drm/mcde: Add new driver for ST-Ericsson MCDE

This adds a new DRM driver for the ST-Ericsson Multi Channel
Display Engine, MCDE display controller.

This hardware has three independent DSI hosts and can composit
and display several memory buffers onto an LCD display. It
was developed for several years inside of ST-Ericsson and
shipped with a few million mobile phones from Sony and Samsung,
as well as with the Snowball community development board.

The driver is currently pretty rudimentary but supports a
simple framebuffer so we can get penguins and graphics when
using these SoCs.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190524092019.19355-1-linus.walleij@linaro.org

1 files changed, 1044 insertions, 0 deletions

diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c
new file mode 100644
index 000000000000..456b43482448
--- /dev/null
+++ b/drivers/gpu/drm/mcde/mcde_dsi.c
@@ -0,0 +1,1044 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_bridge.h>
+#include <drm/drm_device.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modeset_helper_vtables.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+#include <drm/drm_probe_helper.h>
+
+#include "mcde_drm.h"
+#include "mcde_dsi_regs.h"
+
+#define DSI_DEFAULT_LP_FREQ_HZ	19200000
+#define DSI_DEFAULT_HS_FREQ_HZ	420160000
+
+/* PRCMU DSI reset registers */
+#define PRCM_DSI_SW_RESET 0x324
+#define PRCM_DSI_SW_RESET_DSI0_SW_RESETN BIT(0)
+#define PRCM_DSI_SW_RESET_DSI1_SW_RESETN BIT(1)
+#define PRCM_DSI_SW_RESET_DSI2_SW_RESETN BIT(2)
+
+struct mcde_dsi {
+	struct device *dev;
+	struct mcde *mcde;
+	struct drm_bridge bridge;
+	struct drm_connector connector;
+	struct drm_panel *panel;
+	struct drm_bridge *bridge_out;
+	struct mipi_dsi_host dsi_host;
+	struct mipi_dsi_device *mdsi;
+	struct clk *hs_clk;
+	struct clk *lp_clk;
+	unsigned long hs_freq;
+	unsigned long lp_freq;
+	bool unused;
+
+	void __iomem *regs;
+	struct regmap *prcmu;
+};
+
+static inline struct mcde_dsi *bridge_to_mcde_dsi(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct mcde_dsi, bridge);
+}
+
+static inline struct mcde_dsi *host_to_mcde_dsi(struct mipi_dsi_host *h)
+{
+	return container_of(h, struct mcde_dsi, dsi_host);
+}
+
+static inline struct mcde_dsi *connector_to_mcde_dsi(struct drm_connector *c)
+{
+	return container_of(c, struct mcde_dsi, connector);
+}
+
+bool mcde_dsi_irq(struct mipi_dsi_device *mdsi)
+{
+	struct mcde_dsi *d;
+	u32 val;
+	bool te_received = false;
+
+	d = host_to_mcde_dsi(mdsi->host);
+
+	dev_dbg(d->dev, "%s called\n", __func__);
+
+	val = readl(d->regs + DSI_DIRECT_CMD_STS_FLAG);
+	if (val)
+		dev_dbg(d->dev, "DSI_DIRECT_CMD_STS_FLAG = %08x\n", val);
+	if (val & DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
+		dev_dbg(d->dev, "direct command write completed\n");
+	if (val & DSI_DIRECT_CMD_STS_TE_RECEIVED) {
+		te_received = true;
+		dev_dbg(d->dev, "direct command TE received\n");
+	}
+	if (val & DSI_DIRECT_CMD_STS_ACKNOWLEDGE_WITH_ERR_RECEIVED)
+		dev_err(d->dev, "direct command ACK ERR received\n");
+	if (val & DSI_DIRECT_CMD_STS_READ_COMPLETED_WITH_ERR)
+		dev_err(d->dev, "direct command read ERR received\n");
+	/* Mask off the ACK value and clear status */
+	writel(val, d->regs + DSI_DIRECT_CMD_STS_CLR);
+
+	val = readl(d->regs + DSI_CMD_MODE_STS_FLAG);
+	if (val)
+		dev_dbg(d->dev, "DSI_CMD_MODE_STS_FLAG = %08x\n", val);
+	if (val & DSI_CMD_MODE_STS_ERR_NO_TE)
+		/* This happens all the time (safe to ignore) */
+		dev_dbg(d->dev, "CMD mode no TE\n");
+	if (val & DSI_CMD_MODE_STS_ERR_TE_MISS)
+		/* This happens all the time (safe to ignore) */
+		dev_dbg(d->dev, "CMD mode TE miss\n");
+	if (val & DSI_CMD_MODE_STS_ERR_SDI1_UNDERRUN)
+		dev_err(d->dev, "CMD mode SD1 underrun\n");
+	if (val & DSI_CMD_MODE_STS_ERR_SDI2_UNDERRUN)
+		dev_err(d->dev, "CMD mode SD2 underrun\n");
+	if (val & DSI_CMD_MODE_STS_ERR_UNWANTED_RD)
+		dev_err(d->dev, "CMD mode unwanted RD\n");
+	writel(val, d->regs + DSI_CMD_MODE_STS_CLR);
+
+	val = readl(d->regs + DSI_DIRECT_CMD_RD_STS_FLAG);
+	if (val)
+		dev_dbg(d->dev, "DSI_DIRECT_CMD_RD_STS_FLAG = %08x\n", val);
+	writel(val, d->regs + DSI_DIRECT_CMD_RD_STS_CLR);
+
+	val = readl(d->regs + DSI_TG_STS_FLAG);
+	if (val)
+		dev_dbg(d->dev, "DSI_TG_STS_FLAG = %08x\n", val);
+	writel(val, d->regs + DSI_TG_STS_CLR);
+
+	val = readl(d->regs + DSI_VID_MODE_STS_FLAG);
+	if (val)
+		dev_err(d->dev, "some video mode error status\n");
+	writel(val, d->regs + DSI_VID_MODE_STS_CLR);
+
+	return te_received;
+}
+
+static int mcde_dsi_host_attach(struct mipi_dsi_host *host,
+				struct mipi_dsi_device *mdsi)
+{
+	struct mcde_dsi *d = host_to_mcde_dsi(host);
+
+	if (mdsi->lanes < 1 || mdsi->lanes > 2) {
+		DRM_ERROR("dsi device params invalid, 1 or 2 lanes supported\n");
+		return -EINVAL;
+	}
+
+	dev_info(d->dev, "attached DSI device with %d lanes\n", mdsi->lanes);
+	/* MIPI_DSI_FMT_RGB88 etc */
+	dev_info(d->dev, "format %08x, %dbpp\n", mdsi->format,
+		 mipi_dsi_pixel_format_to_bpp(mdsi->format));
+	dev_info(d->dev, "mode flags: %08lx\n", mdsi->mode_flags);
+
+	d->mdsi = mdsi;
+	if (d->mcde)
+		d->mcde->mdsi = mdsi;
+
+	return 0;
+}
+
+static int mcde_dsi_host_detach(struct mipi_dsi_host *host,
+				struct mipi_dsi_device *mdsi)
+{
+	struct mcde_dsi *d = host_to_mcde_dsi(host);
+
+	d->mdsi = NULL;
+	if (d->mcde)
+		d->mcde->mdsi = NULL;
+
+	return 0;
+}
+
+#define MCDE_DSI_HOST_IS_READ(type)			    \
+	((type == MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM) || \
+	 (type == MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM) || \
+	 (type == MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM) || \
+	 (type == MIPI_DSI_DCS_READ))
+
+static ssize_t mcde_dsi_host_transfer(struct mipi_dsi_host *host,
+				      const struct mipi_dsi_msg *msg)
+{
+	struct mcde_dsi *d = host_to_mcde_dsi(host);
+	const u32 loop_delay_us = 10; /* us */
+	const u8 *tx = msg->tx_buf;
+	u32 loop_counter;
+	size_t txlen;
+	u32 val;
+	int ret;
+	int i;
+
+	txlen = msg->tx_len;
+	if (txlen > 12) {
+		dev_err(d->dev,
+			"dunno how to write more than 12 bytes yet\n");
+		return -EIO;
+	}
+
+	dev_dbg(d->dev,
+		"message to channel %d, %u bytes",
+		msg->channel,
+		txlen);
+
+	/* Command "nature" */
+	if (MCDE_DSI_HOST_IS_READ(msg->type))
+		/* MCTL_MAIN_DATA_CTL already set up */
+		val = DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_NAT_READ;
+	else
+		val = DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_NAT_WRITE;
+	/*
+	 * More than 2 bytes will not fit in a single packet, so it's
+	 * time to set the "long not short" bit. One byte is used by
+	 * the MIPI DCS command leaving just one byte for the payload
+	 * in a short package.
+	 */
+	if (mipi_dsi_packet_format_is_long(msg->type))
+		val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LONGNOTSHORT;
+	val |= 0 << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_ID_SHIFT;
+	/* Add one to the length for the MIPI DCS command */
+	val |= txlen
+		<< DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
+	val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LP_EN;
+	val |= msg->type << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_HEAD_SHIFT;
+	writel(val, d->regs + DSI_DIRECT_CMD_MAIN_SETTINGS);
+
+	/* MIPI DCS command is part of the data */
+	if (txlen > 0) {
+		val = 0;
+		for (i = 0; i < 4 && i < txlen; i++)
+			val |= tx[i] << (i & 3) * 8;
+	}
+	writel(val, d->regs + DSI_DIRECT_CMD_WRDAT0);
+	if (txlen > 4) {
+		val = 0;
+		for (i = 0; i < 4 && (i + 4) < txlen; i++)
+			val |= tx[i + 4] << (i & 3) * 8;
+		writel(val, d->regs + DSI_DIRECT_CMD_WRDAT1);
+	}
+	if (txlen > 8) {
+		val = 0;
+		for (i = 0; i < 4 && (i + 8) < txlen; i++)
+			val |= tx[i + 8] << (i & 3) * 8;
+		writel(val, d->regs + DSI_DIRECT_CMD_WRDAT2);
+	}
+	if (txlen > 12) {
+		val = 0;
+		for (i = 0; i < 4 && (i + 12) < txlen; i++)
+			val |= tx[i + 12] << (i & 3) * 8;
+		writel(val, d->regs + DSI_DIRECT_CMD_WRDAT3);
+	}
+
+	writel(~0, d->regs + DSI_DIRECT_CMD_STS_CLR);
+	writel(~0, d->regs + DSI_CMD_MODE_STS_CLR);
+	/* Send command */
+	writel(1, d->regs + DSI_DIRECT_CMD_SEND);
+
+	loop_counter = 1000 * 1000 / loop_delay_us;
+	while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
+		 DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
+	       && --loop_counter)
+		usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
+
+	if (!loop_counter) {
+		dev_err(d->dev, "DSI write timeout!\n");
+		return -ETIME;
+	}
+
+	val = readl(d->regs + DSI_DIRECT_CMD_STS);
+	if (val & DSI_DIRECT_CMD_STS_ACKNOWLEDGE_WITH_ERR_RECEIVED) {
+		val >>= DSI_DIRECT_CMD_STS_ACK_VAL_SHIFT;
+		dev_err(d->dev, "error during transmission: %04x\n",
+			val);
+		return -EIO;
+	}
+
+	if (!MCDE_DSI_HOST_IS_READ(msg->type)) {
+		/* Return number of bytes written */
+		if (mipi_dsi_packet_format_is_long(msg->type))
+			ret = 4 + txlen;
+		else
+			ret = 4;
+	} else {
+		/* OK this is a read command, get the response */
+		u32 rdsz;
+		u32 rddat;
+		u8 *rx = msg->rx_buf;
+
+		rdsz = readl(d->regs + DSI_DIRECT_CMD_RD_PROPERTY);
+		rdsz &= DSI_DIRECT_CMD_RD_PROPERTY_RD_SIZE_MASK;
+		rddat = readl(d->regs + DSI_DIRECT_CMD_RDDAT);
+		for (i = 0; i < 4 && i < rdsz; i++)
+			rx[i] = (rddat >> (i * 8)) & 0xff;
+		ret = rdsz;
+	}
+
+	writel(~0, d->regs + DSI_DIRECT_CMD_STS_CLR);
+	writel(~0, d->regs + DSI_CMD_MODE_STS_CLR);
+
+	return ret;
+}
+
+static const struct mipi_dsi_host_ops mcde_dsi_host_ops = {
+	.attach = mcde_dsi_host_attach,
+	.detach = mcde_dsi_host_detach,
+	.transfer = mcde_dsi_host_transfer,
+};
+
+/* This sends a direct (short) command to request TE */
+void mcde_dsi_te_request(struct mipi_dsi_device *mdsi)
+{
+	struct mcde_dsi *d;
+	u32 val;
+
+	d = host_to_mcde_dsi(mdsi->host);
+
+	/* Command "nature" TE request */
+	val = DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_NAT_TE_REQ;
+	val |= 0 << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_ID_SHIFT;
+	val |= 2 << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
+	val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LP_EN;
+	val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_HEAD_DCS_SHORT_WRITE_1 <<
+		DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_HEAD_SHIFT;
+	writel(val, d->regs + DSI_DIRECT_CMD_MAIN_SETTINGS);
+
+	/* Clear TE reveived and error status bits and enables them */
+	writel(DSI_DIRECT_CMD_STS_CLR_TE_RECEIVED_CLR |
+	       DSI_DIRECT_CMD_STS_CLR_ACKNOWLEDGE_WITH_ERR_RECEIVED_CLR,
+	       d->regs + DSI_DIRECT_CMD_STS_CLR);
+	val = readl(d->regs + DSI_DIRECT_CMD_STS_CTL);
+	val |= DSI_DIRECT_CMD_STS_CTL_TE_RECEIVED_EN;
+	val |= DSI_DIRECT_CMD_STS_CTL_ACKNOWLEDGE_WITH_ERR_EN;
+	writel(val, d->regs + DSI_DIRECT_CMD_STS_CTL);
+
+	/* Clear and enable no TE or TE missing status */
+	writel(DSI_CMD_MODE_STS_CLR_ERR_NO_TE_CLR |
+	       DSI_CMD_MODE_STS_CLR_ERR_TE_MISS_CLR,
+	       d->regs + DSI_CMD_MODE_STS_CLR);
+	val = readl(d->regs + DSI_CMD_MODE_STS_CTL);
+	val |= DSI_CMD_MODE_STS_CTL_ERR_NO_TE_EN;
+	val |= DSI_CMD_MODE_STS_CTL_ERR_TE_MISS_EN;
+	writel(val, d->regs + DSI_CMD_MODE_STS_CTL);
+
+	/* Send this TE request command */
+	writel(1, d->regs + DSI_DIRECT_CMD_SEND);
+}
+
+static void mcde_dsi_setup_video_mode(struct mcde_dsi *d,
+				      const struct drm_display_mode *mode)
+{
+	u8 bpp = mipi_dsi_pixel_format_to_bpp(d->mdsi->format);
+	u64 bpl;
+	u32 hfp;
+	u32 hbp;
+	u32 hsa;
+	u32 blkline_pck, line_duration;
+	u32 blkeol_pck, blkeol_duration;
+	u32 val;
+
+	val = 0;
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+		val |= DSI_VID_MAIN_CTL_BURST_MODE;
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
+		val |= DSI_VID_MAIN_CTL_SYNC_PULSE_ACTIVE;
+		val |= DSI_VID_MAIN_CTL_SYNC_PULSE_HORIZONTAL;
+	}
+	/* RGB header and pixel mode */
+	switch (d->mdsi->format) {
+	case MIPI_DSI_FMT_RGB565:
+		val |= MIPI_DSI_PACKED_PIXEL_STREAM_16 <<
+			DSI_VID_MAIN_CTL_HEADER_SHIFT;
+		val |= DSI_VID_MAIN_CTL_VID_PIXEL_MODE_16BITS;
+		break;
+	case MIPI_DSI_FMT_RGB666_PACKED:
+		val |= MIPI_DSI_PACKED_PIXEL_STREAM_18 <<
+			DSI_VID_MAIN_CTL_HEADER_SHIFT;
+		val |= DSI_VID_MAIN_CTL_VID_PIXEL_MODE_18BITS;
+		break;
+	case MIPI_DSI_FMT_RGB666:
+		val |= MIPI_DSI_PIXEL_STREAM_3BYTE_18
+			<< DSI_VID_MAIN_CTL_HEADER_SHIFT;
+		val |= DSI_VID_MAIN_CTL_VID_PIXEL_MODE_18BITS_LOOSE;
+		break;
+	case MIPI_DSI_FMT_RGB888:
+		val |= MIPI_DSI_PACKED_PIXEL_STREAM_24 <<
+			DSI_VID_MAIN_CTL_HEADER_SHIFT;
+		val |= DSI_VID_MAIN_CTL_VID_PIXEL_MODE_24BITS;
+		break;
+	default:
+		dev_err(d->dev, "unknown pixel mode\n");
+		return;
+	}
+
+	/* TODO: TVG could be enabled here */
+
+	/* Send blanking packet */
+	val |= DSI_VID_MAIN_CTL_REG_BLKLINE_MODE_LP_0;
+	/* Send EOL packet */
+	val |= DSI_VID_MAIN_CTL_REG_BLKEOL_MODE_LP_0;
+	/* Recovery mode 1 */
+	val |= 1 << DSI_VID_MAIN_CTL_RECOVERY_MODE_SHIFT;
+	/* All other fields zero */
+	writel(val, d->regs + DSI_VID_MAIN_CTL);
+
+	/* Vertical frame parameters are pretty straight-forward */
+	val = mode->vdisplay << DSI_VID_VSIZE_VSA_LENGTH_SHIFT;
+	/* vertical front porch */
+	val |= (mode->vsync_start - mode->vdisplay)
+		<< DSI_VID_VSIZE_VFP_LENGTH_SHIFT;
+	/* vertical sync active */
+	val |= (mode->vsync_end - mode->vsync_start)
+		<< DSI_VID_VSIZE_VACT_LENGTH_SHIFT;
+	/* vertical back porch */
+	val |= (mode->vtotal - mode->vsync_end)
+		<< DSI_VID_VSIZE_VBP_LENGTH_SHIFT;
+	writel(val, d->regs + DSI_VID_VSIZE);
+
+	/*
+	 * Horizontal frame parameters:
+	 * horizontal resolution is given in pixels and must be re-calculated
+	 * into bytes since this is what the hardware expects.
+	 *
+	 * 6 + 2 is HFP header + checksum
+	 */
+	hfp = (mode->hsync_start - mode->hdisplay) * bpp - 6 - 2;
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
+		/*
+		 * 6 is HBP header + checksum
+		 * 4 is RGB header + checksum
+		 */
+		hbp = (mode->htotal - mode->hsync_end) * bpp - 4 - 6;
+		/*
+		 * 6 is HBP header + checksum
+		 * 4 is HSW packet bytes
+		 * 4 is RGB header + checksum
+		 */
+		hsa = (mode->hsync_end - mode->hsync_start) * bpp - 4 - 4 - 6;
+	} else {
+		/*
+		 * HBP includes both back porch and sync
+		 * 6 is HBP header + checksum
+		 * 4 is HSW packet bytes
+		 * 4 is RGB header + checksum
+		 */
+		hbp = (mode->htotal - mode->hsync_start) * bpp - 4 - 4 - 6;
+		/* HSA is not considered in this mode and set to 0 */
+		hsa = 0;
+	}
+	dev_dbg(d->dev, "hfp: %u, hbp: %u, hsa: %u\n",
+		hfp, hbp, hsa);
+
+	/* Frame parameters: horizontal sync active */
+	val = hsa << DSI_VID_HSIZE1_HSA_LENGTH_SHIFT;
+	/* horizontal back porch */
+	val |= hbp << DSI_VID_HSIZE1_HBP_LENGTH_SHIFT;
+	/* horizontal front porch */
+	val |= hfp << DSI_VID_HSIZE1_HFP_LENGTH_SHIFT;
+	writel(val, d->regs + DSI_VID_HSIZE1);
+
+	/* RGB data length (bytes on one scanline) */
+	val = mode->hdisplay * (bpp / 8);
+	writel(val, d->regs + DSI_VID_HSIZE2);
+
+	/* TODO: further adjustments for TVG mode here */
+
+	/*
+	 * EOL packet length from bits per line calculations: pixel clock
+	 * is given in kHz, calculate the time between two pixels in
+	 * picoseconds.
+	 */
+	bpl = mode->clock * mode->htotal;
+	bpl *= (d->hs_freq / 8);
+	do_div(bpl, 1000000); /* microseconds */
+	do_div(bpl, 1000000); /* seconds */
+	bpl *= d->mdsi->lanes;
+	dev_dbg(d->dev, "calculated bytes per line: %llu\n", bpl);
+	/*
+	 * 6 is header + checksum, header = 4 bytes, checksum = 2 bytes
+	 * 4 is short packet for vsync/hsync
+	 */
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) {
+		/* Fixme: isn't the hsync width in pixels? */
+		blkline_pck = bpl - (mode->hsync_end - mode->hsync_start) - 6;
+		val = blkline_pck << DSI_VID_BLKSIZE2_BLKLINE_PULSE_PCK_SHIFT;
+		writel(val, d->regs + DSI_VID_BLKSIZE2);
+	} else {
+		blkline_pck = bpl - 4 - 6;
+		val = blkline_pck << DSI_VID_BLKSIZE1_BLKLINE_EVENT_PCK_SHIFT;
+		writel(val, d->regs + DSI_VID_BLKSIZE1);
+	}
+
+	line_duration = (blkline_pck + 6) / d->mdsi->lanes;
+	dev_dbg(d->dev, "line duration %u\n", line_duration);
+	val = line_duration << DSI_VID_DPHY_TIME_REG_LINE_DURATION_SHIFT;
+	/*
+	 * This is the time to perform LP->HS on D-PHY
+	 * FIXME: nowhere to get this from: DT property on the DSI?
+	 */
+	val |= 0 << DSI_VID_DPHY_TIME_REG_WAKEUP_TIME_SHIFT;
+	writel(val, d->regs + DSI_VID_DPHY_TIME);
+
+	/* Calculate block end of line */
+	blkeol_pck = bpl - mode->hdisplay * bpp - 6;
+	blkeol_duration = (blkeol_pck + 6) / d->mdsi->lanes;
+	dev_dbg(d->dev, "blkeol pck: %u, duration: %u\n",
+		 blkeol_pck, blkeol_duration);
+
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
+		/* Set up EOL clock for burst mode */
+		val = readl(d->regs + DSI_VID_BLKSIZE1);
+		val |= blkeol_pck << DSI_VID_BLKSIZE1_BLKEOL_PCK_SHIFT;
+		writel(val, d->regs + DSI_VID_BLKSIZE1);
+		writel(blkeol_pck, d->regs + DSI_VID_VCA_SETTING2);
+
+		writel(blkeol_duration, d->regs + DSI_VID_PCK_TIME);
+		writel(blkeol_duration - 6, d->regs + DSI_VID_VCA_SETTING1);
+	}
+
+	/* Maximum line limit */
+	val = readl(d->regs + DSI_VID_VCA_SETTING2);
+	val |= blkline_pck <<
+		DSI_VID_VCA_SETTING2_EXACT_BURST_LIMIT_SHIFT;
+	writel(val, d->regs + DSI_VID_VCA_SETTING2);
+
+	/* Put IF1 into video mode */
+	val = readl(d->regs + DSI_MCTL_MAIN_DATA_CTL);
+	val |= DSI_MCTL_MAIN_DATA_CTL_IF1_MODE;
+	writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
+
+	/* Disable command mode on IF1 */
+	val = readl(d->regs + DSI_CMD_MODE_CTL);
+	val &= ~DSI_CMD_MODE_CTL_IF1_LP_EN;
+	writel(val, d->regs + DSI_CMD_MODE_CTL);
+
+	/* Enable some error interrupts */
+	val = readl(d->regs + DSI_VID_MODE_STS_CTL);
+	val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_VSYNC;
+	val |= DSI_VID_MODE_STS_CTL_ERR_MISSING_DATA;
+	writel(val, d->regs + DSI_VID_MODE_STS_CTL);
+
+	/* Enable video mode */
+	val = readl(d->regs + DSI_MCTL_MAIN_DATA_CTL);
+	val |= DSI_MCTL_MAIN_DATA_CTL_VID_EN;
+	writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
+}
+
+static void mcde_dsi_start(struct mcde_dsi *d)
+{
+	unsigned long hs_freq;
+	u32 val;
+	int i;
+
+	/* No integration mode */
+	writel(0, d->regs + DSI_MCTL_INTEGRATION_MODE);
+
+	/* Enable the DSI port, from drivers/video/mcde/dsilink_v2.c */
+	val = DSI_MCTL_MAIN_DATA_CTL_LINK_EN |
+		DSI_MCTL_MAIN_DATA_CTL_BTA_EN |
+		DSI_MCTL_MAIN_DATA_CTL_READ_EN |
+		DSI_MCTL_MAIN_DATA_CTL_REG_TE_EN;
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_EOT_PACKET)
+		val |= DSI_MCTL_MAIN_DATA_CTL_HOST_EOT_GEN;
+	writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
+
+	/* Set a high command timeout, clear other fields */
+	val = 0x3ff << DSI_CMD_MODE_CTL_TE_TIMEOUT_SHIFT;
+	writel(val, d->regs + DSI_CMD_MODE_CTL);
+
+	/*
+	 * UI_X4 is described as "unit interval times four"
+	 * I guess since DSI packets are 4 bytes wide, one unit
+	 * is one byte.
+	 */
+	hs_freq = clk_get_rate(d->hs_clk);
+	hs_freq /= 1000000; /* MHz */
+	val = 4000 / hs_freq;
+	dev_dbg(d->dev, "UI value: %d\n", val);
+	val <<= DSI_MCTL_DPHY_STATIC_UI_X4_SHIFT;
+	val &= DSI_MCTL_DPHY_STATIC_UI_X4_MASK;
+	writel(val, d->regs + DSI_MCTL_DPHY_STATIC);
+
+	/*
+	 * Enable clocking: 0x0f (something?) between each burst,
+	 * enable the second lane if needed, enable continuous clock if
+	 * needed, enable switch into ULPM (ultra-low power mode) on
+	 * all the lines.
+	 */
+	val = 0x0f << DSI_MCTL_MAIN_PHY_CTL_WAIT_BURST_TIME_SHIFT;
+	if (d->mdsi->lanes == 2)
+		val |= DSI_MCTL_MAIN_PHY_CTL_LANE2_EN;
+	if (!(d->mdsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
+		val |= DSI_MCTL_MAIN_PHY_CTL_CLK_CONTINUOUS;
+	val |= DSI_MCTL_MAIN_PHY_CTL_CLK_ULPM_EN |
+		DSI_MCTL_MAIN_PHY_CTL_DAT1_ULPM_EN |
+		DSI_MCTL_MAIN_PHY_CTL_DAT2_ULPM_EN;
+	writel(val, d->regs + DSI_MCTL_MAIN_PHY_CTL);
+
+	val = (1 << DSI_MCTL_ULPOUT_TIME_CKLANE_ULPOUT_TIME_SHIFT) |
+		(1 << DSI_MCTL_ULPOUT_TIME_DATA_ULPOUT_TIME_SHIFT);
+	writel(val, d->regs + DSI_MCTL_ULPOUT_TIME);
+
+	writel(DSI_DPHY_LANES_TRIM_DPHY_SPECS_90_81B_0_90,
+	       d->regs + DSI_DPHY_LANES_TRIM);
+
+	/* High PHY timeout */
+	val = (0x0f << DSI_MCTL_DPHY_TIMEOUT_CLK_DIV_SHIFT) |
+		(0x3fff << DSI_MCTL_DPHY_TIMEOUT_HSTX_TO_VAL_SHIFT) |
+		(0x3fff << DSI_MCTL_DPHY_TIMEOUT_LPRX_TO_VAL_SHIFT);
+	writel(val, d->regs + DSI_MCTL_DPHY_TIMEOUT);
+
+	val = DSI_MCTL_MAIN_EN_PLL_START |
+		DSI_MCTL_MAIN_EN_CKLANE_EN |
+		DSI_MCTL_MAIN_EN_DAT1_EN |
+		DSI_MCTL_MAIN_EN_IF1_EN;
+	if (d->mdsi->lanes == 2)
+		val |= DSI_MCTL_MAIN_EN_DAT2_EN;
+	writel(val, d->regs + DSI_MCTL_MAIN_EN);
+
+	/* Wait for the PLL to lock and the clock and data lines to come up */
+	i = 0;
+	val = DSI_MCTL_MAIN_STS_PLL_LOCK |
+		DSI_MCTL_MAIN_STS_CLKLANE_READY |
+		DSI_MCTL_MAIN_STS_DAT1_READY;
+	if (d->mdsi->lanes == 2)
+		val |= DSI_MCTL_MAIN_STS_DAT2_READY;
+	while ((readl(d->regs + DSI_MCTL_MAIN_STS) & val) != val) {
+		/* Sleep for a millisecond */
+		usleep_range(1000, 1500);
+		if (i++ == 100) {
+			dev_warn(d->dev, "DSI lanes did not start up\n");
+			return;
+		}
+	}
+
+	/* TODO needed? */
+
+	/* Command mode, clear IF1 ID */
+	val = readl(d->regs + DSI_CMD_MODE_CTL);
+	/*
+	 * If we enable low-power mode here, with
+	 * val |= DSI_CMD_MODE_CTL_IF1_LP_EN
+	 * then display updates become really slow.
+	 */
+	val &= ~DSI_CMD_MODE_CTL_IF1_ID_MASK;
+	writel(val, d->regs + DSI_CMD_MODE_CTL);
+
+	/* Wait for DSI PHY to initialize */
+	usleep_range(100, 200);
+	dev_info(d->dev, "DSI link enabled\n");
+}
+
+
+static void mcde_dsi_bridge_enable(struct drm_bridge *bridge)
+{
+	struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
+
+	dev_info(d->dev, "enable DSI master\n");
+};
+
+static void mcde_dsi_bridge_mode_set(struct drm_bridge *bridge,
+				     const struct drm_display_mode *mode,
+				     const struct drm_display_mode *adj)
+{
+	struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
+	unsigned long pixel_clock_hz = mode->clock * 1000;
+	unsigned long hs_freq, lp_freq;
+	u32 val;
+	int ret;
+
+	if (!d->mdsi) {
+		dev_err(d->dev, "no DSI device attached to encoder!\n");
+		return;
+	}
+
+	dev_info(d->dev, "set DSI master to %dx%d %lu Hz %s mode\n",
+		 mode->hdisplay, mode->vdisplay, pixel_clock_hz,
+		 (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) ? "VIDEO" : "CMD"
+		);
+
+	/* Copy maximum clock frequencies */
+	if (d->mdsi->lp_rate)
+		lp_freq = d->mdsi->lp_rate;
+	else
+		lp_freq = DSI_DEFAULT_LP_FREQ_HZ;
+	if (d->mdsi->hs_rate)
+		hs_freq = d->mdsi->hs_rate;
+	else
+		hs_freq = DSI_DEFAULT_HS_FREQ_HZ;
+
+	/* Enable LP (Low Power, Energy Save, ES) and HS (High Speed) clocks */
+	d->lp_freq = clk_round_rate(d->lp_clk, lp_freq);
+	ret = clk_set_rate(d->lp_clk, d->lp_freq);
+	if (ret)
+		dev_err(d->dev, "failed to set LP clock rate %lu Hz\n",
+			d->lp_freq);
+
+	d->hs_freq = clk_round_rate(d->hs_clk, hs_freq);
+	ret = clk_set_rate(d->hs_clk, d->hs_freq);
+	if (ret)
+		dev_err(d->dev, "failed to set HS clock rate %lu Hz\n",
+			d->hs_freq);
+
+	/* Start clocks */
+	ret = clk_prepare_enable(d->lp_clk);
+	if (ret)
+		dev_err(d->dev, "failed to enable LP clock\n");
+	else
+		dev_info(d->dev, "DSI LP clock rate %lu Hz\n",
+			 d->lp_freq);
+	ret = clk_prepare_enable(d->hs_clk);
+	if (ret)
+		dev_err(d->dev, "failed to enable HS clock\n");
+	else
+		dev_info(d->dev, "DSI HS clock rate %lu Hz\n",
+			 d->hs_freq);
+
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
+		mcde_dsi_setup_video_mode(d, mode);
+	} else {
+		/* Command mode, clear IF1 ID */
+		val = readl(d->regs + DSI_CMD_MODE_CTL);
+		/*
+		 * If we enable low-power mode here with
+		 * val |= DSI_CMD_MODE_CTL_IF1_LP_EN
+		 * the display updates become really slow.
+		 */
+		val &= ~DSI_CMD_MODE_CTL_IF1_ID_MASK;
+		writel(val, d->regs + DSI_CMD_MODE_CTL);
+	}
+}
+
+static void mcde_dsi_wait_for_command_mode_stop(struct mcde_dsi *d)
+{
+	u32 val;
+	int i;
+
+	/*
+	 * Wait until we get out of command mode
+	 * CSM = Command State Machine
+	 */
+	i = 0;
+	val = DSI_CMD_MODE_STS_CSM_RUNNING;
+	while ((readl(d->regs + DSI_CMD_MODE_STS) & val) == val) {
+		/* Sleep for a millisecond */
+		usleep_range(1000, 2000);
+		if (i++ == 100) {
+			dev_warn(d->dev,
+				 "could not get out of command mode\n");
+			return;
+		}
+	}
+}
+
+static void mcde_dsi_wait_for_video_mode_stop(struct mcde_dsi *d)
+{
+	u32 val;
+	int i;
+
+	/* Wait until we get out og video mode */
+	i = 0;
+	val = DSI_VID_MODE_STS_VSG_RUNNING;
+	while ((readl(d->regs + DSI_VID_MODE_STS) & val) == val) {
+		/* Sleep for a millisecond */
+		usleep_range(1000, 2000);
+		if (i++ == 100) {
+			dev_warn(d->dev,
+				 "could not get out of video mode\n");
+			return;
+		}
+	}
+}
+
+static void mcde_dsi_bridge_disable(struct drm_bridge *bridge)
+{
+	struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
+	u32 val;
+
+	/* Disable all error interrupts */
+	writel(0, d->regs + DSI_VID_MODE_STS_CTL);
+
+	if (d->mdsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
+		/* Stop video mode */
+		val = readl(d->regs + DSI_MCTL_MAIN_DATA_CTL);
+		val &= ~DSI_MCTL_MAIN_DATA_CTL_VID_EN;
+		writel(val, d->regs + DSI_MCTL_MAIN_DATA_CTL);
+		mcde_dsi_wait_for_video_mode_stop(d);
+	} else {
+		/* Stop command mode */
+		mcde_dsi_wait_for_command_mode_stop(d);
+	}
+
+	/* Stop clocks */
+	clk_disable_unprepare(d->hs_clk);
+	clk_disable_unprepare(d->lp_clk);
+}
+
+/*
+ * This connector needs no special handling, just use the default
+ * helpers for everything. It's pretty dummy.
+ */
+static const struct drm_connector_funcs mcde_dsi_connector_funcs = {
+	.reset = drm_atomic_helper_connector_reset,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.destroy = drm_connector_cleanup,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+static int mcde_dsi_get_modes(struct drm_connector *connector)
+{
+	struct mcde_dsi *d = connector_to_mcde_dsi(connector);
+
+	/* Just pass the question to the panel */
+	if (d->panel)
+		return drm_panel_get_modes(d->panel);
+
+	/* TODO: deal with bridges */
+
+	return 0;
+}
+
+static const struct drm_connector_helper_funcs
+mcde_dsi_connector_helper_funcs = {
+	.get_modes = mcde_dsi_get_modes,
+};
+
+static int mcde_dsi_bridge_attach(struct drm_bridge *bridge)
+{
+	struct mcde_dsi *d = bridge_to_mcde_dsi(bridge);
+	struct drm_device *drm = bridge->dev;
+	int ret;
+
+	drm_connector_helper_add(&d->connector,
+				 &mcde_dsi_connector_helper_funcs);
+
+	if (!drm_core_check_feature(drm, DRIVER_ATOMIC)) {
+		dev_err(d->dev, "we need atomic updates\n");
+		return -ENOTSUPP;
+	}
+
+	ret = drm_connector_init(drm, &d->connector,
+				 &mcde_dsi_connector_funcs,
+				 DRM_MODE_CONNECTOR_DSI);
+	if (ret) {
+		dev_err(d->dev, "failed to initialize DSI bridge connector\n");
+		return ret;
+	}
+	d->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
+	/* The encoder in the bridge attached to the DSI bridge */
+	drm_connector_attach_encoder(&d->connector, bridge->encoder);
+	/* Then we attach the DSI bridge to the output (panel etc) bridge */
+	ret = drm_bridge_attach(bridge->encoder, d->bridge_out, bridge);
+	if (ret) {
+		dev_err(d->dev, "failed to attach the DSI bridge\n");
+		return ret;
+	}
+	d->connector.status = connector_status_connected;
+
+	return 0;
+}
+
+static const struct drm_bridge_funcs mcde_dsi_bridge_funcs = {
+	.attach = mcde_dsi_bridge_attach,
+	.mode_set = mcde_dsi_bridge_mode_set,
+	.disable = mcde_dsi_bridge_disable,
+	.enable = mcde_dsi_bridge_enable,
+};
+
+static int mcde_dsi_bind(struct device *dev, struct device *master,
+			 void *data)
+{
+	struct drm_device *drm = data;
+	struct mcde *mcde = drm->dev_private;
+	struct mcde_dsi *d = dev_get_drvdata(dev);
+	struct device_node *child;
+	struct drm_panel *panel = NULL;
+	struct drm_bridge *bridge = NULL;
+
+	if (!of_get_available_child_count(dev->of_node)) {
+		dev_info(dev, "unused DSI interface\n");
+		d->unused = true;
+		return 0;
+	}
+	d->mcde = mcde;
+	/* If the display attached before binding, set this up */
+	if (d->mdsi)
+		d->mcde->mdsi = d->mdsi;
+
+	/* Obtain the clocks */
+	d->hs_clk = devm_clk_get(dev, "hs");
+	if (IS_ERR(d->hs_clk)) {
+		dev_err(dev, "unable to get HS clock\n");
+		return PTR_ERR(d->hs_clk);
+	}
+
+	d->lp_clk = devm_clk_get(dev, "lp");
+	if (IS_ERR(d->lp_clk)) {
+		dev_err(dev, "unable to get LP clock\n");
+		return PTR_ERR(d->lp_clk);
+	}
+
+	/* Assert RESET through the PRCMU, active low */
+	/* FIXME: which DSI block? */
+	regmap_update_bits(d->prcmu, PRCM_DSI_SW_RESET,
+			   PRCM_DSI_SW_RESET_DSI0_SW_RESETN, 0);
+
+	usleep_range(100, 200);
+
+	/* De-assert RESET again */
+	regmap_update_bits(d->prcmu, PRCM_DSI_SW_RESET,
+			   PRCM_DSI_SW_RESET_DSI0_SW_RESETN,
+			   PRCM_DSI_SW_RESET_DSI0_SW_RESETN);
+
+	/* Start up the hardware */
+	mcde_dsi_start(d);
+
+	/* Look for a panel as a child to this node */
+	for_each_available_child_of_node(dev->of_node, child) {
+		panel = of_drm_find_panel(child);
+		if (IS_ERR(panel)) {
+			dev_err(dev, "failed to find panel try bridge (%lu)\n",
+				PTR_ERR(panel));
+			bridge = of_drm_find_bridge(child);
+			if (IS_ERR(bridge)) {
+				dev_err(dev, "failed to find bridge (%lu)\n",
+					PTR_ERR(bridge));
+				return PTR_ERR(bridge);
+			}
+		}
+	}
+	if (panel) {
+		bridge = drm_panel_bridge_add(panel,
+					      DRM_MODE_CONNECTOR_DSI);
+		if (IS_ERR(bridge)) {
+			dev_err(dev, "error adding panel bridge\n");
+			return PTR_ERR(bridge);
+		}
+		dev_info(dev, "connected to panel\n");
+		d->panel = panel;
+	} else if (bridge) {
+		/* TODO: AV8100 HDMI encoder goes here for example */
+		dev_info(dev, "connected to non-panel bridge (unsupported)\n");
+		return -ENODEV;
+	} else {
+		dev_err(dev, "no panel or bridge\n");
+		return -ENODEV;
+	}
+
+	d->bridge_out = bridge;
+
+	/* Create a bridge for this DSI channel */
+	d->bridge.funcs = &mcde_dsi_bridge_funcs;
+	d->bridge.of_node = dev->of_node;
+	drm_bridge_add(&d->bridge);
+
+	/* TODO: first come first serve, use a list */
+	mcde->bridge = &d->bridge;
+
+	dev_info(dev, "initialized MCDE DSI bridge\n");
+
+	return 0;
+}
+
+static void mcde_dsi_unbind(struct device *dev, struct device *master,
+			    void *data)
+{
+	struct mcde_dsi *d = dev_get_drvdata(dev);
+
+	if (d->panel)
+		drm_panel_bridge_remove(d->bridge_out);
+	regmap_update_bits(d->prcmu, PRCM_DSI_SW_RESET,
+			   PRCM_DSI_SW_RESET_DSI0_SW_RESETN, 0);
+}
+
+static const struct component_ops mcde_dsi_component_ops = {
+	.bind   = mcde_dsi_bind,
+	.unbind = mcde_dsi_unbind,
+};
+
+static int mcde_dsi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mcde_dsi *d;
+	struct mipi_dsi_host *host;
+	struct resource *res;
+	u32 dsi_id;
+	int ret;
+
+	d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+	d->dev = dev;
+	platform_set_drvdata(pdev, d);
+
+	/* Get a handle on the PRCMU so we can do reset */
+	d->prcmu =
+		syscon_regmap_lookup_by_compatible("stericsson,db8500-prcmu");
+	if (IS_ERR(d->prcmu)) {
+		dev_err(dev, "no PRCMU regmap\n");
+		return PTR_ERR(d->prcmu);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	d->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(d->regs)) {
+		dev_err(dev, "no DSI regs\n");
+		return PTR_ERR(d->regs);
+	}
+
+	dsi_id = readl(d->regs + DSI_ID_REG);
+	dev_info(dev, "HW revision 0x%08x\n", dsi_id);
+
+	host = &d->dsi_host;
+	host->dev = dev;
+	host->ops = &mcde_dsi_host_ops;
+	ret = mipi_dsi_host_register(host);
+	if (ret < 0) {
+		dev_err(dev, "failed to register DSI host: %d\n", ret);
+		return ret;
+	}
+	dev_info(dev, "registered DSI host\n");
+
+	platform_set_drvdata(pdev, d);
+	return component_add(dev, &mcde_dsi_component_ops);
+}
+
+static int mcde_dsi_remove(struct platform_device *pdev)
+{
+	struct mcde_dsi *d = platform_get_drvdata(pdev);
+
+	component_del(&pdev->dev, &mcde_dsi_component_ops);
+	mipi_dsi_host_unregister(&d->dsi_host);
+
+	return 0;
+}
+
+static const struct of_device_id mcde_dsi_of_match[] = {
+	{
+		.compatible = "ste,mcde-dsi",
+	},
+	{},
+};
+
+struct platform_driver mcde_dsi_driver = {
+	.driver = {
+		.name           = "mcde-dsi",
+		.of_match_table = of_match_ptr(mcde_dsi_of_match),
+	},
+	.probe = mcde_dsi_probe,
+	.remove = mcde_dsi_remove,
+};