[PATCH v4 3/6] drm/bridge/synopsys: Add MIPI DSI host controller bridge

Andrzej Hajda a.hajda at samsung.com
Wed Jun 28 09:05:54 UTC 2017


On 28.06.2017 08:44, Archit Taneja wrote:
>
> On 06/19/2017 09:58 PM, Philippe CORNU wrote:
>> Add a Synopsys Designware MIPI DSI host DRM bridge driver, based on the
>> Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge APIs.
>>
>> Signed-off-by: Philippe CORNU <philippe.cornu at st.com>
>> ---
>>   drivers/gpu/drm/bridge/synopsys/Kconfig       |   6 +
>>   drivers/gpu/drm/bridge/synopsys/Makefile      |   2 +
>>   drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 976 ++++++++++++++++++++++++++
>>   include/drm/bridge/dw_mipi_dsi.h              |  39 +
>>   4 files changed, 1023 insertions(+)
>>   create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>>   create mode 100644 include/drm/bridge/dw_mipi_dsi.h
>>
>> diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig
>> index 40d2827..f00ee26 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/Kconfig
>> +++ b/drivers/gpu/drm/bridge/synopsys/Kconfig
>> @@ -21,3 +21,9 @@ config DRM_DW_HDMI_I2S_AUDIO
>>   	help
>>   	  Support the I2S Audio interface which is part of the Synopsys
>>   	  Designware HDMI block.
>> +
>> +config DRM_DW_MIPI_DSI
>> +	tristate
>> +	select DRM_KMS_HELPER
>> +	select DRM_MIPI_DSI
>> +	select DRM_PANEL_BRIDGE
>> diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile
>> index 17aa7a6..5f57d36 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/Makefile
>> +++ b/drivers/gpu/drm/bridge/synopsys/Makefile
>> @@ -3,3 +3,5 @@
>>   obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
>>   obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
>>   obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o
>> +
>> +obj-$(CONFIG_DRM_DW_MIPI_DSI) += dw-mipi-dsi.o
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> new file mode 100644
>> index 0000000..416ed7f
>> --- /dev/null
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
>> @@ -0,0 +1,976 @@
>> +/*
>> + * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
>> + * Copyright (C) STMicroelectronics SA 2017
>> + *
>> + * 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.
>> + *
>> + * Modified by Philippe Cornu <philippe.cornu at st.com>
>> + * This generic Synopsys DesignWare MIPI DSI host driver is based on the
>> + * Rockchip version from rockchip/dw-mipi-dsi.c with phy & bridge APIs.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/component.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/reset.h>
>> +#include <drm/drmP.h>
>> +#include <drm/drm_atomic_helper.h>
>> +#include <drm/drm_bridge.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/bridge/dw_mipi_dsi.h>
>> +#include <video/mipi_display.h>
>> +
>> +#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_NON_BURST_SYNC_PULSES	0x0
>> +#define VID_MODE_TYPE_NON_BURST_SYNC_EVENTS	0x1
>> +#define VID_MODE_TYPE_BURST			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
>> +
>> +struct dw_mipi_dsi {
>> +	struct drm_bridge bridge;
>> +	struct mipi_dsi_host dsi_host;
>> +	struct drm_bridge *panel_bridge;
>> +	bool is_panel_bridge;
>> +	struct device *dev;
>> +	void __iomem *base;
>> +
>> +	struct clk *pclk;
>> +
>> +	unsigned int lane_mbps; /* per lane */
>> +	u32 channel;
>> +	u32 lanes;
>> +	u32 format;
>> +	unsigned long mode_flags;
>> +
>> +	const struct dw_mipi_dsi_plat_data *plat_data;
>> +};
>> +
>> +/*
>> + * 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 *bridge_to_dsi(struct drm_bridge *bridge)
>> +{
>> +	return container_of(bridge, struct dw_mipi_dsi, bridge);
>> +}
>> +
>> +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 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);
>> +	struct drm_bridge *bridge;
>> +	struct drm_panel *panel;
>> +	int ret;
>> +
>> +	if (device->lanes > dsi->plat_data->max_data_lanes) {
>> +		dev_err(dsi->dev, "the number of data lanes(%u) is too many\n",
>> +			device->lanes);
>> +		return -EINVAL;
>> +	}
>> +
>> +	dsi->lanes = device->lanes;
>> +	dsi->channel = device->channel;
>> +	dsi->format = device->format;
>> +	dsi->mode_flags = device->mode_flags;
>> +
>> +	ret = drm_of_find_panel_or_bridge(host->dev->of_node, 1, 0,
>> +					  &panel, &bridge);
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (panel) {
>> +		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_DSI);
>> +		if (IS_ERR(bridge))
>> +			return PTR_ERR(bridge);
>> +		dsi->is_panel_bridge = true;
>> +	}
>> +
>> +	dsi->panel_bridge = bridge;
>> +
>> +	return drm_bridge_add(&dsi->bridge);
>> +}
>> +
>> +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);
>> +
>> +	if (dsi->is_panel_bridge)
>> +		drm_panel_bridge_remove(dsi->panel_bridge);
>> +
>> +	drm_bridge_remove(&dsi->bridge);
>> +
>> +	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 = readl_poll_timeout(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 = readl_poll_timeout(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 = readl_poll_timeout(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;
>> +
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * use mipi_dsi_create_packet() instead of all following
>> +	 * functions and code (no switch cases, no
>> +	 * dw_mipi_dsi_dcs_short_write(), only the loop in long_write...)
>> +	 * and use packet.header...
>> +	 */
>> +	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;
>> +
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * enabling low power is panel-dependent, we should use the
>> +	 * panel configuration here...
>> +	 */
>> +	val = ENABLE_LOW_POWER;
>> +
>> +	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
>> +		val |= VID_MODE_TYPE_BURST;
>> +	else if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE)
>> +		val |= VID_MODE_TYPE_NON_BURST_SYNC_PULSES;
>> +	else
>> +		val |= VID_MODE_TYPE_NON_BURST_SYNC_EVENTS;
>> +
>> +	dsi_write(dsi, DSI_VID_MODE_CFG, val);
>> +}
>> +
>> +static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
>> +				 unsigned long mode_flags)
>> +{
>> +	dsi_write(dsi, DSI_PWR_UP, RESET);
>> +
>> +	if (mode_flags & MIPI_DSI_MODE_VIDEO) {
>> +		dsi_write(dsi, DSI_MODE_CFG, ENABLE_VIDEO_MODE);
>> +		dw_mipi_dsi_video_mode_config(dsi);
>> +		dsi_write(dsi, DSI_LPCLK_CTRL, PHY_TXREQUESTCLKHS);
>> +	} else {
>> +		dsi_write(dsi, DSI_MODE_CFG, ENABLE_CMD_MODE);
>> +	}
>> +
>> +	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);
>> +
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * timeout clock division should be computed with the
>> +	 * high speed transmission counter timeout and byte lane...
>> +	 */
>> +	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_NVSYNC)
>> +		val |= VSYNC_ACTIVE_LOW;
>> +	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
>> +		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);
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * largest packet sizes during hfp or during vsa/vpb/vfp
>> +	 * should be computed according to byte lane, lane number and only
>> +	 * if sending lp cmds in high speed is enable (PHY_TXREQUESTCLKHS)
>> +	 */
>> +	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)
>> +{
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * only burst mode is supported here. For non-burst video modes,
>> +	 * we should compute DSI_VID_PKT_SIZE, DSI_VCCR.NUMC &
>> +	 * DSI_VNPCR.NPSIZE... especially because this driver supports
>> +	 * non-burst video modes, see dw_mipi_dsi_video_mode_config()...
>> +	 */
>> +	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)
>> +{
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * compute high speed transmission counter timeout according
>> +	 * to the timeout clock division (TO_CLK_DIVIDSION) and byte lane...
>> +	 */
>> +	dsi_write(dsi, DSI_TO_CNT_CFG, HSTX_TO_CNT(1000) | LPRX_TO_CNT(1000));
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * the Bus-Turn-Around Timeout Counter should be computed
>> +	 * according to byte lane...
>> +	 */
>> +	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;
>> +
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * computations below may be improved...
>> +	 */
>> +	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)
>> +{
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * data & clock lane timers should be computed according to panel
>> +	 * blankings and to the automatic clock lane control mode...
>> +	 * note: DSI_PHY_TMR_CFG.MAX_RD_TIME should be in line with
>> +	 * DSI_CMD_MODE_CFG.MAX_RD_PKT_SIZE_LP (see CMD_MODE_ALL_LP)
>> +	 */
>> +	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)
>> +{
>> +	/*
>> +	 * TODO dw drv improvements
>> +	 * stop wait time should be the maximum between host dsi
>> +	 * and panel stop wait times
>> +	 */
>> +	dsi_write(dsi, DSI_PHY_IF_CFG, PHY_STOP_WAIT_TIME(0x20) |
>> +		  N_LANES(dsi->lanes));
>> +}
>> +
>> +static void dw_mipi_dsi_dphy_init(struct dw_mipi_dsi *dsi)
>> +{
>> +	/* Clear PHY state */
>> +	dsi_write(dsi, DSI_PHY_RSTZ, PHY_DISFORCEPLL | PHY_DISABLECLK
>> +		  | PHY_RSTZ | PHY_SHUTDOWNZ);
>> +	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
>> +	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_TESTCLR);
>> +	dsi_write(dsi, DSI_PHY_TST_CTRL0, PHY_UNTESTCLR);
>> +}
>> +
>> +static void dw_mipi_dsi_dphy_enable(struct dw_mipi_dsi *dsi)
>> +{
>> +	u32 val;
>> +	int ret;
>> +
>> +	dsi_write(dsi, DSI_PHY_RSTZ, PHY_ENFORCEPLL | PHY_ENABLECLK |
>> +		  PHY_UNRSTZ | PHY_UNSHUTDOWNZ);
>> +
>> +	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
>> +				 val, val & LOCK, 1000, PHY_STATUS_TIMEOUT_US);
>> +	if (ret < 0)
>> +		DRM_DEBUG_DRIVER("failed to wait phy lock state\n");
>> +
>> +	ret = readl_poll_timeout(dsi->base + DSI_PHY_STATUS,
>> +				 val, val & STOP_STATE_CLK_LANE, 1000,
>> +				 PHY_STATUS_TIMEOUT_US);
>> +	if (ret < 0)
>> +		DRM_DEBUG_DRIVER("failed to wait phy clk lane stop state\n");
>> +}
>> +
>> +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_bridge_post_disable(struct drm_bridge *bridge)
>> +{
>> +	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>> +
>> +	/*
>> +	 * Switch to cmd mode before panel-bridge disable & panel unprepare.
>> +	 * Note: panel-bridge disable & panel disable has been called
>> +	 * before by the drm framework.
> I don't think that's exactly the case. I think the sequence should be as in the
> call chain below.
>
>> +	 */
>> +	dw_mipi_dsi_set_mode(dsi, 0);
>> +
>> +	/*
>> +	 * TODO Only way found to call panel-bridge disable & panel unprepare
>> +	 * before the dsi "final" disable... can we do better?
> I agree, this is a problem. More below.
>
>> +	 */
>> +	drm_bridge_post_disable(dsi->panel_bridge);
>> +
> I'm guessing our display chain is something like:
>
> KMS_encoder -> DW_DSI_bridge -> Panel_bridge -> Panel
>
> The order in which the disable ops are called:
>
> drm_bridge_disable(Panel_bridge)
>    - drm_panel_disable(Panel)
> drm_bridge_disable(DW_DSI_bridge)
> encoder_funcs->prepare(KMS_encoder)
> drm_bridge_post_disable(DW_DSI_bridge)
> drm_bridge_post_disable(Panel_bridge)
>    - drm_panel_unprepare(Panel)
>
> Assuming that only drm_panel_unprepare() requires sending DSI commands, you could have
> switched to command mode in DW_DSI_bridge's disable() op, and do the "final" DSI disable
> in DW_DSI_bridge's post_disable(), but that would still result in drm_panel_unprepare()
> being called with the DSI host dead.
>
> The existing call chain of consecutive bridges is the most symmetric one, and the one
> expected to work in most cases, but it clearly doesn't work in your use case.
>
> We have a few options:
>
> - Undo the drm-panel-bridge stuff, and have the freedom of calling drm_panel ops in
> whatever order we want.
>
> - Put a big TODO/HACK comment here, saying that this needs to be fixed in the drm_bridge
> framework and the API needs to be updated to manage our own call chains. Also,
> instead of calling "drm_bridge_post_disable(dsi->panel_bridge);" explicitly, we
> can manually call panel_bridge->post_disable() op directly. This avoids us doing
> things recursively.
>
> We would implement the TODO task in drm_bridges only when there are more people
> desperately in the need to have customizable call chains of bridge ops for long
> display chains, so I don't see it being implemented in the near future, but I don't
> think there should be any problem keeping this hack in the dw dsi driver for now.
>
> What choice do you prefer?
>
> Eric, Daniel,
>
> Fyi, this is another case where the panel-bridge stuff doesn't work so well. Not
> criticizing or anything, just pointing out :)

I have just looked at existing panel drivers, most of them (probably all
supporting DCS commands) sends commands to the panel in unprepare
callback, and it looks correct.

I am not sure what should be fixed in the framework, some alternatives I
see:
1. change order of disable callbacks, usually it should be reverse of
order of enable callbacks,
    but I guess it could break other devices with different requirements,
2. do not use call-chain, instead every bridge will be responsible to
call attached sink's callbacks, this way dsi bridge can turn off dsi
bus, after calling panel_bridge.post_disable,
it looks for me the most flexible solution, but it leaves the
responsibility to the drivers.
3. move DSI host power management to mipi_dsi bus, ie it should be
enabled on dsi device request, and disabled after dsi device does not
need power anymore.

Regards
Andrzej

>
> Archit
>
>
>> +	dw_mipi_dsi_disable(dsi);
>> +	clk_disable_unprepare(dsi->pclk);
>> +	pm_runtime_put(dsi->dev);
>> +}
>> +
>> +void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
>> +				 struct drm_display_mode *mode,
>> +				 struct drm_display_mode *adjusted_mode)
>> +{
>> +	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>> +	const struct dw_mipi_dsi_phy_ops *phy_ops = dsi->plat_data->phy_ops;
>> +	void *priv_data = dsi->plat_data->priv_data;
>> +	int ret;
>> +
>> +	clk_prepare_enable(dsi->pclk);
>> +
>> +	ret = phy_ops->get_lane_mbps(priv_data, mode, dsi->mode_flags,
>> +				     dsi->lanes, dsi->format, &dsi->lane_mbps);
>> +	if (ret)
>> +		DRM_DEBUG_DRIVER("Phy get_lane_mbps() failed\n");
>> +
>> +	pm_runtime_get_sync(dsi->dev);
>> +	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_init(dsi);
>> +	dw_mipi_dsi_dphy_timing_config(dsi);
>> +	dw_mipi_dsi_dphy_interface_config(dsi);
>> +
>> +	dw_mipi_dsi_clear_err(dsi);
>> +
>> +	ret = phy_ops->init(priv_data);
>> +	if (ret)
>> +		DRM_DEBUG_DRIVER("Phy init() failed\n");
>> +
>> +	dw_mipi_dsi_dphy_enable(dsi);
>> +
>> +	dw_mipi_dsi_wait_for_two_frames(mode);
>> +
>> +	/* Switch to cmd mode for panel-bridge pre_enable & panel prepare */
>> +	dw_mipi_dsi_set_mode(dsi, 0);
>> +}
>> +
>> +static void dw_mipi_dsi_bridge_enable(struct drm_bridge *bridge)
>> +{
>> +	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>> +
>> +	/* Switch to video mode for panel-bridge enable & panel enable */
>> +	dw_mipi_dsi_set_mode(dsi, MIPI_DSI_MODE_VIDEO);
>> +}
>> +
>> +static enum drm_mode_status
>> +dw_mipi_dsi_bridge_mode_valid(struct drm_bridge *bridge,
>> +			      const struct drm_display_mode *mode)
>> +{
>> +	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>> +	const struct dw_mipi_dsi_plat_data *pdata = dsi->plat_data;
>> +	enum drm_mode_status mode_status = MODE_OK;
>> +
>> +	if (pdata->mode_valid)
>> +		mode_status = pdata->mode_valid(pdata->priv_data, mode);
>> +
>> +	return mode_status;
>> +}
>> +
>> +static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
>> +{
>> +	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
>> +
>> +	if (!bridge->encoder) {
>> +		DRM_ERROR("Parent encoder object not found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	/* Set the encoder type as caller does not know it */
>> +	bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;
>> +
>> +	/* Attach the panel-bridge to the dsi bridge */
>> +	return drm_bridge_attach(bridge->encoder, dsi->panel_bridge, bridge);
>> +}
>> +
>> +static struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
>> +	.mode_set     = dw_mipi_dsi_bridge_mode_set,
>> +	.enable	      = dw_mipi_dsi_bridge_enable,
>> +	.post_disable = dw_mipi_dsi_bridge_post_disable,
>> +	.mode_valid   = dw_mipi_dsi_bridge_mode_valid,
>> +	.attach	      = dw_mipi_dsi_bridge_attach,
>> +};
>> +
>> +static struct dw_mipi_dsi *
>> +__dw_mipi_dsi_probe(struct platform_device *pdev,
>> +		    const struct dw_mipi_dsi_plat_data *plat_data)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct reset_control *apb_rst;
>> +	struct dw_mipi_dsi *dsi;
>> +	struct resource *res;
>> +	int ret;
>> +
>> +	dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
>> +	if (!dsi)
>> +		return ERR_PTR(-ENOMEM);
>> +
>> +	dsi->dev = dev;
>> +	dsi->plat_data = plat_data;
>> +
>> +	if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps) {
>> +		DRM_ERROR("Phy not properly configured\n");
>> +		return ERR_PTR(-ENODEV);
>> +	}
>> +
>> +	if (!plat_data->base) {
>> +		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +		if (!res)
>> +			return ERR_PTR(-ENODEV);
>> +
>> +		dsi->base = devm_ioremap_resource(dev, res);
>> +		if (IS_ERR(dsi->base))
>> +			return ERR_PTR(-ENODEV);
>> +
>> +	} else {
>> +		dsi->base = plat_data->base;
>> +	}
>> +
>> +	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 ERR_PTR(ret);
>> +	}
>> +
>> +	/*
>> +	 * Note that the reset was not defined in the initial device tree, so
>> +	 * we have to be prepared for it not being found.
>> +	 */
>> +	apb_rst = devm_reset_control_get(dev, "apb");
>> +	if (IS_ERR(apb_rst)) {
>> +		ret = PTR_ERR(apb_rst);
>> +		if (ret == -ENOENT) {
>> +			apb_rst = NULL;
>> +		} else {
>> +			dev_err(dev, "Unable to get reset control: %d\n", ret);
>> +			return ERR_PTR(ret);
>> +		}
>> +	}
>> +
>> +	if (apb_rst) {
>> +		ret = clk_prepare_enable(dsi->pclk);
>> +		if (ret) {
>> +			dev_err(dev, "%s: Failed to enable pclk\n", __func__);
>> +			return ERR_PTR(ret);
>> +		}
>> +
>> +		reset_control_assert(apb_rst);
>> +		usleep_range(10, 20);
>> +		reset_control_deassert(apb_rst);
>> +
>> +		clk_disable_unprepare(dsi->pclk);
>> +	}
>> +
>> +	pm_runtime_enable(dev);
>> +
>> +	dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
>> +	dsi->dsi_host.dev = dev;
>> +	ret = mipi_dsi_host_register(&dsi->dsi_host);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to register MIPI host: %d\n", ret);
>> +		return ERR_PTR(ret);
>> +	}
>> +
>> +	dsi->bridge.driver_private = dsi;
>> +	dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
>> +#ifdef CONFIG_OF
>> +	dsi->bridge.of_node = pdev->dev.of_node;
>> +#endif
>> +
>> +	dev_set_drvdata(dev, dsi);
>> +
>> +	return dsi;
>> +}
>> +
>> +static void __dw_mipi_dsi_remove(struct dw_mipi_dsi *dsi)
>> +{
>> +	pm_runtime_disable(dsi->dev);
>> +}
>> +
>> +/*
>> + * Probe/remove API, used from platforms based on the DRM bridge API.
>> + */
>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>> +		      const struct dw_mipi_dsi_plat_data *plat_data)
>> +{
>> +	struct dw_mipi_dsi *dsi;
>> +
>> +	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>> +	if (IS_ERR(dsi))
>> +		return PTR_ERR(dsi);
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_probe);
>> +
>> +void dw_mipi_dsi_remove(struct platform_device *pdev)
>> +{
>> +	struct dw_mipi_dsi *dsi = platform_get_drvdata(pdev);
>> +
>> +	mipi_dsi_host_unregister(&dsi->dsi_host);
>> +
>> +	__dw_mipi_dsi_remove(dsi);
>> +}
>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_remove);
>> +
>> +/*
>> + * Bind/unbind API, used from platforms based on the component framework.
>> + */
>> +int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
>> +		     const struct dw_mipi_dsi_plat_data *plat_data)
>> +{
>> +	struct dw_mipi_dsi *dsi;
>> +	int ret;
>> +
>> +	dsi = __dw_mipi_dsi_probe(pdev, plat_data);
>> +	if (IS_ERR(dsi))
>> +		return PTR_ERR(dsi);
>> +
>> +	ret = drm_bridge_attach(encoder, &dsi->bridge, NULL);
>> +	if (ret) {
>> +		dw_mipi_dsi_remove(pdev);
>> +		DRM_ERROR("Failed to initialize bridge with drm\n");
>> +		return ret;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_bind);
>> +
>> +void dw_mipi_dsi_unbind(struct device *dev)
>> +{
>> +	struct dw_mipi_dsi *dsi = dev_get_drvdata(dev);
>> +
>> +	__dw_mipi_dsi_remove(dsi);
>> +}
>> +EXPORT_SYMBOL_GPL(dw_mipi_dsi_unbind);
>> +
>> +MODULE_AUTHOR("Chris Zhong <zyw at rock-chips.com>");
>> +MODULE_AUTHOR("Philippe Cornu <philippe.cornu at st.com>");
>> +MODULE_DESCRIPTION("DW MIPI DSI host controller driver");
>> +MODULE_LICENSE("GPL");
>> +MODULE_ALIAS("platform:dw-mipi-dsi");
>> diff --git a/include/drm/bridge/dw_mipi_dsi.h b/include/drm/bridge/dw_mipi_dsi.h
>> new file mode 100644
>> index 0000000..9b30fec
>> --- /dev/null
>> +++ b/include/drm/bridge/dw_mipi_dsi.h
>> @@ -0,0 +1,39 @@
>> +/*
>> + * Copyright (C) STMicroelectronics SA 2017
>> + *
>> + * Authors: Philippe Cornu <philippe.cornu at st.com>
>> + *          Yannick Fertre <yannick.fertre at st.com>
>> + *
>> + * License terms:  GNU General Public License (GPL), version 2
>> + */
>> +
>> +#ifndef __DW_MIPI_DSI__
>> +#define __DW_MIPI_DSI__
>> +
>> +struct dw_mipi_dsi_phy_ops {
>> +	int (*init)(void *priv_data);
>> +	int (*get_lane_mbps)(void *priv_data, struct drm_display_mode *mode,
>> +			     unsigned long mode_flags, u32 lanes, u32 format,
>> +			     unsigned int *lane_mbps);
>> +};
>> +
>> +struct dw_mipi_dsi_plat_data {
>> +	void __iomem *base;
>> +	unsigned int max_data_lanes;
>> +
>> +	enum drm_mode_status (*mode_valid)(void *priv_data,
>> +					   const struct drm_display_mode *mode);
>> +
>> +	const struct dw_mipi_dsi_phy_ops *phy_ops;
>> +
>> +	void *priv_data;
>> +};
>> +
>> +int dw_mipi_dsi_probe(struct platform_device *pdev,
>> +		      const struct dw_mipi_dsi_plat_data *plat_data);
>> +void dw_mipi_dsi_remove(struct platform_device *pdev);
>> +int dw_mipi_dsi_bind(struct platform_device *pdev, struct drm_encoder *encoder,
>> +		     const struct dw_mipi_dsi_plat_data *plat_data);
>> +void dw_mipi_dsi_unbind(struct device *dev);
>> +
>> +#endif /* __DW_MIPI_DSI__ */
>>



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