X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fgpu%2Fdrm%2Ftegra%2Fdsi.c;fp=kernel%2Fdrivers%2Fgpu%2Fdrm%2Ftegra%2Fdsi.c;h=ed970f62290306e5c78158f9600211d51251dc78;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git

diff --git a/kernel/drivers/gpu/drm/tegra/dsi.c b/kernel/drivers/gpu/drm/tegra/dsi.c
new file mode 100644
index 000000000..ed970f622
--- /dev/null
+++ b/kernel/drivers/gpu/drm/tegra/dsi.c
@@ -0,0 +1,1636 @@
+/*
+ * Copyright (C) 2013 NVIDIA Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/debugfs.h>
+#include <linux/host1x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+#include "dc.h"
+#include "drm.h"
+#include "dsi.h"
+#include "mipi-phy.h"
+
+struct tegra_dsi_state {
+	struct drm_connector_state base;
+
+	struct mipi_dphy_timing timing;
+	unsigned long period;
+
+	unsigned int vrefresh;
+	unsigned int lanes;
+	unsigned long pclk;
+	unsigned long bclk;
+
+	enum tegra_dsi_format format;
+	unsigned int mul;
+	unsigned int div;
+};
+
+static inline struct tegra_dsi_state *
+to_dsi_state(struct drm_connector_state *state)
+{
+	return container_of(state, struct tegra_dsi_state, base);
+}
+
+struct tegra_dsi {
+	struct host1x_client client;
+	struct tegra_output output;
+	struct device *dev;
+
+	void __iomem *regs;
+
+	struct reset_control *rst;
+	struct clk *clk_parent;
+	struct clk *clk_lp;
+	struct clk *clk;
+
+	struct drm_info_list *debugfs_files;
+	struct drm_minor *minor;
+	struct dentry *debugfs;
+
+	unsigned long flags;
+	enum mipi_dsi_pixel_format format;
+	unsigned int lanes;
+
+	struct tegra_mipi_device *mipi;
+	struct mipi_dsi_host host;
+
+	struct regulator *vdd;
+
+	unsigned int video_fifo_depth;
+	unsigned int host_fifo_depth;
+
+	/* for ganged-mode support */
+	struct tegra_dsi *master;
+	struct tegra_dsi *slave;
+};
+
+static inline struct tegra_dsi *
+host1x_client_to_dsi(struct host1x_client *client)
+{
+	return container_of(client, struct tegra_dsi, client);
+}
+
+static inline struct tegra_dsi *host_to_tegra(struct mipi_dsi_host *host)
+{
+	return container_of(host, struct tegra_dsi, host);
+}
+
+static inline struct tegra_dsi *to_dsi(struct tegra_output *output)
+{
+	return container_of(output, struct tegra_dsi, output);
+}
+
+static struct tegra_dsi_state *tegra_dsi_get_state(struct tegra_dsi *dsi)
+{
+	return to_dsi_state(dsi->output.connector.state);
+}
+
+static inline u32 tegra_dsi_readl(struct tegra_dsi *dsi, unsigned long reg)
+{
+	return readl(dsi->regs + (reg << 2));
+}
+
+static inline void tegra_dsi_writel(struct tegra_dsi *dsi, u32 value,
+				    unsigned long reg)
+{
+	writel(value, dsi->regs + (reg << 2));
+}
+
+static int tegra_dsi_show_regs(struct seq_file *s, void *data)
+{
+	struct drm_info_node *node = s->private;
+	struct tegra_dsi *dsi = node->info_ent->data;
+
+#define DUMP_REG(name)						\
+	seq_printf(s, "%-32s %#05x %08x\n", #name, name,	\
+		   tegra_dsi_readl(dsi, name))
+
+	DUMP_REG(DSI_INCR_SYNCPT);
+	DUMP_REG(DSI_INCR_SYNCPT_CONTROL);
+	DUMP_REG(DSI_INCR_SYNCPT_ERROR);
+	DUMP_REG(DSI_CTXSW);
+	DUMP_REG(DSI_RD_DATA);
+	DUMP_REG(DSI_WR_DATA);
+	DUMP_REG(DSI_POWER_CONTROL);
+	DUMP_REG(DSI_INT_ENABLE);
+	DUMP_REG(DSI_INT_STATUS);
+	DUMP_REG(DSI_INT_MASK);
+	DUMP_REG(DSI_HOST_CONTROL);
+	DUMP_REG(DSI_CONTROL);
+	DUMP_REG(DSI_SOL_DELAY);
+	DUMP_REG(DSI_MAX_THRESHOLD);
+	DUMP_REG(DSI_TRIGGER);
+	DUMP_REG(DSI_TX_CRC);
+	DUMP_REG(DSI_STATUS);
+
+	DUMP_REG(DSI_INIT_SEQ_CONTROL);
+	DUMP_REG(DSI_INIT_SEQ_DATA_0);
+	DUMP_REG(DSI_INIT_SEQ_DATA_1);
+	DUMP_REG(DSI_INIT_SEQ_DATA_2);
+	DUMP_REG(DSI_INIT_SEQ_DATA_3);
+	DUMP_REG(DSI_INIT_SEQ_DATA_4);
+	DUMP_REG(DSI_INIT_SEQ_DATA_5);
+	DUMP_REG(DSI_INIT_SEQ_DATA_6);
+	DUMP_REG(DSI_INIT_SEQ_DATA_7);
+
+	DUMP_REG(DSI_PKT_SEQ_0_LO);
+	DUMP_REG(DSI_PKT_SEQ_0_HI);
+	DUMP_REG(DSI_PKT_SEQ_1_LO);
+	DUMP_REG(DSI_PKT_SEQ_1_HI);
+	DUMP_REG(DSI_PKT_SEQ_2_LO);
+	DUMP_REG(DSI_PKT_SEQ_2_HI);
+	DUMP_REG(DSI_PKT_SEQ_3_LO);
+	DUMP_REG(DSI_PKT_SEQ_3_HI);
+	DUMP_REG(DSI_PKT_SEQ_4_LO);
+	DUMP_REG(DSI_PKT_SEQ_4_HI);
+	DUMP_REG(DSI_PKT_SEQ_5_LO);
+	DUMP_REG(DSI_PKT_SEQ_5_HI);
+
+	DUMP_REG(DSI_DCS_CMDS);
+
+	DUMP_REG(DSI_PKT_LEN_0_1);
+	DUMP_REG(DSI_PKT_LEN_2_3);
+	DUMP_REG(DSI_PKT_LEN_4_5);
+	DUMP_REG(DSI_PKT_LEN_6_7);
+
+	DUMP_REG(DSI_PHY_TIMING_0);
+	DUMP_REG(DSI_PHY_TIMING_1);
+	DUMP_REG(DSI_PHY_TIMING_2);
+	DUMP_REG(DSI_BTA_TIMING);
+
+	DUMP_REG(DSI_TIMEOUT_0);
+	DUMP_REG(DSI_TIMEOUT_1);
+	DUMP_REG(DSI_TO_TALLY);
+
+	DUMP_REG(DSI_PAD_CONTROL_0);
+	DUMP_REG(DSI_PAD_CONTROL_CD);
+	DUMP_REG(DSI_PAD_CD_STATUS);
+	DUMP_REG(DSI_VIDEO_MODE_CONTROL);
+	DUMP_REG(DSI_PAD_CONTROL_1);
+	DUMP_REG(DSI_PAD_CONTROL_2);
+	DUMP_REG(DSI_PAD_CONTROL_3);
+	DUMP_REG(DSI_PAD_CONTROL_4);
+
+	DUMP_REG(DSI_GANGED_MODE_CONTROL);
+	DUMP_REG(DSI_GANGED_MODE_START);
+	DUMP_REG(DSI_GANGED_MODE_SIZE);
+
+	DUMP_REG(DSI_RAW_DATA_BYTE_COUNT);
+	DUMP_REG(DSI_ULTRA_LOW_POWER_CONTROL);
+
+	DUMP_REG(DSI_INIT_SEQ_DATA_8);
+	DUMP_REG(DSI_INIT_SEQ_DATA_9);
+	DUMP_REG(DSI_INIT_SEQ_DATA_10);
+	DUMP_REG(DSI_INIT_SEQ_DATA_11);
+	DUMP_REG(DSI_INIT_SEQ_DATA_12);
+	DUMP_REG(DSI_INIT_SEQ_DATA_13);
+	DUMP_REG(DSI_INIT_SEQ_DATA_14);
+	DUMP_REG(DSI_INIT_SEQ_DATA_15);
+
+#undef DUMP_REG
+
+	return 0;
+}
+
+static struct drm_info_list debugfs_files[] = {
+	{ "regs", tegra_dsi_show_regs, 0, NULL },
+};
+
+static int tegra_dsi_debugfs_init(struct tegra_dsi *dsi,
+				  struct drm_minor *minor)
+{
+	const char *name = dev_name(dsi->dev);
+	unsigned int i;
+	int err;
+
+	dsi->debugfs = debugfs_create_dir(name, minor->debugfs_root);
+	if (!dsi->debugfs)
+		return -ENOMEM;
+
+	dsi->debugfs_files = kmemdup(debugfs_files, sizeof(debugfs_files),
+				     GFP_KERNEL);
+	if (!dsi->debugfs_files) {
+		err = -ENOMEM;
+		goto remove;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(debugfs_files); i++)
+		dsi->debugfs_files[i].data = dsi;
+
+	err = drm_debugfs_create_files(dsi->debugfs_files,
+				       ARRAY_SIZE(debugfs_files),
+				       dsi->debugfs, minor);
+	if (err < 0)
+		goto free;
+
+	dsi->minor = minor;
+
+	return 0;
+
+free:
+	kfree(dsi->debugfs_files);
+	dsi->debugfs_files = NULL;
+remove:
+	debugfs_remove(dsi->debugfs);
+	dsi->debugfs = NULL;
+
+	return err;
+}
+
+static void tegra_dsi_debugfs_exit(struct tegra_dsi *dsi)
+{
+	drm_debugfs_remove_files(dsi->debugfs_files, ARRAY_SIZE(debugfs_files),
+				 dsi->minor);
+	dsi->minor = NULL;
+
+	kfree(dsi->debugfs_files);
+	dsi->debugfs_files = NULL;
+
+	debugfs_remove(dsi->debugfs);
+	dsi->debugfs = NULL;
+}
+
+#define PKT_ID0(id)	((((id) & 0x3f) <<  3) | (1 <<  9))
+#define PKT_LEN0(len)	(((len) & 0x07) <<  0)
+#define PKT_ID1(id)	((((id) & 0x3f) << 13) | (1 << 19))
+#define PKT_LEN1(len)	(((len) & 0x07) << 10)
+#define PKT_ID2(id)	((((id) & 0x3f) << 23) | (1 << 29))
+#define PKT_LEN2(len)	(((len) & 0x07) << 20)
+
+#define PKT_LP		(1 << 30)
+#define NUM_PKT_SEQ	12
+
+/*
+ * non-burst mode with sync pulses
+ */
+static const u32 pkt_seq_video_non_burst_sync_pulses[NUM_PKT_SEQ] = {
+	[ 0] = PKT_ID0(MIPI_DSI_V_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
+	       PKT_LP,
+	[ 1] = 0,
+	[ 2] = PKT_ID0(MIPI_DSI_V_SYNC_END) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
+	       PKT_LP,
+	[ 3] = 0,
+	[ 4] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
+	       PKT_LP,
+	[ 5] = 0,
+	[ 6] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0),
+	[ 7] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(2) |
+	       PKT_ID1(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN1(3) |
+	       PKT_ID2(MIPI_DSI_BLANKING_PACKET) | PKT_LEN2(4),
+	[ 8] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0) |
+	       PKT_LP,
+	[ 9] = 0,
+	[10] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(1) |
+	       PKT_ID2(MIPI_DSI_H_SYNC_END) | PKT_LEN2(0),
+	[11] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(2) |
+	       PKT_ID1(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN1(3) |
+	       PKT_ID2(MIPI_DSI_BLANKING_PACKET) | PKT_LEN2(4),
+};
+
+/*
+ * non-burst mode with sync events
+ */
+static const u32 pkt_seq_video_non_burst_sync_events[NUM_PKT_SEQ] = {
+	[ 0] = PKT_ID0(MIPI_DSI_V_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_END_OF_TRANSMISSION) | PKT_LEN1(7) |
+	       PKT_LP,
+	[ 1] = 0,
+	[ 2] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_END_OF_TRANSMISSION) | PKT_LEN1(7) |
+	       PKT_LP,
+	[ 3] = 0,
+	[ 4] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_END_OF_TRANSMISSION) | PKT_LEN1(7) |
+	       PKT_LP,
+	[ 5] = 0,
+	[ 6] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(2) |
+	       PKT_ID2(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN2(3),
+	[ 7] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(4),
+	[ 8] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_END_OF_TRANSMISSION) | PKT_LEN1(7) |
+	       PKT_LP,
+	[ 9] = 0,
+	[10] = PKT_ID0(MIPI_DSI_H_SYNC_START) | PKT_LEN0(0) |
+	       PKT_ID1(MIPI_DSI_BLANKING_PACKET) | PKT_LEN1(2) |
+	       PKT_ID2(MIPI_DSI_PACKED_PIXEL_STREAM_24) | PKT_LEN2(3),
+	[11] = PKT_ID0(MIPI_DSI_BLANKING_PACKET) | PKT_LEN0(4),
+};
+
+static const u32 pkt_seq_command_mode[NUM_PKT_SEQ] = {
+	[ 0] = 0,
+	[ 1] = 0,
+	[ 2] = 0,
+	[ 3] = 0,
+	[ 4] = 0,
+	[ 5] = 0,
+	[ 6] = PKT_ID0(MIPI_DSI_DCS_LONG_WRITE) | PKT_LEN0(3) | PKT_LP,
+	[ 7] = 0,
+	[ 8] = 0,
+	[ 9] = 0,
+	[10] = PKT_ID0(MIPI_DSI_DCS_LONG_WRITE) | PKT_LEN0(5) | PKT_LP,
+	[11] = 0,
+};
+
+static void tegra_dsi_set_phy_timing(struct tegra_dsi *dsi,
+				     unsigned long period,
+				     const struct mipi_dphy_timing *timing)
+{
+	u32 value;
+
+	value = DSI_TIMING_FIELD(timing->hsexit, period, 1) << 24 |
+		DSI_TIMING_FIELD(timing->hstrail, period, 0) << 16 |
+		DSI_TIMING_FIELD(timing->hszero, period, 3) << 8 |
+		DSI_TIMING_FIELD(timing->hsprepare, period, 1);
+	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_0);
+
+	value = DSI_TIMING_FIELD(timing->clktrail, period, 1) << 24 |
+		DSI_TIMING_FIELD(timing->clkpost, period, 1) << 16 |
+		DSI_TIMING_FIELD(timing->clkzero, period, 1) << 8 |
+		DSI_TIMING_FIELD(timing->lpx, period, 1);
+	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_1);
+
+	value = DSI_TIMING_FIELD(timing->clkprepare, period, 1) << 16 |
+		DSI_TIMING_FIELD(timing->clkpre, period, 1) << 8 |
+		DSI_TIMING_FIELD(0xff * period, period, 0) << 0;
+	tegra_dsi_writel(dsi, value, DSI_PHY_TIMING_2);
+
+	value = DSI_TIMING_FIELD(timing->taget, period, 1) << 16 |
+		DSI_TIMING_FIELD(timing->tasure, period, 1) << 8 |
+		DSI_TIMING_FIELD(timing->tago, period, 1);
+	tegra_dsi_writel(dsi, value, DSI_BTA_TIMING);
+
+	if (dsi->slave)
+		tegra_dsi_set_phy_timing(dsi->slave, period, timing);
+}
+
+static int tegra_dsi_get_muldiv(enum mipi_dsi_pixel_format format,
+				unsigned int *mulp, unsigned int *divp)
+{
+	switch (format) {
+	case MIPI_DSI_FMT_RGB666_PACKED:
+	case MIPI_DSI_FMT_RGB888:
+		*mulp = 3;
+		*divp = 1;
+		break;
+
+	case MIPI_DSI_FMT_RGB565:
+		*mulp = 2;
+		*divp = 1;
+		break;
+
+	case MIPI_DSI_FMT_RGB666:
+		*mulp = 9;
+		*divp = 4;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int tegra_dsi_get_format(enum mipi_dsi_pixel_format format,
+				enum tegra_dsi_format *fmt)
+{
+	switch (format) {
+	case MIPI_DSI_FMT_RGB888:
+		*fmt = TEGRA_DSI_FORMAT_24P;
+		break;
+
+	case MIPI_DSI_FMT_RGB666:
+		*fmt = TEGRA_DSI_FORMAT_18NP;
+		break;
+
+	case MIPI_DSI_FMT_RGB666_PACKED:
+		*fmt = TEGRA_DSI_FORMAT_18P;
+		break;
+
+	case MIPI_DSI_FMT_RGB565:
+		*fmt = TEGRA_DSI_FORMAT_16P;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void tegra_dsi_ganged_enable(struct tegra_dsi *dsi, unsigned int start,
+				    unsigned int size)
+{
+	u32 value;
+
+	tegra_dsi_writel(dsi, start, DSI_GANGED_MODE_START);
+	tegra_dsi_writel(dsi, size << 16 | size, DSI_GANGED_MODE_SIZE);
+
+	value = DSI_GANGED_MODE_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_GANGED_MODE_CONTROL);
+}
+
+static void tegra_dsi_enable(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+	value |= DSI_POWER_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+	if (dsi->slave)
+		tegra_dsi_enable(dsi->slave);
+}
+
+static unsigned int tegra_dsi_get_lanes(struct tegra_dsi *dsi)
+{
+	if (dsi->master)
+		return dsi->master->lanes + dsi->lanes;
+
+	if (dsi->slave)
+		return dsi->lanes + dsi->slave->lanes;
+
+	return dsi->lanes;
+}
+
+static void tegra_dsi_configure(struct tegra_dsi *dsi, unsigned int pipe,
+				const struct drm_display_mode *mode)
+{
+	unsigned int hact, hsw, hbp, hfp, i, mul, div;
+	struct tegra_dsi_state *state;
+	const u32 *pkt_seq;
+	u32 value;
+
+	/* XXX: pass in state into this function? */
+	if (dsi->master)
+		state = tegra_dsi_get_state(dsi->master);
+	else
+		state = tegra_dsi_get_state(dsi);
+
+	mul = state->mul;
+	div = state->div;
+
+	if (dsi->flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
+		DRM_DEBUG_KMS("Non-burst video mode with sync pulses\n");
+		pkt_seq = pkt_seq_video_non_burst_sync_pulses;
+	} else if (dsi->flags & MIPI_DSI_MODE_VIDEO) {
+		DRM_DEBUG_KMS("Non-burst video mode with sync events\n");
+		pkt_seq = pkt_seq_video_non_burst_sync_events;
+	} else {
+		DRM_DEBUG_KMS("Command mode\n");
+		pkt_seq = pkt_seq_command_mode;
+	}
+
+	value = DSI_CONTROL_CHANNEL(0) |
+		DSI_CONTROL_FORMAT(state->format) |
+		DSI_CONTROL_LANES(dsi->lanes - 1) |
+		DSI_CONTROL_SOURCE(pipe);
+	tegra_dsi_writel(dsi, value, DSI_CONTROL);
+
+	tegra_dsi_writel(dsi, dsi->video_fifo_depth, DSI_MAX_THRESHOLD);
+
+	value = DSI_HOST_CONTROL_HS;
+	tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+
+	value = tegra_dsi_readl(dsi, DSI_CONTROL);
+
+	if (dsi->flags & MIPI_DSI_CLOCK_NON_CONTINUOUS)
+		value |= DSI_CONTROL_HS_CLK_CTRL;
+
+	value &= ~DSI_CONTROL_TX_TRIG(3);
+
+	/* enable DCS commands for command mode */
+	if (dsi->flags & MIPI_DSI_MODE_VIDEO)
+		value &= ~DSI_CONTROL_DCS_ENABLE;
+	else
+		value |= DSI_CONTROL_DCS_ENABLE;
+
+	value |= DSI_CONTROL_VIDEO_ENABLE;
+	value &= ~DSI_CONTROL_HOST_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_CONTROL);
+
+	for (i = 0; i < NUM_PKT_SEQ; i++)
+		tegra_dsi_writel(dsi, pkt_seq[i], DSI_PKT_SEQ_0_LO + i);
+
+	if (dsi->flags & MIPI_DSI_MODE_VIDEO) {
+		/* horizontal active pixels */
+		hact = mode->hdisplay * mul / div;
+
+		/* horizontal sync width */
+		hsw = (mode->hsync_end - mode->hsync_start) * mul / div;
+		hsw -= 10;
+
+		/* horizontal back porch */
+		hbp = (mode->htotal - mode->hsync_end) * mul / div;
+		hbp -= 14;
+
+		/* horizontal front porch */
+		hfp = (mode->hsync_start - mode->hdisplay) * mul / div;
+		hfp -= 8;
+
+		tegra_dsi_writel(dsi, hsw << 16 | 0, DSI_PKT_LEN_0_1);
+		tegra_dsi_writel(dsi, hact << 16 | hbp, DSI_PKT_LEN_2_3);
+		tegra_dsi_writel(dsi, hfp, DSI_PKT_LEN_4_5);
+		tegra_dsi_writel(dsi, 0x0f0f << 16, DSI_PKT_LEN_6_7);
+
+		/* set SOL delay (for non-burst mode only) */
+		tegra_dsi_writel(dsi, 8 * mul / div, DSI_SOL_DELAY);
+
+		/* TODO: implement ganged mode */
+	} else {
+		u16 bytes;
+
+		if (dsi->master || dsi->slave) {
+			/*
+			 * For ganged mode, assume symmetric left-right mode.
+			 */
+			bytes = 1 + (mode->hdisplay / 2) * mul / div;
+		} else {
+			/* 1 byte (DCS command) + pixel data */
+			bytes = 1 + mode->hdisplay * mul / div;
+		}
+
+		tegra_dsi_writel(dsi, 0, DSI_PKT_LEN_0_1);
+		tegra_dsi_writel(dsi, bytes << 16, DSI_PKT_LEN_2_3);
+		tegra_dsi_writel(dsi, bytes << 16, DSI_PKT_LEN_4_5);
+		tegra_dsi_writel(dsi, 0, DSI_PKT_LEN_6_7);
+
+		value = MIPI_DCS_WRITE_MEMORY_START << 8 |
+			MIPI_DCS_WRITE_MEMORY_CONTINUE;
+		tegra_dsi_writel(dsi, value, DSI_DCS_CMDS);
+
+		/* set SOL delay */
+		if (dsi->master || dsi->slave) {
+			unsigned long delay, bclk, bclk_ganged;
+			unsigned int lanes = state->lanes;
+
+			/* SOL to valid, valid to FIFO and FIFO write delay */
+			delay = 4 + 4 + 2;
+			delay = DIV_ROUND_UP(delay * mul, div * lanes);
+			/* FIFO read delay */
+			delay = delay + 6;
+
+			bclk = DIV_ROUND_UP(mode->htotal * mul, div * lanes);
+			bclk_ganged = DIV_ROUND_UP(bclk * lanes / 2, lanes);
+			value = bclk - bclk_ganged + delay + 20;
+		} else {
+			/* TODO: revisit for non-ganged mode */
+			value = 8 * mul / div;
+		}
+
+		tegra_dsi_writel(dsi, value, DSI_SOL_DELAY);
+	}
+
+	if (dsi->slave) {
+		tegra_dsi_configure(dsi->slave, pipe, mode);
+
+		/*
+		 * TODO: Support modes other than symmetrical left-right
+		 * split.
+		 */
+		tegra_dsi_ganged_enable(dsi, 0, mode->hdisplay / 2);
+		tegra_dsi_ganged_enable(dsi->slave, mode->hdisplay / 2,
+					mode->hdisplay / 2);
+	}
+}
+
+static int tegra_dsi_wait_idle(struct tegra_dsi *dsi, unsigned long timeout)
+{
+	u32 value;
+
+	timeout = jiffies + msecs_to_jiffies(timeout);
+
+	while (time_before(jiffies, timeout)) {
+		value = tegra_dsi_readl(dsi, DSI_STATUS);
+		if (value & DSI_STATUS_IDLE)
+			return 0;
+
+		usleep_range(1000, 2000);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static void tegra_dsi_video_disable(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	value = tegra_dsi_readl(dsi, DSI_CONTROL);
+	value &= ~DSI_CONTROL_VIDEO_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_CONTROL);
+
+	if (dsi->slave)
+		tegra_dsi_video_disable(dsi->slave);
+}
+
+static void tegra_dsi_ganged_disable(struct tegra_dsi *dsi)
+{
+	tegra_dsi_writel(dsi, 0, DSI_GANGED_MODE_START);
+	tegra_dsi_writel(dsi, 0, DSI_GANGED_MODE_SIZE);
+	tegra_dsi_writel(dsi, 0, DSI_GANGED_MODE_CONTROL);
+}
+
+static void tegra_dsi_set_timeout(struct tegra_dsi *dsi, unsigned long bclk,
+				  unsigned int vrefresh)
+{
+	unsigned int timeout;
+	u32 value;
+
+	/* one frame high-speed transmission timeout */
+	timeout = (bclk / vrefresh) / 512;
+	value = DSI_TIMEOUT_LRX(0x2000) | DSI_TIMEOUT_HTX(timeout);
+	tegra_dsi_writel(dsi, value, DSI_TIMEOUT_0);
+
+	/* 2 ms peripheral timeout for panel */
+	timeout = 2 * bclk / 512 * 1000;
+	value = DSI_TIMEOUT_PR(timeout) | DSI_TIMEOUT_TA(0x2000);
+	tegra_dsi_writel(dsi, value, DSI_TIMEOUT_1);
+
+	value = DSI_TALLY_TA(0) | DSI_TALLY_LRX(0) | DSI_TALLY_HTX(0);
+	tegra_dsi_writel(dsi, value, DSI_TO_TALLY);
+
+	if (dsi->slave)
+		tegra_dsi_set_timeout(dsi->slave, bclk, vrefresh);
+}
+
+static void tegra_dsi_disable(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	if (dsi->slave) {
+		tegra_dsi_ganged_disable(dsi->slave);
+		tegra_dsi_ganged_disable(dsi);
+	}
+
+	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+	value &= ~DSI_POWER_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+	if (dsi->slave)
+		tegra_dsi_disable(dsi->slave);
+
+	usleep_range(5000, 10000);
+}
+
+static void tegra_dsi_soft_reset(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+	value &= ~DSI_POWER_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+	usleep_range(300, 1000);
+
+	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+	value |= DSI_POWER_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+	usleep_range(300, 1000);
+
+	value = tegra_dsi_readl(dsi, DSI_TRIGGER);
+	if (value)
+		tegra_dsi_writel(dsi, 0, DSI_TRIGGER);
+
+	if (dsi->slave)
+		tegra_dsi_soft_reset(dsi->slave);
+}
+
+static void tegra_dsi_connector_dpms(struct drm_connector *connector, int mode)
+{
+}
+
+static void tegra_dsi_connector_reset(struct drm_connector *connector)
+{
+	struct tegra_dsi_state *state;
+
+	kfree(connector->state);
+	connector->state = NULL;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		connector->state = &state->base;
+}
+
+static struct drm_connector_state *
+tegra_dsi_connector_duplicate_state(struct drm_connector *connector)
+{
+	struct tegra_dsi_state *state = to_dsi_state(connector->state);
+	struct tegra_dsi_state *copy;
+
+	copy = kmemdup(state, sizeof(*state), GFP_KERNEL);
+	if (!copy)
+		return NULL;
+
+	return &copy->base;
+}
+
+static const struct drm_connector_funcs tegra_dsi_connector_funcs = {
+	.dpms = tegra_dsi_connector_dpms,
+	.reset = tegra_dsi_connector_reset,
+	.detect = tegra_output_connector_detect,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = tegra_output_connector_destroy,
+	.atomic_duplicate_state = tegra_dsi_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static enum drm_mode_status
+tegra_dsi_connector_mode_valid(struct drm_connector *connector,
+			       struct drm_display_mode *mode)
+{
+	return MODE_OK;
+}
+
+static const struct drm_connector_helper_funcs tegra_dsi_connector_helper_funcs = {
+	.get_modes = tegra_output_connector_get_modes,
+	.mode_valid = tegra_dsi_connector_mode_valid,
+	.best_encoder = tegra_output_connector_best_encoder,
+};
+
+static const struct drm_encoder_funcs tegra_dsi_encoder_funcs = {
+	.destroy = tegra_output_encoder_destroy,
+};
+
+static void tegra_dsi_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+}
+
+static void tegra_dsi_encoder_prepare(struct drm_encoder *encoder)
+{
+}
+
+static void tegra_dsi_encoder_commit(struct drm_encoder *encoder)
+{
+}
+
+static void tegra_dsi_encoder_mode_set(struct drm_encoder *encoder,
+				       struct drm_display_mode *mode,
+				       struct drm_display_mode *adjusted)
+{
+	struct tegra_output *output = encoder_to_output(encoder);
+	struct tegra_dc *dc = to_tegra_dc(encoder->crtc);
+	struct tegra_dsi *dsi = to_dsi(output);
+	struct tegra_dsi_state *state;
+	u32 value;
+
+	state = tegra_dsi_get_state(dsi);
+
+	tegra_dsi_set_timeout(dsi, state->bclk, state->vrefresh);
+
+	/*
+	 * The D-PHY timing fields are expressed in byte-clock cycles, so
+	 * multiply the period by 8.
+	 */
+	tegra_dsi_set_phy_timing(dsi, state->period * 8, &state->timing);
+
+	if (output->panel)
+		drm_panel_prepare(output->panel);
+
+	tegra_dsi_configure(dsi, dc->pipe, mode);
+
+	/* enable display controller */
+	value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
+	value |= DSI_ENABLE;
+	tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);
+
+	tegra_dc_commit(dc);
+
+	/* enable DSI controller */
+	tegra_dsi_enable(dsi);
+
+	if (output->panel)
+		drm_panel_enable(output->panel);
+
+	return;
+}
+
+static void tegra_dsi_encoder_disable(struct drm_encoder *encoder)
+{
+	struct tegra_output *output = encoder_to_output(encoder);
+	struct tegra_dc *dc = to_tegra_dc(encoder->crtc);
+	struct tegra_dsi *dsi = to_dsi(output);
+	u32 value;
+	int err;
+
+	if (output->panel)
+		drm_panel_disable(output->panel);
+
+	tegra_dsi_video_disable(dsi);
+
+	/*
+	 * The following accesses registers of the display controller, so make
+	 * sure it's only executed when the output is attached to one.
+	 */
+	if (dc) {
+		value = tegra_dc_readl(dc, DC_DISP_DISP_WIN_OPTIONS);
+		value &= ~DSI_ENABLE;
+		tegra_dc_writel(dc, value, DC_DISP_DISP_WIN_OPTIONS);
+
+		tegra_dc_commit(dc);
+	}
+
+	err = tegra_dsi_wait_idle(dsi, 100);
+	if (err < 0)
+		dev_dbg(dsi->dev, "failed to idle DSI: %d\n", err);
+
+	tegra_dsi_soft_reset(dsi);
+
+	if (output->panel)
+		drm_panel_unprepare(output->panel);
+
+	tegra_dsi_disable(dsi);
+
+	return;
+}
+
+static int
+tegra_dsi_encoder_atomic_check(struct drm_encoder *encoder,
+			       struct drm_crtc_state *crtc_state,
+			       struct drm_connector_state *conn_state)
+{
+	struct tegra_output *output = encoder_to_output(encoder);
+	struct tegra_dsi_state *state = to_dsi_state(conn_state);
+	struct tegra_dc *dc = to_tegra_dc(conn_state->crtc);
+	struct tegra_dsi *dsi = to_dsi(output);
+	unsigned int scdiv;
+	unsigned long plld;
+	int err;
+
+	state->pclk = crtc_state->mode.clock * 1000;
+
+	err = tegra_dsi_get_muldiv(dsi->format, &state->mul, &state->div);
+	if (err < 0)
+		return err;
+
+	state->lanes = tegra_dsi_get_lanes(dsi);
+
+	err = tegra_dsi_get_format(dsi->format, &state->format);
+	if (err < 0)
+		return err;
+
+	state->vrefresh = drm_mode_vrefresh(&crtc_state->mode);
+
+	/* compute byte clock */
+	state->bclk = (state->pclk * state->mul) / (state->div * state->lanes);
+
+	DRM_DEBUG_KMS("mul: %u, div: %u, lanes: %u\n", state->mul, state->div,
+		      state->lanes);
+	DRM_DEBUG_KMS("format: %u, vrefresh: %u\n", state->format,
+		      state->vrefresh);
+	DRM_DEBUG_KMS("bclk: %lu\n", state->bclk);
+
+	/*
+	 * Compute bit clock and round up to the next MHz.
+	 */
+	plld = DIV_ROUND_UP(state->bclk * 8, USEC_PER_SEC) * USEC_PER_SEC;
+	state->period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, plld);
+
+	err = mipi_dphy_timing_get_default(&state->timing, state->period);
+	if (err < 0)
+		return err;
+
+	err = mipi_dphy_timing_validate(&state->timing, state->period);
+	if (err < 0) {
+		dev_err(dsi->dev, "failed to validate D-PHY timing: %d\n", err);
+		return err;
+	}
+
+	/*
+	 * We divide the frequency by two here, but we make up for that by
+	 * setting the shift clock divider (further below) to half of the
+	 * correct value.
+	 */
+	plld /= 2;
+
+	/*
+	 * Derive pixel clock from bit clock using the shift clock divider.
+	 * Note that this is only half of what we would expect, but we need
+	 * that to make up for the fact that we divided the bit clock by a
+	 * factor of two above.
+	 *
+	 * It's not clear exactly why this is necessary, but the display is
+	 * not working properly otherwise. Perhaps the PLLs cannot generate
+	 * frequencies sufficiently high.
+	 */
+	scdiv = ((8 * state->mul) / (state->div * state->lanes)) - 2;
+
+	err = tegra_dc_state_setup_clock(dc, crtc_state, dsi->clk_parent,
+					 plld, scdiv);
+	if (err < 0) {
+		dev_err(output->dev, "failed to setup CRTC state: %d\n", err);
+		return err;
+	}
+
+	return err;
+}
+
+static const struct drm_encoder_helper_funcs tegra_dsi_encoder_helper_funcs = {
+	.dpms = tegra_dsi_encoder_dpms,
+	.prepare = tegra_dsi_encoder_prepare,
+	.commit = tegra_dsi_encoder_commit,
+	.mode_set = tegra_dsi_encoder_mode_set,
+	.disable = tegra_dsi_encoder_disable,
+	.atomic_check = tegra_dsi_encoder_atomic_check,
+};
+
+static int tegra_dsi_pad_enable(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	value = DSI_PAD_CONTROL_VS1_PULLDN(0) | DSI_PAD_CONTROL_VS1_PDIO(0);
+	tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_0);
+
+	return 0;
+}
+
+static int tegra_dsi_pad_calibrate(struct tegra_dsi *dsi)
+{
+	u32 value;
+
+	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_0);
+	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_1);
+	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_2);
+	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_3);
+	tegra_dsi_writel(dsi, 0, DSI_PAD_CONTROL_4);
+
+	/* start calibration */
+	tegra_dsi_pad_enable(dsi);
+
+	value = DSI_PAD_SLEW_UP(0x7) | DSI_PAD_SLEW_DN(0x7) |
+		DSI_PAD_LP_UP(0x1) | DSI_PAD_LP_DN(0x1) |
+		DSI_PAD_OUT_CLK(0x0);
+	tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_2);
+
+	return tegra_mipi_calibrate(dsi->mipi);
+}
+
+static int tegra_dsi_init(struct host1x_client *client)
+{
+	struct drm_device *drm = dev_get_drvdata(client->parent);
+	struct tegra_dsi *dsi = host1x_client_to_dsi(client);
+	int err;
+
+	reset_control_deassert(dsi->rst);
+
+	err = tegra_dsi_pad_calibrate(dsi);
+	if (err < 0) {
+		dev_err(dsi->dev, "MIPI calibration failed: %d\n", err);
+		goto reset;
+	}
+
+	/* Gangsters must not register their own outputs. */
+	if (!dsi->master) {
+		dsi->output.dev = client->dev;
+
+		drm_connector_init(drm, &dsi->output.connector,
+				   &tegra_dsi_connector_funcs,
+				   DRM_MODE_CONNECTOR_DSI);
+		drm_connector_helper_add(&dsi->output.connector,
+					 &tegra_dsi_connector_helper_funcs);
+		dsi->output.connector.dpms = DRM_MODE_DPMS_OFF;
+
+		drm_encoder_init(drm, &dsi->output.encoder,
+				 &tegra_dsi_encoder_funcs,
+				 DRM_MODE_ENCODER_DSI);
+		drm_encoder_helper_add(&dsi->output.encoder,
+				       &tegra_dsi_encoder_helper_funcs);
+
+		drm_mode_connector_attach_encoder(&dsi->output.connector,
+						  &dsi->output.encoder);
+		drm_connector_register(&dsi->output.connector);
+
+		err = tegra_output_init(drm, &dsi->output);
+		if (err < 0) {
+			dev_err(client->dev,
+				"failed to initialize output: %d\n",
+				err);
+			goto reset;
+		}
+
+		dsi->output.encoder.possible_crtcs = 0x3;
+	}
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS)) {
+		err = tegra_dsi_debugfs_init(dsi, drm->primary);
+		if (err < 0)
+			dev_err(dsi->dev, "debugfs setup failed: %d\n", err);
+	}
+
+	return 0;
+
+reset:
+	reset_control_assert(dsi->rst);
+	return err;
+}
+
+static int tegra_dsi_exit(struct host1x_client *client)
+{
+	struct tegra_dsi *dsi = host1x_client_to_dsi(client);
+
+	tegra_output_exit(&dsi->output);
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+		tegra_dsi_debugfs_exit(dsi);
+
+	reset_control_assert(dsi->rst);
+
+	return 0;
+}
+
+static const struct host1x_client_ops dsi_client_ops = {
+	.init = tegra_dsi_init,
+	.exit = tegra_dsi_exit,
+};
+
+static int tegra_dsi_setup_clocks(struct tegra_dsi *dsi)
+{
+	struct clk *parent;
+	int err;
+
+	parent = clk_get_parent(dsi->clk);
+	if (!parent)
+		return -EINVAL;
+
+	err = clk_set_parent(parent, dsi->clk_parent);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static const char * const error_report[16] = {
+	"SoT Error",
+	"SoT Sync Error",
+	"EoT Sync Error",
+	"Escape Mode Entry Command Error",
+	"Low-Power Transmit Sync Error",
+	"Peripheral Timeout Error",
+	"False Control Error",
+	"Contention Detected",
+	"ECC Error, single-bit",
+	"ECC Error, multi-bit",
+	"Checksum Error",
+	"DSI Data Type Not Recognized",
+	"DSI VC ID Invalid",
+	"Invalid Transmission Length",
+	"Reserved",
+	"DSI Protocol Violation",
+};
+
+static ssize_t tegra_dsi_read_response(struct tegra_dsi *dsi,
+				       const struct mipi_dsi_msg *msg,
+				       size_t count)
+{
+	u8 *rx = msg->rx_buf;
+	unsigned int i, j, k;
+	size_t size = 0;
+	u16 errors;
+	u32 value;
+
+	/* read and parse packet header */
+	value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+
+	switch (value & 0x3f) {
+	case MIPI_DSI_RX_ACKNOWLEDGE_AND_ERROR_REPORT:
+		errors = (value >> 8) & 0xffff;
+		dev_dbg(dsi->dev, "Acknowledge and error report: %04x\n",
+			errors);
+		for (i = 0; i < ARRAY_SIZE(error_report); i++)
+			if (errors & BIT(i))
+				dev_dbg(dsi->dev, "  %2u: %s\n", i,
+					error_report[i]);
+		break;
+
+	case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_1BYTE:
+		rx[0] = (value >> 8) & 0xff;
+		size = 1;
+		break;
+
+	case MIPI_DSI_RX_DCS_SHORT_READ_RESPONSE_2BYTE:
+		rx[0] = (value >>  8) & 0xff;
+		rx[1] = (value >> 16) & 0xff;
+		size = 2;
+		break;
+
+	case MIPI_DSI_RX_DCS_LONG_READ_RESPONSE:
+		size = ((value >> 8) & 0xff00) | ((value >> 8) & 0xff);
+		break;
+
+	case MIPI_DSI_RX_GENERIC_LONG_READ_RESPONSE:
+		size = ((value >> 8) & 0xff00) | ((value >> 8) & 0xff);
+		break;
+
+	default:
+		dev_err(dsi->dev, "unhandled response type: %02x\n",
+			value & 0x3f);
+		return -EPROTO;
+	}
+
+	size = min(size, msg->rx_len);
+
+	if (msg->rx_buf && size > 0) {
+		for (i = 0, j = 0; i < count - 1; i++, j += 4) {
+			u8 *rx = msg->rx_buf + j;
+
+			value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+
+			for (k = 0; k < 4 && (j + k) < msg->rx_len; k++)
+				rx[j + k] = (value >> (k << 3)) & 0xff;
+		}
+	}
+
+	return size;
+}
+
+static int tegra_dsi_transmit(struct tegra_dsi *dsi, unsigned long timeout)
+{
+	tegra_dsi_writel(dsi, DSI_TRIGGER_HOST, DSI_TRIGGER);
+
+	timeout = jiffies + msecs_to_jiffies(timeout);
+
+	while (time_before(jiffies, timeout)) {
+		u32 value = tegra_dsi_readl(dsi, DSI_TRIGGER);
+		if ((value & DSI_TRIGGER_HOST) == 0)
+			return 0;
+
+		usleep_range(1000, 2000);
+	}
+
+	DRM_DEBUG_KMS("timeout waiting for transmission to complete\n");
+	return -ETIMEDOUT;
+}
+
+static int tegra_dsi_wait_for_response(struct tegra_dsi *dsi,
+				       unsigned long timeout)
+{
+	timeout = jiffies + msecs_to_jiffies(250);
+
+	while (time_before(jiffies, timeout)) {
+		u32 value = tegra_dsi_readl(dsi, DSI_STATUS);
+		u8 count = value & 0x1f;
+
+		if (count > 0)
+			return count;
+
+		usleep_range(1000, 2000);
+	}
+
+	DRM_DEBUG_KMS("peripheral returned no data\n");
+	return -ETIMEDOUT;
+}
+
+static void tegra_dsi_writesl(struct tegra_dsi *dsi, unsigned long offset,
+			      const void *buffer, size_t size)
+{
+	const u8 *buf = buffer;
+	size_t i, j;
+	u32 value;
+
+	for (j = 0; j < size; j += 4) {
+		value = 0;
+
+		for (i = 0; i < 4 && j + i < size; i++)
+			value |= buf[j + i] << (i << 3);
+
+		tegra_dsi_writel(dsi, value, DSI_WR_DATA);
+	}
+}
+
+static ssize_t tegra_dsi_host_transfer(struct mipi_dsi_host *host,
+				       const struct mipi_dsi_msg *msg)
+{
+	struct tegra_dsi *dsi = host_to_tegra(host);
+	struct mipi_dsi_packet packet;
+	const u8 *header;
+	size_t count;
+	ssize_t err;
+	u32 value;
+
+	err = mipi_dsi_create_packet(&packet, msg);
+	if (err < 0)
+		return err;
+
+	header = packet.header;
+
+	/* maximum FIFO depth is 1920 words */
+	if (packet.size > dsi->video_fifo_depth * 4)
+		return -ENOSPC;
+
+	/* reset underflow/overflow flags */
+	value = tegra_dsi_readl(dsi, DSI_STATUS);
+	if (value & (DSI_STATUS_UNDERFLOW | DSI_STATUS_OVERFLOW)) {
+		value = DSI_HOST_CONTROL_FIFO_RESET;
+		tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+		usleep_range(10, 20);
+	}
+
+	value = tegra_dsi_readl(dsi, DSI_POWER_CONTROL);
+	value |= DSI_POWER_CONTROL_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_POWER_CONTROL);
+
+	usleep_range(5000, 10000);
+
+	value = DSI_HOST_CONTROL_CRC_RESET | DSI_HOST_CONTROL_TX_TRIG_HOST |
+		DSI_HOST_CONTROL_CS | DSI_HOST_CONTROL_ECC;
+
+	if ((msg->flags & MIPI_DSI_MSG_USE_LPM) == 0)
+		value |= DSI_HOST_CONTROL_HS;
+
+	/*
+	 * The host FIFO has a maximum of 64 words, so larger transmissions
+	 * need to use the video FIFO.
+	 */
+	if (packet.size > dsi->host_fifo_depth * 4)
+		value |= DSI_HOST_CONTROL_FIFO_SEL;
+
+	tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+
+	/*
+	 * For reads and messages with explicitly requested ACK, generate a
+	 * BTA sequence after the transmission of the packet.
+	 */
+	if ((msg->flags & MIPI_DSI_MSG_REQ_ACK) ||
+	    (msg->rx_buf && msg->rx_len > 0)) {
+		value = tegra_dsi_readl(dsi, DSI_HOST_CONTROL);
+		value |= DSI_HOST_CONTROL_PKT_BTA;
+		tegra_dsi_writel(dsi, value, DSI_HOST_CONTROL);
+	}
+
+	value = DSI_CONTROL_LANES(0) | DSI_CONTROL_HOST_ENABLE;
+	tegra_dsi_writel(dsi, value, DSI_CONTROL);
+
+	/* write packet header, ECC is generated by hardware */
+	value = header[2] << 16 | header[1] << 8 | header[0];
+	tegra_dsi_writel(dsi, value, DSI_WR_DATA);
+
+	/* write payload (if any) */
+	if (packet.payload_length > 0)
+		tegra_dsi_writesl(dsi, DSI_WR_DATA, packet.payload,
+				  packet.payload_length);
+
+	err = tegra_dsi_transmit(dsi, 250);
+	if (err < 0)
+		return err;
+
+	if ((msg->flags & MIPI_DSI_MSG_REQ_ACK) ||
+	    (msg->rx_buf && msg->rx_len > 0)) {
+		err = tegra_dsi_wait_for_response(dsi, 250);
+		if (err < 0)
+			return err;
+
+		count = err;
+
+		value = tegra_dsi_readl(dsi, DSI_RD_DATA);
+		switch (value) {
+		case 0x84:
+			/*
+			dev_dbg(dsi->dev, "ACK\n");
+			*/
+			break;
+
+		case 0x87:
+			/*
+			dev_dbg(dsi->dev, "ESCAPE\n");
+			*/
+			break;
+
+		default:
+			dev_err(dsi->dev, "unknown status: %08x\n", value);
+			break;
+		}
+
+		if (count > 1) {
+			err = tegra_dsi_read_response(dsi, msg, count);
+			if (err < 0)
+				dev_err(dsi->dev,
+					"failed to parse response: %zd\n",
+					err);
+			else {
+				/*
+				 * For read commands, return the number of
+				 * bytes returned by the peripheral.
+				 */
+				count = err;
+			}
+		}
+	} else {
+		/*
+		 * For write commands, we have transmitted the 4-byte header
+		 * plus the variable-length payload.
+		 */
+		count = 4 + packet.payload_length;
+	}
+
+	return count;
+}
+
+static int tegra_dsi_ganged_setup(struct tegra_dsi *dsi)
+{
+	struct clk *parent;
+	int err;
+
+	/* make sure both DSI controllers share the same PLL */
+	parent = clk_get_parent(dsi->slave->clk);
+	if (!parent)
+		return -EINVAL;
+
+	err = clk_set_parent(parent, dsi->clk_parent);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static int tegra_dsi_host_attach(struct mipi_dsi_host *host,
+				 struct mipi_dsi_device *device)
+{
+	struct tegra_dsi *dsi = host_to_tegra(host);
+
+	dsi->flags = device->mode_flags;
+	dsi->format = device->format;
+	dsi->lanes = device->lanes;
+
+	if (dsi->slave) {
+		int err;
+
+		dev_dbg(dsi->dev, "attaching dual-channel device %s\n",
+			dev_name(&device->dev));
+
+		err = tegra_dsi_ganged_setup(dsi);
+		if (err < 0) {
+			dev_err(dsi->dev, "failed to set up ganged mode: %d\n",
+				err);
+			return err;
+		}
+	}
+
+	/*
+	 * Slaves don't have a panel associated with them, so they provide
+	 * merely the second channel.
+	 */
+	if (!dsi->master) {
+		struct tegra_output *output = &dsi->output;
+
+		output->panel = of_drm_find_panel(device->dev.of_node);
+		if (output->panel && output->connector.dev) {
+			drm_panel_attach(output->panel, &output->connector);
+			drm_helper_hpd_irq_event(output->connector.dev);
+		}
+	}
+
+	return 0;
+}
+
+static int tegra_dsi_host_detach(struct mipi_dsi_host *host,
+				 struct mipi_dsi_device *device)
+{
+	struct tegra_dsi *dsi = host_to_tegra(host);
+	struct tegra_output *output = &dsi->output;
+
+	if (output->panel && &device->dev == output->panel->dev) {
+		output->panel = NULL;
+
+		if (output->connector.dev)
+			drm_helper_hpd_irq_event(output->connector.dev);
+	}
+
+	return 0;
+}
+
+static const struct mipi_dsi_host_ops tegra_dsi_host_ops = {
+	.attach = tegra_dsi_host_attach,
+	.detach = tegra_dsi_host_detach,
+	.transfer = tegra_dsi_host_transfer,
+};
+
+static int tegra_dsi_ganged_probe(struct tegra_dsi *dsi)
+{
+	struct device_node *np;
+
+	np = of_parse_phandle(dsi->dev->of_node, "nvidia,ganged-mode", 0);
+	if (np) {
+		struct platform_device *gangster = of_find_device_by_node(np);
+
+		dsi->slave = platform_get_drvdata(gangster);
+		of_node_put(np);
+
+		if (!dsi->slave)
+			return -EPROBE_DEFER;
+
+		dsi->slave->master = dsi;
+	}
+
+	return 0;
+}
+
+static int tegra_dsi_probe(struct platform_device *pdev)
+{
+	struct tegra_dsi *dsi;
+	struct resource *regs;
+	int err;
+
+	dsi = devm_kzalloc(&pdev->dev, sizeof(*dsi), GFP_KERNEL);
+	if (!dsi)
+		return -ENOMEM;
+
+	dsi->output.dev = dsi->dev = &pdev->dev;
+	dsi->video_fifo_depth = 1920;
+	dsi->host_fifo_depth = 64;
+
+	err = tegra_dsi_ganged_probe(dsi);
+	if (err < 0)
+		return err;
+
+	err = tegra_output_probe(&dsi->output);
+	if (err < 0)
+		return err;
+
+	dsi->output.connector.polled = DRM_CONNECTOR_POLL_HPD;
+
+	/*
+	 * Assume these values by default. When a DSI peripheral driver
+	 * attaches to the DSI host, the parameters will be taken from
+	 * the attached device.
+	 */
+	dsi->flags = MIPI_DSI_MODE_VIDEO;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 4;
+
+	dsi->rst = devm_reset_control_get(&pdev->dev, "dsi");
+	if (IS_ERR(dsi->rst))
+		return PTR_ERR(dsi->rst);
+
+	dsi->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(dsi->clk)) {
+		dev_err(&pdev->dev, "cannot get DSI clock\n");
+		err = PTR_ERR(dsi->clk);
+		goto reset;
+	}
+
+	err = clk_prepare_enable(dsi->clk);
+	if (err < 0) {
+		dev_err(&pdev->dev, "cannot enable DSI clock\n");
+		goto reset;
+	}
+
+	dsi->clk_lp = devm_clk_get(&pdev->dev, "lp");
+	if (IS_ERR(dsi->clk_lp)) {
+		dev_err(&pdev->dev, "cannot get low-power clock\n");
+		err = PTR_ERR(dsi->clk_lp);
+		goto disable_clk;
+	}
+
+	err = clk_prepare_enable(dsi->clk_lp);
+	if (err < 0) {
+		dev_err(&pdev->dev, "cannot enable low-power clock\n");
+		goto disable_clk;
+	}
+
+	dsi->clk_parent = devm_clk_get(&pdev->dev, "parent");
+	if (IS_ERR(dsi->clk_parent)) {
+		dev_err(&pdev->dev, "cannot get parent clock\n");
+		err = PTR_ERR(dsi->clk_parent);
+		goto disable_clk_lp;
+	}
+
+	dsi->vdd = devm_regulator_get(&pdev->dev, "avdd-dsi-csi");
+	if (IS_ERR(dsi->vdd)) {
+		dev_err(&pdev->dev, "cannot get VDD supply\n");
+		err = PTR_ERR(dsi->vdd);
+		goto disable_clk_lp;
+	}
+
+	err = regulator_enable(dsi->vdd);
+	if (err < 0) {
+		dev_err(&pdev->dev, "cannot enable VDD supply\n");
+		goto disable_clk_lp;
+	}
+
+	err = tegra_dsi_setup_clocks(dsi);
+	if (err < 0) {
+		dev_err(&pdev->dev, "cannot setup clocks\n");
+		goto disable_vdd;
+	}
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dsi->regs = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(dsi->regs)) {
+		err = PTR_ERR(dsi->regs);
+		goto disable_vdd;
+	}
+
+	dsi->mipi = tegra_mipi_request(&pdev->dev);
+	if (IS_ERR(dsi->mipi)) {
+		err = PTR_ERR(dsi->mipi);
+		goto disable_vdd;
+	}
+
+	dsi->host.ops = &tegra_dsi_host_ops;
+	dsi->host.dev = &pdev->dev;
+
+	err = mipi_dsi_host_register(&dsi->host);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register DSI host: %d\n", err);
+		goto mipi_free;
+	}
+
+	INIT_LIST_HEAD(&dsi->client.list);
+	dsi->client.ops = &dsi_client_ops;
+	dsi->client.dev = &pdev->dev;
+
+	err = host1x_client_register(&dsi->client);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register host1x client: %d\n",
+			err);
+		goto unregister;
+	}
+
+	platform_set_drvdata(pdev, dsi);
+
+	return 0;
+
+unregister:
+	mipi_dsi_host_unregister(&dsi->host);
+mipi_free:
+	tegra_mipi_free(dsi->mipi);
+disable_vdd:
+	regulator_disable(dsi->vdd);
+disable_clk_lp:
+	clk_disable_unprepare(dsi->clk_lp);
+disable_clk:
+	clk_disable_unprepare(dsi->clk);
+reset:
+	reset_control_assert(dsi->rst);
+	return err;
+}
+
+static int tegra_dsi_remove(struct platform_device *pdev)
+{
+	struct tegra_dsi *dsi = platform_get_drvdata(pdev);
+	int err;
+
+	err = host1x_client_unregister(&dsi->client);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to unregister host1x client: %d\n",
+			err);
+		return err;
+	}
+
+	tegra_output_remove(&dsi->output);
+
+	mipi_dsi_host_unregister(&dsi->host);
+	tegra_mipi_free(dsi->mipi);
+
+	regulator_disable(dsi->vdd);
+	clk_disable_unprepare(dsi->clk_lp);
+	clk_disable_unprepare(dsi->clk);
+	reset_control_assert(dsi->rst);
+
+	return 0;
+}
+
+static const struct of_device_id tegra_dsi_of_match[] = {
+	{ .compatible = "nvidia,tegra114-dsi", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, tegra_dsi_of_match);
+
+struct platform_driver tegra_dsi_driver = {
+	.driver = {
+		.name = "tegra-dsi",
+		.of_match_table = tegra_dsi_of_match,
+	},
+	.probe = tegra_dsi_probe,
+	.remove = tegra_dsi_remove,
+};