi_dsi_host_register(&dsi->dsi_host);

err_pllref:
        clk_disable_unprepare(dsi->pllref_clk);
        return ret;
}

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

        mipi_dsi_host_unregister(&dsi->dsi_host);
        clk_disable_unprepare(dsi->pllref_clk);
}

static const struct component_ops dw_mipi_dsi_ops = {
        .bind   = dw_mipi_dsi_bind,
        .unbind = dw_mipi_dsi_unbind,
};

static int dw_mipi_dsi_probe(struct platform_device *pdev)
{
        return component_add(&pdev->dev, &dw_mipi_dsi_ops);
}

static int dw_mipi_dsi_remove(struct platform_device *pdev)
{
        component_del(&pdev->dev, &dw_mipi_dsi_ops);
        return 0;
}

static struct platform_driver dw_mipi_dsi_driver = {
        .probe          = dw_mipi_dsi_probe,
        .remove         = dw_mipi_dsi_remove,
        .driver         = {
                .of_match_table = dw_mipi_dsi_dt_ids,
                .name   = DRIVER_NAME,
        },
};
module_platform_driver(dw_mipi_dsi_driver);

MODULE_DESCRIPTION("ROCKCHIP MIPI DSI host controller driver");
MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);