drm/stm: Add STM32 LTDC driver

This controller provides output signals to interface directly a variety
of LCD and TFT panels. These output signals are: RGB signals
(up to 24bpp), vertical & horizontal synchronisations, data enable and
the pixel clock.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Link: http://patchwork.freedesktop.org/patch/msgid/1492164819-10513-5-git-send-email-yannick.fertre@st.com
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

7 files changed, 1447 insertions, 0 deletions

diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 78d7fc0ebb57..f57540d2a783 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -246,6 +246,8 @@ source "drivers/gpu/drm/fsl-dcu/Kconfig"
 
 source "drivers/gpu/drm/tegra/Kconfig"
 
+source "drivers/gpu/drm/stm/Kconfig"
+
 source "drivers/gpu/drm/panel/Kconfig"
 
 source "drivers/gpu/drm/bridge/Kconfig"
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 59f0f9b696eb..aa62ded7144e 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_DRM_BOCHS) += bochs/
 obj-$(CONFIG_DRM_VIRTIO_GPU) += virtio/
 obj-$(CONFIG_DRM_MSM) += msm/
 obj-$(CONFIG_DRM_TEGRA) += tegra/
+obj-$(CONFIG_DRM_STM) += stm/
 obj-$(CONFIG_DRM_STI) += sti/
 obj-$(CONFIG_DRM_IMX) += imx/
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek/
diff --git a/drivers/gpu/drm/stm/Kconfig b/drivers/gpu/drm/stm/Kconfig
new file mode 100644
index 000000000000..2c4817fb0890
--- /dev/null
+++ b/drivers/gpu/drm/stm/Kconfig
@@ -0,0 +1,16 @@
+config DRM_STM
+	tristate "DRM Support for STMicroelectronics SoC Series"
+	depends on DRM && (ARCH_STM32 || ARCH_MULTIPLATFORM)
+	select DRM_KMS_HELPER
+	select DRM_GEM_CMA_HELPER
+	select DRM_KMS_CMA_HELPER
+	select DRM_PANEL
+	select VIDEOMODE_HELPERS
+	select FB_PROVIDE_GET_FB_UNMAPPED_AREA
+	default y
+
+	help
+	  Enable support for the on-chip display controller on
+	  STMicroelectronics STM32 MCUs.
+	  To compile this driver as a module, choose M here: the module
+	  will be called stm-drm.
diff --git a/drivers/gpu/drm/stm/Makefile b/drivers/gpu/drm/stm/Makefile
new file mode 100644
index 000000000000..e114d45dbd42
--- /dev/null
+++ b/drivers/gpu/drm/stm/Makefile
@@ -0,0 +1,7 @@
+ccflags-y := -Iinclude/drm
+
+stm-drm-y := \
+	drv.o \
+	ltdc.o
+
+obj-$(CONFIG_DRM_STM) += stm-drm.o
diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
new file mode 100644
index 000000000000..83ab48f1fd00
--- /dev/null
+++ b/drivers/gpu/drm/stm/drv.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/component.h>
+#include <linux/of_platform.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+
+#include "ltdc.h"
+
+#define DRIVER_NAME		"stm"
+#define DRIVER_DESC		"STMicroelectronics SoC DRM"
+#define DRIVER_DATE		"20170330"
+#define DRIVER_MAJOR		1
+#define DRIVER_MINOR		0
+#define DRIVER_PATCH_LEVEL	0
+
+#define STM_MAX_FB_WIDTH	2048
+#define STM_MAX_FB_HEIGHT	2048 /* same as width to handle orientation */
+
+static void drv_output_poll_changed(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	drm_fbdev_cma_hotplug_event(ldev->fbdev);
+}
+
+static const struct drm_mode_config_funcs drv_mode_config_funcs = {
+	.fb_create = drm_fb_cma_create,
+	.output_poll_changed = drv_output_poll_changed,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
+};
+
+static void drv_lastclose(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	drm_fbdev_cma_restore_mode(ldev->fbdev);
+}
+
+DEFINE_DRM_GEM_CMA_FOPS(drv_driver_fops);
+
+static struct drm_driver drv_driver = {
+	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
+			   DRIVER_ATOMIC,
+	.lastclose = drv_lastclose,
+	.name = DRIVER_NAME,
+	.desc = DRIVER_DESC,
+	.date = DRIVER_DATE,
+	.major = DRIVER_MAJOR,
+	.minor = DRIVER_MINOR,
+	.patchlevel = DRIVER_PATCH_LEVEL,
+	.fops = &drv_driver_fops,
+	.dumb_create = drm_gem_cma_dumb_create,
+	.dumb_map_offset = drm_gem_cma_dumb_map_offset,
+	.dumb_destroy = drm_gem_dumb_destroy,
+	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
+	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+	.gem_free_object_unlocked = drm_gem_cma_free_object,
+	.gem_vm_ops = &drm_gem_cma_vm_ops,
+	.gem_prime_export = drm_gem_prime_export,
+	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
+	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
+	.gem_prime_vmap = drm_gem_cma_prime_vmap,
+	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
+	.gem_prime_mmap = drm_gem_cma_prime_mmap,
+	.enable_vblank = ltdc_crtc_enable_vblank,
+	.disable_vblank = ltdc_crtc_disable_vblank,
+};
+
+static int drv_load(struct drm_device *ddev)
+{
+	struct platform_device *pdev = to_platform_device(ddev->dev);
+	struct drm_fbdev_cma *fbdev;
+	struct ltdc_device *ldev;
+	int ret;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	ldev = devm_kzalloc(ddev->dev, sizeof(*ldev), GFP_KERNEL);
+	if (!ldev)
+		return -ENOMEM;
+
+	ddev->dev_private = (void *)ldev;
+
+	drm_mode_config_init(ddev);
+
+	/*
+	 * set max width and height as default value.
+	 * this value would be used to check framebuffer size limitation
+	 * at drm_mode_addfb().
+	 */
+	ddev->mode_config.min_width = 0;
+	ddev->mode_config.min_height = 0;
+	ddev->mode_config.max_width = STM_MAX_FB_WIDTH;
+	ddev->mode_config.max_height = STM_MAX_FB_HEIGHT;
+	ddev->mode_config.funcs = &drv_mode_config_funcs;
+
+	ret = ltdc_load(ddev);
+	if (ret)
+		goto err;
+
+	drm_mode_config_reset(ddev);
+	drm_kms_helper_poll_init(ddev);
+
+	if (ddev->mode_config.num_connector) {
+		ldev = ddev->dev_private;
+		fbdev = drm_fbdev_cma_init(ddev, 16,
+					   ddev->mode_config.num_connector);
+		if (IS_ERR(fbdev)) {
+			DRM_DEBUG("Warning: fails to create fbdev\n");
+			fbdev = NULL;
+		}
+		ldev->fbdev = fbdev;
+	}
+
+	platform_set_drvdata(pdev, ddev);
+
+	return 0;
+err:
+	drm_mode_config_cleanup(ddev);
+	return ret;
+}
+
+static void drv_unload(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	if (ldev->fbdev) {
+		drm_fbdev_cma_fini(ldev->fbdev);
+		ldev->fbdev = NULL;
+	}
+	drm_kms_helper_poll_fini(ddev);
+	ltdc_unload(ddev);
+	drm_mode_config_cleanup(ddev);
+}
+
+static int stm_drm_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct drm_device *ddev;
+	int ret;
+
+	DRM_DEBUG("%s\n", __func__);
+
+	dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
+
+	ddev = drm_dev_alloc(&drv_driver, dev);
+	if (IS_ERR(ddev))
+		return PTR_ERR(ddev);
+
+	ret = drv_load(ddev);
+	if (ret)
+		goto err_unref;
+
+	ret = drm_dev_register(ddev, 0);
+	if (ret)
+		goto err_unref;
+
+	return 0;
+
+err_unref:
+	drm_dev_unref(ddev);
+
+	return ret;
+}
+
+static int stm_drm_platform_remove(struct platform_device *pdev)
+{
+	struct drm_device *ddev = platform_get_drvdata(pdev);
+
+	DRM_DEBUG("%s\n", __func__);
+
+	drm_dev_unregister(ddev);
+	drv_unload(ddev);
+	drm_dev_unref(ddev);
+
+	return 0;
+}
+
+static const struct of_device_id drv_dt_ids[] = {
+	{ .compatible = "st,stm32-ltdc"},
+	{ /* end node */ },
+};
+MODULE_DEVICE_TABLE(of, drv_dt_ids);
+
+static struct platform_driver stm_drm_platform_driver = {
+	.probe = stm_drm_platform_probe,
+	.remove = stm_drm_platform_remove,
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = drv_dt_ids,
+	},
+};
+
+module_platform_driver(stm_drm_platform_driver);
+
+MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
new file mode 100644
index 000000000000..a40418cda74a
--- /dev/null
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -0,0 +1,1160 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/component.h>
+#include <linux/of_address.h>
+#include <linux/of_graph.h>
+#include <linux/reset.h>
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_fb_cma_helper.h>
+#include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_of.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_plane_helper.h>
+
+#include <video/videomode.h>
+
+#include "ltdc.h"
+
+#define NB_CRTC 1
+#define CRTC_MASK GENMASK(NB_CRTC - 1, 0)
+
+#define MAX_IRQ 4
+
+#define HWVER_10200 0x010200
+#define HWVER_10300 0x010300
+#define HWVER_20101 0x020101
+
+/*
+ * The address of some registers depends on the HW version: such registers have
+ * an extra offset specified with reg_ofs.
+ */
+#define REG_OFS_NONE	0
+#define REG_OFS_4	4 /* Insertion of "Layer Configuration 2" reg */
+#define REG_OFS		(ldev->caps.reg_ofs)
+#define LAY_OFS		0x80	/* Register Offset between 2 layers */
+
+/* Global register offsets */
+#define LTDC_IDR	0x0000 /* IDentification */
+#define LTDC_LCR	0x0004 /* Layer Count */
+#define LTDC_SSCR	0x0008 /* Synchronization Size Configuration */
+#define LTDC_BPCR	0x000C /* Back Porch Configuration */
+#define LTDC_AWCR	0x0010 /* Active Width Configuration */
+#define LTDC_TWCR	0x0014 /* Total Width Configuration */
+#define LTDC_GCR	0x0018 /* Global Control */
+#define LTDC_GC1R	0x001C /* Global Configuration 1 */
+#define LTDC_GC2R	0x0020 /* Global Configuration 2 */
+#define LTDC_SRCR	0x0024 /* Shadow Reload Configuration */
+#define LTDC_GACR	0x0028 /* GAmma Correction */
+#define LTDC_BCCR	0x002C /* Background Color Configuration */
+#define LTDC_IER	0x0034 /* Interrupt Enable */
+#define LTDC_ISR	0x0038 /* Interrupt Status */
+#define LTDC_ICR	0x003C /* Interrupt Clear */
+#define LTDC_LIPCR	0x0040 /* Line Interrupt Position Configuration */
+#define LTDC_CPSR	0x0044 /* Current Position Status */
+#define LTDC_CDSR	0x0048 /* Current Display Status */
+
+/* Layer register offsets */
+#define LTDC_L1LC1R	(0x0080)	   /* L1 Layer Configuration 1 */
+#define LTDC_L1LC2R	(0x0084)	   /* L1 Layer Configuration 2 */
+#define LTDC_L1CR	(0x0084 + REG_OFS) /* L1 Control */
+#define LTDC_L1WHPCR	(0x0088 + REG_OFS) /* L1 Window Hor Position Config */
+#define LTDC_L1WVPCR	(0x008C + REG_OFS) /* L1 Window Vert Position Config */
+#define LTDC_L1CKCR	(0x0090 + REG_OFS) /* L1 Color Keying Configuration */
+#define LTDC_L1PFCR	(0x0094 + REG_OFS) /* L1 Pixel Format Configuration */
+#define LTDC_L1CACR	(0x0098 + REG_OFS) /* L1 Constant Alpha Config */
+#define LTDC_L1DCCR	(0x009C + REG_OFS) /* L1 Default Color Configuration */
+#define LTDC_L1BFCR	(0x00A0 + REG_OFS) /* L1 Blend Factors Configuration */
+#define LTDC_L1FBBCR	(0x00A4 + REG_OFS) /* L1 FrameBuffer Bus Control */
+#define LTDC_L1AFBCR	(0x00A8 + REG_OFS) /* L1 AuxFB Control */
+#define LTDC_L1CFBAR	(0x00AC + REG_OFS) /* L1 Color FrameBuffer Address */
+#define LTDC_L1CFBLR	(0x00B0 + REG_OFS) /* L1 Color FrameBuffer Length */
+#define LTDC_L1CFBLNR	(0x00B4 + REG_OFS) /* L1 Color FrameBuffer Line Nb */
+#define LTDC_L1AFBAR	(0x00B8 + REG_OFS) /* L1 AuxFB Address */
+#define LTDC_L1AFBLR	(0x00BC + REG_OFS) /* L1 AuxFB Length */
+#define LTDC_L1AFBLNR	(0x00C0 + REG_OFS) /* L1 AuxFB Line Number */
+#define LTDC_L1CLUTWR	(0x00C4 + REG_OFS) /* L1 CLUT Write */
+#define LTDC_L1YS1R	(0x00E0 + REG_OFS) /* L1 YCbCr Scale 1 */
+#define LTDC_L1YS2R	(0x00E4 + REG_OFS) /* L1 YCbCr Scale 2 */
+
+/* Bit definitions */
+#define SSCR_VSH	GENMASK(10, 0)	/* Vertical Synchronization Height */
+#define SSCR_HSW	GENMASK(27, 16)	/* Horizontal Synchronization Width */
+
+#define BPCR_AVBP	GENMASK(10, 0)	/* Accumulated Vertical Back Porch */
+#define BPCR_AHBP	GENMASK(27, 16)	/* Accumulated Horizontal Back Porch */
+
+#define AWCR_AAH	GENMASK(10, 0)	/* Accumulated Active Height */
+#define AWCR_AAW	GENMASK(27, 16)	/* Accumulated Active Width */
+
+#define TWCR_TOTALH	GENMASK(10, 0)	/* TOTAL Height */
+#define TWCR_TOTALW	GENMASK(27, 16)	/* TOTAL Width */
+
+#define GCR_LTDCEN	BIT(0)		/* LTDC ENable */
+#define GCR_DEN		BIT(16)		/* Dither ENable */
+#define GCR_PCPOL	BIT(28)		/* Pixel Clock POLarity */
+#define GCR_DEPOL	BIT(29)		/* Data Enable POLarity */
+#define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity */
+#define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity */
+
+#define GC1R_WBCH	GENMASK(3, 0)	/* Width of Blue CHannel output */
+#define GC1R_WGCH	GENMASK(7, 4)	/* Width of Green Channel output */
+#define GC1R_WRCH	GENMASK(11, 8)	/* Width of Red Channel output */
+#define GC1R_PBEN	BIT(12)		/* Precise Blending ENable */
+#define GC1R_DT		GENMASK(15, 14)	/* Dithering Technique */
+#define GC1R_GCT	GENMASK(19, 17)	/* Gamma Correction Technique */
+#define GC1R_SHREN	BIT(21)		/* SHadow Registers ENabled */
+#define GC1R_BCP	BIT(22)		/* Background Colour Programmable */
+#define GC1R_BBEN	BIT(23)		/* Background Blending ENabled */
+#define GC1R_LNIP	BIT(24)		/* Line Number IRQ Position */
+#define GC1R_TP		BIT(25)		/* Timing Programmable */
+#define GC1R_IPP	BIT(26)		/* IRQ Polarity Programmable */
+#define GC1R_SPP	BIT(27)		/* Sync Polarity Programmable */
+#define GC1R_DWP	BIT(28)		/* Dither Width Programmable */
+#define GC1R_STREN	BIT(29)		/* STatus Registers ENabled */
+#define GC1R_BMEN	BIT(31)		/* Blind Mode ENabled */
+
+#define GC2R_EDCA	BIT(0)		/* External Display Control Ability  */
+#define GC2R_STSAEN	BIT(1)		/* Slave Timing Sync Ability ENabled */
+#define GC2R_DVAEN	BIT(2)		/* Dual-View Ability ENabled */
+#define GC2R_DPAEN	BIT(3)		/* Dual-Port Ability ENabled */
+#define GC2R_BW		GENMASK(6, 4)	/* Bus Width (log2 of nb of bytes) */
+#define GC2R_EDCEN	BIT(7)		/* External Display Control ENabled */
+
+#define SRCR_IMR	BIT(0)		/* IMmediate Reload */
+#define SRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
+
+#define BCCR_BCBLACK	0x00		/* Background Color BLACK */
+#define BCCR_BCBLUE	GENMASK(7, 0)	/* Background Color BLUE */
+#define BCCR_BCGREEN	GENMASK(15, 8)	/* Background Color GREEN */
+#define BCCR_BCRED	GENMASK(23, 16)	/* Background Color RED */
+#define BCCR_BCWHITE	GENMASK(23, 0)	/* Background Color WHITE */
+
+#define IER_LIE		BIT(0)		/* Line Interrupt Enable */
+#define IER_FUIE	BIT(1)		/* Fifo Underrun Interrupt Enable */
+#define IER_TERRIE	BIT(2)		/* Transfer ERRor Interrupt Enable */
+#define IER_RRIE	BIT(3)		/* Register Reload Interrupt enable */
+
+#define ISR_LIF		BIT(0)		/* Line Interrupt Flag */
+#define ISR_FUIF	BIT(1)		/* Fifo Underrun Interrupt Flag */
+#define ISR_TERRIF	BIT(2)		/* Transfer ERRor Interrupt Flag */
+#define ISR_RRIF	BIT(3)		/* Register Reload Interrupt Flag */
+
+#define LXCR_LEN	BIT(0)		/* Layer ENable */
+#define LXCR_COLKEN	BIT(1)		/* Color Keying Enable */
+#define LXCR_CLUTEN	BIT(4)		/* Color Look-Up Table ENable */
+
+#define LXWHPCR_WHSTPOS	GENMASK(11, 0)	/* Window Horizontal StarT POSition */
+#define LXWHPCR_WHSPPOS	GENMASK(27, 16)	/* Window Horizontal StoP POSition */
+
+#define LXWVPCR_WVSTPOS	GENMASK(10, 0)	/* Window Vertical StarT POSition */
+#define LXWVPCR_WVSPPOS	GENMASK(26, 16)	/* Window Vertical StoP POSition */
+
+#define LXPFCR_PF	GENMASK(2, 0)	/* Pixel Format */
+
+#define LXCACR_CONSTA	GENMASK(7, 0)	/* CONSTant Alpha */
+
+#define LXBFCR_BF2	GENMASK(2, 0)	/* Blending Factor 2 */
+#define LXBFCR_BF1	GENMASK(10, 8)	/* Blending Factor 1 */
+
+#define LXCFBLR_CFBLL	GENMASK(12, 0)	/* Color Frame Buffer Line Length */
+#define LXCFBLR_CFBP	GENMASK(28, 16)	/* Color Frame Buffer Pitch in bytes */
+
+#define LXCFBLNR_CFBLN	GENMASK(10, 0)	 /* Color Frame Buffer Line Number */
+
+#define HSPOL_AL   0		/* Horizontal Sync POLarity Active Low */
+#define VSPOL_AL   0		/* Vertical Sync POLarity Active Low */
+#define DEPOL_AL   0		/* Data Enable POLarity Active Low */
+#define PCPOL_IPC  0		/* Input Pixel Clock */
+#define HSPOL_AH   GCR_HSPOL	/* Horizontal Sync POLarity Active High */
+#define VSPOL_AH   GCR_VSPOL	/* Vertical Sync POLarity Active High */
+#define DEPOL_AH   GCR_DEPOL	/* Data Enable POLarity Active High */
+#define PCPOL_IIPC GCR_PCPOL	/* Inverted Input Pixel Clock */
+#define CONSTA_MAX 0xFF		/* CONSTant Alpha MAX= 1.0 */
+#define BF1_PAXCA  0x600	/* Pixel Alpha x Constant Alpha */
+#define BF1_CA     0x400	/* Constant Alpha */
+#define BF2_1PAXCA 0x007	/* 1 - (Pixel Alpha x Constant Alpha) */
+#define BF2_1CA	   0x005	/* 1 - Constant Alpha */
+
+#define NB_PF           8       /* Max nb of HW pixel format */
+
+enum ltdc_pix_fmt {
+	PF_NONE,
+	/* RGB formats */
+	PF_ARGB8888,    /* ARGB [32 bits] */
+	PF_RGBA8888,    /* RGBA [32 bits] */
+	PF_RGB888,      /* RGB [24 bits] */
+	PF_RGB565,      /* RGB [16 bits] */
+	PF_ARGB1555,    /* ARGB A:1 bit RGB:15 bits [16 bits] */
+	PF_ARGB4444,    /* ARGB A:4 bits R/G/B: 4 bits each [16 bits] */
+	/* Indexed formats */
+	PF_L8,          /* Indexed 8 bits [8 bits] */
+	PF_AL44,        /* Alpha:4 bits + indexed 4 bits [8 bits] */
+	PF_AL88         /* Alpha:8 bits + indexed 8 bits [16 bits] */
+};
+
+/* The index gives the encoding of the pixel format for an HW version */
+static const enum ltdc_pix_fmt ltdc_pix_fmt_a0[NB_PF] = {
+	PF_ARGB8888,	/* 0x00 */
+	PF_RGB888,	/* 0x01 */
+	PF_RGB565,	/* 0x02 */
+	PF_ARGB1555,	/* 0x03 */
+	PF_ARGB4444,	/* 0x04 */
+	PF_L8,		/* 0x05 */
+	PF_AL44,	/* 0x06 */
+	PF_AL88		/* 0x07 */
+};
+
+static const enum ltdc_pix_fmt ltdc_pix_fmt_a1[NB_PF] = {
+	PF_ARGB8888,	/* 0x00 */
+	PF_RGB888,	/* 0x01 */
+	PF_RGB565,	/* 0x02 */
+	PF_RGBA8888,	/* 0x03 */
+	PF_AL44,	/* 0x04 */
+	PF_L8,		/* 0x05 */
+	PF_ARGB1555,	/* 0x06 */
+	PF_ARGB4444	/* 0x07 */
+};
+
+static inline u32 reg_read(void __iomem *base, u32 reg)
+{
+	return readl_relaxed(base + reg);
+}
+
+static inline void reg_write(void __iomem *base, u32 reg, u32 val)
+{
+	writel_relaxed(val, base + reg);
+}
+
+static inline void reg_set(void __iomem *base, u32 reg, u32 mask)
+{
+	reg_write(base, reg, reg_read(base, reg) | mask);
+}
+
+static inline void reg_clear(void __iomem *base, u32 reg, u32 mask)
+{
+	reg_write(base, reg, reg_read(base, reg) & ~mask);
+}
+
+static inline void reg_update_bits(void __iomem *base, u32 reg, u32 mask,
+				   u32 val)
+{
+	reg_write(base, reg, (reg_read(base, reg) & ~mask) | val);
+}
+
+static inline struct ltdc_device *crtc_to_ltdc(struct drm_crtc *crtc)
+{
+	return (struct ltdc_device *)crtc->dev->dev_private;
+}
+
+static inline struct ltdc_device *plane_to_ltdc(struct drm_plane *plane)
+{
+	return (struct ltdc_device *)plane->dev->dev_private;
+}
+
+static inline struct ltdc_device *encoder_to_ltdc(struct drm_encoder *enc)
+{
+	return (struct ltdc_device *)enc->dev->dev_private;
+}
+
+static inline struct ltdc_device *connector_to_ltdc(struct drm_connector *con)
+{
+	return (struct ltdc_device *)con->dev->dev_private;
+}
+
+static inline enum ltdc_pix_fmt to_ltdc_pixelformat(u32 drm_fmt)
+{
+	enum ltdc_pix_fmt pf;
+
+	switch (drm_fmt) {
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_XRGB8888:
+		pf = PF_ARGB8888;
+		break;
+	case DRM_FORMAT_RGBA8888:
+	case DRM_FORMAT_RGBX8888:
+		pf = PF_RGBA8888;
+		break;
+	case DRM_FORMAT_RGB888:
+		pf = PF_RGB888;
+		break;
+	case DRM_FORMAT_RGB565:
+		pf = PF_RGB565;
+		break;
+	case DRM_FORMAT_ARGB1555:
+	case DRM_FORMAT_XRGB1555:
+		pf = PF_ARGB1555;
+		break;
+	case DRM_FORMAT_ARGB4444:
+	case DRM_FORMAT_XRGB4444:
+		pf = PF_ARGB4444;
+		break;
+	case DRM_FORMAT_C8:
+		pf = PF_L8;
+		break;
+	default:
+		pf = PF_NONE;
+		break;
+	/* Note: There are no DRM_FORMAT for AL44 and AL88 */
+	}
+
+	return pf;
+}
+
+static inline u32 to_drm_pixelformat(enum ltdc_pix_fmt pf)
+{
+	switch (pf) {
+	case PF_ARGB8888:
+		return DRM_FORMAT_ARGB8888;
+	case PF_RGBA8888:
+		return DRM_FORMAT_RGBA8888;
+	case PF_RGB888:
+		return DRM_FORMAT_RGB888;
+	case PF_RGB565:
+		return DRM_FORMAT_RGB565;
+	case PF_ARGB1555:
+		return DRM_FORMAT_ARGB1555;
+	case PF_ARGB4444:
+		return DRM_FORMAT_ARGB4444;
+	case PF_L8:
+		return DRM_FORMAT_C8;
+	case PF_AL44: /* No DRM support */
+	case PF_AL88: /* No DRM support */
+	case PF_NONE:
+	default:
+		return 0;
+	}
+}
+
+static irqreturn_t ltdc_irq_thread(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct drm_crtc *crtc = drm_crtc_from_index(ddev, 0);
+
+	/* Line IRQ : trigger the vblank event */
+	if (ldev->irq_status & ISR_LIF)
+		drm_crtc_handle_vblank(crtc);
+
+	/* Save FIFO Underrun & Transfer Error status */
+	mutex_lock(&ldev->err_lock);
+	if (ldev->irq_status & ISR_FUIF)
+		ldev->error_status |= ISR_FUIF;
+	if (ldev->irq_status & ISR_TERRIF)
+		ldev->error_status |= ISR_TERRIF;
+	mutex_unlock(&ldev->err_lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ltdc_irq(int irq, void *arg)
+{
+	struct drm_device *ddev = arg;
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	/* Read & Clear the interrupt status */
+	ldev->irq_status = reg_read(ldev->regs, LTDC_ISR);
+	reg_write(ldev->regs, LTDC_ICR, ldev->irq_status);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/*
+ * DRM_CRTC
+ */
+
+static void ltdc_crtc_load_lut(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	unsigned int i, lay;
+
+	for (lay = 0; lay < ldev->caps.nb_layers; lay++)
+		for (i = 0; i < 256; i++)
+			reg_write(ldev->regs, LTDC_L1CLUTWR + lay * LAY_OFS,
+				  ldev->clut[i]);
+}
+
+static void ltdc_crtc_enable(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	/* Sets the background color value */
+	reg_write(ldev->regs, LTDC_BCCR, BCCR_BCBLACK);
+
+	/* Enable IRQ */
+	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	/* Immediately commit the planes */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
+
+	/* Enable LTDC */
+	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
+
+	drm_crtc_vblank_on(crtc);
+}
+
+static void ltdc_crtc_disable(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_crtc_vblank_off(crtc);
+
+	/* disable LTDC */
+	reg_clear(ldev->regs, LTDC_GCR, GCR_LTDCEN);
+
+	/* disable IRQ */
+	reg_clear(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	/* immediately commit disable of layers before switching off LTDC */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
+}
+
+static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	struct videomode vm;
+	int rate = mode->clock * 1000;
+	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
+	u32 total_width, total_height;
+	u32 val;
+
+	drm_display_mode_to_videomode(mode, &vm);
+
+	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
+	DRM_DEBUG_DRIVER("Video mode: %dx%d", vm.hactive, vm.vactive);
+	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
+			 vm.hfront_porch, vm.hback_porch, vm.hsync_len,
+			 vm.vfront_porch, vm.vback_porch, vm.vsync_len);
+
+	/* Convert video timings to ltdc timings */
+	hsync = vm.hsync_len - 1;
+	vsync = vm.vsync_len - 1;
+	accum_hbp = hsync + vm.hback_porch;
+	accum_vbp = vsync + vm.vback_porch;
+	accum_act_w = accum_hbp + vm.hactive;
+	accum_act_h = accum_vbp + vm.vactive;
+	total_width = accum_act_w + vm.hfront_porch;
+	total_height = accum_act_h + vm.vfront_porch;
+
+	clk_disable(ldev->pixel_clk);
+
+	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
+		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
+		return;
+	}
+
+	clk_enable(ldev->pixel_clk);
+
+	/* Configures the HS, VS, DE and PC polarities. */
+	val = HSPOL_AL | HSPOL_AL | DEPOL_AL | PCPOL_IPC;
+
+	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
+		val |= HSPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_VSYNC_HIGH)
+		val |= VSPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+		val |= DEPOL_AH;
+
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+		val |= PCPOL_IIPC;
+
+	reg_update_bits(ldev->regs, LTDC_GCR,
+			GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);
+
+	/* Set Synchronization size */
+	val = (hsync << 16) | vsync;
+	reg_update_bits(ldev->regs, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);
+
+	/* Set Accumulated Back porch */
+	val = (accum_hbp << 16) | accum_vbp;
+	reg_update_bits(ldev->regs, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);
+
+	/* Set Accumulated Active Width */
+	val = (accum_act_w << 16) | accum_act_h;
+	reg_update_bits(ldev->regs, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);
+
+	/* Set total width & height */
+	val = (total_width << 16) | total_height;
+	reg_update_bits(ldev->regs, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);
+
+	reg_write(ldev->regs, LTDC_LIPCR, (accum_act_h + 1));
+}
+
+static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
+				   struct drm_crtc_state *old_crtc_state)
+{
+	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
+	struct drm_pending_vblank_event *event = crtc->state->event;
+
+	DRM_DEBUG_ATOMIC("\n");
+
+	/* Commit shadow registers = update planes at next vblank */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
+
+	if (event) {
+		crtc->state->event = NULL;
+
+		spin_lock_irq(&crtc->dev->event_lock);
+		if (drm_crtc_vblank_get(crtc) == 0)
+			drm_crtc_arm_vblank_event(crtc, event);
+		else
+			drm_crtc_send_vblank_event(crtc, event);
+		spin_unlock_irq(&crtc->dev->event_lock);
+	}
+}
+
+static struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
+	.load_lut = ltdc_crtc_load_lut,
+	.enable = ltdc_crtc_enable,
+	.disable = ltdc_crtc_disable,
+	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
+	.atomic_flush = ltdc_crtc_atomic_flush,
+};
+
+int ltdc_crtc_enable_vblank(struct drm_device *ddev, unsigned int pipe)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+	reg_set(ldev->regs, LTDC_IER, IER_LIE);
+
+	return 0;
+}
+
+void ltdc_crtc_disable_vblank(struct drm_device *ddev, unsigned int pipe)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+	reg_clear(ldev->regs, LTDC_IER, IER_LIE);
+}
+
+static struct drm_crtc_funcs ltdc_crtc_funcs = {
+	.destroy = drm_crtc_cleanup,
+	.set_config = drm_atomic_helper_set_config,
+	.page_flip = drm_atomic_helper_page_flip,
+	.reset = drm_atomic_helper_crtc_reset,
+	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+};
+
+/*
+ * DRM_PLANE
+ */
+
+static int ltdc_plane_atomic_check(struct drm_plane *plane,
+				   struct drm_plane_state *state)
+{
+	struct drm_framebuffer *fb = state->fb;
+	u32 src_x, src_y, src_w, src_h;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (!fb)
+		return 0;
+
+	/* convert src_ from 16:16 format */
+	src_x = state->src_x >> 16;
+	src_y = state->src_y >> 16;
+	src_w = state->src_w >> 16;
+	src_h = state->src_h >> 16;
+
+	/* Reject scaling */
+	if ((src_w != state->crtc_w) || (src_h != state->crtc_h)) {
+		DRM_ERROR("Scaling is not supported");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void ltdc_plane_atomic_update(struct drm_plane *plane,
+				     struct drm_plane_state *oldstate)
+{
+	struct ltdc_device *ldev = plane_to_ltdc(plane);
+	struct drm_plane_state *state = plane->state;
+	struct drm_framebuffer *fb = state->fb;
+	u32 lofs = plane->index * LAY_OFS;
+	u32 x0 = state->crtc_x;
+	u32 x1 = state->crtc_x + state->crtc_w - 1;
+	u32 y0 = state->crtc_y;
+	u32 y1 = state->crtc_y + state->crtc_h - 1;
+	u32 src_x, src_y, src_w, src_h;
+	u32 val, pitch_in_bytes, line_length, paddr, ahbp, avbp, bpcr;
+	enum ltdc_pix_fmt pf;
+
+	if (!state->crtc || !fb) {
+		DRM_DEBUG_DRIVER("fb or crtc NULL");
+		return;
+	}
+
+	/* convert src_ from 16:16 format */
+	src_x = state->src_x >> 16;
+	src_y = state->src_y >> 16;
+	src_w = state->src_w >> 16;
+	src_h = state->src_h >> 16;
+
+	DRM_DEBUG_DRIVER(
+		"plane:%d fb:%d (%dx%d)@(%d,%d) -> (%dx%d)@(%d,%d)\n",
+		plane->base.id, fb->base.id,
+		src_w, src_h, src_x, src_y,
+		state->crtc_w, state->crtc_h, state->crtc_x, state->crtc_y);
+
+	bpcr = reg_read(ldev->regs, LTDC_BPCR);
+	ahbp = (bpcr & BPCR_AHBP) >> 16;
+	avbp = bpcr & BPCR_AVBP;
+
+	/* Configures the horizontal start and stop position */
+	val = ((x1 + 1 + ahbp) << 16) + (x0 + 1 + ahbp);
+	reg_update_bits(ldev->regs, LTDC_L1WHPCR + lofs,
+			LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);
+
+	/* Configures the vertical start and stop position */
+	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
+	reg_update_bits(ldev->regs, LTDC_L1WVPCR + lofs,
+			LXWVPCR_WVSTPOS | LXWVPCR_WVSPPOS, val);
+
+	/* Specifies the pixel format */
+	pf = to_ltdc_pixelformat(fb->format->format);
+	for (val = 0; val < NB_PF; val++)
+		if (ldev->caps.pix_fmt_hw[val] == pf)
+			break;
+
+	if (val == NB_PF) {
+		DRM_ERROR("Pixel format %.4s not supported\n",
+			  (char *)&fb->format->format);
+		val = 0; /* set by default ARGB 32 bits */
+	}
+	reg_update_bits(ldev->regs, LTDC_L1PFCR + lofs, LXPFCR_PF, val);
+
+	/* Configures the color frame buffer pitch in bytes & line length */
+	pitch_in_bytes = fb->pitches[0];
+	line_length = drm_format_plane_cpp(fb->format->format, 0) *
+		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
+	val = ((pitch_in_bytes << 16) | line_length);
+	reg_update_bits(ldev->regs, LTDC_L1CFBLR + lofs,
+			LXCFBLR_CFBLL | LXCFBLR_CFBP, val);
+
+	/* Specifies the constant alpha value */
+	val = CONSTA_MAX;
+	reg_update_bits(ldev->regs, LTDC_L1CACR + lofs,
+			LXCACR_CONSTA, val);
+
+	/* Specifies the blending factors */
+	val = BF1_PAXCA | BF2_1PAXCA;
+	reg_update_bits(ldev->regs, LTDC_L1BFCR + lofs,
+			LXBFCR_BF2 | LXBFCR_BF1, val);
+
+	/* Configures the frame buffer line number */
+	val = y1 - y0 + 1;
+	reg_update_bits(ldev->regs, LTDC_L1CFBLNR + lofs,
+			LXCFBLNR_CFBLN, val);
+
+	/* Sets the FB address */
+	paddr = (u32)drm_fb_cma_get_gem_addr(fb, state, 0);
+
+	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
+	reg_write(ldev->regs, LTDC_L1CFBAR + lofs, paddr);
+
+	/* Enable layer and CLUT if needed */
+	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
+	val |= LXCR_LEN;
+	reg_update_bits(ldev->regs, LTDC_L1CR + lofs,
+			LXCR_LEN | LXCR_CLUTEN, val);
+
+	mutex_lock(&ldev->err_lock);
+	if (ldev->error_status & ISR_FUIF) {
+		DRM_DEBUG_DRIVER("Fifo underrun\n");
+		ldev->error_status &= ~ISR_FUIF;
+	}
+	if (ldev->error_status & ISR_TERRIF) {
+		DRM_DEBUG_DRIVER("Transfer error\n");
+		ldev->error_status &= ~ISR_TERRIF;
+	}
+	mutex_unlock(&ldev->err_lock);
+}
+
+static void ltdc_plane_atomic_disable(struct drm_plane *plane,
+				      struct drm_plane_state *oldstate)
+{
+	struct ltdc_device *ldev = plane_to_ltdc(plane);
+	u32 lofs = plane->index * LAY_OFS;
+
+	/* disable layer */
+	reg_clear(ldev->regs, LTDC_L1CR + lofs, LXCR_LEN);
+
+	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
+			 oldstate->crtc->base.id, plane->base.id);
+}
+
+static struct drm_plane_funcs ltdc_plane_funcs = {
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
+	.destroy = drm_plane_cleanup,
+	.set_property = drm_atomic_helper_plane_set_property,
+	.reset = drm_atomic_helper_plane_reset,
+	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
+};
+
+static const struct drm_plane_helper_funcs ltdc_plane_helper_funcs = {
+	.atomic_check = ltdc_plane_atomic_check,
+	.atomic_update = ltdc_plane_atomic_update,
+	.atomic_disable = ltdc_plane_atomic_disable,
+};
+
+static struct drm_plane *ltdc_plane_create(struct drm_device *ddev,
+					   enum drm_plane_type type)
+{
+	unsigned long possible_crtcs = CRTC_MASK;
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct device *dev = ddev->dev;
+	struct drm_plane *plane;
+	unsigned int i, nb_fmt = 0;
+	u32 formats[NB_PF];
+	u32 drm_fmt;
+	int ret;
+
+	/* Get supported pixel formats */
+	for (i = 0; i < NB_PF; i++) {
+		drm_fmt = to_drm_pixelformat(ldev->caps.pix_fmt_hw[i]);
+		if (!drm_fmt)
+			continue;
+		formats[nb_fmt++] = drm_fmt;
+	}
+
+	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
+	if (!plane)
+		return 0;
+
+	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
+				       &ltdc_plane_funcs, formats, nb_fmt,
+				       type, NULL);
+	if (ret < 0)
+		return 0;
+
+	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);
+
+	DRM_DEBUG_DRIVER("plane:%d created\n", plane->base.id);
+
+	return plane;
+}
+
+static void ltdc_plane_destroy_all(struct drm_device *ddev)
+{
+	struct drm_plane *plane, *plane_temp;
+
+	list_for_each_entry_safe(plane, plane_temp,
+				 &ddev->mode_config.plane_list, head)
+		drm_plane_cleanup(plane);
+}
+
+static int ltdc_crtc_init(struct drm_device *ddev, struct drm_crtc *crtc)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct drm_plane *primary, *overlay;
+	unsigned int i;
+	int res;
+
+	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY);
+	if (!primary) {
+		DRM_ERROR("Can not create primary plane\n");
+		return -EINVAL;
+	}
+
+	res = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
+					&ltdc_crtc_funcs, NULL);
+	if (res) {
+		DRM_ERROR("Can not initialize CRTC\n");
+		goto cleanup;
+	}
+
+	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);
+
+	DRM_DEBUG_DRIVER("CRTC:%d created\n", crtc->base.id);
+
+	/* Add planes. Note : the first layer is used by primary plane */
+	for (i = 1; i < ldev->caps.nb_layers; i++) {
+		overlay = ltdc_plane_create(ddev, DRM_PLANE_TYPE_OVERLAY);
+		if (!overlay) {
+			res = -ENOMEM;
+			DRM_ERROR("Can not create overlay plane %d\n", i);
+			goto cleanup;
+		}
+	}
+
+	return 0;
+
+cleanup:
+	ltdc_plane_destroy_all(ddev);
+	return res;
+}
+
+/*
+ * DRM_ENCODER
+ */
+
+static void ltdc_rgb_encoder_enable(struct drm_encoder *encoder)
+{
+	struct ltdc_device *ldev = encoder_to_ltdc(encoder);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_panel_prepare(ldev->panel);
+	drm_panel_enable(ldev->panel);
+}
+
+static void ltdc_rgb_encoder_disable(struct drm_encoder *encoder)
+{
+	struct ltdc_device *ldev = encoder_to_ltdc(encoder);
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_panel_disable(ldev->panel);
+	drm_panel_unprepare(ldev->panel);
+}
+
+static const struct drm_encoder_helper_funcs ltdc_rgb_encoder_helper_funcs = {
+	.enable = ltdc_rgb_encoder_enable,
+	.disable = ltdc_rgb_encoder_disable,
+};
+
+static const struct drm_encoder_funcs ltdc_rgb_encoder_funcs = {
+	.destroy = drm_encoder_cleanup,
+};
+
+static struct drm_encoder *ltdc_rgb_encoder_create(struct drm_device *ddev)
+{
+	struct drm_encoder *encoder;
+
+	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
+	if (!encoder)
+		return NULL;
+
+	encoder->possible_crtcs = CRTC_MASK;
+	encoder->possible_clones = 0; /* No cloning support */
+
+	drm_encoder_init(ddev, encoder, &ltdc_rgb_encoder_funcs,
+			 DRM_MODE_ENCODER_DPI, NULL);
+
+	drm_encoder_helper_add(encoder, &ltdc_rgb_encoder_helper_funcs);
+
+	DRM_DEBUG_DRIVER("RGB encoder:%d created\n", encoder->base.id);
+
+	return encoder;
+}
+
+/*
+ * DRM_CONNECTOR
+ */
+
+static int ltdc_rgb_connector_get_modes(struct drm_connector *connector)
+{
+	struct drm_device *ddev = connector->dev;
+	struct ltdc_device *ldev = ddev->dev_private;
+	int ret = 0;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	if (ldev->panel)
+		ret = drm_panel_get_modes(ldev->panel);
+
+	return ret < 0 ? 0 : ret;
+}
+
+static struct drm_connector_helper_funcs ltdc_rgb_connector_helper_funcs = {
+	.get_modes = ltdc_rgb_connector_get_modes,
+};
+
+static enum drm_connector_status
+ltdc_rgb_connector_detect(struct drm_connector *connector, bool force)
+{
+	struct ltdc_device *ldev = connector_to_ltdc(connector);
+
+	return ldev->panel ? connector_status_connected :
+	       connector_status_disconnected;
+}
+
+static void ltdc_rgb_connector_destroy(struct drm_connector *connector)
+{
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_connector_unregister(connector);
+	drm_connector_cleanup(connector);
+}
+
+static const struct drm_connector_funcs ltdc_rgb_connector_funcs = {
+	.dpms = drm_atomic_helper_connector_dpms,
+	.fill_modes = drm_helper_probe_single_connector_modes,
+	.detect = ltdc_rgb_connector_detect,
+	.destroy = ltdc_rgb_connector_destroy,
+	.reset = drm_atomic_helper_connector_reset,
+	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+};
+
+struct drm_connector *ltdc_rgb_connector_create(struct drm_device *ddev)
+{
+	struct drm_connector *connector;
+	int err;
+
+	connector = devm_kzalloc(ddev->dev, sizeof(*connector), GFP_KERNEL);
+	if (!connector) {
+		DRM_ERROR("Failed to allocate connector\n");
+		return NULL;
+	}
+
+	connector->polled = DRM_CONNECTOR_POLL_HPD;
+
+	err = drm_connector_init(ddev, connector, &ltdc_rgb_connector_funcs,
+				 DRM_MODE_CONNECTOR_DPI);
+	if (err) {
+		DRM_ERROR("Failed to initialize connector\n");
+		return NULL;
+	}
+
+	drm_connector_helper_add(connector, &ltdc_rgb_connector_helper_funcs);
+
+	DRM_DEBUG_DRIVER("RGB connector:%d created\n", connector->base.id);
+
+	return connector;
+}
+
+static int ltdc_get_caps(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+	u32 bus_width_log2, lcr, gc2r;
+
+	/* at least 1 layer must be managed */
+	lcr = reg_read(ldev->regs, LTDC_LCR);
+
+	ldev->caps.nb_layers = max_t(int, lcr, 1);
+
+	/* set data bus width */
+	gc2r = reg_read(ldev->regs, LTDC_GC2R);
+	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
+	ldev->caps.bus_width = 8 << bus_width_log2;
+	ldev->caps.hw_version = reg_read(ldev->regs, LTDC_IDR);
+
+	switch (ldev->caps.hw_version) {
+	case HWVER_10200:
+	case HWVER_10300:
+		ldev->caps.reg_ofs = REG_OFS_NONE;
+		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
+		break;
+	case HWVER_20101:
+		ldev->caps.reg_ofs = REG_OFS_4;
+		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static struct drm_panel *ltdc_get_panel(struct drm_device *ddev)
+{
+	struct device *dev = ddev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *entity, *port = NULL;
+	struct drm_panel *panel = NULL;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	/*
+	 * Parse ltdc node to get remote port and find RGB panel / HDMI slave
+	 * If a dsi or a bridge (hdmi, lvds...) is connected to ltdc,
+	 * a remote port & RGB panel will not be found.
+	 */
+	for_each_endpoint_of_node(np, entity) {
+		if (!of_device_is_available(entity))
+			continue;
+
+		port = of_graph_get_remote_port_parent(entity);
+		if (port) {
+			panel = of_drm_find_panel(port);
+			of_node_put(port);
+			if (panel) {
+				DRM_DEBUG_DRIVER("remote panel %s\n",
+						 port->full_name);
+			} else {
+				DRM_DEBUG_DRIVER("panel missing\n");
+				of_node_put(entity);
+			}
+		}
+	}
+
+	return panel;
+}
+
+int ltdc_load(struct drm_device *ddev)
+{
+	struct platform_device *pdev = to_platform_device(ddev->dev);
+	struct ltdc_device *ldev = ddev->dev_private;
+	struct device *dev = ddev->dev;
+	struct device_node *np = dev->of_node;
+	struct drm_encoder *encoder;
+	struct drm_connector *connector = NULL;
+	struct drm_crtc *crtc;
+	struct reset_control *rstc;
+	struct resource res;
+	int irq, ret, i;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	ldev->panel = ltdc_get_panel(ddev);
+	if (!ldev->panel)
+		return -EPROBE_DEFER;
+
+	rstc = of_reset_control_get(np, NULL);
+
+	mutex_init(&ldev->err_lock);
+
+	ldev->pixel_clk = devm_clk_get(dev, "lcd");
+	if (IS_ERR(ldev->pixel_clk)) {
+		DRM_ERROR("Unable to get lcd clock\n");
+		return -ENODEV;
+	}
+
+	if (clk_prepare_enable(ldev->pixel_clk)) {
+		DRM_ERROR("Unable to prepare pixel clock\n");
+		return -ENODEV;
+	}
+
+	if (of_address_to_resource(np, 0, &res)) {
+		DRM_ERROR("Unable to get resource\n");
+		return -ENODEV;
+	}
+
+	ldev->regs = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(ldev->regs)) {
+		DRM_ERROR("Unable to get ltdc registers\n");
+		return PTR_ERR(ldev->regs);
+	}
+
+	for (i = 0; i < MAX_IRQ; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			continue;
+
+		ret = devm_request_threaded_irq(dev, irq, ltdc_irq,
+						ltdc_irq_thread, IRQF_ONESHOT,
+						dev_name(dev), ddev);
+		if (ret) {
+			DRM_ERROR("Failed to register LTDC interrupt\n");
+			return ret;
+		}
+	}
+
+	if (!IS_ERR(rstc))
+		reset_control_deassert(rstc);
+
+	/* Disable interrupts */
+	reg_clear(ldev->regs, LTDC_IER,
+		  IER_LIE | IER_RRIE | IER_FUIE | IER_TERRIE);
+
+	ret = ltdc_get_caps(ddev);
+	if (ret) {
+		DRM_ERROR("hardware identifier (0x%08x) not supported!\n",
+			  ldev->caps.hw_version);
+		return ret;
+	}
+
+	DRM_INFO("ltdc hw version 0x%08x - ready\n", ldev->caps.hw_version);
+
+	if (ldev->panel) {
+		encoder = ltdc_rgb_encoder_create(ddev);
+		if (!encoder) {
+			DRM_ERROR("Failed to create RGB encoder\n");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		connector = ltdc_rgb_connector_create(ddev);
+		if (!connector) {
+			DRM_ERROR("Failed to create RGB connector\n");
+			ret = -EINVAL;
+			goto err;
+		}
+
+		ret = drm_mode_connector_attach_encoder(connector, encoder);
+		if (ret) {
+			DRM_ERROR("Failed to attach connector to encoder\n");
+			goto err;
+		}
+
+		drm_panel_attach(ldev->panel, connector);
+	}
+
+	crtc = devm_kzalloc(dev, sizeof(*crtc), GFP_KERNEL);
+	if (!crtc) {
+		DRM_ERROR("Failed to allocate crtc\n");
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	ret = ltdc_crtc_init(ddev, crtc);
+	if (ret) {
+		DRM_ERROR("Failed to init crtc\n");
+		goto err;
+	}
+
+	ret = drm_vblank_init(ddev, NB_CRTC);
+	if (ret) {
+		DRM_ERROR("Failed calling drm_vblank_init()\n");
+		goto err;
+	}
+
+	/* Allow usage of vblank without having to call drm_irq_install */
+	ddev->irq_enabled = 1;
+
+	return 0;
+err:
+	if (ldev->panel)
+		drm_panel_detach(ldev->panel);
+
+	clk_disable_unprepare(ldev->pixel_clk);
+
+	return ret;
+}
+
+void ltdc_unload(struct drm_device *ddev)
+{
+	struct ltdc_device *ldev = ddev->dev_private;
+
+	DRM_DEBUG_DRIVER("\n");
+
+	drm_vblank_cleanup(ddev);
+
+	if (ldev->panel)
+		drm_panel_detach(ldev->panel);
+
+	clk_disable_unprepare(ldev->pixel_clk);
+}
+
+MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_AUTHOR("Mickael Reulier <mickael.reulier@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics ST DRM LTDC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/stm/ltdc.h b/drivers/gpu/drm/stm/ltdc.h
new file mode 100644
index 000000000000..d7a9c736ac1e
--- /dev/null
+++ b/drivers/gpu/drm/stm/ltdc.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *          Fabien Dessenne <fabien.dessenne@st.com>
+ *          Mickael Reulier <mickael.reulier@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#ifndef _LTDC_H_
+#define _LTDC_H_
+
+struct ltdc_caps {
+	u32 hw_version;		/* hardware version */
+	u32 nb_layers;		/* number of supported layers */
+	u32 reg_ofs;		/* register offset for applicable regs */
+	u32 bus_width;		/* bus width (32 or 64 bits) */
+	const u32 *pix_fmt_hw;	/* supported pixel formats */
+};
+
+struct ltdc_device {
+	struct drm_fbdev_cma *fbdev;
+	void __iomem *regs;
+	struct clk *pixel_clk;	/* lcd pixel clock */
+	struct drm_panel *panel;
+	struct mutex err_lock;	/* protecting error_status */
+	struct ltdc_caps caps;
+	u32 clut[256];		/* color look up table */
+	u32 error_status;
+	u32 irq_status;
+};
+
+int ltdc_crtc_enable_vblank(struct drm_device *dev, unsigned int pipe);
+void ltdc_crtc_disable_vblank(struct drm_device *dev, unsigned int pipe);
+int ltdc_load(struct drm_device *ddev);
+void ltdc_unload(struct drm_device *ddev);
+
+#endif