// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 Broadcom
 */

/**
 * DOC: VC4 DSI0/DSI1 module
 *
 * BCM2835 contains two DSI modules, DSI0 and DSI1.  DSI0 is a
 * single-lane DSI controller, while DSI1 is a more modern 4-lane DSI
 * controller.
 *
 * Most Raspberry Pi boards expose DSI1 as their "DISPLAY" connector,
 * while the compute module brings both DSI0 and DSI1 out.
 *
 * This driver has been tested for DSI1 video-mode display only
 * currently, with most of the information necessary for DSI0
 * hopefully present.
 */

#include <drm/drm_atomic_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_mipi_dsi.h>
#include <drm/drm_of.h>
#include <drm/drm_panel.h>
#include <drm/drm_probe_helper.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/completion.h>
#include <linux/component.h>
#include <linux/dmaengine.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pm_runtime.h>
#include "vc4_drv.h"
#include "vc4_regs.h"

#define DSI_CMD_FIFO_DEPTH  16
#define DSI_PIX_FIFO_DEPTH 256
#define DSI_PIX_FIFO_WIDTH   4

#define DSI0_CTRL               0x00

/* Command packet control. */
#define DSI0_TXPKT1C            0x04 /* AKA PKTC */
#define DSI1_TXPKT1C            0x04
# define DSI_TXPKT1C_TRIG_CMD_MASK      VC4_MASK(31, 24)
# define DSI_TXPKT1C_TRIG_CMD_SHIFT     24
# define DSI_TXPKT1C_CMD_REPEAT_MASK    VC4_MASK(23, 10)
# define DSI_TXPKT1C_CMD_REPEAT_SHIFT   10

# define DSI_TXPKT1C_DISPLAY_NO_MASK    VC4_MASK(9, 8)
# define DSI_TXPKT1C_DISPLAY_NO_SHIFT   8
/* Short, trigger, BTA, or a long packet that fits all in CMDFIFO. */
# define DSI_TXPKT1C_DISPLAY_NO_SHORT           0
/* Primary display where cmdfifo provides part of the payload and
 * pixelvalve the rest.
 */
# define DSI_TXPKT1C_DISPLAY_NO_PRIMARY         1
/* Secondary display where cmdfifo provides part of the payload and
 * pixfifo the rest.
 */
# define DSI_TXPKT1C_DISPLAY_NO_SECONDARY       2

# define DSI_TXPKT1C_CMD_TX_TIME_MASK   VC4_MASK(7, 6)
# define DSI_TXPKT1C_CMD_TX_TIME_SHIFT  6

# define DSI_TXPKT1C_CMD_CTRL_MASK      VC4_MASK(5, 4)
# define DSI_TXPKT1C_CMD_CTRL_SHIFT     4
/* Command only.  Uses TXPKT1H and DISPLAY_NO */
# define DSI_TXPKT1C_CMD_CTRL_TX        0
/* Command with BTA for either ack or read data. */
# define DSI_TXPKT1C_CMD_CTRL_RX        1
/* Trigger according to TRIG_CMD */
# define DSI_TXPKT1C_CMD_CTRL_TRIG      2
/* BTA alone for getting error status after a command, or a TE trigger
 * without a previous command.
 */
# define DSI_TXPKT1C_CMD_CTRL_BTA       3

# define DSI_TXPKT1C_CMD_MODE_LP        BIT(3)
# define DSI_TXPKT1C_CMD_TYPE_LONG      BIT(2)
# define DSI_TXPKT1C_CMD_TE_EN          BIT(1)
# define DSI_TXPKT1C_CMD_EN             BIT(0)

/* Command packet header. */
#define DSI0_TXPKT1H            0x08 /* AKA PKTH */
#define DSI1_TXPKT1H            0x08
# define DSI_TXPKT1H_BC_CMDFIFO_MASK    VC4_MASK(31, 24)
# define DSI_TXPKT1H_BC_CMDFIFO_SHIFT   24
# define DSI_TXPKT1H_BC_PARAM_MASK      VC4_MASK(23, 8)
# define DSI_TXPKT1H_BC_PARAM_SHIFT     8
# define DSI_TXPKT1H_BC_DT_MASK         VC4_MASK(7, 0)
# define DSI_TXPKT1H_BC_DT_SHIFT        0

#define DSI0_RXPKT1H            0x0c /* AKA RX1_PKTH */
#define DSI1_RXPKT1H            0x14
# define DSI_RXPKT1H_CRC_ERR            BIT(31)
# define DSI_RXPKT1H_DET_ERR            BIT(30)
# define DSI_RXPKT1H_ECC_ERR            BIT(29)
# define DSI_RXPKT1H_COR_ERR            BIT(28)
# define DSI_RXPKT1H_INCOMP_PKT         BIT(25)
# define DSI_RXPKT1H_PKT_TYPE_LONG      BIT(24)
/* Byte count if DSI_RXPKT1H_PKT_TYPE_LONG */
# define DSI_RXPKT1H_BC_PARAM_MASK      VC4_MASK(23, 8)
# define DSI_RXPKT1H_BC_PARAM_SHIFT     8
/* Short return bytes if !DSI_RXPKT1H_PKT_TYPE_LONG */
# define DSI_RXPKT1H_SHORT_1_MASK       VC4_MASK(23, 16)
# define DSI_RXPKT1H_SHORT_1_SHIFT      16
# define DSI_RXPKT1H_SHORT_0_MASK       VC4_MASK(15, 8)
# define DSI_RXPKT1H_SHORT_0_SHIFT      8
# define DSI_RXPKT1H_DT_LP_CMD_MASK     VC4_MASK(7, 0)
# define DSI_RXPKT1H_DT_LP_CMD_SHIFT    0

#define DSI0_RXPKT2H            0x10 /* AKA RX2_PKTH */
#define DSI1_RXPKT2H            0x18
# define DSI_RXPKT1H_DET_ERR            BIT(30)
# define DSI_RXPKT1H_ECC_ERR            BIT(29)
# define DSI_RXPKT1H_COR_ERR            BIT(28)
# define DSI_RXPKT1H_INCOMP_PKT         BIT(25)
# define DSI_RXPKT1H_BC_PARAM_MASK      VC4_MASK(23, 8)
# define DSI_RXPKT1H_BC_PARAM_SHIFT     8
# define DSI_RXPKT1H_DT_MASK            VC4_MASK(7, 0)
# define DSI_RXPKT1H_DT_SHIFT           0

#define DSI0_TXPKT_CMD_FIFO     0x14 /* AKA CMD_DATAF */
#define DSI1_TXPKT_CMD_FIFO     0x1c

#define DSI0_DISP0_CTRL         0x18
# define DSI_DISP0_PIX_CLK_DIV_MASK     VC4_MASK(21, 13)
# define DSI_DISP0_PIX_CLK_DIV_SHIFT    13
# define DSI_DISP0_LP_STOP_CTRL_MASK    VC4_MASK(12, 11)
# define DSI_DISP0_LP_STOP_CTRL_SHIFT   11
# define DSI_DISP0_LP_STOP_DISABLE      0
# define DSI_DISP0_LP_STOP_PERLINE      1
# define DSI_DISP0_LP_STOP_PERFRAME     2

/* Transmit RGB pixels and null packets only during HACTIVE, instead
 * of going to LP-STOP.
 */
# define DSI_DISP_HACTIVE_NULL          BIT(10)
/* Transmit blanking packet only during vblank, instead of allowing LP-STOP. */
# define DSI_DISP_VBLP_CTRL             BIT(9)
/* Transmit blanking packet only during HFP, instead of allowing LP-STOP. */
# define DSI_DISP_HFP_CTRL              BIT(8)
/* Transmit blanking packet only during HBP, instead of allowing LP-STOP. */
# define DSI_DISP_HBP_CTRL              BIT(7)
# define DSI_DISP0_CHANNEL_MASK         VC4_MASK(6, 5)
# define DSI_DISP0_CHANNEL_SHIFT        5
/* Enables end events for HSYNC/VSYNC, not just start events. */
# define DSI_DISP0_ST_END               BIT(4)
# define DSI_DISP0_PFORMAT_MASK         VC4_MASK(3, 2)
# define DSI_DISP0_PFORMAT_SHIFT        2
# define DSI_PFORMAT_RGB565             0
# define DSI_PFORMAT_RGB666_PACKED      1
# define DSI_PFORMAT_RGB666             2
# define DSI_PFORMAT_RGB888             3
/* Default is VIDEO mode. */
# define DSI_DISP0_COMMAND_MODE         BIT(1)
# define DSI_DISP0_ENABLE               BIT(0)

#define DSI0_DISP1_CTRL         0x1c
#define DSI1_DISP1_CTRL         0x2c
/* Format of the data written to TXPKT_PIX_FIFO. */
# define DSI_DISP1_PFORMAT_MASK         VC4_MASK(2, 1)
# define DSI_DISP1_PFORMAT_SHIFT        1
# define DSI_DISP1_PFORMAT_16BIT        0
# define DSI_DISP1_PFORMAT_24BIT        1
# define DSI_DISP1_PFORMAT_32BIT_LE     2
# define DSI_DISP1_PFORMAT_32BIT_BE     3

/* DISP1 is always command mode. */
# define DSI_DISP1_ENABLE               BIT(0)

#define DSI0_TXPKT_PIX_FIFO             0x20 /* AKA PIX_FIFO */

#define DSI0_INT_STAT           0x24
#define DSI0_INT_EN             0x28
# define DSI1_INT_PHY_D3_ULPS           BIT(30)
# define DSI1_INT_PHY_D3_STOP           BIT(29)
# define DSI1_INT_PHY_D2_ULPS           BIT(28)
# define DSI1_INT_PHY_D2_STOP           BIT(27)
# define DSI1_INT_PHY_D1_ULPS           BIT(26)
# define DSI1_INT_PHY_D1_STOP           BIT(25)
# define DSI1_INT_PHY_D0_ULPS           BIT(24)
# define DSI1_INT_PHY_D0_STOP           BIT(23)
# define DSI1_INT_FIFO_ERR              BIT(22)
# define DSI1_INT_PHY_DIR_RTF           BIT(21)
# define DSI1_INT_PHY_RXLPDT            BIT(20)
# define DSI1_INT_PHY_RXTRIG            BIT(19)
# define DSI1_INT_PHY_D0_LPDT           BIT(18)
# define DSI1_INT_PHY_DIR_FTR           BIT(17)

/* Signaled when the clock lane enters the given state. */
# define DSI1_INT_PHY_CLOCK_ULPS        BIT(16)
# define DSI1_INT_PHY_CLOCK_HS          BIT(15)
# define DSI1_INT_PHY_CLOCK_STOP        BIT(14)

/* Signaled on timeouts */
# define DSI1_INT_PR_TO                 BIT(13)
# define DSI1_INT_TA_TO                 BIT(12)
# define DSI1_INT_LPRX_TO               BIT(11)
# define DSI1_INT_HSTX_TO               BIT(10)

/* Contention on a line when trying to drive the line low */
# define DSI1_INT_ERR_CONT_LP1          BIT(9)
# define DSI1_INT_ERR_CONT_LP0          BIT(8)

/* Control error: incorrect line state sequence on data lane 0. */
# define DSI1_INT_ERR_CONTROL           BIT(7)
/* LPDT synchronization error (bits received not a multiple of 8. */

# define DSI1_INT_ERR_SYNC_ESC          BIT(6)
/* Signaled after receiving an error packet from the display in
 * response to a read.
 */
# define DSI1_INT_RXPKT2                BIT(5)
/* Signaled after receiving a packet.  The header and optional short
 * response will be in RXPKT1H, and a long response will be in the
 * RXPKT_FIFO.
 */
# define DSI1_INT_RXPKT1                BIT(4)
# define DSI1_INT_TXPKT2_DONE           BIT(3)
# define DSI1_INT_TXPKT2_END            BIT(2)
/* Signaled after all repeats of TXPKT1 are transferred. */
# define DSI1_INT_TXPKT1_DONE           BIT(1)
/* Signaled after each TXPKT1 repeat is scheduled. */
# define DSI1_INT_TXPKT1_END            BIT(0)

#define DSI1_INTERRUPTS_ALWAYS_ENABLED  (DSI1_INT_ERR_SYNC_ESC | \
                                         DSI1_INT_ERR_CONTROL |  \
                                         DSI1_INT_ERR_CONT_LP0 | \
                                         DSI1_INT_ERR_CONT_LP1 | \
                                         DSI1_INT_HSTX_TO |      \
                                         DSI1_INT_LPRX_TO |      \
                                         DSI1_INT_TA_TO |        \
                                         DSI1_INT_PR_TO)

#define DSI0_STAT               0x2c
#define DSI0_HSTX_TO_CNT        0x30
#define DSI0_LPRX_TO_CNT        0x34
#define DSI0_TA_TO_CNT          0x38
#define DSI0_PR_TO_CNT          0x3c
#define DSI0_PHYC               0x40
# define DSI1_PHYC_ESC_CLK_LPDT_MASK    VC4_MASK(25, 20)
# define DSI1_PHYC_ESC_CLK_LPDT_SHIFT   20
# define DSI1_PHYC_HS_CLK_CONTINUOUS    BIT(18)
# define DSI0_PHYC_ESC_CLK_LPDT_MASK    VC4_MASK(17, 12)
# define DSI0_PHYC_ESC_CLK_LPDT_SHIFT   12
# define DSI1_PHYC_CLANE_ULPS           BIT(17)
# define DSI1_PHYC_CLANE_ENABLE         BIT(16)
# define DSI_PHYC_DLANE3_ULPS           BIT(13)
# define DSI_PHYC_DLANE3_ENABLE         BIT(12)
# define DSI0_PHYC_HS_CLK_CONTINUOUS    BIT(10)
# define DSI0_PHYC_CLANE_ULPS           BIT(9)
# define DSI_PHYC_DLANE2_ULPS           BIT(9)
# define DSI0_PHYC_CLANE_ENABLE         BIT(8)
# define DSI_PHYC_DLANE2_ENABLE         BIT(8)
# define DSI_PHYC_DLANE1_ULPS           BIT(5)
# define DSI_PHYC_DLANE1_ENABLE         BIT(4)
# define DSI_PHYC_DLANE0_FORCE_STOP     BIT(2)
# define DSI_PHYC_DLANE0_ULPS           BIT(1)
# define DSI_PHYC_DLANE0_ENABLE         BIT(0)

#define DSI0_HS_CLT0            0x44
#define DSI0_HS_CLT1            0x48
#define DSI0_HS_CLT2            0x4c
#define DSI0_HS_DLT3            0x50
#define DSI0_HS_DLT4            0x54
#define DSI0_HS_DLT5            0x58
#define DSI0_HS_DLT6            0x5c
#define DSI0_HS_DLT7            0x60

#define DSI0_PHY_AFEC0          0x64
# define DSI0_PHY_AFEC0_DDR2CLK_EN              BIT(26)
# define DSI0_PHY_AFEC0_DDRCLK_EN               BIT(25)
# define DSI0_PHY_AFEC0_LATCH_ULPS              BIT(24)
# define DSI1_PHY_AFEC0_IDR_DLANE3_MASK         VC4_MASK(31, 29)
# define DSI1_PHY_AFEC0_IDR_DLANE3_SHIFT        29
# define DSI1_PHY_AFEC0_IDR_DLANE2_MASK         VC4_MASK(28, 26)
# define DSI1_PHY_AFEC0_IDR_DLANE2_SHIFT        26
# define DSI1_PHY_AFEC0_IDR_DLANE1_MASK         VC4_MASK(27, 23)
# define DSI1_PHY_AFEC0_IDR_DLANE1_SHIFT        23
# define DSI1_PHY_AFEC0_IDR_DLANE0_MASK         VC4_MASK(22, 20)
# define DSI1_PHY_AFEC0_IDR_DLANE0_SHIFT        20
# define DSI1_PHY_AFEC0_IDR_CLANE_MASK          VC4_MASK(19, 17)
# define DSI1_PHY_AFEC0_IDR_CLANE_SHIFT         17
# define DSI0_PHY_AFEC0_ACTRL_DLANE1_MASK       VC4_MASK(23, 20)
# define DSI0_PHY_AFEC0_ACTRL_DLANE1_SHIFT      20
# define DSI0_PHY_AFEC0_ACTRL_DLANE0_MASK       VC4_MASK(19, 16)
# define DSI0_PHY_AFEC0_ACTRL_DLANE0_SHIFT      16
# define DSI0_PHY_AFEC0_ACTRL_CLANE_MASK        VC4_MASK(15, 12)
# define DSI0_PHY_AFEC0_ACTRL_CLANE_SHIFT       12
# define DSI1_PHY_AFEC0_DDR2CLK_EN              BIT(16)
# define DSI1_PHY_AFEC0_DDRCLK_EN               BIT(15)
# define DSI1_PHY_AFEC0_LATCH_ULPS              BIT(14)
# define DSI1_PHY_AFEC0_RESET                   BIT(13)
# define DSI1_PHY_AFEC0_PD                      BIT(12)
# define DSI0_PHY_AFEC0_RESET                   BIT(11)
# define DSI1_PHY_AFEC0_PD_BG                   BIT(11)
# define DSI0_PHY_AFEC0_PD                      BIT(10)
# define DSI1_PHY_AFEC0_PD_DLANE3               BIT(10)
# define DSI0_PHY_AFEC0_PD_BG                   BIT(9)
# define DSI1_PHY_AFEC0_PD_DLANE2               BIT(9)
# define DSI0_PHY_AFEC0_PD_DLANE1               BIT(8)
# define DSI1_PHY_AFEC0_PD_DLANE1               BIT(8)
# define DSI_PHY_AFEC0_PTATADJ_MASK             VC4_MASK(7, 4)
# define DSI_PHY_AFEC0_PTATADJ_SHIFT            4
# define DSI_PHY_AFEC0_CTATADJ_MASK             VC4_MASK(3, 0)
# define DSI_PHY_AFEC0_CTATADJ_SHIFT            0

#define DSI0_PHY_AFEC1          0x68
# define DSI0_PHY_AFEC1_IDR_DLANE1_MASK         VC4_MASK(10, 8)
# define DSI0_PHY_AFEC1_IDR_DLANE1_SHIFT        8
# define DSI0_PHY_AFEC1_IDR_DLANE0_MASK         VC4_MASK(6, 4)
# define DSI0_PHY_AFEC1_IDR_DLANE0_SHIFT        4
# define DSI0_PHY_AFEC1_IDR_CLANE_MASK          VC4_MASK(2, 0)
# define DSI0_PHY_AFEC1_IDR_CLANE_SHIFT         0

#define DSI0_TST_SEL            0x6c
#define DSI0_TST_MON            0x70
#define DSI0_ID                 0x74
# define DSI_ID_VALUE           0x00647369

#define DSI1_CTRL               0x00
# define DSI_CTRL_HS_CLKC_MASK          VC4_MASK(15, 14)
# define DSI_CTRL_HS_CLKC_SHIFT         14
# define DSI_CTRL_HS_CLKC_BYTE          0
# define DSI_CTRL_HS_CLKC_DDR2          1
# define DSI_CTRL_HS_CLKC_DDR           2

# define DSI_CTRL_RX_LPDT_EOT_DISABLE   BIT(13)
# define DSI_CTRL_LPDT_EOT_DISABLE      BIT(12)
# define DSI_CTRL_HSDT_EOT_DISABLE      BIT(11)
# define DSI_CTRL_SOFT_RESET_CFG        BIT(10)
# define DSI_CTRL_CAL_BYTE              BIT(9)
# define DSI_CTRL_INV_BYTE              BIT(8)
# define DSI_CTRL_CLR_LDF               BIT(7)
# define DSI0_CTRL_CLR_PBCF             BIT(6)
# define DSI1_CTRL_CLR_RXF              BIT(6)
# define DSI0_CTRL_CLR_CPBCF            BIT(5)
# define DSI1_CTRL_CLR_PDF              BIT(5)
# define DSI0_CTRL_CLR_PDF              BIT(4)
# define DSI1_CTRL_CLR_CDF              BIT(4)
# define DSI0_CTRL_CLR_CDF              BIT(3)
# define DSI0_CTRL_CTRL2                BIT(2)
# define DSI1_CTRL_DISABLE_DISP_CRCC    BIT(2)
# define DSI0_CTRL_CTRL1                BIT(1)
# define DSI1_CTRL_DISABLE_DISP_ECCC    BIT(1)
# define DSI0_CTRL_CTRL0                BIT(0)
# define DSI1_CTRL_EN                   BIT(0)
# define DSI0_CTRL_RESET_FIFOS          (DSI_CTRL_CLR_LDF | \
                                         DSI0_CTRL_CLR_PBCF | \
                                         DSI0_CTRL_CLR_CPBCF |  \
                                         DSI0_CTRL_CLR_PDF | \
                                         DSI0_CTRL_CLR_CDF)
# define DSI1_CTRL_RESET_FIFOS          (DSI_CTRL_CLR_LDF | \
                                         DSI1_CTRL_CLR_RXF | \
                                         DSI1_CTRL_CLR_PDF | \
                                         DSI1_CTRL_CLR_CDF)

#define DSI1_TXPKT2C            0x0c
#define DSI1_TXPKT2H            0x10
#define DSI1_TXPKT_PIX_FIFO     0x20
#define DSI1_RXPKT_FIFO         0x24
#define DSI1_DISP0_CTRL         0x28
#define DSI1_INT_STAT           0x30
#define DSI1_INT_EN             0x34
/* State reporting bits.  These mostly behave like INT_STAT, where
 * writing a 1 clears the bit.
 */
#define DSI1_STAT               0x38
# define DSI1_STAT_PHY_D3_ULPS          BIT(31)
# define DSI1_STAT_PHY_D3_STOP          BIT(30)
# define DSI1_STAT_PHY_D2_ULPS          BIT(29)
# define DSI1_STAT_PHY_D2_STOP          BIT(28)
# define DSI1_STAT_PHY_D1_ULPS          BIT(27)
# define DSI1_STAT_PHY_D1_STOP          BIT(26)
# define DSI1_STAT_PHY_D0_ULPS          BIT(25)
# define DSI1_STAT_PHY_D0_STOP          BIT(24)
# define DSI1_STAT_FIFO_ERR             BIT(23)
# define DSI1_STAT_PHY_RXLPDT           BIT(22)
# define DSI1_STAT_PHY_RXTRIG           BIT(21)
# define DSI1_STAT_PHY_D0_LPDT          BIT(20)
/* Set when in forward direction */
# define DSI1_STAT_PHY_DIR              BIT(19)
# define DSI1_STAT_PHY_CLOCK_ULPS       BIT(18)
# define DSI1_STAT_PHY_CLOCK_HS         BIT(17)
# define DSI1_STAT_PHY_CLOCK_STOP       BIT(16)
# define DSI1_STAT_PR_TO                BIT(15)
# define DSI1_STAT_TA_TO                BIT(14)
# define DSI1_STAT_LPRX_TO              BIT(13)
# define DSI1_STAT_HSTX_TO              BIT(12)
# define DSI1_STAT_ERR_CONT_LP1         BIT(11)
# define DSI1_STAT_ERR_CONT_LP0         BIT(10)
# define DSI1_STAT_ERR_CONTROL          BIT(9)
# define DSI1_STAT_ERR_SYNC_ESC         BIT(8)
# define DSI1_STAT_RXPKT2               BIT(7)
# define DSI1_STAT_RXPKT1               BIT(6)
# define DSI1_STAT_TXPKT2_BUSY          BIT(5)
# define DSI1_STAT_TXPKT2_DONE          BIT(4)
# define DSI1_STAT_TXPKT2_END           BIT(3)
# define DSI1_STAT_TXPKT1_BUSY          BIT(2)
# define DSI1_STAT_TXPKT1_DONE          BIT(1)
# define DSI1_STAT_TXPKT1_END           BIT(0)

#define DSI1_HSTX_TO_CNT        0x3c
#define DSI1_LPRX_TO_CNT        0x40
#define DSI1_TA_TO_CNT          0x44
#define DSI1_PR_TO_CNT          0x48
#define DSI1_PHYC               0x4c

#define DSI1_HS_CLT0            0x50
# define DSI_HS_CLT0_CZERO_MASK         VC4_MASK(26, 18)
# define DSI_HS_CLT0_CZERO_SHIFT        18
# define DSI_HS_CLT0_CPRE_MASK          VC4_MASK(17, 9)
# define DSI_HS_CLT0_CPRE_SHIFT         9
# define DSI_HS_CLT0_CPREP_MASK         VC4_MASK(8, 0)
# define DSI_HS_CLT0_CPREP_SHIFT        0

#define DSI1_HS_CLT1            0x54
# define DSI_HS_CLT1_CTRAIL_MASK        VC4_MASK(17, 9)
# define DSI_HS_CLT1_CTRAIL_SHIFT       9
# define DSI_HS_CLT1_CPOST_MASK         VC4_MASK(8, 0)
# define DSI_HS_CLT1_CPOST_SHIFT        0

#define DSI1_HS_CLT2            0x58
# define DSI_HS_CLT2_WUP_MASK           VC4_MASK(23, 0)
# define DSI_HS_CLT2_WUP_SHIFT          0

#define DSI1_HS_DLT3            0x5c
# define DSI_HS_DLT3_EXIT_MASK          VC4_MASK(26, 18)
# define DSI_HS_DLT3_EXIT_SHIFT         18
# define DSI_HS_DLT3_ZERO_MASK          VC4_MASK(17, 9)
# define DSI_HS_DLT3_ZERO_SHIFT         9
# define DSI_HS_DLT3_PRE_MASK           VC4_MASK(8, 0)
# define DSI_HS_DLT3_PRE_SHIFT          0

#define DSI1_HS_DLT4            0x60
# define DSI_HS_DLT4_ANLAT_MASK         VC4_MASK(22, 18)
# define DSI_HS_DLT4_ANLAT_SHIFT        18
# define DSI_HS_DLT4_TRAIL_MASK         VC4_MASK(17, 9)
# define DSI_HS_DLT4_TRAIL_SHIFT        9
# define DSI_HS_DLT4_LPX_MASK           VC4_MASK(8, 0)
# define DSI_HS_DLT4_LPX_SHIFT          0

#define DSI1_HS_DLT5            0x64
# define DSI_HS_DLT5_INIT_MASK          VC4_MASK(23, 0)
# define DSI_HS_DLT5_INIT_SHIFT         0

#define DSI1_HS_DLT6            0x68
# define DSI_HS_DLT6_TA_GET_MASK        VC4_MASK(31, 24)
# define DSI_HS_DLT6_TA_GET_SHIFT       24
# define DSI_HS_DLT6_TA_SURE_MASK       VC4_MASK(23, 16)
# define DSI_HS_DLT6_TA_SURE_SHIFT      16
# define DSI_HS_DLT6_TA_GO_MASK         VC4_MASK(15, 8)
# define DSI_HS_DLT6_TA_GO_SHIFT        8
# define DSI_HS_DLT6_LP_LPX_MASK        VC4_MASK(7, 0)
# define DSI_HS_DLT6_LP_LPX_SHIFT       0

#define DSI1_HS_DLT7            0x6c
# define DSI_HS_DLT7_LP_WUP_MASK        VC4_MASK(23, 0)
# define DSI_HS_DLT7_LP_WUP_SHIFT       0

#define DSI1_PHY_AFEC0          0x70

#define DSI1_PHY_AFEC1          0x74
# define DSI1_PHY_AFEC1_ACTRL_DLANE3_MASK       VC4_MASK(19, 16)
# define DSI1_PHY_AFEC1_ACTRL_DLANE3_SHIFT      16
# define DSI1_PHY_AFEC1_ACTRL_DLANE2_MASK       VC4_MASK(15, 12)
# define DSI1_PHY_AFEC1_ACTRL_DLANE2_SHIFT      12
# define DSI1_PHY_AFEC1_ACTRL_DLANE1_MASK       VC4_MASK(11, 8)
# define DSI1_PHY_AFEC1_ACTRL_DLANE1_SHIFT      8
# define DSI1_PHY_AFEC1_ACTRL_DLANE0_MASK       VC4_MASK(7, 4)
# define DSI1_PHY_AFEC1_ACTRL_DLANE0_SHIFT      4
# define DSI1_PHY_AFEC1_ACTRL_CLANE_MASK        VC4_MASK(3, 0)
# define DSI1_PHY_AFEC1_ACTRL_CLANE_SHIFT       0

#define DSI1_TST_SEL            0x78
#define DSI1_TST_MON            0x7c
#define DSI1_PHY_TST1           0x80
#define DSI1_PHY_TST2           0x84
#define DSI1_PHY_FIFO_STAT      0x88
/* Actually, all registers in the range that aren't otherwise claimed
 * will return the ID.
 */
#define DSI1_ID                 0x8c

/* General DSI hardware state. */
struct vc4_dsi {
        struct platform_device *pdev;

        struct mipi_dsi_host dsi_host;
        struct drm_encoder *encoder;
        struct drm_bridge *bridge;

        void __iomem *regs;

        struct dma_chan *reg_dma_chan;
        dma_addr_t reg_dma_paddr;
        u32 *reg_dma_mem;
        dma_addr_t reg_paddr;

        /* Whether we're on bcm2835's DSI0 or DSI1. */
        int port;

        /* DSI channel for the panel we're connected to. */
        u32 channel;
        u32 lanes;
        u32 format;
        u32 divider;
        u32 mode_flags;

        /* Input clock from CPRMAN to the digital PHY, for the DSI
         * escape clock.
         */
        struct clk *escape_clock;

        /* Input clock to the analog PHY, used to generate the DSI bit
         * clock.
         */
        struct clk *pll_phy_clock;

        /* HS Clocks generated within the DSI analog PHY. */
        struct clk_fixed_factor phy_clocks[3];

        struct clk_hw_onecell_data *clk_onecell;

        /* Pixel clock output to the pixelvalve, generated from the HS
         * clock.
         */
        struct clk *pixel_clock;

        struct completion xfer_completion;
        int xfer_result;

        struct debugfs_regset32 regset;
};

#define host_to_dsi(host) container_of(host, struct vc4_dsi, dsi_host)

static inline void
dsi_dma_workaround_write(struct vc4_dsi *dsi, u32 offset, u32 val)
{
        struct dma_chan *chan = dsi->reg_dma_chan;
        struct dma_async_tx_descriptor *tx;
        dma_cookie_t cookie;
        int ret;

        /* DSI0 should be able to write normally. */
        if (!chan) {
                writel(val, dsi->regs + offset);
                return;
        }

        *dsi->reg_dma_mem = val;

        tx = chan->device->device_prep_dma_memcpy(chan,
                                                  dsi->reg_paddr + offset,
                                                  dsi->reg_dma_paddr,
                                                  4, 0);
        if (!tx) {
                DRM_ERROR("Failed to set up DMA register write\n");
                return;
        }

        cookie = tx->tx_submit(tx);
        ret = dma_submit_error(cookie);
        if (ret) {
                DRM_ERROR("Failed to submit DMA: %d\n", ret);
                return;
        }
        ret = dma_sync_wait(chan, cookie);
        if (ret)
                DRM_ERROR("Failed to wait for DMA: %d\n", ret);
}

#define DSI_READ(offset) readl(dsi->regs + (offset))
#define DSI_WRITE(offset, val) dsi_dma_workaround_write(dsi, offset, val)
#define DSI_PORT_READ(offset) \
        DSI_READ(dsi->port ? DSI1_##offset : DSI0_##offset)
#define DSI_PORT_WRITE(offset, val) \
        DSI_WRITE(dsi->port ? DSI1_##offset : DSI0_##offset, val)
#define DSI_PORT_BIT(bit) (dsi->port ? DSI1_##bit : DSI0_##bit)

/* VC4 DSI encoder KMS struct */
struct vc4_dsi_encoder {
        struct vc4_encoder base;
        struct vc4_dsi *dsi;
};

static inline struct vc4_dsi_encoder *
to_vc4_dsi_encoder(struct drm_encoder *encoder)
{
        return container_of(encoder, struct vc4_dsi_encoder, base.base);
}

static const struct debugfs_reg32 dsi0_regs[] = {
        VC4_REG32(DSI0_CTRL),
        VC4_REG32(DSI0_STAT),
        VC4_REG32(DSI0_HSTX_TO_CNT),
        VC4_REG32(DSI0_LPRX_TO_CNT),
        VC4_REG32(DSI0_TA_TO_CNT),
        VC4_REG32(DSI0_PR_TO_CNT),
        VC4_REG32(DSI0_DISP0_CTRL),
        VC4_REG32(DSI0_DISP1_CTRL),
        VC4_REG32(DSI0_INT_STAT),
        VC4_REG32(DSI0_INT_EN),
        VC4_REG32(DSI0_PHYC),
        VC4_REG32(DSI0_HS_CLT0),
        VC4_REG32(DSI0_HS_CLT1),
        VC4_REG32(DSI0_HS_CLT2),
        VC4_REG32(DSI0_HS_DLT3),
        VC4_REG32(DSI0_HS_DLT4),
        VC4_REG32(DSI0_HS_DLT5),
        VC4_REG32(DSI0_HS_DLT6),
        VC4_REG32(DSI0_HS_DLT7),
        VC4_REG32(DSI0_PHY_AFEC0),
        VC4_REG32(DSI0_PHY_AFEC1),
        VC4_REG32(DSI0_ID),
};

static const struct debugfs_reg32 dsi1_regs[] = {
        VC4_REG32(DSI1_CTRL),
        VC4_REG32(DSI1_STAT),
        VC4_REG32(DSI1_HSTX_TO_CNT),
        VC4_REG32(DSI1_LPRX_TO_CNT),
        VC4_REG32(DSI1_TA_TO_CNT),
        VC4_REG32(DSI1_PR_TO_CNT),
        VC4_REG32(DSI1_DISP0_CTRL),
        VC4_REG32(DSI1_DISP1_CTRL),
        VC4_REG32(DSI1_INT_STAT),
        VC4_REG32(DSI1_INT_EN),
        VC4_REG32(DSI1_PHYC),
        VC4_REG32(DSI1_HS_CLT0),
        VC4_REG32(DSI1_HS_CLT1),
        VC4_REG32(DSI1_HS_CLT2),
        VC4_REG32(DSI1_HS_DLT3),
        VC4_REG32(DSI1_HS_DLT4),
        VC4_REG32(DSI1_HS_DLT5),
        VC4_REG32(DSI1_HS_DLT6),
        VC4_REG32(DSI1_HS_DLT7),
        VC4_REG32(DSI1_PHY_AFEC0),
        VC4_REG32(DSI1_PHY_AFEC1),
        VC4_REG32(DSI1_ID),
};

static void vc4_dsi_encoder_destroy(struct drm_encoder *encoder)
{
        drm_encoder_cleanup(encoder);
}

static const struct drm_encoder_funcs vc4_dsi_encoder_funcs = {
        .destroy = vc4_dsi_encoder_destroy,
};

static void vc4_dsi_latch_ulps(struct vc4_dsi *dsi, bool latch)
{
        u32 afec0 = DSI_PORT_READ(PHY_AFEC0);

        if (latch)
                afec0 |= DSI_PORT_BIT(PHY_AFEC0_LATCH_ULPS);
        else
                afec0 &= ~DSI_PORT_BIT(PHY_AFEC0_LATCH_ULPS);

        DSI_PORT_WRITE(PHY_AFEC0, afec0);
}

/* Enters or exits Ultra Low Power State. */
static void vc4_dsi_ulps(struct vc4_dsi *dsi, bool ulps)
{
        bool non_continuous = dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS;
        u32 phyc_ulps = ((non_continuous ? DSI_PORT_BIT(PHYC_CLANE_ULPS) : 0) |
                         DSI_PHYC_DLANE0_ULPS |
                         (dsi->lanes > 1 ? DSI_PHYC_DLANE1_ULPS : 0) |
                         (dsi->lanes > 2 ? DSI_PHYC_DLANE2_ULPS : 0) |
                         (dsi->lanes > 3 ? DSI_PHYC_DLANE3_ULPS : 0));
        u32 stat_ulps = ((non_continuous ? DSI1_STAT_PHY_CLOCK_ULPS : 0) |
                         DSI1_STAT_PHY_D0_ULPS |
                         (dsi->lanes > 1 ? DSI1_STAT_PHY_D1_ULPS : 0) |
                         (dsi->lanes > 2 ? DSI1_STAT_PHY_D2_ULPS : 0) |
                         (dsi->lanes > 3 ? DSI1_STAT_PHY_D3_ULPS : 0));
        u32 stat_stop = ((non_continuous ? DSI1_STAT_PHY_CLOCK_STOP : 0) |
                         DSI1_STAT_PHY_D0_STOP |
                         (dsi->lanes > 1 ? DSI1_STAT_PHY_D1_STOP : 0) |
                         (dsi->lanes > 2 ? DSI1_STAT_PHY_D2_STOP : 0) |
                         (dsi->lanes > 3 ? DSI1_STAT_PHY_D3_STOP : 0));
        int ret;
        bool ulps_currently_enabled = (DSI_PORT_READ(PHY_AFEC0) &
                                       DSI_PORT_BIT(PHY_AFEC0_LATCH_ULPS));

        if (ulps == ulps_currently_enabled)
                return;

        DSI_PORT_WRITE(STAT, stat_ulps);
        DSI_PORT_WRITE(PHYC, DSI_PORT_READ(PHYC) | phyc_ulps);
        ret = wait_for((DSI_PORT_READ(STAT) & stat_ulps) == stat_ulps, 200);
        if (ret) {
                dev_warn(&dsi->pdev->dev,
                         "Timeout waiting for DSI ULPS entry: STAT 0x%08x",
                         DSI_PORT_READ(STAT));
                DSI_PORT_WRITE(PHYC, DSI_PORT_READ(PHYC) & ~phyc_ulps);
                vc4_dsi_latch_ulps(dsi, false);
                return;
        }

        /* The DSI module can't be disabled while the module is
         * generating ULPS state.  So, to be able to disable the
         * module, we have the AFE latch the ULPS state and continue
         * on to having the module enter STOP.
         */
        vc4_dsi_latch_ulps(dsi, ulps);

        DSI_PORT_WRITE(STAT, stat_stop);
        DSI_PORT_WRITE(PHYC, DSI_PORT_READ(PHYC) & ~phyc_ulps);
        ret = wait_for((DSI_PORT_READ(STAT) & stat_stop) == stat_stop, 200);
        if (ret) {
                dev_warn(&dsi->pdev->dev,
                         "Timeout waiting for DSI STOP entry: STAT 0x%08x",
                         DSI_PORT_READ(STAT));
                DSI_PORT_WRITE(PHYC, DSI_PORT_READ(PHYC) & ~phyc_ulps);
                return;
        }
}

static u32
dsi_hs_timing(u32 ui_ns, u32 ns, u32 ui)
{
        /* The HS timings have to be rounded up to a multiple of 8
         * because we're using the byte clock.
         */
        return roundup(ui + DIV_ROUND_UP(ns, ui_ns), 8);
}

/* ESC always runs at 100Mhz. */
#define ESC_TIME_NS 10

static u32
dsi_esc_timing(u32 ns)
{
        return DIV_ROUND_UP(ns, ESC_TIME_NS);
}

static void vc4_dsi_encoder_disable(struct drm_encoder *encoder)
{
        struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
        struct vc4_dsi *dsi = vc4_encoder->dsi;
        struct device *dev = &dsi->pdev->dev;

        drm_bridge_disable(dsi->bridge);
        vc4_dsi_ulps(dsi, true);
        drm_bridge_post_disable(dsi->bridge);

        clk_disable_unprepare(dsi->pll_phy_clock);
        clk_disable_unprepare(dsi->escape_clock);
        clk_disable_unprepare(dsi->pixel_clock);

        pm_runtime_put(dev);
}

/* Extends the mode's blank intervals to handle BCM2835's integer-only
 * DSI PLL divider.
 *
 * On 2835, PLLD is set to 2Ghz, and may not be changed by the display
 * driver since most peripherals are hanging off of the PLLD_PER
 * divider.  PLLD_DSI1, which drives our DSI bit clock (and therefore
 * the pixel clock), only has an integer divider off of DSI.
 *
 * To get our panel mode to refresh at the expected 60Hz, we need to
 * extend the horizontal blank time.  This means we drive a
 * higher-than-expected clock rate to the panel, but that's what the
 * firmware does too.
 */
static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
                                       const struct drm_display_mode *mode,
                                       struct drm_display_mode *adjusted_mode)
{
        struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
        struct vc4_dsi *dsi = vc4_encoder->dsi;
        struct clk *phy_parent = clk_get_parent(dsi->pll_phy_clock);
        unsigned long parent_rate = clk_get_rate(phy_parent);
        unsigned long pixel_clock_hz = mode->clock * 1000;
        unsigned long pll_clock = pixel_clock_hz * dsi->divider;
        int divider;

        /* Find what divider gets us a faster clock than the requested
         * pixel clock.
         */
        for (divider = 1; divider < 8; divider++) {
                if (parent_rate / divider < pll_clock) {
                        divider--;
                        break;
                }
        }

        /* Now that we've picked a PLL divider, calculate back to its
         * pixel clock.
         */
        pll_clock = parent_rate / divider;
        pixel_clock_hz = pll_clock / dsi->divider;

        adjusted_mode->clock = pixel_clock_hz / 1000;

        /* Given the new pixel clock, adjust HFP to keep vrefresh the same. */
        adjusted_mode->htotal = adjusted_mode->clock * mode->htotal /
                                mode->clock;
        adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal;
        adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal;

        return true;
}

static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
{
        struct drm_display_mode *mode = &encoder->crtc->state->adjusted_mode;
        struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
        struct vc4_dsi *dsi = vc4_encoder->dsi;
        struct device *dev = &dsi->pdev->dev;
        bool debug_dump_regs = false;
        unsigned long hs_clock;
        u32 ui_ns;
        /* Minimum LP state duration in escape clock cycles. */
        u32 lpx = dsi_esc_timing(60);
        unsigned long pixel_clock_hz = mode->clock * 1000;
        unsigned long dsip_clock;
        unsigned long phy_clock;
        int ret;

        ret = pm_runtime_get_sync(dev);
        if (ret) {
                DRM_ERROR("Failed to runtime PM enable on DSI%d\n", dsi->port);
                return;
        }

        if (debug_dump_regs) {
                struct drm_printer p = drm_info_printer(&dsi->pdev->dev);
                dev_info(&dsi->pdev->dev, "DSI regs before:\n");
                drm_print_regset32(&p, &dsi->regset);
        }

        /* Round up the clk_set_rate() request slightly, since
         * PLLD_DSI1 is an integer divider and its rate selection will
         * never round up.
         */
        phy_clock = (pixel_clock_hz + 1000) * dsi->divider;
        ret = clk_set_rate(dsi->pll_phy_clock, phy_clock);
        if (ret) {
                dev_err(&dsi->pdev->dev,
                        "Failed to set phy clock to %ld: %d\n", phy_clock, ret);
        }

        /* Reset the DSI and all its fifos. */
        DSI_PORT_WRITE(CTRL,
                       DSI_CTRL_SOFT_RESET_CFG |
                       DSI_PORT_BIT(CTRL_RESET_FIFOS));

        DSI_PORT_WRITE(CTRL,
                       DSI_CTRL_HSDT_EOT_DISABLE |
                       DSI_CTRL_RX_LPDT_EOT_DISABLE);

        /* Clear all stat bits so we see what has happened during enable. */
        DSI_PORT_WRITE(STAT, DSI_PORT_READ(STAT));

        /* Set AFE CTR00/CTR1 to release powerdown of analog. */
        if (dsi->port == 0) {
                u32 afec0 = (VC4_SET_FIELD(7, DSI_PHY_AFEC0_PTATADJ) |
                             VC4_SET_FIELD(7, DSI_PHY_AFEC0_CTATADJ));

                if (dsi->lanes < 2)
                        afec0 |= DSI0_PHY_AFEC0_PD_DLANE1;

                if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO))
                        afec0 |= DSI0_PHY_AFEC0_RESET;

                DSI_PORT_WRITE(PHY_AFEC0, afec0);

                DSI_PORT_WRITE(PHY_AFEC1,
                               VC4_SET_FIELD(6,  DSI0_PHY_AFEC1_IDR_DLANE1) |
                               VC4_SET_FIELD(6,  DSI0_PHY_AFEC1_IDR_DLANE0) |
                               VC4_SET_FIELD(6,  DSI0_PHY_AFEC1_IDR_CLANE));
        } else {
                u32 afec0 = (VC4_SET_FIELD(7, DSI_PHY_AFEC0_PTATADJ) |
                             VC4_SET_FIELD(7, DSI_PHY_AFEC0_CTATADJ) |
                             VC4_SET_FIELD(6, DSI1_PHY_AFEC0_IDR_CLANE) |
                             VC4_SET_FIELD(6, DSI1_PHY_AFEC0_IDR_DLANE0) |
                             VC4_SET_FIELD(6, DSI1_PHY_AFEC0_IDR_DLANE1) |
                             VC4_SET_FIELD(6, DSI1_PHY_AFEC0_IDR_DLANE2) |
                             VC4_SET_FIELD(6, DSI1_PHY_AFEC0_IDR_DLANE3));

                if (dsi->lanes < 4)
                        afec0 |= DSI1_PHY_AFEC0_PD_DLANE3;
                if (dsi->lanes < 3)
                        afec0 |= DSI1_PHY_AFEC0_PD_DLANE2;
                if (dsi->lanes < 2)
                        afec0 |= DSI1_PHY_AFEC0_PD_DLANE1;

                afec0 |= DSI1_PHY_AFEC0_RESET;

                DSI_PORT_WRITE(PHY_AFEC0, afec0);

                DSI_PORT_WRITE(PHY_AFEC1, 0);

                /* AFEC reset hold time */
                mdelay(1);
        }

        ret = clk_prepare_enable(dsi->escape_clock);
        if (ret) {
                DRM_ERROR("Failed to turn on DSI escape clock: %d\n", ret);
                return;
        }

        ret = clk_prepare_enable(dsi->pll_phy_clock);
        if (ret) {
                DRM_ERROR("Failed to turn on DSI PLL: %d\n", ret);
                return;
        }

        hs_clock = clk_get_rate(dsi->pll_phy_clock);

        /* Yes, we set the DSI0P/DSI1P pixel clock to the byte rate,
         * not the pixel clock rate.  DSIxP take from the APHY's byte,
         * DDR2, or DDR4 clock (we use byte) and feed into the PV at
         * that rate.  Separately, a value derived from PIX_CLK_DIV
         * and HS_CLKC is fed into the PV to divide down to the actual
         * pixel clock for pushing pixels into DSI.
         */
        dsip_clock = phy_clock / 8;
        ret = clk_set_rate(dsi->pixel_clock, dsip_clock);
        if (ret) {
                dev_err(dev, "Failed to set pixel clock to %ldHz: %d\n",
                        dsip_clock, ret);
        }

        ret = clk_prepare_enable(dsi->pixel_clock);
        if (ret) {
                DRM_ERROR("Failed to turn on DSI pixel clock: %d\n", ret);
                return;
        }

        /* How many ns one DSI unit interval is.  Note that the clock
         * is DDR, so there's an extra divide by 2.
         */
        ui_ns = DIV_ROUND_UP(500000000, hs_clock);

        DSI_PORT_WRITE(HS_CLT0,
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 262, 0),
                                     DSI_HS_CLT0_CZERO) |
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 0, 8),
                                     DSI_HS_CLT0_CPRE) |
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 38, 0),
                                     DSI_HS_CLT0_CPREP));

        DSI_PORT_WRITE(HS_CLT1,
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 60, 0),
                                     DSI_HS_CLT1_CTRAIL) |
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 60, 52),
                                     DSI_HS_CLT1_CPOST));

        DSI_PORT_WRITE(HS_CLT2,
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 1000000, 0),
                                     DSI_HS_CLT2_WUP));

        DSI_PORT_WRITE(HS_DLT3,
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 100, 0),
                                     DSI_HS_DLT3_EXIT) |
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 105, 6),
                                     DSI_HS_DLT3_ZERO) |
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, 40, 4),
                                     DSI_HS_DLT3_PRE));

        DSI_PORT_WRITE(HS_DLT4,
                       VC4_SET_FIELD(dsi_hs_timing(ui_ns, lpx * ESC_TIME_NS, 0),
                                     DSI_HS_DLT4_LPX) |
                       VC4_SET_FIELD(max(dsi_hs_timing(ui_ns, 0, 8),
                                         dsi_hs_timing(ui_ns, 60, 4)),
                                     DSI_HS_DLT4_TRAIL) |
                       VC4_SET_FIELD(0, DSI_HS_DLT4_ANLAT));

        /* T_INIT is how long STOP is driven after power-up to
         * indicate to the slave (also coming out of power-up) that
         * master init is complete, and should be greater than the
         * maximum of two value: T_INIT,MASTER and T_INIT,SLAVE.  The
         * D-PHY spec gives a minimum 100us for T_INIT,MASTER and
         * T_INIT,SLAVE, while allowing protocols on top of it to give
         * greater minimums.  The vc4 firmware uses an extremely
         * conservative 5ms, and we maintain that here.
         */
        DSI_PORT_WRITE(HS_DLT5, VC4_SET_FIELD(dsi_hs_timing(ui_ns,
                                                            5 * 1000 * 1000, 0),
                                              DSI_HS_DLT5_INIT));

        DSI_PORT_WRITE(HS_DLT6,
                       VC4_SET_FIELD(lpx * 5, DSI_HS_DLT6_TA_GET) |
                       VC4_SET_FIELD(lpx, DSI_HS_DLT6_TA_SURE) |
                       VC4_SET_FIELD(lpx * 4, DSI_HS_DLT6_TA_GO) |
                       VC4_SET_FIELD(lpx, DSI_HS_DLT6_LP_LPX));

        DSI_PORT_WRITE(HS_DLT7,
                       VC4_SET_FIELD(dsi_esc_timing(1000000),
                                     DSI_HS_DLT7_LP_WUP));

        DSI_PORT_WRITE(PHYC,
                       DSI_PHYC_DLANE0_ENABLE |
                       (dsi->lanes >= 2 ? DSI_PHYC_DLANE1_ENABLE : 0) |
                       (dsi->lanes >= 3 ? DSI_PHYC_DLANE2_ENABLE : 0) |
                       (dsi->lanes >= 4 ? DSI_PHYC_DLANE3_ENABLE : 0) |
                       DSI_PORT_BIT(PHYC_CLANE_ENABLE) |
                       ((dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) ?
                        0 : DSI_PORT_BIT(PHYC_HS_CLK_CONTINUOUS)) |
                       (dsi->port == 0 ?
                        VC4_SET_FIELD(lpx - 1, DSI0_PHYC_ESC_CLK_LPDT) :
                        VC4_SET_FIELD(lpx - 1, DSI1_PHYC_ESC_CLK_LPDT)));

        DSI_PORT_WRITE(CTRL,
                       DSI_PORT_READ(CTRL) |
                       DSI_CTRL_CAL_BYTE);

        /* HS timeout in HS clock cycles: disabled. */
        DSI_PORT_WRITE(HSTX_TO_CNT, 0);
        /* LP receive timeout in HS clocks. */
        DSI_PORT_WRITE(LPRX_TO_CNT, 0xffffff);
        /* Bus turnaround timeout */
        DSI_PORT_WRITE(TA_TO_CNT, 100000);
        /* Display reset sequence timeout */
        DSI_PORT_WRITE(PR_TO_CNT, 100000);

        /* Set up DISP1 for transferring long command payloads through
         * the pixfifo.
         */
        DSI_PORT_WRITE(DISP1_CTRL,
                       VC4_SET_FIELD(DSI_DISP1_PFORMAT_32BIT_LE,
                                     DSI_DISP1_PFORMAT) |
                       DSI_DISP1_ENABLE);

        /* Ungate the block. */
        if (dsi->port == 0)
                DSI_PORT_WRITE(CTRL, DSI_PORT_READ(CTRL) | DSI0_CTRL_CTRL0);
        else
                DSI_PORT_WRITE(CTRL, DSI_PORT_READ(CTRL) | DSI1_CTRL_EN);

        /* Bring AFE out of reset. */
        if (dsi->port == 0) {
        } else {
                DSI_PORT_WRITE(PHY_AFEC0,
                               DSI_PORT_READ(PHY_AFEC0) &
                               ~DSI1_PHY_AFEC0_RESET);
        }

        vc4_dsi_ulps(dsi, false);

        drm_bridge_pre_enable(dsi->bridge);

        if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
                DSI_PORT_WRITE(DISP0_CTRL,
                               VC4_SET_FIELD(dsi->divider,
                                             DSI_DISP0_PIX_CLK_DIV) |
                               VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
                               VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
                                             DSI_DISP0_LP_STOP_CTRL) |
                               DSI_DISP0_ST_END |
                               DSI_DISP0_ENABLE);
        } else {
                DSI_PORT_WRITE(DISP0_CTRL,
                               DSI_DISP0_COMMAND_MODE |
                               DSI_DISP0_ENABLE);
        }

        drm_bridge_enable(dsi->bridge);

        if (debug_dump_regs) {
                struct drm_printer p = drm_info_printer(&dsi->pdev->dev);
                dev_info(&dsi->pdev->dev, "DSI regs after:\n");
                drm_print_regset32(&p, &dsi->regset);
        }
}

static ssize_t vc4_dsi_host_transfer(struct mipi_dsi_host *host,
                                     const struct mipi_dsi_msg *msg)
{
        struct vc4_dsi *dsi = host_to_dsi(host);
        struct mipi_dsi_packet packet;
        u32 pkth = 0, pktc = 0;
        int i, ret;
        bool is_long = mipi_dsi_packet_format_is_long(msg->type);
        u32 cmd_fifo_len = 0, pix_fifo_len = 0;

        mipi_dsi_create_packet(&packet, msg);

        pkth |= VC4_SET_FIELD(packet.header[0], DSI_TXPKT1H_BC_DT);
        pkth |= VC4_SET_FIELD(packet.header[1] |
                              (packet.header[2] << 8),
                              DSI_TXPKT1H_BC_PARAM);
        if (is_long) {
                /* Divide data across the various FIFOs we have available.
                 * The command FIFO takes byte-oriented data, but is of
                 * limited size. The pixel FIFO (never actually used for
                 * pixel data in reality) is word oriented, and substantially
                 * larger. So, we use the pixel FIFO for most of the data,
                 * sending the residual bytes in the command FIFO at the start.
                 *
                 * With this arrangement, the command FIFO will never get full.
                 */
                if (packet.payload_length <= 16) {
                        cmd_fifo_len = packet.payload_length;
                        pix_fifo_len = 0;
                } else {
                        cmd_fifo_len = (packet.payload_length %
                                        DSI_PIX_FIFO_WIDTH);
                        pix_fifo_len = ((packet.payload_length - cmd_fifo_len) /
                                        DSI_PIX_FIFO_WIDTH);
                }

                WARN_ON_ONCE(pix_fifo_len >= DSI_PIX_FIFO_DEPTH);

                pkth |= VC4_SET_FIELD(cmd_fifo_len, DSI_TXPKT1H_BC_CMDFIFO);
        }

        if (msg->rx_len) {
                pktc |= VC4_SET_FIELD(DSI_TXPKT1C_CMD_CTRL_RX,
                                      DSI_TXPKT1C_CMD_CTRL);
        } else {
                pktc |= VC4_SET_FIELD(DSI_TXPKT1C_CMD_CTRL_TX,
                                      DSI_TXPKT1C_CMD_CTRL);
        }

        for (i = 0; i < cmd_fifo_len; i++)
                DSI_PORT_WRITE(TXPKT_CMD_FIFO, packet.payload[i]);
        for (i = 0; i < pix_fifo_len; i++) {
                const u8 *pix = packet.payload + cmd_fifo_len + i * 4;

                DSI_PORT_WRITE(TXPKT_PIX_FIFO,
                               pix[0] |
                               pix[1] << 8 |
                               pix[2] << 16 |
                               pix[3] << 24);
        }

        if (msg->flags & MIPI_DSI_MSG_USE_LPM)
                pktc |= DSI_TXPKT1C_CMD_MODE_LP;
        if (is_long)
                pktc |= DSI_TXPKT1C_CMD_TYPE_LONG;

        /* Send one copy of the packet.  Larger repeats are used for pixel
         * data in command mode.
         */
        pktc |= VC4_SET_FIELD(1, DSI_TXPKT1C_CMD_REPEAT);

        pktc |= DSI_TXPKT1C_CMD_EN;
        if (pix_fifo_len) {
                pktc |= VC4_SET_FIELD(DSI_TXPKT1C_DISPLAY_NO_SECONDARY,
                                      DSI_TXPKT1C_DISPLAY_NO);
        } else {
                pktc |= VC4_SET_FIELD(DSI_TXPKT1C_DISPLAY_NO_SHORT,
                                      DSI_TXPKT1C_DISPLAY_NO);
        }

        /* Enable the appropriate interrupt for the transfer completion. */
        dsi->xfer_result = 0;
        reinit_completion(&dsi->xfer_completion);
        DSI_PORT_WRITE(INT_STAT, DSI1_INT_TXPKT1_DONE | DSI1_INT_PHY_DIR_RTF);
        if (msg->rx_len) {
                DSI_PORT_WRITE(INT_EN, (DSI1_INTERRUPTS_ALWAYS_ENABLED |
                                        DSI1_INT_PHY_DIR_RTF));
        } else {
                DSI_PORT_WRITE(INT_EN, (DSI1_INTERRUPTS_ALWAYS_ENABLED |
                                        DSI1_INT_TXPKT1_DONE));
        }

        /* Send the packet. */
        DSI_PORT_WRITE(TXPKT1H, pkth);
        DSI_PORT_WRITE(TXPKT1C, pktc);

        if (!wait_for_completion_timeout(&dsi->xfer_completion,
                                         msecs_to_jiffies(1000))) {
                dev_err(&dsi->pdev->dev, "transfer interrupt wait timeout");
                dev_err(&dsi->pdev->dev, "instat: 0x%08x\n",
                        DSI_PORT_READ(INT_STAT));
                ret = -ETIMEDOUT;
        } else {
                ret = dsi->xfer_result;
        }

        DSI_PORT_WRITE(INT_EN, DSI1_INTERRUPTS_ALWAYS_ENABLED);

        if (ret)
                goto reset_fifo_and_return;

        if (ret == 0 && msg->rx_len) {
                u32 rxpkt1h = DSI_PORT_READ(RXPKT1H);
                u8 *msg_rx = msg->rx_buf;

                if (rxpkt1h & DSI_RXPKT1H_PKT_TYPE_LONG) {
                        u32 rxlen = VC4_GET_FIELD(rxpkt1h,
                                                  DSI_RXPKT1H_BC_PARAM);

                        if (rxlen != msg->rx_len) {
                                DRM_ERROR("DSI returned %db, expecting %db\n",
                                          rxlen, (int)msg->rx_len);
                                ret = -ENXIO;
                                goto reset_fifo_and_return;
                        }

                        for (i = 0; i < msg->rx_len; i++)
                                msg_rx[i] = DSI_READ(DSI1_RXPKT_FIFO);
                } else {
                        /* FINISHME: Handle AWER */

                        msg_rx[0] = VC4_GET_FIELD(rxpkt1h,
                                                  DSI_RXPKT1H_SHORT_0);
                        if (msg->rx_len > 1) {
                                msg_rx[1] = VC4_GET_FIELD(rxpkt1h,
                                                          DSI_RXPKT1H_SHORT_1);
                        }
                }
        }

        return ret;

reset_fifo_and_return:
        DRM_ERROR("DSI transfer failed, resetting: %d\n", ret);

        DSI_PORT_WRITE(TXPKT1C, DSI_PORT_READ(TXPKT1C) & ~DSI_TXPKT1C_CMD_EN);
        udelay(1);
        DSI_PORT_WRITE(CTRL,
                       DSI_PORT_READ(CTRL) |
                       DSI_PORT_BIT(CTRL_RESET_FIFOS));

        DSI_PORT_WRITE(TXPKT1C, 0);
        DSI_PORT_WRITE(INT_EN, DSI1_INTERRUPTS_ALWAYS_ENABLED);
        return ret;
}

static int vc4_dsi_host_attach(struct mipi_dsi_host *host,
                               struct mipi_dsi_device *device)
{
        struct vc4_dsi *dsi = host_to_dsi(host);

        dsi->lanes = device->lanes;
        dsi->channel = device->channel;
        dsi->mode_flags = device->mode_flags;

        switch (device->format) {
        case MIPI_DSI_FMT_RGB888:
                dsi->format = DSI_PFORMAT_RGB888;
                dsi->divider = 24 / dsi->lanes;
                break;
        case MIPI_DSI_FMT_RGB666:
                dsi->format = DSI_PFORMAT_RGB666;
                dsi->divider = 24 / dsi->lanes;
                break;
        case MIPI_DSI_FMT_RGB666_PACKED:
                dsi->format = DSI_PFORMAT_RGB666_PACKED;
                dsi->divider = 18 / dsi->lanes;
                break;
        case MIPI_DSI_FMT_RGB565:
                dsi->format = DSI_PFORMAT_RGB565;
                dsi->divider = 16 / dsi->lanes;
                break;
        default:
                dev_err(&dsi->pdev->dev, "Unknown DSI format: %d.\n",
                        dsi->format);
                return 0;
        }

        if (!(dsi->mode_flags & MIPI_DSI_MODE_VIDEO)) {
                dev_err(&dsi->pdev->dev,
                        "Only VIDEO mode panels supported currently.\n");
                return 0;
        }

        return 0;
}

static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
                               struct mipi_dsi_device *device)
{
        return 0;
}

static const struct mipi_dsi_host_ops vc4_dsi_host_ops = {
        .attach = vc4_dsi_host_attach,
        .detach = vc4_dsi_host_detach,
        .transfer = vc4_dsi_host_transfer,
};

static const struct drm_encoder_helper_funcs vc4_dsi_encoder_helper_funcs = {
        .disable = vc4_dsi_encoder_disable,
        .enable = vc4_dsi_encoder_enable,
        .mode_fixup = vc4_dsi_encoder_mode_fixup,
};

static const struct of_device_id vc4_dsi_dt_match[] = {
        { .compatible = "brcm,bcm2835-dsi1", (void *)(uintptr_t)1 },
        {}
};

static void dsi_handle_error(struct vc4_dsi *dsi,
                             irqreturn_t *ret, u32 stat, u32 bit,
                             const char *type)
{
        if (!(stat & bit))
                return;

        DRM_ERROR("DSI%d: %s error\n", dsi->port, type);
        *ret = IRQ_HANDLED;
}

/*
 * Initial handler for port 1 where we need the reg_dma workaround.
 * The register DMA writes sleep, so we can't do it in the top half.
 * Instead we use IRQF_ONESHOT so that the IRQ gets disabled in the
 * parent interrupt contrller until our interrupt thread is done.
 */
static irqreturn_t vc4_dsi_irq_defer_to_thread_handler(int irq, void *data)
{
        struct vc4_dsi *dsi = data;
        u32 stat = DSI_PORT_READ(INT_STAT);

        if (!stat)
                return IRQ_NONE;

        return IRQ_WAKE_THREAD;
}

/*
 * Normal IRQ handler for port 0, or the threaded IRQ handler for port
 * 1 where we need the reg_dma workaround.
 */
static irqreturn_t vc4_dsi_irq_handler(int irq, void *data)
{
        struct vc4_dsi *dsi = data;
        u32 stat = DSI_PORT_READ(INT_STAT);
        irqreturn_t ret = IRQ_NONE;

        DSI_PORT_WRITE(INT_STAT, stat);

        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_ERR_SYNC_ESC, "LPDT sync");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_ERR_CONTROL, "data lane 0 sequence");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_ERR_CONT_LP0, "LP0 contention");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_ERR_CONT_LP1, "LP1 contention");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_HSTX_TO, "HSTX timeout");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_LPRX_TO, "LPRX timeout");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_TA_TO, "turnaround timeout");
        dsi_handle_error(dsi, &ret, stat,
                         DSI1_INT_PR_TO, "peripheral reset timeout");

        if (stat & (DSI1_INT_TXPKT1_DONE | DSI1_INT_PHY_DIR_RTF)) {
                complete(&dsi->xfer_completion);
                ret = IRQ_HANDLED;
        } else if (stat & DSI1_INT_HSTX_TO) {
                complete(&dsi->xfer_completion);
                dsi->xfer_result = -ETIMEDOUT;
                ret = IRQ_HANDLED;
        }

        return ret;
}

/**
 * vc4_dsi_init_phy_clocks - Exposes clocks generated by the analog
 * PHY that are consumed by CPRMAN (clk-bcm2835.c).
 * @dsi: DSI encoder
 */
static int
vc4_dsi_init_phy_clocks(struct vc4_dsi *dsi)
{
        struct device *dev = &dsi->pdev->dev;
        const char *parent_name = __clk_get_name(dsi->pll_phy_clock);
        static const struct {
                const char *dsi0_name, *dsi1_name;
                int div;
        } phy_clocks[] = {
                { "dsi0_byte", "dsi1_byte", 8 },
                { "dsi0_ddr2", "dsi1_ddr2", 4 },
                { "dsi0_ddr", "dsi1_ddr", 2 },
        };
        int i;

        dsi->clk_onecell = devm_kzalloc(dev,
                                        sizeof(*dsi->clk_onecell) +
                                        ARRAY_SIZE(phy_clocks) *
                                        sizeof(struct clk_hw *),
                                        GFP_KERNEL);
        if (!dsi->clk_onecell)
                return -ENOMEM;
        dsi->clk_onecell->num = ARRAY_SIZE(phy_clocks);

        for (i = 0; i < ARRAY_SIZE(phy_clocks); i++) {
                struct clk_fixed_factor *fix = &dsi->phy_clocks[i];
                struct clk_init_data init;
                int ret;

                /* We just use core fixed factor clock ops for the PHY
                 * clocks.  The clocks are actually gated by the
                 * PHY_AFEC0_DDRCLK_EN bits, which we should be
                 * setting if we use the DDR/DDR2 clocks.  However,
                 * vc4_dsi_encoder_enable() is setting up both AFEC0,
                 * setting both our parent DSI PLL's rate and this
                 * clock's rate, so it knows if DDR/DDR2 are going to
                 * be used and could enable the gates itself.
                 */
                fix->mult = 1;
                fix->div = phy_clocks[i].div;
                fix->hw.init = &init;

                memset(&init, 0, sizeof(init));
                init.parent_names = &parent_name;
                init.num_parents = 1;
                if (dsi->port == 1)
                        init.name = phy_clocks[i].dsi1_name;
                else
                        init.name = phy_clocks[i].dsi0_name;
                init.ops = &clk_fixed_factor_ops;

                ret = devm_clk_hw_register(dev, &fix->hw);
                if (ret)
                        return ret;

                dsi->clk_onecell->hws[i] = &fix->hw;
        }

        return of_clk_add_hw_provider(dev->of_node,
                                      of_clk_hw_onecell_get,
                                      dsi->clk_onecell);
}

static int vc4_dsi_bind(struct device *dev, struct device *master, void *data)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct drm_device *drm = dev_get_drvdata(master);
        struct vc4_dev *vc4 = to_vc4_dev(drm);
        struct vc4_dsi *dsi = dev_get_drvdata(dev);
        struct vc4_dsi_encoder *vc4_dsi_encoder;
        struct drm_panel *panel;
        const struct of_device_id *match;
        dma_cap_mask_t dma_mask;
        int ret;

        match = of_match_device(vc4_dsi_dt_match, dev);
        if (!match)
                return -ENODEV;

        dsi->port = (uintptr_t)match->data;

        vc4_dsi_encoder = devm_kzalloc(dev, sizeof(*vc4_dsi_encoder),
                                       GFP_KERNEL);
        if (!vc4_dsi_encoder)
                return -ENOMEM;
        vc4_dsi_encoder->base.type = VC4_ENCODER_TYPE_DSI1;
        vc4_dsi_encoder->dsi = dsi;
        dsi->encoder = &vc4_dsi_encoder->base.base;

        dsi->regs = vc4_ioremap_regs(pdev, 0);
        if (IS_ERR(dsi->regs))
                return PTR_ERR(dsi->regs);

        dsi->regset.base = dsi->regs;
        if (dsi->port == 0) {
                dsi->regset.regs = dsi0_regs;
                dsi->regset.nregs = ARRAY_SIZE(dsi0_regs);
        } else {
                dsi->regset.regs = dsi1_regs;
                dsi->regset.nregs = ARRAY_SIZE(dsi1_regs);
        }

        if (DSI_PORT_READ(ID) != DSI_ID_VALUE) {
                dev_err(dev, "Port returned 0x%08x for ID instead of 0x%08x\n",
                        DSI_PORT_READ(ID), DSI_ID_VALUE);
                return -ENODEV;
        }

        /* DSI1 has a broken AXI slave that doesn't respond to writes
         * from the ARM.  It does handle writes from the DMA engine,
         * so set up a channel for talking to it.
         */
        if (dsi->port == 1) {
                dsi->reg_dma_mem = dma_alloc_coherent(dev, 4,
                                                      &dsi->reg_dma_paddr,
                                                      GFP_KERNEL);
                if (!dsi->reg_dma_mem) {
                        DRM_ERROR("Failed to get DMA memory\n");
                        return -ENOMEM;
                }

                dma_cap_zero(dma_mask);
                dma_cap_set(DMA_MEMCPY, dma_mask);
                dsi->reg_dma_chan = dma_request_chan_by_mask(&dma_mask);
                if (IS_ERR(dsi->reg_dma_chan)) {
                        ret = PTR_ERR(dsi->reg_dma_chan);
                        if (ret != -EPROBE_DEFER)
                                DRM_ERROR("Failed to get DMA channel: %d\n",
                                          ret);
                        return ret;
                }

                /* Get the physical address of the device's registers.  The
                 * struct resource for the regs gives us the bus address
                 * instead.
                 */
                dsi->reg_paddr = be32_to_cpup(of_get_address(dev->of_node,
                                                             0, NULL, NULL));
        }

        init_completion(&dsi->xfer_completion);
        /* At startup enable error-reporting interrupts and nothing else. */
        DSI_PORT_WRITE(INT_EN, DSI1_INTERRUPTS_ALWAYS_ENABLED);
        /* Clear any existing interrupt state. */
        DSI_PORT_WRITE(INT_STAT, DSI_PORT_READ(INT_STAT));

        if (dsi->reg_dma_mem)
                ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
                                                vc4_dsi_irq_defer_to_thread_handler,
                                                vc4_dsi_irq_handler,
                                                IRQF_ONESHOT,
                                                "vc4 dsi", dsi);
        else
                ret = devm_request_irq(dev, platform_get_irq(pdev, 0),
                                       vc4_dsi_irq_handler, 0, "vc4 dsi", dsi);
        if (ret) {
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "Failed to get interrupt: %d\n", ret);
                return ret;
        }

        dsi->escape_clock = devm_clk_get(dev, "escape");
        if (IS_ERR(dsi->escape_clock)) {
                ret = PTR_ERR(dsi->escape_clock);
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "Failed to get escape clock: %d\n", ret);
                return ret;
        }

        dsi->pll_phy_clock = devm_clk_get(dev, "phy");
        if (IS_ERR(dsi->pll_phy_clock)) {
                ret = PTR_ERR(dsi->pll_phy_clock);
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "Failed to get phy clock: %d\n", ret);
                return ret;
        }

        dsi->pixel_clock = devm_clk_get(dev, "pixel");
        if (IS_ERR(dsi->pixel_clock)) {
                ret = PTR_ERR(dsi->pixel_clock);
                if (ret != -EPROBE_DEFER)
                        dev_err(dev, "Failed to get pixel clock: %d\n", ret);
                return ret;
        }

        ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
                                          &panel, &dsi->bridge);
        if (ret) {
                /* If the bridge or panel pointed by dev->of_node is not
                 * enabled, just return 0 here so that we don't prevent the DRM
                 * dev from being registered. Of course that means the DSI
                 * encoder won't be exposed, but that's not a problem since
                 * nothing is connected to it.
                 */
                if (ret == -ENODEV)
                        return 0;

                return ret;
        }

        if (panel) {
                dsi->bridge = devm_drm_panel_bridge_add(dev, panel,
                                                        DRM_MODE_CONNECTOR_DSI);
                if (IS_ERR(dsi->bridge))
                        return PTR_ERR(dsi->bridge);
        }

        /* The esc clock rate is supposed to always be 100Mhz. */
        ret = clk_set_rate(dsi->escape_clock, 100 * 1000000);
        if (ret) {
                dev_err(dev, "Failed to set esc clock: %d\n", ret);
                return ret;
        }

        ret = vc4_dsi_init_phy_clocks(dsi);
        if (ret)
                return ret;

        if (dsi->port == 1)
                vc4->dsi1 = dsi;

        drm_encoder_init(drm, dsi->encoder, &vc4_dsi_encoder_funcs,
                         DRM_MODE_ENCODER_DSI, NULL);
        drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);

        ret = drm_bridge_attach(dsi->encoder, dsi->bridge, NULL);
        if (ret) {
                dev_err(dev, "bridge attach failed: %d\n", ret);
                return ret;
        }
        /* Disable the atomic helper calls into the bridge.  We
         * manually call the bridge pre_enable / enable / etc. calls
         * from our driver, since we need to sequence them within the
         * encoder's enable/disable paths.
         */
        dsi->encoder->bridge = NULL;

        if (dsi->port == 0)
                vc4_debugfs_add_regset32(drm, "dsi0_regs", &dsi->regset);
        else
                vc4_debugfs_add_regset32(drm, "dsi1_regs", &dsi->regset);

        pm_runtime_enable(dev);

        return 0;
}

static void vc4_dsi_unbind(struct device *dev, struct device *master,
                           void *data)
{
        struct drm_device *drm = dev_get_drvdata(master);
        struct vc4_dev *vc4 = to_vc4_dev(drm);
        struct vc4_dsi *dsi = dev_get_drvdata(dev);

        if (dsi->bridge)
                pm_runtime_disable(dev);

        vc4_dsi_encoder_destroy(dsi->encoder);

        if (dsi->port == 1)
                vc4->dsi1 = NULL;
}

static const struct component_ops vc4_dsi_ops = {
        .bind   = vc4_dsi_bind,
        .unbind = vc4_dsi_unbind,
};

static int vc4_dsi_dev_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct vc4_dsi *dsi;
        int ret;

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

        dsi->pdev = pdev;

        /* Note, the initialization sequence for DSI and panels is
         * tricky.  The component bind above won't get past its
         * -EPROBE_DEFER until the panel/bridge probes.  The
         * panel/bridge will return -EPROBE_DEFER until it has a
         * mipi_dsi_host to register its device to.  So, we register
         * the host during pdev probe time, so vc4 as a whole can then
         * -EPROBE_DEFER its component bind process until the panel
         * successfully attaches.
         */
        dsi->dsi_host.ops = &vc4_dsi_host_ops;
        dsi->dsi_host.dev = dev;
        mipi_dsi_host_register(&dsi->dsi_host);

        ret = component_add(&pdev->dev, &vc4_dsi_ops);
        if (ret) {
                mipi_dsi_host_unregister(&dsi->dsi_host);
                return ret;
        }

        return 0;
}

static int vc4_dsi_dev_remove(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct vc4_dsi *dsi = dev_get_drvdata(dev);

        component_del(&pdev->dev, &vc4_dsi_ops);
        mipi_dsi_host_unregister(&dsi->dsi_host);

        return 0;
}

struct platform_driver vc4_dsi_driver = {
        .probe = vc4_dsi_dev_probe,
        .remove = vc4_dsi_dev_remove,
        .driver = {
                .name = "vc4_dsi",
                .of_match_table = vc4_dsi_dt_match,
        },
};