From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Tue, 18 Jun 2013 01:23:57 +0000 (+0800)
Subject: staging: drm/imx: Add LDB support
X-Git-Tag: v3.11-rc1~158^2~77
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ac4c1a9b33005969b05de0f13ec90ec426a76769;p=platform%2Fkernel%2Flinux-stable.git

staging: drm/imx: Add LDB support

This adds support for the LVDS Display Bridge contained
in i.MX5 and i.MX6 SoCs.

Bit mapping, data width, and video timings are configurable
via device tree. Dual-channel mode is supported for a single
high-resolution source.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt b/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt
new file mode 100644
index 0000000..ed93778
--- /dev/null
+++ b/Documentation/devicetree/bindings/staging/imx-drm/ldb.txt
@@ -0,0 +1,99 @@
+Device-Tree bindings for LVDS Display Bridge (ldb)
+
+LVDS Display Bridge
+===================
+
+The LVDS Display Bridge device tree node contains up to two lvds-channel
+nodes describing each of the two LVDS encoder channels of the bridge.
+
+Required properties:
+ - #address-cells : should be <1>
+ - #size-cells : should be <0>
+ - compatible : should be "fsl,imx53-ldb" or "fsl,imx6q-ldb".
+                Both LDB versions are similar, but i.MX6 has an additional
+                multiplexer in the front to select any of the four IPU display
+                interfaces as input for each LVDS channel.
+ - gpr : should be <&gpr> on i.MX53 and i.MX6q.
+         The phandle points to the iomuxc-gpr region containing the LVDS
+         control register.
+- clocks, clock-names : phandles to the LDB divider and selector clocks and to
+                        the display interface selector clocks, as described in
+                        Documentation/devicetree/bindings/clock/clock-bindings.txt
+        The following clocks are expected on i.MX53:
+                "di0_pll" - LDB LVDS channel 0 mux
+                "di1_pll" - LDB LVDS channel 1 mux
+                "di0" - LDB LVDS channel 0 gate
+                "di1" - LDB LVDS channel 1 gate
+                "di0_sel" - IPU1 DI0 mux
+                "di1_sel" - IPU1 DI1 mux
+        On i.MX6q the following additional clocks are needed:
+                "di2_sel" - IPU2 DI0 mux
+                "di3_sel" - IPU2 DI1 mux
+        The needed clock numbers for each are documented in
+        Documentation/devicetree/bindings/clock/imx5-clock.txt, and in
+        Documentation/devicetree/bindings/clock/imx6q-clock.txt.
+
+Optional properties:
+ - pinctrl-names : should be "default" on i.MX53, not used on i.MX6q
+ - pinctrl-0 : a phandle pointing to LVDS pin settings on i.MX53,
+               not used on i.MX6q
+ - fsl,dual-channel : boolean. if it exists, only LVDS channel 0 should
+   be configured - one input will be distributed on both outputs in dual
+   channel mode
+
+LVDS Channel
+============
+
+Each LVDS Channel has to contain a display-timings node that describes the
+video timings for the connected LVDS display. For detailed information, also
+have a look at Documentation/devicetree/bindings/video/display-timing.txt.
+
+Required properties:
+ - reg : should be <0> or <1>
+ - crtcs : a list of phandles with index pointing to the IPU display interfaces
+           that can be used as video source for this channel.
+ - fsl,data-mapping : should be "spwg" or "jeida"
+                      This describes how the color bits are laid out in the
+                      serialized LVDS signal.
+ - fsl,data-width : should be <18> or <24>
+
+example:
+
+gpr: iomuxc-gpr@53fa8000 {
+	/* ... */
+};
+
+ldb: ldb@53fa8008 {
+	#address-cells = <1>;
+	#size-cells = <0>;
+	compatible = "fsl,imx53-ldb";
+	gpr = <&gpr>;
+	clocks = <&clks 122>, <&clks 120>,
+		 <&clks 115>, <&clks 116>,
+		 <&clks 123>, <&clks 85>;
+	clock-names = "di0_pll", "di1_pll",
+		      "di0_sel", "di1_sel",
+		      "di0", "di1";
+
+	lvds-channel@0 {
+		reg = <0>;
+		crtcs = <&ipu 0>;
+		fsl,data-mapping = "spwg";
+		fsl,data-width = <24>;
+
+		display-timings {
+			/* ... */
+		};
+	};
+
+	lvds-channel@1 {
+		reg = <1>;
+		crtcs = <&ipu 1>;
+		fsl,data-mapping = "spwg";
+		fsl,data-width = <24>;
+
+		display-timings {
+			/* ... */
+		};
+	};
+};
diff --git a/drivers/staging/imx-drm/Kconfig b/drivers/staging/imx-drm/Kconfig
index ef699f7..2233905 100644
--- a/drivers/staging/imx-drm/Kconfig
+++ b/drivers/staging/imx-drm/Kconfig
@@ -30,6 +30,14 @@ config DRM_IMX_TVE
 	  Choose this to enable the internal Television Encoder (TVe)
 	  found on i.MX53 processors.
 
+config DRM_IMX_LDB
+	tristate "Support for LVDS displays"
+	depends on DRM_IMX
+	select OF_VIDEOMODE
+	help
+	  Choose this to enable the internal LVDS Display Bridge (LDB)
+	  found on i.MX53 and i.MX6 processors.
+
 config DRM_IMX_IPUV3_CORE
 	tristate "IPUv3 core support"
 	depends on DRM_IMX
diff --git a/drivers/staging/imx-drm/Makefile b/drivers/staging/imx-drm/Makefile
index 7e50184..bfaf693 100644
--- a/drivers/staging/imx-drm/Makefile
+++ b/drivers/staging/imx-drm/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_DRM_IMX) += imxdrm.o
 
 obj-$(CONFIG_DRM_IMX_PARALLEL_DISPLAY) += parallel-display.o
 obj-$(CONFIG_DRM_IMX_TVE) += imx-tve.o
+obj-$(CONFIG_DRM_IMX_LDB) += imx-ldb.o
 obj-$(CONFIG_DRM_IMX_FB_HELPER) += imx-fbdev.o
 obj-$(CONFIG_DRM_IMX_IPUV3_CORE) += ipu-v3/
 obj-$(CONFIG_DRM_IMX_IPUV3)	+= ipuv3-crtc.o
diff --git a/drivers/staging/imx-drm/imx-ldb.c b/drivers/staging/imx-drm/imx-ldb.c
new file mode 100644
index 0000000..75607b3
--- /dev/null
+++ b/drivers/staging/imx-drm/imx-ldb.c
@@ -0,0 +1,609 @@
+/*
+ * i.MX drm driver - LVDS display bridge
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ *
+ * 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.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <drm/drmP.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <video/of_videomode.h>
+#include <linux/regmap.h>
+#include <linux/videodev2.h>
+
+#include "imx-drm.h"
+
+#define DRIVER_NAME "imx-ldb"
+
+#define LDB_CH0_MODE_EN_TO_DI0		(1 << 0)
+#define LDB_CH0_MODE_EN_TO_DI1		(3 << 0)
+#define LDB_CH0_MODE_EN_MASK		(3 << 0)
+#define LDB_CH1_MODE_EN_TO_DI0		(1 << 2)
+#define LDB_CH1_MODE_EN_TO_DI1		(3 << 2)
+#define LDB_CH1_MODE_EN_MASK		(3 << 2)
+#define LDB_SPLIT_MODE_EN		(1 << 4)
+#define LDB_DATA_WIDTH_CH0_24		(1 << 5)
+#define LDB_BIT_MAP_CH0_JEIDA		(1 << 6)
+#define LDB_DATA_WIDTH_CH1_24		(1 << 7)
+#define LDB_BIT_MAP_CH1_JEIDA		(1 << 8)
+#define LDB_DI0_VS_POL_ACT_LOW		(1 << 9)
+#define LDB_DI1_VS_POL_ACT_LOW		(1 << 10)
+#define LDB_BGREF_RMODE_INT		(1 << 15)
+
+#define con_to_imx_ldb_ch(x) container_of(x, struct imx_ldb_channel, connector)
+#define enc_to_imx_ldb_ch(x) container_of(x, struct imx_ldb_channel, encoder)
+
+struct imx_ldb;
+
+struct imx_ldb_channel {
+	struct imx_ldb *ldb;
+	struct drm_connector connector;
+	struct imx_drm_connector *imx_drm_connector;
+	struct drm_encoder encoder;
+	struct imx_drm_encoder *imx_drm_encoder;
+	int chno;
+	void *edid;
+	int edid_len;
+	struct drm_display_mode mode;
+	int mode_valid;
+};
+
+struct bus_mux {
+	int reg;
+	int shift;
+	int mask;
+};
+
+struct imx_ldb {
+	struct regmap *regmap;
+	struct device *dev;
+	struct imx_ldb_channel channel[2];
+	struct clk *clk[2]; /* our own clock */
+	struct clk *clk_sel[4]; /* parent of display clock */
+	struct clk *clk_pll[2]; /* upstream clock we can adjust */
+	u32 ldb_ctrl;
+	const struct bus_mux *lvds_mux;
+};
+
+static enum drm_connector_status imx_ldb_connector_detect(
+		struct drm_connector *connector, bool force)
+{
+	return connector_status_connected;
+}
+
+static void imx_ldb_connector_destroy(struct drm_connector *connector)
+{
+	/* do not free here */
+}
+
+static int imx_ldb_connector_get_modes(struct drm_connector *connector)
+{
+	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
+	int num_modes = 0;
+
+	if (imx_ldb_ch->edid) {
+		drm_mode_connector_update_edid_property(connector,
+							imx_ldb_ch->edid);
+		num_modes = drm_add_edid_modes(connector, imx_ldb_ch->edid);
+	}
+
+	if (imx_ldb_ch->mode_valid) {
+		struct drm_display_mode *mode;
+
+		mode = drm_mode_create(connector->dev);
+		drm_mode_copy(mode, &imx_ldb_ch->mode);
+		mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+		drm_mode_probed_add(connector, mode);
+		num_modes++;
+	}
+
+	return num_modes;
+}
+
+static int imx_ldb_connector_mode_valid(struct drm_connector *connector,
+			  struct drm_display_mode *mode)
+{
+	return 0;
+}
+
+static struct drm_encoder *imx_ldb_connector_best_encoder(
+		struct drm_connector *connector)
+{
+	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
+
+	return &imx_ldb_ch->encoder;
+}
+
+static void imx_ldb_encoder_dpms(struct drm_encoder *encoder, int mode)
+{
+}
+
+static bool imx_ldb_encoder_mode_fixup(struct drm_encoder *encoder,
+			   const struct drm_display_mode *mode,
+			   struct drm_display_mode *adjusted_mode)
+{
+	return true;
+}
+
+static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
+		unsigned long serial_clk, unsigned long di_clk)
+{
+	int ret;
+
+	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
+			clk_get_rate(ldb->clk_pll[chno]), serial_clk);
+	clk_set_rate(ldb->clk_pll[chno], serial_clk);
+
+	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
+			clk_get_rate(ldb->clk_pll[chno]));
+
+	dev_dbg(ldb->dev, "%s: now: %ld want: %ld\n", __func__,
+			clk_get_rate(ldb->clk[chno]),
+			(long int)di_clk);
+	clk_set_rate(ldb->clk[chno], di_clk);
+
+	dev_dbg(ldb->dev, "%s after: %ld\n", __func__,
+			clk_get_rate(ldb->clk[chno]));
+
+	/* set display clock mux to LDB input clock */
+	ret = clk_set_parent(ldb->clk_sel[mux], ldb->clk[chno]);
+	if (ret) {
+		dev_err(ldb->dev, "unable to set di%d parent clock to ldb_di%d\n", mux, chno);
+	}
+}
+
+static void imx_ldb_encoder_prepare(struct drm_encoder *encoder)
+{
+	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
+	struct imx_ldb *ldb = imx_ldb_ch->ldb;
+	struct drm_display_mode *mode = &encoder->crtc->mode;
+	unsigned long serial_clk;
+	unsigned long di_clk = mode->clock * 1000;
+	int mux = imx_drm_encoder_get_mux_id(imx_ldb_ch->imx_drm_encoder,
+					     encoder->crtc);
+
+	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
+		/* dual channel LVDS mode */
+		serial_clk = 3500UL * mode->clock;
+		imx_ldb_set_clock(ldb, mux, 0, serial_clk, di_clk);
+		imx_ldb_set_clock(ldb, mux, 1, serial_clk, di_clk);
+	} else {
+		serial_clk = 7000UL * mode->clock;
+		imx_ldb_set_clock(ldb, mux, imx_ldb_ch->chno, serial_clk, di_clk);
+	}
+
+	imx_drm_crtc_panel_format(encoder->crtc, DRM_MODE_ENCODER_LVDS,
+			V4L2_PIX_FMT_RGB24);
+}
+
+static void imx_ldb_encoder_commit(struct drm_encoder *encoder)
+{
+	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
+	struct imx_ldb *ldb = imx_ldb_ch->ldb;
+	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
+	int mux = imx_drm_encoder_get_mux_id(imx_ldb_ch->imx_drm_encoder,
+					     encoder->crtc);
+
+	if (dual) {
+		clk_prepare_enable(ldb->clk[0]);
+		clk_prepare_enable(ldb->clk[1]);
+	}
+
+	if (imx_ldb_ch == &ldb->channel[0] || dual) {
+		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
+		if (mux == 0 || ldb->lvds_mux)
+			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI0;
+		else if (mux == 1)
+			ldb->ldb_ctrl |= LDB_CH0_MODE_EN_TO_DI1;
+	}
+	if (imx_ldb_ch == &ldb->channel[1] || dual) {
+		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
+		if (mux == 1 || ldb->lvds_mux)
+			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI1;
+		else if (mux == 0)
+			ldb->ldb_ctrl |= LDB_CH1_MODE_EN_TO_DI0;
+	}
+
+	if (ldb->lvds_mux) {
+		const struct bus_mux *lvds_mux = NULL;
+
+		if (imx_ldb_ch == &ldb->channel[0])
+			lvds_mux = &ldb->lvds_mux[0];
+		else if (imx_ldb_ch == &ldb->channel[1])
+			lvds_mux = &ldb->lvds_mux[1];
+
+		regmap_update_bits(ldb->regmap, lvds_mux->reg, lvds_mux->mask,
+				   mux << lvds_mux->shift);
+	}
+
+	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
+}
+
+static void imx_ldb_encoder_mode_set(struct drm_encoder *encoder,
+			 struct drm_display_mode *mode,
+			 struct drm_display_mode *adjusted_mode)
+{
+	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
+	struct imx_ldb *ldb = imx_ldb_ch->ldb;
+	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
+
+	if (mode->clock > 170000) {
+		dev_warn(ldb->dev,
+			 "%s: mode exceeds 170 MHz pixel clock\n", __func__);
+	}
+	if (mode->clock > 85000 && !dual) {
+		dev_warn(ldb->dev,
+			 "%s: mode exceeds 85 MHz pixel clock\n", __func__);
+	}
+
+	/* FIXME - assumes straight connections DI0 --> CH0, DI1 --> CH1 */
+	if (imx_ldb_ch == &ldb->channel[0]) {
+		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+			ldb->ldb_ctrl |= LDB_DI0_VS_POL_ACT_LOW;
+		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+			ldb->ldb_ctrl &= ~LDB_DI0_VS_POL_ACT_LOW;
+	}
+	if (imx_ldb_ch == &ldb->channel[1]) {
+		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+			ldb->ldb_ctrl |= LDB_DI1_VS_POL_ACT_LOW;
+		else if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+			ldb->ldb_ctrl &= ~LDB_DI1_VS_POL_ACT_LOW;
+	}
+}
+
+static void imx_ldb_encoder_disable(struct drm_encoder *encoder)
+{
+	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
+	struct imx_ldb *ldb = imx_ldb_ch->ldb;
+
+	/*
+	 * imx_ldb_encoder_disable is called by
+	 * drm_helper_disable_unused_functions without
+	 * the encoder being enabled before.
+	 */
+	if (imx_ldb_ch == &ldb->channel[0] &&
+	    (ldb->ldb_ctrl & LDB_CH0_MODE_EN_MASK) == 0)
+		return;
+	else if (imx_ldb_ch == &ldb->channel[1] &&
+		 (ldb->ldb_ctrl & LDB_CH1_MODE_EN_MASK) == 0)
+		return;
+
+	if (imx_ldb_ch == &ldb->channel[0])
+		ldb->ldb_ctrl &= ~LDB_CH0_MODE_EN_MASK;
+	else if (imx_ldb_ch == &ldb->channel[1])
+		ldb->ldb_ctrl &= ~LDB_CH1_MODE_EN_MASK;
+
+	regmap_write(ldb->regmap, IOMUXC_GPR2, ldb->ldb_ctrl);
+
+	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
+		clk_disable_unprepare(ldb->clk[0]);
+		clk_disable_unprepare(ldb->clk[1]);
+	}
+}
+
+static void imx_ldb_encoder_destroy(struct drm_encoder *encoder)
+{
+	/* do not free here */
+}
+
+static struct drm_connector_funcs imx_ldb_connector_funcs = {
+	.dpms = drm_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = imx_ldb_connector_detect,
+	.destroy = imx_ldb_connector_destroy,
+};
+
+static struct drm_connector_helper_funcs imx_ldb_connector_helper_funcs = {
+	.get_modes = imx_ldb_connector_get_modes,
+	.best_encoder = imx_ldb_connector_best_encoder,
+	.mode_valid = imx_ldb_connector_mode_valid,
+};
+
+static struct drm_encoder_funcs imx_ldb_encoder_funcs = {
+	.destroy = imx_ldb_encoder_destroy,
+};
+
+static struct drm_encoder_helper_funcs imx_ldb_encoder_helper_funcs = {
+	.dpms = imx_ldb_encoder_dpms,
+	.mode_fixup = imx_ldb_encoder_mode_fixup,
+	.prepare = imx_ldb_encoder_prepare,
+	.commit = imx_ldb_encoder_commit,
+	.mode_set = imx_ldb_encoder_mode_set,
+	.disable = imx_ldb_encoder_disable,
+};
+
+static int imx_ldb_get_clk(struct imx_ldb *ldb, int chno)
+{
+	char clkname[16];
+
+	sprintf(clkname, "di%d", chno);
+	ldb->clk[chno] = devm_clk_get(ldb->dev, clkname);
+	if (IS_ERR(ldb->clk[chno]))
+		return PTR_ERR(ldb->clk[chno]);
+
+	sprintf(clkname, "di%d_pll", chno);
+	ldb->clk_pll[chno] = devm_clk_get(ldb->dev, clkname);
+	if (IS_ERR(ldb->clk_pll[chno]))
+		return PTR_ERR(ldb->clk_pll[chno]);
+
+	return 0;
+}
+
+static int imx_ldb_register(struct imx_ldb_channel *imx_ldb_ch)
+{
+	int ret;
+	struct imx_ldb *ldb = imx_ldb_ch->ldb;
+
+	ret = imx_ldb_get_clk(ldb, imx_ldb_ch->chno);
+	if (ret)
+		return ret;
+	if (ldb->ldb_ctrl & LDB_SPLIT_MODE_EN) {
+		ret |= imx_ldb_get_clk(ldb, 1);
+		if (ret)
+			return ret;
+	}
+
+	imx_ldb_ch->connector.funcs = &imx_ldb_connector_funcs;
+	imx_ldb_ch->encoder.funcs = &imx_ldb_encoder_funcs;
+
+	imx_ldb_ch->encoder.encoder_type = DRM_MODE_ENCODER_LVDS;
+	imx_ldb_ch->connector.connector_type = DRM_MODE_CONNECTOR_LVDS;
+
+	drm_encoder_helper_add(&imx_ldb_ch->encoder,
+			&imx_ldb_encoder_helper_funcs);
+	ret = imx_drm_add_encoder(&imx_ldb_ch->encoder,
+			&imx_ldb_ch->imx_drm_encoder, THIS_MODULE);
+	if (ret) {
+		dev_err(ldb->dev, "adding encoder failed with %d\n", ret);
+		return ret;
+	}
+
+	drm_connector_helper_add(&imx_ldb_ch->connector,
+			&imx_ldb_connector_helper_funcs);
+
+	ret = imx_drm_add_connector(&imx_ldb_ch->connector,
+			&imx_ldb_ch->imx_drm_connector, THIS_MODULE);
+	if (ret) {
+		imx_drm_remove_encoder(imx_ldb_ch->imx_drm_encoder);
+		dev_err(ldb->dev, "adding connector failed with %d\n", ret);
+		return ret;
+	}
+
+	drm_mode_connector_attach_encoder(&imx_ldb_ch->connector,
+			&imx_ldb_ch->encoder);
+
+	return 0;
+}
+
+enum {
+	LVDS_BIT_MAP_SPWG,
+	LVDS_BIT_MAP_JEIDA
+};
+
+static const char *imx_ldb_bit_mappings[] = {
+	[LVDS_BIT_MAP_SPWG]  = "spwg",
+	[LVDS_BIT_MAP_JEIDA] = "jeida",
+};
+
+const int of_get_data_mapping(struct device_node *np)
+{
+	const char *bm;
+	int ret, i;
+
+	ret = of_property_read_string(np, "fsl,data-mapping", &bm);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(imx_ldb_bit_mappings); i++)
+		if (!strcasecmp(bm, imx_ldb_bit_mappings[i]))
+			return i;
+
+	return -EINVAL;
+}
+
+static struct bus_mux imx6q_lvds_mux[2] = {
+	{
+		.reg = IOMUXC_GPR3,
+		.shift = 6,
+		.mask = IMX6Q_GPR3_LVDS0_MUX_CTL_MASK,
+	}, {
+		.reg = IOMUXC_GPR3,
+		.shift = 8,
+		.mask = IMX6Q_GPR3_LVDS1_MUX_CTL_MASK,
+	}
+};
+
+/*
+ * For a device declaring compatible = "fsl,imx6q-ldb", "fsl,imx53-ldb",
+ * of_match_device will walk through this list and take the first entry
+ * matching any of its compatible values. Therefore, the more generic
+ * entries (in this case fsl,imx53-ldb) need to be ordered last.
+ */
+static const struct of_device_id imx_ldb_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-ldb", .data = imx6q_lvds_mux, },
+	{ .compatible = "fsl,imx53-ldb", .data = NULL, },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, imx_ldb_dt_ids);
+
+static int imx_ldb_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *of_id =
+			of_match_device(of_match_ptr(imx_ldb_dt_ids),
+					&pdev->dev);
+	struct device_node *child;
+	const u8 *edidp;
+	struct imx_ldb *imx_ldb;
+	int datawidth;
+	int mapping;
+	int dual;
+	int ret;
+	int i;
+
+	imx_ldb = devm_kzalloc(&pdev->dev, sizeof(*imx_ldb), GFP_KERNEL);
+	if (!imx_ldb)
+		return -ENOMEM;
+
+	imx_ldb->regmap = syscon_regmap_lookup_by_phandle(np, "gpr");
+	if (IS_ERR(imx_ldb->regmap)) {
+		dev_err(&pdev->dev, "failed to get parent regmap\n");
+		return PTR_ERR(imx_ldb->regmap);
+	}
+
+	imx_ldb->dev = &pdev->dev;
+
+	if (of_id)
+		imx_ldb->lvds_mux = of_id->data;
+
+	dual = of_property_read_bool(np, "fsl,dual-channel");
+	if (dual)
+		imx_ldb->ldb_ctrl |= LDB_SPLIT_MODE_EN;
+
+	/*
+	 * There are three diferent possible clock mux configurations:
+	 * i.MX53:  ipu1_di0_sel, ipu1_di1_sel
+	 * i.MX6q:  ipu1_di0_sel, ipu1_di1_sel, ipu2_di0_sel, ipu2_di1_sel
+	 * i.MX6dl: ipu1_di0_sel, ipu1_di1_sel, lcdif_sel
+	 * Map them all to di0_sel...di3_sel.
+	 */
+	for (i = 0; i < 4; i++) {
+		char clkname[16];
+
+		sprintf(clkname, "di%d_sel", i);
+		imx_ldb->clk_sel[i] = devm_clk_get(imx_ldb->dev, clkname);
+		if (IS_ERR(imx_ldb->clk_sel[i])) {
+			ret = PTR_ERR(imx_ldb->clk_sel[i]);
+			imx_ldb->clk_sel[i] = NULL;
+			break;
+		}
+	}
+	if (i == 0)
+		return ret;
+
+	for_each_child_of_node(np, child) {
+		struct imx_ldb_channel *channel;
+
+		ret = of_property_read_u32(child, "reg", &i);
+		if (ret || i < 0 || i > 1)
+			return -EINVAL;
+
+		if (dual && i > 0) {
+			dev_warn(&pdev->dev, "dual-channel mode, ignoring second output\n");
+			continue;
+		}
+
+		if (!of_device_is_available(child))
+			continue;
+
+		channel = &imx_ldb->channel[i];
+		channel->ldb = imx_ldb;
+		channel->chno = i;
+
+		edidp = of_get_property(child, "edid", &channel->edid_len);
+		if (edidp) {
+			channel->edid = kmemdup(edidp, channel->edid_len,
+						GFP_KERNEL);
+		} else {
+			ret = of_get_drm_display_mode(child, &channel->mode, 0);
+			if (!ret)
+				channel->mode_valid = 1;
+		}
+
+		ret = of_property_read_u32(child, "fsl,data-width", &datawidth);
+		if (ret)
+			datawidth = 0;
+		else if (datawidth != 18 && datawidth != 24)
+			return -EINVAL;
+
+		mapping = of_get_data_mapping(child);
+		switch (mapping) {
+		case LVDS_BIT_MAP_SPWG:
+			if (datawidth == 24) {
+				if (i == 0 || dual)
+					imx_ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24;
+				if (i == 1 || dual)
+					imx_ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24;
+			}
+			break;
+		case LVDS_BIT_MAP_JEIDA:
+			if (datawidth == 18) {
+				dev_err(&pdev->dev, "JEIDA standard only supported in 24 bit\n");
+				return -EINVAL;
+			}
+			if (i == 0 || dual)
+				imx_ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH0_24 | LDB_BIT_MAP_CH0_JEIDA;
+			if (i == 1 || dual)
+				imx_ldb->ldb_ctrl |= LDB_DATA_WIDTH_CH1_24 | LDB_BIT_MAP_CH1_JEIDA;
+			break;
+		default:
+			dev_err(&pdev->dev, "data mapping not specified or invalid\n");
+			return -EINVAL;
+		}
+
+		ret = imx_ldb_register(channel);
+		if (ret)
+			return ret;
+
+		imx_drm_encoder_add_possible_crtcs(channel->imx_drm_encoder, child);
+	}
+
+	platform_set_drvdata(pdev, imx_ldb);
+
+	return 0;
+}
+
+static int imx_ldb_remove(struct platform_device *pdev)
+{
+	struct imx_ldb *imx_ldb = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < 2; i++) {
+		struct imx_ldb_channel *channel = &imx_ldb->channel[i];
+		struct drm_connector *connector = &channel->connector;
+		struct drm_encoder *encoder = &channel->encoder;
+
+		drm_mode_connector_detach_encoder(connector, encoder);
+
+		imx_drm_remove_connector(channel->imx_drm_connector);
+		imx_drm_remove_encoder(channel->imx_drm_encoder);
+	}
+
+	return 0;
+}
+
+static struct platform_driver imx_ldb_driver = {
+	.probe		= imx_ldb_probe,
+	.remove		= imx_ldb_remove,
+	.driver		= {
+		.of_match_table = imx_ldb_dt_ids,
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+module_platform_driver(imx_ldb_driver);
+
+MODULE_DESCRIPTION("i.MX LVDS driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");