Merge branch 'for-next' of http://git.agner.ch/git/linux-drm-fsl-dcu into drm-next

This adds very rudimentary TCON (timing controller for raw LCD displays)
support to enable the bypass mode in order to use the DCU controller on
Freescale/NXP Vybrid SoC's.

Additionally the register clock and pixel clock has been separated, but
are currently still enabled and disabled pairwise.

Other than that, fixes and cleanups accross the driver.

* 'for-next' of http://git.agner.ch/git/linux-drm-fsl-dcu:
  drm/fsl-dcu: increment version and date
  drm/fsl-dcu: implement lastclose callback
  drm/fsl-dcu: disable output polling on driver unload
  drm/fsl-dcu: deallocate fbdev CMA on unload
  drm/fsl-dcu: use variable name dev for struct drm_device
  drm/fsl-dcu: handle missing panel gracefully
  drm/fsl-dcu: detach panel on destroy
  drm/layerscape: reduce excessive stack usage
  drm/fsl-dcu: add TCON driver
  drm/fsl-dcu: use common clock framework for pixel clock divider
  drm/fsl-dcu: add extra clock for pixel clock
  drm/fsl-dcu: disable clock on initialization failure and remove

10 files changed, 298 insertions, 57 deletions

diff --git a/Documentation/devicetree/bindings/display/fsl,dcu.txt b/Documentation/devicetree/bindings/display/fsl,dcu.txt
index ebf1be9ae393..ae55cde1b69e 100644
--- a/Documentation/devicetree/bindings/display/fsl,dcu.txt
+++ b/Documentation/devicetree/bindings/display/fsl,dcu.txt
@@ -6,17 +6,24 @@ Required properties:
 	* "fsl,vf610-dcu".
 
 - reg:			Address and length of the register set for dcu.
-- clocks:		From common clock binding: handle to dcu clock.
-- clock-names:		From common clock binding: Shall be "dcu".
+- clocks:		Handle to "dcu" and "pix" clock (in the order below)
+			This can be the same clock (e.g. LS1021a)
+			See ../clocks/clock-bindings.txt for details.
+- clock-names:		Should be "dcu" and "pix"
+			See ../clocks/clock-bindings.txt for details.
 - big-endian		Boolean property, LS1021A DCU registers are big-endian.
 - fsl,panel:		The phandle to panel node.
 
+Optional properties:
+- fsl,tcon:		The phandle to the timing controller node.
+
 Examples:
 dcu: dcu@2ce0000 {
 	compatible = "fsl,ls1021a-dcu";
 	reg = <0x0 0x2ce0000 0x0 0x10000>;
-	clocks = <&platform_clk 0>;
-	clock-names = "dcu";
+	clocks = <&platform_clk 0>, <&platform_clk 0>;
+	clock-names = "dcu", "pix";
 	big-endian;
 	fsl,panel = <&panel>;
+	fsl,tcon = <&tcon>;
 };
diff --git a/Documentation/devicetree/bindings/display/fsl,tcon.txt b/Documentation/devicetree/bindings/display/fsl,tcon.txt
new file mode 100644
index 000000000000..6fa4ab668db5
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/fsl,tcon.txt
@@ -0,0 +1,18 @@
+Device Tree bindings for Freescale TCON Driver
+
+Required properties:
+- compatible:		Should be one of
+	* "fsl,vf610-tcon".
+
+- reg:			Address and length of the register set for tcon.
+- clocks:		From common clock binding: handle to tcon ipg clock.
+- clock-names:		From common clock binding: Shall be "ipg".
+
+Examples:
+timing-controller@4003d000 {
+	compatible = "fsl,vf610-tcon";
+	reg = <0x4003d000 0x1000>;
+	clocks = <&clks VF610_CLK_TCON0>;
+	clock-names = "ipg";
+	status = "okay";
+};
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c38e9e7ef62..9ef7b408beb3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3835,6 +3835,7 @@ L:	dri-devel@lists.freedesktop.org
 S:	Supported
 F:	drivers/gpu/drm/fsl-dcu/
 F:	Documentation/devicetree/bindings/display/fsl,dcu.txt
+F:	Documentation/devicetree/bindings/display/fsl,tcon.txt
 F:	Documentation/devicetree/bindings/display/panel/nec,nl4827hc19_05b.txt
 
 DRM DRIVERS FOR FREESCALE IMX
diff --git a/drivers/gpu/drm/fsl-dcu/Makefile b/drivers/gpu/drm/fsl-dcu/Makefile
index 6ea1523ae6ec..b35a292287f3 100644
--- a/drivers/gpu/drm/fsl-dcu/Makefile
+++ b/drivers/gpu/drm/fsl-dcu/Makefile
@@ -3,5 +3,6 @@ fsl-dcu-drm-y := fsl_dcu_drm_drv.o \
 		 fsl_dcu_drm_rgb.o \
 		 fsl_dcu_drm_plane.o \
 		 fsl_dcu_drm_crtc.o \
-		 fsl_dcu_drm_fbdev.o
+		 fsl_dcu_drm_fbdev.o \
+		 fsl_tcon.o
 obj-$(CONFIG_DRM_FSL_DCU)	+= fsl-dcu-drm.o
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
index 4ed7798533f9..365809edf29a 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
@@ -67,12 +67,10 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	struct drm_device *dev = crtc->dev;
 	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
 	struct drm_display_mode *mode = &crtc->state->mode;
-	unsigned int hbp, hfp, hsw, vbp, vfp, vsw, div, index, pol = 0;
-	unsigned long dcuclk;
+	unsigned int hbp, hfp, hsw, vbp, vfp, vsw, index, pol = 0;
 
 	index = drm_crtc_index(crtc);
-	dcuclk = clk_get_rate(fsl_dev->clk);
-	div = dcuclk / mode->clock / 1000;
+	clk_set_rate(fsl_dev->pix_clk, mode->clock * 1000);
 
 	/* Configure timings: */
 	hbp = mode->htotal - mode->hsync_end;
@@ -99,7 +97,6 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	regmap_write(fsl_dev->regmap, DCU_DISP_SIZE,
 		     DCU_DISP_SIZE_DELTA_Y(mode->vdisplay) |
 		     DCU_DISP_SIZE_DELTA_X(mode->hdisplay));
-	regmap_write(fsl_dev->regmap, DCU_DIV_RATIO, div);
 	regmap_write(fsl_dev->regmap, DCU_SYN_POL, pol);
 	regmap_write(fsl_dev->regmap, DCU_BGND, DCU_BGND_R(0) |
 		     DCU_BGND_G(0) | DCU_BGND_B(0));
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
index e8d9337a66d8..44f6f262d75a 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c
@@ -23,10 +23,12 @@
 
 #include <drm/drmP.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 
 #include "fsl_dcu_drm_crtc.h"
 #include "fsl_dcu_drm_drv.h"
+#include "fsl_tcon.h"
 
 static bool fsl_dcu_drm_is_volatile_reg(struct device *dev, unsigned int reg)
 {
@@ -62,46 +64,55 @@ static int fsl_dcu_drm_irq_init(struct drm_device *dev)
 	return ret;
 }
 
-static int fsl_dcu_load(struct drm_device *drm, unsigned long flags)
+static int fsl_dcu_load(struct drm_device *dev, unsigned long flags)
 {
-	struct device *dev = drm->dev;
-	struct fsl_dcu_drm_device *fsl_dev = drm->dev_private;
+	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
 	int ret;
 
 	ret = fsl_dcu_drm_modeset_init(fsl_dev);
 	if (ret < 0) {
-		dev_err(dev, "failed to initialize mode setting\n");
+		dev_err(dev->dev, "failed to initialize mode setting\n");
 		return ret;
 	}
 
-	ret = drm_vblank_init(drm, drm->mode_config.num_crtc);
+	ret = drm_vblank_init(dev, dev->mode_config.num_crtc);
 	if (ret < 0) {
-		dev_err(dev, "failed to initialize vblank\n");
+		dev_err(dev->dev, "failed to initialize vblank\n");
 		goto done;
 	}
-	drm->vblank_disable_allowed = true;
+	dev->vblank_disable_allowed = true;
 
-	ret = fsl_dcu_drm_irq_init(drm);
+	ret = fsl_dcu_drm_irq_init(dev);
 	if (ret < 0)
 		goto done;
-	drm->irq_enabled = true;
+	dev->irq_enabled = true;
 
-	fsl_dcu_fbdev_init(drm);
+	fsl_dcu_fbdev_init(dev);
 
 	return 0;
 done:
-	if (ret) {
-		drm_mode_config_cleanup(drm);
-		drm_vblank_cleanup(drm);
-		drm_irq_uninstall(drm);
-		drm->dev_private = NULL;
-	}
+	drm_kms_helper_poll_fini(dev);
+
+	if (fsl_dev->fbdev)
+		drm_fbdev_cma_fini(fsl_dev->fbdev);
+
+	drm_mode_config_cleanup(dev);
+	drm_vblank_cleanup(dev);
+	drm_irq_uninstall(dev);
+	dev->dev_private = NULL;
 
 	return ret;
 }
 
 static int fsl_dcu_unload(struct drm_device *dev)
 {
+	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
+
+	drm_kms_helper_poll_fini(dev);
+
+	if (fsl_dev->fbdev)
+		drm_fbdev_cma_fini(fsl_dev->fbdev);
+
 	drm_mode_config_cleanup(dev);
 	drm_vblank_cleanup(dev);
 	drm_irq_uninstall(dev);
@@ -157,6 +168,13 @@ static void fsl_dcu_drm_disable_vblank(struct drm_device *dev,
 	regmap_write(fsl_dev->regmap, DCU_INT_MASK, value);
 }
 
+static void fsl_dcu_drm_lastclose(struct drm_device *dev)
+{
+	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
+
+	drm_fbdev_cma_restore_mode(fsl_dev->fbdev);
+}
+
 static const struct file_operations fsl_dcu_drm_fops = {
 	.owner		= THIS_MODULE,
 	.open		= drm_open,
@@ -174,6 +192,7 @@ static const struct file_operations fsl_dcu_drm_fops = {
 static struct drm_driver fsl_dcu_drm_driver = {
 	.driver_features	= DRIVER_HAVE_IRQ | DRIVER_GEM | DRIVER_MODESET
 				| DRIVER_PRIME | DRIVER_ATOMIC,
+	.lastclose		= fsl_dcu_drm_lastclose,
 	.load			= fsl_dcu_load,
 	.unload			= fsl_dcu_unload,
 	.irq_handler		= fsl_dcu_drm_irq,
@@ -197,9 +216,9 @@ static struct drm_driver fsl_dcu_drm_driver = {
 	.fops			= &fsl_dcu_drm_fops,
 	.name			= "fsl-dcu-drm",
 	.desc			= "Freescale DCU DRM",
-	.date			= "20150213",
+	.date			= "20160425",
 	.major			= 1,
-	.minor			= 0,
+	.minor			= 1,
 };
 
 #ifdef CONFIG_PM_SLEEP
@@ -283,6 +302,9 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	struct drm_driver *driver = &fsl_dcu_drm_driver;
+	struct clk *pix_clk_in;
+	char pix_clk_name[32];
+	const char *pix_clk_in_name;
 	const struct of_device_id *id;
 	int ret;
 
@@ -290,6 +312,11 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
 	if (!fsl_dev)
 		return -ENOMEM;
 
+	id = of_match_node(fsl_dcu_of_match, pdev->dev.of_node);
+	if (!id)
+		return -ENODEV;
+	fsl_dev->soc = id->data;
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(dev, "could not get memory IO resource\n");
@@ -308,39 +335,54 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
+	fsl_dev->regmap = devm_regmap_init_mmio(dev, base,
+			&fsl_dcu_regmap_config);
+	if (IS_ERR(fsl_dev->regmap)) {
+		dev_err(dev, "regmap init failed\n");
+		return PTR_ERR(fsl_dev->regmap);
+	}
+
 	fsl_dev->clk = devm_clk_get(dev, "dcu");
 	if (IS_ERR(fsl_dev->clk)) {
-		ret = PTR_ERR(fsl_dev->clk);
 		dev_err(dev, "failed to get dcu clock\n");
-		return ret;
-	}
-	ret = clk_prepare(fsl_dev->clk);
-	if (ret < 0) {
-		dev_err(dev, "failed to prepare dcu clk\n");
-		return ret;
+		return PTR_ERR(fsl_dev->clk);
 	}
-	ret = clk_enable(fsl_dev->clk);
+	ret = clk_prepare_enable(fsl_dev->clk);
 	if (ret < 0) {
 		dev_err(dev, "failed to enable dcu clk\n");
-		clk_unprepare(fsl_dev->clk);
 		return ret;
 	}
 
-	fsl_dev->regmap = devm_regmap_init_mmio(dev, base,
-			&fsl_dcu_regmap_config);
-	if (IS_ERR(fsl_dev->regmap)) {
-		dev_err(dev, "regmap init failed\n");
-		return PTR_ERR(fsl_dev->regmap);
+	pix_clk_in = devm_clk_get(dev, "pix");
+	if (IS_ERR(pix_clk_in)) {
+		/* legancy binding, use dcu clock as pixel clock input */
+		pix_clk_in = fsl_dev->clk;
 	}
 
-	id = of_match_node(fsl_dcu_of_match, pdev->dev.of_node);
-	if (!id)
-		return -ENODEV;
-	fsl_dev->soc = id->data;
+	pix_clk_in_name = __clk_get_name(pix_clk_in);
+	snprintf(pix_clk_name, sizeof(pix_clk_name), "%s_pix", pix_clk_in_name);
+	fsl_dev->pix_clk = clk_register_divider(dev, pix_clk_name,
+			pix_clk_in_name, 0, base + DCU_DIV_RATIO,
+			0, 8, CLK_DIVIDER_ROUND_CLOSEST, NULL);
+	if (IS_ERR(fsl_dev->pix_clk)) {
+		dev_err(dev, "failed to register pix clk\n");
+		ret = PTR_ERR(fsl_dev->pix_clk);
+		goto disable_clk;
+	}
+
+	ret = clk_prepare_enable(fsl_dev->pix_clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to enable pix clk\n");
+		goto unregister_pix_clk;
+	}
+
+	fsl_dev->tcon = fsl_tcon_init(dev);
 
 	drm = drm_dev_alloc(driver, dev);
-	if (!drm)
-		return -ENOMEM;
+	if (!drm) {
+		ret = -ENOMEM;
+		goto disable_pix_clk;
+	}
 
 	fsl_dev->dev = dev;
 	fsl_dev->drm = drm;
@@ -360,6 +402,12 @@ static int fsl_dcu_drm_probe(struct platform_device *pdev)
 
 unref:
 	drm_dev_unref(drm);
+disable_pix_clk:
+	clk_disable_unprepare(fsl_dev->pix_clk);
+unregister_pix_clk:
+	clk_unregister(fsl_dev->pix_clk);
+disable_clk:
+	clk_disable_unprepare(fsl_dev->clk);
 	return ret;
 }
 
@@ -367,6 +415,9 @@ static int fsl_dcu_drm_remove(struct platform_device *pdev)
 {
 	struct fsl_dcu_drm_device *fsl_dev = platform_get_drvdata(pdev);
 
+	clk_disable_unprepare(fsl_dev->clk);
+	clk_disable_unprepare(fsl_dev->pix_clk);
+	clk_unregister(fsl_dev->pix_clk);
 	drm_put_dev(fsl_dev->drm);
 
 	return 0;
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
index 6413ac9e4769..5bb7c261fe95 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.h
@@ -183,6 +183,8 @@ struct fsl_dcu_drm_device {
 	struct regmap *regmap;
 	int irq;
 	struct clk *clk;
+	struct clk *pix_clk;
+	struct fsl_tcon *tcon;
 	/*protects hardware register*/
 	spinlock_t irq_lock;
 	struct drm_device *drm;
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
index 8780deba5e8a..98c998da91eb 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c
@@ -17,6 +17,7 @@
 #include <drm/drm_panel.h>
 
 #include "fsl_dcu_drm_drv.h"
+#include "fsl_tcon.h"
 
 static int
 fsl_dcu_drm_encoder_atomic_check(struct drm_encoder *encoder,
@@ -28,10 +29,20 @@ fsl_dcu_drm_encoder_atomic_check(struct drm_encoder *encoder,
 
 static void fsl_dcu_drm_encoder_disable(struct drm_encoder *encoder)
 {
+	struct drm_device *dev = encoder->dev;
+	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
+
+	if (fsl_dev->tcon)
+		fsl_tcon_bypass_disable(fsl_dev->tcon);
 }
 
 static void fsl_dcu_drm_encoder_enable(struct drm_encoder *encoder)
 {
+	struct drm_device *dev = encoder->dev;
+	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
+
+	if (fsl_dev->tcon)
+		fsl_tcon_bypass_enable(fsl_dev->tcon);
 }
 
 static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
@@ -68,7 +79,10 @@ int fsl_dcu_drm_encoder_create(struct fsl_dcu_drm_device *fsl_dev,
 
 static void fsl_dcu_drm_connector_destroy(struct drm_connector *connector)
 {
+	struct fsl_dcu_drm_connector *fsl_con = to_fsl_dcu_connector(connector);
+
 	drm_connector_unregister(connector);
+	drm_panel_detach(fsl_con->panel);
 	drm_connector_cleanup(connector);
 }
 
@@ -131,7 +145,7 @@ int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
 				 struct drm_encoder *encoder)
 {
 	struct drm_connector *connector = &fsl_dev->connector.base;
-	struct drm_mode_config mode_config = fsl_dev->drm->mode_config;
+	struct drm_mode_config *mode_config = &fsl_dev->drm->mode_config;
 	struct device_node *panel_node;
 	int ret;
 
@@ -153,19 +167,23 @@ int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
 		goto err_sysfs;
 
 	drm_object_property_set_value(&connector->base,
-				      mode_config.dpms_property,
+				      mode_config->dpms_property,
 				      DRM_MODE_DPMS_OFF);
 
 	panel_node = of_parse_phandle(fsl_dev->np, "fsl,panel", 0);
-	if (panel_node) {
-		fsl_dev->connector.panel = of_drm_find_panel(panel_node);
-		if (!fsl_dev->connector.panel) {
-			ret = -EPROBE_DEFER;
-			goto err_sysfs;
-		}
-	of_node_put(panel_node);
+	if (!panel_node) {
+		dev_err(fsl_dev->dev, "fsl,panel property not found\n");
+		ret = -ENODEV;
+		goto err_sysfs;
 	}
 
+	fsl_dev->connector.panel = of_drm_find_panel(panel_node);
+	if (!fsl_dev->connector.panel) {
+		ret = -EPROBE_DEFER;
+		goto err_panel;
+	}
+	of_node_put(panel_node);
+
 	ret = drm_panel_attach(fsl_dev->connector.panel, connector);
 	if (ret) {
 		dev_err(fsl_dev->dev, "failed to attach panel\n");
@@ -174,6 +192,8 @@ int fsl_dcu_drm_connector_create(struct fsl_dcu_drm_device *fsl_dev,
 
 	return 0;
 
+err_panel:
+	of_node_put(panel_node);
 err_sysfs:
 	drm_connector_unregister(connector);
 err_cleanup:
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_tcon.c b/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
new file mode 100644
index 000000000000..bbe34f1c0505
--- /dev/null
+++ b/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2015 Toradex AG
+ *
+ * Stefan Agner <stefan@agner.ch>
+ *
+ * Freescale TCON device driver
+ *
+ * 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.
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "fsl_tcon.h"
+
+void fsl_tcon_bypass_disable(struct fsl_tcon *tcon)
+{
+	regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
+			   FSL_TCON_CTRL1_TCON_BYPASS, 0);
+}
+
+void fsl_tcon_bypass_enable(struct fsl_tcon *tcon)
+{
+	regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
+			   FSL_TCON_CTRL1_TCON_BYPASS,
+			   FSL_TCON_CTRL1_TCON_BYPASS);
+}
+
+static struct regmap_config fsl_tcon_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+
+	.name = "tcon",
+};
+
+static int fsl_tcon_init_regmap(struct device *dev,
+				struct fsl_tcon *tcon,
+				struct device_node *np)
+{
+	struct resource res;
+	void __iomem *regs;
+
+	if (of_address_to_resource(np, 0, &res))
+		return -EINVAL;
+
+	regs = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	tcon->regs = devm_regmap_init_mmio(dev, regs,
+					   &fsl_tcon_regmap_config);
+	if (IS_ERR(tcon->regs))
+		return PTR_ERR(tcon->regs);
+
+	return 0;
+}
+
+struct fsl_tcon *fsl_tcon_init(struct device *dev)
+{
+	struct fsl_tcon *tcon;
+	struct device_node *np;
+	int ret;
+
+	/* TCON node is not mandatory, some devices do not provide TCON */
+	np = of_parse_phandle(dev->of_node, "fsl,tcon", 0);
+	if (!np)
+		return NULL;
+
+	tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
+	if (!tcon) {
+		ret = -ENOMEM;
+		goto err_node_put;
+	}
+
+	ret = fsl_tcon_init_regmap(dev, tcon, np);
+	if (ret) {
+		dev_err(dev, "Couldn't create the TCON regmap\n");
+		goto err_node_put;
+	}
+
+	tcon->ipg_clk = of_clk_get_by_name(np, "ipg");
+	if (IS_ERR(tcon->ipg_clk)) {
+		dev_err(dev, "Couldn't get the TCON bus clock\n");
+		goto err_node_put;
+	}
+
+	clk_prepare_enable(tcon->ipg_clk);
+
+	dev_info(dev, "Using TCON in bypass mode\n");
+
+	return tcon;
+
+err_node_put:
+	of_node_put(np);
+	return NULL;
+}
+
+void fsl_tcon_free(struct fsl_tcon *tcon)
+{
+	clk_disable_unprepare(tcon->ipg_clk);
+	clk_put(tcon->ipg_clk);
+}
+
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_tcon.h b/drivers/gpu/drm/fsl-dcu/fsl_tcon.h
new file mode 100644
index 000000000000..80a7617de58f
--- /dev/null
+++ b/drivers/gpu/drm/fsl-dcu/fsl_tcon.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2015 Toradex AG
+ *
+ * Stefan Agner <stefan@agner.ch>
+ *
+ * Freescale TCON device driver
+ *
+ * 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.
+ */
+
+#ifndef __FSL_TCON_H__
+#define __FSL_TCON_H__
+
+#include <linux/bitops.h>
+
+#define FSL_TCON_CTRL1			0x0
+#define FSL_TCON_CTRL1_TCON_BYPASS	BIT(29)
+
+struct fsl_tcon {
+	struct regmap		*regs;
+	struct clk		*ipg_clk;
+};
+
+struct fsl_tcon *fsl_tcon_init(struct device *dev);
+void fsl_tcon_free(struct fsl_tcon *tcon);
+
+void fsl_tcon_bypass_disable(struct fsl_tcon *tcon);
+void fsl_tcon_bypass_enable(struct fsl_tcon *tcon);
+
+#endif /* __FSL_TCON_H__ */