path: root/drivers/gpu/drm/stm/ltdc.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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>
 */

#include <linux/clk.h>
#include <linux/component.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_graph.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_bridge.h>
#include <drm/drm_device.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_of.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.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
#define HWVER_40100 0x040100

/*
 * The address of some registers depends on the HW version: such registers have
 * an extra offset specified with layer_ofs.
 */
#define LAY_OFS_0	0x80
#define LAY_OFS_1	0x100
#define LAY_OFS	(ldev->caps.layer_ofs)

/* 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 Conf. */
#define LTDC_CPSR	0x0044		/* Current Position Status */
#define LTDC_CDSR	0x0048		/* Current Display Status */
#define LTDC_EDCR	0x0060		/* External Display Control */
#define LTDC_FUT	0x0090		/* Fifo underrun Threshold */

/* Layer register offsets */
#define LTDC_L1C0R	(ldev->caps.layer_regs[0])	/* L1 configuration 0 */
#define LTDC_L1C1R	(ldev->caps.layer_regs[1])	/* L1 configuration 1 */
#define LTDC_L1RCR	(ldev->caps.layer_regs[2])	/* L1 reload control */
#define LTDC_L1CR	(ldev->caps.layer_regs[3])	/* L1 control register */
#define LTDC_L1WHPCR	(ldev->caps.layer_regs[4])	/* L1 window horizontal position configuration */
#define LTDC_L1WVPCR	(ldev->caps.layer_regs[5])	/* L1 window vertical position configuration */
#define LTDC_L1CKCR	(ldev->caps.layer_regs[6])	/* L1 color keying configuration */
#define LTDC_L1PFCR	(ldev->caps.layer_regs[7])	/* L1 pixel format configuration */
#define LTDC_L1CACR	(ldev->caps.layer_regs[8])	/* L1 constant alpha configuration */
#define LTDC_L1DCCR	(ldev->caps.layer_regs[9])	/* L1 default color configuration */
#define LTDC_L1BFCR	(ldev->caps.layer_regs[10])	/* L1 blending factors configuration */
#define LTDC_L1BLCR	(ldev->caps.layer_regs[11])	/* L1 burst length configuration */
#define LTDC_L1PCR	(ldev->caps.layer_regs[12])	/* L1 planar configuration */
#define LTDC_L1CFBAR	(ldev->caps.layer_regs[13])	/* L1 color frame buffer address */
#define LTDC_L1CFBLR	(ldev->caps.layer_regs[14])	/* L1 color frame buffer length */
#define LTDC_L1CFBLNR	(ldev->caps.layer_regs[15])	/* L1 color frame buffer line number */
#define LTDC_L1AFBA0R	(ldev->caps.layer_regs[16])	/* L1 auxiliary frame buffer address 0 */
#define LTDC_L1AFBA1R	(ldev->caps.layer_regs[17])	/* L1 auxiliary frame buffer address 1 */
#define LTDC_L1AFBLR	(ldev->caps.layer_regs[18])	/* L1 auxiliary frame buffer length */
#define LTDC_L1AFBLNR	(ldev->caps.layer_regs[19])	/* L1 auxiliary frame buffer line number */
#define LTDC_L1CLUTWR	(ldev->caps.layer_regs[20])	/* L1 CLUT write */
#define LTDC_L1CYR0R	(ldev->caps.layer_regs[21])	/* L1 Conversion YCbCr RGB 0 */
#define LTDC_L1CYR1R	(ldev->caps.layer_regs[22])	/* L1 Conversion YCbCr RGB 1 */
#define LTDC_L1FPF0R	(ldev->caps.layer_regs[23])	/* L1 Flexible Pixel Format 0 */
#define LTDC_L1FPF1R	(ldev->caps.layer_regs[24])	/* L1 Flexible Pixel Format 1 */

/* 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-Inverted */
#define GCR_DEPOL	BIT(29)		/* Data Enable POLarity-High */
#define GCR_VSPOL	BIT(30)		/* Vertical Synchro POLarity-High */
#define GCR_HSPOL	BIT(31)		/* Horizontal Synchro POLarity-High */

#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 CPSR_CYPOS	GENMASK(15, 0)	/* Current Y position */

#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 EDCR_OCYEN	BIT(25)		/* Output Conversion to YCbCr 422: ENable */
#define EDCR_OCYSEL	BIT(26)		/* Output Conversion to YCbCr 422: SELection of the CCIR */
#define EDCR_OCYCO	BIT(27)		/* Output Conversion to YCbCr 422: Chrominance Order */

#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 PF_FLEXIBLE	0x7		/* Flexible Pixel Format selected */

#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 LXCR_C1R_YIA	BIT(0)		/* Ycbcr 422 Interleaved Ability */
#define LXCR_C1R_YSPA	BIT(1)		/* Ycbcr 420 Semi-Planar Ability */
#define LXCR_C1R_YFPA	BIT(2)		/* Ycbcr 420 Full-Planar Ability */
#define LXCR_C1R_SCA	BIT(31)		/* SCaling Ability*/

#define LxPCR_YREN	BIT(9)		/* Y Rescale Enable for the color dynamic range */
#define LxPCR_OF	BIT(8)		/* Odd pixel First */
#define LxPCR_CBF	BIT(7)		/* CB component First */
#define LxPCR_YF	BIT(6)		/* Y component First */
#define LxPCR_YCM	GENMASK(5, 4)	/* Ycbcr Conversion Mode */
#define YCM_I		0x0		/* Interleaved 422 */
#define YCM_SP		0x1		/* Semi-Planar 420 */
#define YCM_FP		0x2		/* Full-Planar 420 */
#define LxPCR_YCEN	BIT(3)		/* YCbCr-to-RGB Conversion Enable */

#define LXRCR_IMR	BIT(0)		/* IMmediate Reload */
#define LXRCR_VBR	BIT(1)		/* Vertical Blanking Reload */
#define LXRCR_GRMSK	BIT(2)		/* Global (centralized) Reload MaSKed */

#define CLUT_SIZE	256

#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_ABGR8888,		/* ABGR [32 bits] */
	PF_BGRA8888,		/* BGRA [32 bits] */
	PF_RGB888,		/* RGB [24 bits] */
	PF_BGR888,		/* BGR [24 bits] */
	PF_RGB565,		/* RGB [16 bits] */
	PF_BGR565,		/* BGR [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 const enum ltdc_pix_fmt ltdc_pix_fmt_a2[NB_PF] = {
	PF_ARGB8888,		/* 0x00 */
	PF_ABGR8888,		/* 0x01 */
	PF_RGBA8888,		/* 0x02 */
	PF_BGRA8888,		/* 0x03 */
	PF_RGB565,		/* 0x04 */
	PF_BGR565,		/* 0x05 */
	PF_RGB888,		/* 0x06 */
	PF_NONE			/* 0x07 */
};

static const u32 ltdc_drm_fmt_a0[] = {
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_RGB888,
	DRM_FORMAT_RGB565,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_XRGB1555,
	DRM_FORMAT_ARGB4444,
	DRM_FORMAT_XRGB4444,
	DRM_FORMAT_C8
};

static const u32 ltdc_drm_fmt_a1[] = {
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_RGB888,
	DRM_FORMAT_RGB565,
	DRM_FORMAT_RGBA8888,
	DRM_FORMAT_RGBX8888,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_XRGB1555,
	DRM_FORMAT_ARGB4444,
	DRM_FORMAT_XRGB4444,
	DRM_FORMAT_C8
};

static const u32 ltdc_drm_fmt_a2[] = {
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_ABGR8888,
	DRM_FORMAT_XBGR8888,
	DRM_FORMAT_RGBA8888,
	DRM_FORMAT_RGBX8888,
	DRM_FORMAT_BGRA8888,
	DRM_FORMAT_BGRX8888,
	DRM_FORMAT_RGB565,
	DRM_FORMAT_BGR565,
	DRM_FORMAT_RGB888,
	DRM_FORMAT_BGR888,
	DRM_FORMAT_ARGB1555,
	DRM_FORMAT_XRGB1555,
	DRM_FORMAT_ARGB4444,
	DRM_FORMAT_XRGB4444,
	DRM_FORMAT_C8
};

static const u32 ltdc_drm_fmt_ycbcr_cp[] = {
	DRM_FORMAT_YUYV,
	DRM_FORMAT_YVYU,
	DRM_FORMAT_UYVY,
	DRM_FORMAT_VYUY
};

static const u32 ltdc_drm_fmt_ycbcr_sp[] = {
	DRM_FORMAT_NV12,
	DRM_FORMAT_NV21
};

static const u32 ltdc_drm_fmt_ycbcr_fp[] = {
	DRM_FORMAT_YUV420,
	DRM_FORMAT_YVU420
};

/* Layer register offsets */
static const u32 ltdc_layer_regs_a0[] = {
	0x80,	/* L1 configuration 0 */
	0x00,	/* not available */
	0x00,	/* not available */
	0x84,	/* L1 control register */
	0x88,	/* L1 window horizontal position configuration */
	0x8c,	/* L1 window vertical position configuration */
	0x90,	/* L1 color keying configuration */
	0x94,	/* L1 pixel format configuration */
	0x98,	/* L1 constant alpha configuration */
	0x9c,	/* L1 default color configuration */
	0xa0,	/* L1 blending factors configuration */
	0x00,	/* not available */
	0x00,	/* not available */
	0xac,	/* L1 color frame buffer address */
	0xb0,	/* L1 color frame buffer length */
	0xb4,	/* L1 color frame buffer line number */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00,	/* not available */
	0xc4,	/* L1 CLUT write */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00	/* not available */
};

static const u32 ltdc_layer_regs_a1[] = {
	0x80,	/* L1 configuration 0 */
	0x84,	/* L1 configuration 1 */
	0x00,	/* L1 reload control */
	0x88,	/* L1 control register */
	0x8c,	/* L1 window horizontal position configuration */
	0x90,	/* L1 window vertical position configuration */
	0x94,	/* L1 color keying configuration */
	0x98,	/* L1 pixel format configuration */
	0x9c,	/* L1 constant alpha configuration */
	0xa0,	/* L1 default color configuration */
	0xa4,	/* L1 blending factors configuration */
	0xa8,	/* L1 burst length configuration */
	0x00,	/* not available */
	0xac,	/* L1 color frame buffer address */
	0xb0,	/* L1 color frame buffer length */
	0xb4,	/* L1 color frame buffer line number */
	0xb8,	/* L1 auxiliary frame buffer address 0 */
	0xbc,	/* L1 auxiliary frame buffer address 1 */
	0xc0,	/* L1 auxiliary frame buffer length */
	0xc4,	/* L1 auxiliary frame buffer line number */
	0xc8,	/* L1 CLUT write */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00,	/* not available */
	0x00	/* not available */
};

static const u32 ltdc_layer_regs_a2[] = {
	0x100,	/* L1 configuration 0 */
	0x104,	/* L1 configuration 1 */
	0x108,	/* L1 reload control */
	0x10c,	/* L1 control register */
	0x110,	/* L1 window horizontal position configuration */
	0x114,	/* L1 window vertical position configuration */
	0x118,	/* L1 color keying configuration */
	0x11c,	/* L1 pixel format configuration */
	0x120,	/* L1 constant alpha configuration */
	0x124,	/* L1 default color configuration */
	0x128,	/* L1 blending factors configuration */
	0x12c,	/* L1 burst length configuration */
	0x130,	/* L1 planar configuration */
	0x134,	/* L1 color frame buffer address */
	0x138,	/* L1 color frame buffer length */
	0x13c,	/* L1 color frame buffer line number */
	0x140,	/* L1 auxiliary frame buffer address 0 */
	0x144,	/* L1 auxiliary frame buffer address 1 */
	0x148,	/* L1 auxiliary frame buffer length */
	0x14c,	/* L1 auxiliary frame buffer line number */
	0x150,	/* L1 CLUT write */
	0x16c,	/* L1 Conversion YCbCr RGB 0 */
	0x170,	/* L1 Conversion YCbCr RGB 1 */
	0x174,	/* L1 Flexible Pixel Format 0 */
	0x178	/* L1 Flexible Pixel Format 1 */
};

static const u64 ltdc_format_modifiers[] = {
	DRM_FORMAT_MOD_LINEAR,
	DRM_FORMAT_MOD_INVALID
};

static const struct regmap_config stm32_ltdc_regmap_cfg = {
	.reg_bits = 32,
	.val_bits = 32,
	.reg_stride = sizeof(u32),
	.max_register = 0x400,
	.use_relaxed_mmio = true,
	.cache_type = REGCACHE_NONE,
};

static const u32 ltdc_ycbcr2rgb_coeffs[DRM_COLOR_ENCODING_MAX][DRM_COLOR_RANGE_MAX][2] = {
	[DRM_COLOR_YCBCR_BT601][DRM_COLOR_YCBCR_LIMITED_RANGE] = {
		0x02040199,	/* (b_cb = 516 / r_cr = 409) */
		0x006400D0	/* (g_cb = 100 / g_cr = 208) */
	},
	[DRM_COLOR_YCBCR_BT601][DRM_COLOR_YCBCR_FULL_RANGE] = {
		0x01C60167,	/* (b_cb = 454 / r_cr = 359) */
		0x005800B7	/* (g_cb = 88 / g_cr = 183) */
	},
	[DRM_COLOR_YCBCR_BT709][DRM_COLOR_YCBCR_LIMITED_RANGE] = {
		0x021D01CB,	/* (b_cb = 541 / r_cr = 459) */
		0x00370089	/* (g_cb = 55 / g_cr = 137) */
	},
	[DRM_COLOR_YCBCR_BT709][DRM_COLOR_YCBCR_FULL_RANGE] = {
		0x01DB0193,	/* (b_cb = 475 / r_cr = 403) */
		0x00300078	/* (g_cb = 48 / g_cr = 120) */
	}
	/* BT2020 not supported */
};

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 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_ABGR8888:
	case DRM_FORMAT_XBGR8888:
		pf = PF_ABGR8888;
		break;
	case DRM_FORMAT_RGBA8888:
	case DRM_FORMAT_RGBX8888:
		pf = PF_RGBA8888;
		break;
	case DRM_FORMAT_BGRA8888:
	case DRM_FORMAT_BGRX8888:
		pf = PF_BGRA8888;
		break;
	case DRM_FORMAT_RGB888:
		pf = PF_RGB888;
		break;
	case DRM_FORMAT_BGR888:
		pf = PF_BGR888;
		break;
	case DRM_FORMAT_RGB565:
		pf = PF_RGB565;
		break;
	case DRM_FORMAT_BGR565:
		pf = PF_BGR565;
		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 ltdc_set_flexible_pixel_format(struct drm_plane *plane, enum ltdc_pix_fmt pix_fmt)
{
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	u32 lofs = plane->index * LAY_OFS, ret = PF_FLEXIBLE;
	int psize, alen, apos, rlen, rpos, glen, gpos, blen, bpos;

	switch (pix_fmt) {
	case PF_BGR888:
		psize = 3;
		alen = 0; apos = 0; rlen = 8; rpos = 0;
		glen = 8; gpos = 8; blen = 8; bpos = 16;
	break;
	case PF_ARGB1555:
		psize = 2;
		alen = 1; apos = 15; rlen = 5; rpos = 10;
		glen = 5; gpos = 5;  blen = 5; bpos = 0;
	break;
	case PF_ARGB4444:
		psize = 2;
		alen = 4; apos = 12; rlen = 4; rpos = 8;
		glen = 4; gpos = 4; blen = 4; bpos = 0;
	break;
	case PF_L8:
		psize = 1;
		alen = 0; apos = 0; rlen = 8; rpos = 0;
		glen = 8; gpos = 0; blen = 8; bpos = 0;
	break;
	case PF_AL44:
		psize = 1;
		alen = 4; apos = 4; rlen = 4; rpos = 0;
		glen = 4; gpos = 0; blen = 4; bpos = 0;
	break;
	case PF_AL88:
		psize = 2;
		alen = 8; apos = 8; rlen = 8; rpos = 0;
		glen = 8; gpos = 0; blen = 8; bpos = 0;
	break;
	default:
		ret = NB_PF; /* error case, trace msg is handled by the caller */
	break;
	}

	if (ret == PF_FLEXIBLE) {
		regmap_write(ldev->regmap, LTDC_L1FPF0R + lofs,
			     (rlen << 14)  + (rpos << 9) + (alen << 5) + apos);

		regmap_write(ldev->regmap, LTDC_L1FPF1R + lofs,
			     (psize << 18) + (blen << 14)  + (bpos << 9) + (glen << 5) + gpos);
	}

	return ret;
}

/*
 * All non-alpha color formats derived from native alpha color formats are
 * either characterized by a FourCC format code
 */
static inline u32 is_xrgb(u32 drm)
{
	return ((drm & 0xFF) == 'X' || ((drm >> 8) & 0xFF) == 'X');
}

static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt)
{
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	struct drm_plane_state *state = plane->state;
	u32 lofs = plane->index * LAY_OFS;
	u32 val;

	switch (drm_pix_fmt) {
	case DRM_FORMAT_YUYV:
		val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF;
		break;
	case DRM_FORMAT_YVYU:
		val = (YCM_I << 4) | LxPCR_YF;
		break;
	case DRM_FORMAT_UYVY:
		val = (YCM_I << 4) | LxPCR_CBF;
		break;
	case DRM_FORMAT_VYUY:
		val = (YCM_I << 4);
		break;
	case DRM_FORMAT_NV12:
		val = (YCM_SP << 4) | LxPCR_CBF;
		break;
	case DRM_FORMAT_NV21:
		val = (YCM_SP << 4);
		break;
	case DRM_FORMAT_YUV420:
	case DRM_FORMAT_YVU420:
		val = (YCM_FP << 4);
		break;
	default:
		/* RGB or not a YCbCr supported format */
		break;
	}

	/* Enable limited range */
	if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE)
		val |= LxPCR_YREN;

	/* enable ycbcr conversion */
	val |= LxPCR_YCEN;

	regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val);
}

static inline void ltdc_set_ycbcr_coeffs(struct drm_plane *plane)
{
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	struct drm_plane_state *state = plane->state;
	enum drm_color_encoding enc = state->color_encoding;
	enum drm_color_range ran = state->color_range;
	u32 lofs = plane->index * LAY_OFS;

	if (enc != DRM_COLOR_YCBCR_BT601 && enc != DRM_COLOR_YCBCR_BT709) {
		DRM_ERROR("color encoding %d not supported, use bt601 by default\n", enc);
		/* set by default color encoding to DRM_COLOR_YCBCR_BT601 */
		enc = DRM_COLOR_YCBCR_BT601;
	}

	if (ran != DRM_COLOR_YCBCR_LIMITED_RANGE && ran != DRM_COLOR_YCBCR_FULL_RANGE) {
		DRM_ERROR("color range %d not supported, use limited range by default\n", ran);
		/* set by default color range to DRM_COLOR_YCBCR_LIMITED_RANGE */
		ran = DRM_COLOR_YCBCR_LIMITED_RANGE;
	}

	DRM_DEBUG_DRIVER("Color encoding=%d, range=%d\n", enc, ran);
	regmap_write(ldev->regmap, LTDC_L1CYR0R + lofs,
		     ltdc_ycbcr2rgb_coeffs[enc][ran][0]);
	regmap_write(ldev->regmap, LTDC_L1CYR1R + lofs,
		     ltdc_ycbcr2rgb_coeffs[enc][ran][1]);
}

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
	 *  In order to write / read registers in this critical section
	 *  very quickly, the regmap functions are not used.
	 */
	ldev->irq_status = readl_relaxed(ldev->regs + LTDC_ISR);
	writel_relaxed(ldev->irq_status, ldev->regs + LTDC_ICR);

	return IRQ_WAKE_THREAD;
}

/*
 * DRM_CRTC
 */

static void ltdc_crtc_update_clut(struct drm_crtc *crtc)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_color_lut *lut;
	u32 val;
	int i;

	if (!crtc->state->color_mgmt_changed || !crtc->state->gamma_lut)
		return;

	lut = (struct drm_color_lut *)crtc->state->gamma_lut->data;

	for (i = 0; i < CLUT_SIZE; i++, lut++) {
		val = ((lut->red << 8) & 0xff0000) | (lut->green & 0xff00) |
			(lut->blue >> 8) | (i << 24);
		regmap_write(ldev->regmap, LTDC_L1CLUTWR, val);
	}
}

static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
				    struct drm_atomic_state *state)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_device *ddev = crtc->dev;

	DRM_DEBUG_DRIVER("\n");

	pm_runtime_get_sync(ddev->dev);

	/* Sets the background color value */
	regmap_write(ldev->regmap, LTDC_BCCR, BCCR_BCBLACK);

	/* Enable IRQ */
	regmap_set_bits(ldev->regmap, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);

	/* Commit shadow registers = update planes at next vblank */
	if (!ldev->caps.plane_reg_shadow)
		regmap_set_bits(ldev->regmap, LTDC_SRCR, SRCR_VBR);

	drm_crtc_vblank_on(crtc);
}

static void ltdc_crtc_atomic_disable(struct drm_crtc *crtc,
				     struct drm_atomic_state *state)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_device *ddev = crtc->dev;

	DRM_DEBUG_DRIVER("\n");

	drm_crtc_vblank_off(crtc);

	/* disable IRQ */
	regmap_clear_bits(ldev->regmap, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);

	/* immediately commit disable of layers before switching off LTDC */
	if (!ldev->caps.plane_reg_shadow)
		regmap_set_bits(ldev->regmap, LTDC_SRCR, SRCR_IMR);

	pm_runtime_put_sync(ddev->dev);
}

#define CLK_TOLERANCE_HZ 50

static enum drm_mode_status
ltdc_crtc_mode_valid(struct drm_crtc *crtc,
		     const struct drm_display_mode *mode)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	int target = mode->clock * 1000;
	int target_min = target - CLK_TOLERANCE_HZ;
	int target_max = target + CLK_TOLERANCE_HZ;
	int result;

	result = clk_round_rate(ldev->pixel_clk, target);

	DRM_DEBUG_DRIVER("clk rate target %d, available %d\n", target, result);

	/* Filter modes according to the max frequency supported by the pads */
	if (result > ldev->caps.pad_max_freq_hz)
		return MODE_CLOCK_HIGH;

	/*
	 * Accept all "preferred" modes:
	 * - this is important for panels because panel clock tolerances are
	 *   bigger than hdmi ones and there is no reason to not accept them
	 *   (the fps may vary a little but it is not a problem).
	 * - the hdmi preferred mode will be accepted too, but userland will
	 *   be able to use others hdmi "valid" modes if necessary.
	 */
	if (mode->type & DRM_MODE_TYPE_PREFERRED)
		return MODE_OK;

	/*
	 * Filter modes according to the clock value, particularly useful for
	 * hdmi modes that require precise pixel clocks.
	 */
	if (result < target_min || result > target_max)
		return MODE_CLOCK_RANGE;

	return MODE_OK;
}

static bool ltdc_crtc_mode_fixup(struct drm_crtc *crtc,
				 const struct drm_display_mode *mode,
				 struct drm_display_mode *adjusted_mode)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	int rate = mode->clock * 1000;

	if (clk_set_rate(ldev->pixel_clk, rate) < 0) {
		DRM_ERROR("Cannot set rate (%dHz) for pixel clk\n", rate);
		return false;
	}

	adjusted_mode->clock = clk_get_rate(ldev->pixel_clk) / 1000;

	DRM_DEBUG_DRIVER("requested clock %dkHz, adjusted clock %dkHz\n",
			 mode->clock, adjusted_mode->clock);

	return true;
}

static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_device *ddev = crtc->dev;
	struct drm_connector_list_iter iter;
	struct drm_connector *connector = NULL;
	struct drm_encoder *encoder = NULL;
	struct drm_bridge *bridge = NULL;
	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
	u32 hsync, vsync, accum_hbp, accum_vbp, accum_act_w, accum_act_h;
	u32 total_width, total_height;
	u32 bus_formats = MEDIA_BUS_FMT_RGB888_1X24;
	u32 bus_flags = 0;
	u32 val;
	int ret;

	/* get encoder from crtc */
	drm_for_each_encoder(encoder, ddev)
		if (encoder->crtc == crtc)
			break;

	if (encoder) {
		/* get bridge from encoder */
		list_for_each_entry(bridge, &encoder->bridge_chain, chain_node)
			if (bridge->encoder == encoder)
				break;

		/* Get the connector from encoder */
		drm_connector_list_iter_begin(ddev, &iter);
		drm_for_each_connector_iter(connector, &iter)
			if (connector->encoder == encoder)
				break;
		drm_connector_list_iter_end(&iter);
	}

	if (bridge && bridge->timings)
		bus_flags = bridge->timings->input_bus_flags;
	else if (connector) {
		bus_flags = connector->display_info.bus_flags;
		if (connector->display_info.num_bus_formats)
			bus_formats = connector->display_info.bus_formats[0];
	}

	if (!pm_runtime_active(ddev->dev)) {
		ret = pm_runtime_get_sync(ddev->dev);
		if (ret) {
			DRM_ERROR("Failed to set mode, cannot get sync\n");
			return;
		}
	}

	DRM_DEBUG_DRIVER("CRTC:%d mode:%s\n", crtc->base.id, mode->name);
	DRM_DEBUG_DRIVER("Video mode: %dx%d", mode->hdisplay, mode->vdisplay);
	DRM_DEBUG_DRIVER(" hfp %d hbp %d hsl %d vfp %d vbp %d vsl %d\n",
			 mode->hsync_start - mode->hdisplay,
			 mode->htotal - mode->hsync_end,
			 mode->hsync_end - mode->hsync_start,
			 mode->vsync_start - mode->vdisplay,
			 mode->vtotal - mode->vsync_end,
			 mode->vsync_end - mode->vsync_start);

	/* Convert video timings to ltdc timings */
	hsync = mode->hsync_end - mode->hsync_start - 1;
	vsync = mode->vsync_end - mode->vsync_start - 1;
	accum_hbp = mode->htotal - mode->hsync_start - 1;
	accum_vbp = mode->vtotal - mode->vsync_start - 1;
	accum_act_w = accum_hbp + mode->hdisplay;
	accum_act_h = accum_vbp + mode->vdisplay;
	total_width = mode->htotal - 1;
	total_height = mode->vtotal - 1;

	/* Configures the HS, VS, DE and PC polarities. Default Active Low */
	val = 0;

	if (mode->flags & DRM_MODE_FLAG_PHSYNC)
		val |= GCR_HSPOL;

	if (mode->flags & DRM_MODE_FLAG_PVSYNC)
		val |= GCR_VSPOL;

	if (bus_flags & DRM_BUS_FLAG_DE_LOW)
		val |= GCR_DEPOL;

	if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
		val |= GCR_PCPOL;

	regmap_update_bits(ldev->regmap, LTDC_GCR,
			   GCR_HSPOL | GCR_VSPOL | GCR_DEPOL | GCR_PCPOL, val);

	/* Set Synchronization size */
	val = (hsync << 16) | vsync;
	regmap_update_bits(ldev->regmap, LTDC_SSCR, SSCR_VSH | SSCR_HSW, val);

	/* Set Accumulated Back porch */
	val = (accum_hbp << 16) | accum_vbp;
	regmap_update_bits(ldev->regmap, LTDC_BPCR, BPCR_AVBP | BPCR_AHBP, val);

	/* Set Accumulated Active Width */
	val = (accum_act_w << 16) | accum_act_h;
	regmap_update_bits(ldev->regmap, LTDC_AWCR, AWCR_AAW | AWCR_AAH, val);

	/* Set total width & height */
	val = (total_width << 16) | total_height;
	regmap_update_bits(ldev->regmap, LTDC_TWCR, TWCR_TOTALH | TWCR_TOTALW, val);

	regmap_write(ldev->regmap, LTDC_LIPCR, (accum_act_h + 1));

	/* Configure the output format (hw version dependent) */
	if (ldev->caps.ycbcr_output) {
		/* Input video dynamic_range & colorimetry */
		int vic = drm_match_cea_mode(mode);
		u32 val;

		if (vic == 6 || vic == 7 || vic == 21 || vic == 22 ||
		    vic == 2 || vic == 3 || vic == 17 || vic == 18)
			/* ITU-R BT.601 */
			val = 0;
		else
			/* ITU-R BT.709 */
			val = EDCR_OCYSEL;

		switch (bus_formats) {
		case MEDIA_BUS_FMT_YUYV8_1X16:
			/* enable ycbcr output converter */
			regmap_write(ldev->regmap, LTDC_EDCR, EDCR_OCYEN | val);
			break;
		case MEDIA_BUS_FMT_YVYU8_1X16:
			/* enable ycbcr output converter & invert chrominance order */
			regmap_write(ldev->regmap, LTDC_EDCR, EDCR_OCYEN | EDCR_OCYCO | val);
			break;
		default:
			/* disable ycbcr output converter */
			regmap_write(ldev->regmap, LTDC_EDCR, 0);
			break;
		}
	}
}

static void ltdc_crtc_atomic_flush(struct drm_crtc *crtc,
				   struct drm_atomic_state *state)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_device *ddev = crtc->dev;
	struct drm_pending_vblank_event *event = crtc->state->event;

	DRM_DEBUG_ATOMIC("\n");

	ltdc_crtc_update_clut(crtc);

	/* Commit shadow registers = update planes at next vblank */
	if (!ldev->caps.plane_reg_shadow)
		regmap_set_bits(ldev->regmap, LTDC_SRCR, SRCR_VBR);

	if (event) {
		crtc->state->event = NULL;

		spin_lock_irq(&ddev->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(&ddev->event_lock);
	}
}

static bool ltdc_crtc_get_scanout_position(struct drm_crtc *crtc,
					   bool in_vblank_irq,
					   int *vpos, int *hpos,
					   ktime_t *stime, ktime_t *etime,
					   const struct drm_display_mode *mode)
{
	struct drm_device *ddev = crtc->dev;
	struct ltdc_device *ldev = ddev->dev_private;
	int line, vactive_start, vactive_end, vtotal;

	if (stime)
		*stime = ktime_get();

	/* The active area starts after vsync + front porch and ends
	 * at vsync + front porc + display size.
	 * The total height also include back porch.
	 * We have 3 possible cases to handle:
	 * - line < vactive_start: vpos = line - vactive_start and will be
	 * negative
	 * - vactive_start < line < vactive_end: vpos = line - vactive_start
	 * and will be positive
	 * - line > vactive_end: vpos = line - vtotal - vactive_start
	 * and will negative
	 *
	 * Computation for the two first cases are identical so we can
	 * simplify the code and only test if line > vactive_end
	 */
	if (pm_runtime_active(ddev->dev)) {
		regmap_read(ldev->regmap, LTDC_CPSR, &line);
		line &= CPSR_CYPOS;
		regmap_read(ldev->regmap, LTDC_BPCR, &vactive_start);
		vactive_start &= BPCR_AVBP;
		regmap_read(ldev->regmap, LTDC_AWCR, &vactive_end);
		vactive_end &= AWCR_AAH;
		regmap_read(ldev->regmap, LTDC_TWCR, &vtotal);
		vtotal &= TWCR_TOTALH;

		if (line > vactive_end)
			*vpos = line - vtotal - vactive_start;
		else
			*vpos = line - vactive_start;
	} else {
		*vpos = 0;
	}

	*hpos = 0;

	if (etime)
		*etime = ktime_get();

	return true;
}

static const struct drm_crtc_helper_funcs ltdc_crtc_helper_funcs = {
	.mode_valid = ltdc_crtc_mode_valid,
	.mode_fixup = ltdc_crtc_mode_fixup,
	.mode_set_nofb = ltdc_crtc_mode_set_nofb,
	.atomic_flush = ltdc_crtc_atomic_flush,
	.atomic_enable = ltdc_crtc_atomic_enable,
	.atomic_disable = ltdc_crtc_atomic_disable,
	.get_scanout_position = ltdc_crtc_get_scanout_position,
};

static int ltdc_crtc_enable_vblank(struct drm_crtc *crtc)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);
	struct drm_crtc_state *state = crtc->state;

	DRM_DEBUG_DRIVER("\n");

	if (state->enable)
		regmap_set_bits(ldev->regmap, LTDC_IER, IER_LIE);
	else
		return -EPERM;

	return 0;
}

static void ltdc_crtc_disable_vblank(struct drm_crtc *crtc)
{
	struct ltdc_device *ldev = crtc_to_ltdc(crtc);

	DRM_DEBUG_DRIVER("\n");
	regmap_clear_bits(ldev->regmap, LTDC_IER, IER_LIE);
}

static const 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,
	.enable_vblank = ltdc_crtc_enable_vblank,
	.disable_vblank = ltdc_crtc_disable_vblank,
	.get_vblank_timestamp = drm_crtc_vblank_helper_get_vblank_timestamp,
};

/*
 * DRM_PLANE
 */

static int ltdc_plane_atomic_check(struct drm_plane *plane,
				   struct drm_atomic_state *state)
{
	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
										 plane);
	struct drm_framebuffer *fb = new_plane_state->fb;
	u32 src_w, src_h;

	DRM_DEBUG_DRIVER("\n");

	if (!fb)
		return 0;

	/* convert src_ from 16:16 format */
	src_w = new_plane_state->src_w >> 16;
	src_h = new_plane_state->src_h >> 16;

	/* Reject scaling */
	if (src_w != new_plane_state->crtc_w || src_h != new_plane_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_atomic_state *state)
{
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	struct drm_plane_state *newstate = drm_atomic_get_new_plane_state(state,
									  plane);
	struct drm_framebuffer *fb = newstate->fb;
	u32 lofs = plane->index * LAY_OFS;
	u32 x0 = newstate->crtc_x;
	u32 x1 = newstate->crtc_x + newstate->crtc_w - 1;
	u32 y0 = newstate->crtc_y;
	u32 y1 = newstate->crtc_y + newstate->crtc_h - 1;
	u32 src_x, src_y, src_w, src_h;
	u32 val, pitch_in_bytes, line_length, line_number, paddr, ahbp, avbp, bpcr;
	enum ltdc_pix_fmt pf;

	if (!newstate->crtc || !fb) {
		DRM_DEBUG_DRIVER("fb or crtc NULL");
		return;
	}

	/* convert src_ from 16:16 format */
	src_x = newstate->src_x >> 16;
	src_y = newstate->src_y >> 16;
	src_w = newstate->src_w >> 16;
	src_h = newstate->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,
			 newstate->crtc_w, newstate->crtc_h,
			 newstate->crtc_x, newstate->crtc_y);

	regmap_read(ldev->regmap, LTDC_BPCR, &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);
	regmap_write_bits(ldev->regmap, LTDC_L1WHPCR + lofs,
			  LXWHPCR_WHSTPOS | LXWHPCR_WHSPPOS, val);

	/* Configures the vertical start and stop position */
	val = ((y1 + 1 + avbp) << 16) + (y0 + 1 + avbp);
	regmap_write_bits(ldev->regmap, 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;

	/* Use the flexible color format feature if necessary and available */
	if (ldev->caps.pix_fmt_flex && val == NB_PF)
		val = ltdc_set_flexible_pixel_format(plane, pf);

	if (val == NB_PF) {
		DRM_ERROR("Pixel format %.4s not supported\n",
			  (char *)&fb->format->format);
		val = 0;	/* set by default ARGB 32 bits */
	}
	regmap_write_bits(ldev->regmap, LTDC_L1PFCR + lofs, LXPFCR_PF, val);

	/* Configures the color frame buffer pitch in bytes & line length */
	pitch_in_bytes = fb->pitches[0];
	line_length = fb->format->cpp[0] *
		      (x1 - x0 + 1) + (ldev->caps.bus_width >> 3) - 1;
	val = ((pitch_in_bytes << 16) | line_length);
	regmap_write_bits(ldev->regmap, LTDC_L1CFBLR + lofs, LXCFBLR_CFBLL | LXCFBLR_CFBP, val);

	/* Specifies the constant alpha value */
	val = newstate->alpha >> 8;
	regmap_write_bits(ldev->regmap, LTDC_L1CACR + lofs, LXCACR_CONSTA, val);

	/* Specifies the blending factors */
	val = BF1_PAXCA | BF2_1PAXCA;
	if (!fb->format->has_alpha)
		val = BF1_CA | BF2_1CA;

	/* Manage hw-specific capabilities */
	if (ldev->caps.non_alpha_only_l1 &&
	    plane->type != DRM_PLANE_TYPE_PRIMARY)
		val = BF1_PAXCA | BF2_1PAXCA;

	regmap_write_bits(ldev->regmap, LTDC_L1BFCR + lofs, LXBFCR_BF2 | LXBFCR_BF1, val);

	/* Configures the frame buffer line number */
	line_number = y1 - y0 + 1;
	regmap_write_bits(ldev->regmap, LTDC_L1CFBLNR + lofs, LXCFBLNR_CFBLN, line_number);

	/* Sets the FB address */
	paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 0);

	DRM_DEBUG_DRIVER("fb: phys 0x%08x", paddr);
	regmap_write(ldev->regmap, LTDC_L1CFBAR + lofs, paddr);

	if (ldev->caps.ycbcr_input) {
		if (fb->format->is_yuv) {
			switch (fb->format->format) {
			case DRM_FORMAT_NV12:
			case DRM_FORMAT_NV21:
			/* Configure the auxiliary frame buffer address 0 & 1 */
			paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
			regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);
			regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr + 1);

			/* Configure the buffer length */
			val = ((pitch_in_bytes << 16) | line_length);
			regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);

			/* Configure the frame buffer line number */
			val = (line_number >> 1);
			regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
			break;
			case DRM_FORMAT_YUV420:
			/* Configure the auxiliary frame buffer address 0 */
			paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
			regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);

			/* Configure the auxiliary frame buffer address 1 */
			paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 2);
			regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr);

			line_length = ((fb->format->cpp[0] * (x1 - x0 + 1)) >> 1) +
				      (ldev->caps.bus_width >> 3) - 1;

			/* Configure the buffer length */
			val = (((pitch_in_bytes >> 1) << 16) | line_length);
			regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);

			/* Configure the frame buffer line number */
			val = (line_number >> 1);
			regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
			break;
			case DRM_FORMAT_YVU420:
			/* Configure the auxiliary frame buffer address 0 */
			paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 2);
			regmap_write(ldev->regmap, LTDC_L1AFBA0R + lofs, paddr);

			/* Configure the auxiliary frame buffer address 1 */
			paddr = (u32)drm_fb_cma_get_gem_addr(fb, newstate, 1);
			regmap_write(ldev->regmap, LTDC_L1AFBA1R + lofs, paddr);

			line_length = ((fb->format->cpp[0] * (x1 - x0 + 1)) >> 1) +
				      (ldev->caps.bus_width >> 3) - 1;

			/* Configure the buffer length */
			val = (((pitch_in_bytes >> 1) << 16) | line_length);
			regmap_write(ldev->regmap, LTDC_L1AFBLR + lofs, val);

			/* Configure the frame buffer line number */
			val = (line_number >> 1);
			regmap_write(ldev->regmap, LTDC_L1AFBLNR + lofs, val);
			break;
			}

			/* Configure YCbC conversion coefficient */
			ltdc_set_ycbcr_coeffs(plane);

			/* Configure YCbCr format and enable/disable conversion */
			ltdc_set_ycbcr_config(plane, fb->format->format);
		} else {
			/* disable ycbcr conversion */
			regmap_write(ldev->regmap, LTDC_L1PCR + lofs, 0);
		}
	}

	/* Enable layer and CLUT if needed */
	val = fb->format->format == DRM_FORMAT_C8 ? LXCR_CLUTEN : 0;
	val |= LXCR_LEN;
	regmap_write_bits(ldev->regmap, LTDC_L1CR + lofs, LXCR_LEN | LXCR_CLUTEN, val);

	/* Commit shadow registers = update plane at next vblank */
	if (ldev->caps.plane_reg_shadow)
		regmap_write_bits(ldev->regmap, LTDC_L1RCR + lofs,
				  LXRCR_IMR | LXRCR_VBR | LXRCR_GRMSK, LXRCR_VBR);

	ldev->plane_fpsi[plane->index].counter++;

	mutex_lock(&ldev->err_lock);
	if (ldev->error_status & ISR_FUIF) {
		DRM_WARN("ltdc fifo underrun: please verify display mode\n");
		ldev->error_status &= ~ISR_FUIF;
	}
	if (ldev->error_status & ISR_TERRIF) {
		DRM_WARN("ltdc 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_atomic_state *state)
{
	struct drm_plane_state *oldstate = drm_atomic_get_old_plane_state(state,
									  plane);
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	u32 lofs = plane->index * LAY_OFS;

	/* disable layer */
	regmap_write_bits(ldev->regmap, LTDC_L1CR + lofs, LXCR_LEN, 0);

	/* Commit shadow registers = update plane at next vblank */
	if (ldev->caps.plane_reg_shadow)
		regmap_write_bits(ldev->regmap, LTDC_L1RCR + lofs,
				  LXRCR_IMR | LXRCR_VBR | LXRCR_GRMSK, LXRCR_VBR);

	DRM_DEBUG_DRIVER("CRTC:%d plane:%d\n",
			 oldstate->crtc->base.id, plane->base.id);
}

static void ltdc_plane_atomic_print_state(struct drm_printer *p,
					  const struct drm_plane_state *state)
{
	struct drm_plane *plane = state->plane;
	struct ltdc_device *ldev = plane_to_ltdc(plane);
	struct fps_info *fpsi = &ldev->plane_fpsi[plane->index];
	int ms_since_last;
	ktime_t now;

	now = ktime_get();
	ms_since_last = ktime_to_ms(ktime_sub(now, fpsi->last_timestamp));

	drm_printf(p, "\tuser_updates=%dfps\n",
		   DIV_ROUND_CLOSEST(fpsi->counter * 1000, ms_since_last));

	fpsi->last_timestamp = now;
	fpsi->counter = 0;
}

static const 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,
	.reset = drm_atomic_helper_plane_reset,
	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
	.atomic_print_state = ltdc_plane_atomic_print_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,
					   int index)
{
	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;
	u32 drm_fmt;
	const u64 *modifiers = ltdc_format_modifiers;
	u32 lofs = index * LAY_OFS;
	u32 val;
	int ret;

	/* Allocate the biggest size according to supported color formats */
	formats = devm_kzalloc(dev, (ldev->caps.pix_fmt_nb +
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp) +
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp) +
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp)) *
			       sizeof(*formats), GFP_KERNEL);

	for (i = 0; i < ldev->caps.pix_fmt_nb; i++) {
		drm_fmt = ldev->caps.pix_fmt_drm[i];

		/* Manage hw-specific capabilities */
		if (ldev->caps.non_alpha_only_l1)
			/* XR24 & RX24 like formats supported only on primary layer */
			if (type != DRM_PLANE_TYPE_PRIMARY && is_xrgb(drm_fmt))
				continue;

		formats[nb_fmt++] = drm_fmt;
	}

	/* Add YCbCr supported pixel formats */
	if (ldev->caps.ycbcr_input) {
		regmap_read(ldev->regmap, LTDC_L1C1R + lofs, &val);
		if (val & LXCR_C1R_YIA) {
			memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_cp,
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp) * sizeof(*formats));
			nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_cp);
		}
		if (val & LXCR_C1R_YSPA) {
			memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_sp,
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp) * sizeof(*formats));
			nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_sp);
		}
		if (val & LXCR_C1R_YFPA) {
			memcpy(&formats[nb_fmt], ltdc_drm_fmt_ycbcr_fp,
			       ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp) * sizeof(*formats));
			nb_fmt += ARRAY_SIZE(ltdc_drm_fmt_ycbcr_fp);
		}
	}

	plane = devm_kzalloc(dev, sizeof(*plane), GFP_KERNEL);
	if (!plane)
		return NULL;

	ret = drm_universal_plane_init(ddev, plane, possible_crtcs,
				       &ltdc_plane_funcs, formats, nb_fmt,
				       modifiers, type, NULL);
	if (ret < 0)
		return NULL;

	if (ldev->caps.ycbcr_input) {
		if (val & (LXCR_C1R_YIA | LXCR_C1R_YSPA | LXCR_C1R_YFPA))
			drm_plane_create_color_properties(plane,
							  BIT(DRM_COLOR_YCBCR_BT601) |
							  BIT(DRM_COLOR_YCBCR_BT709),
							  BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
							  BIT(DRM_COLOR_YCBCR_FULL_RANGE),
							  DRM_COLOR_YCBCR_BT601,
							  DRM_COLOR_YCBCR_LIMITED_RANGE);
	}

	drm_plane_helper_add(plane, &ltdc_plane_helper_funcs);

	drm_plane_create_alpha_property(plane);

	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 ret;

	primary = ltdc_plane_create(ddev, DRM_PLANE_TYPE_PRIMARY, 0);
	if (!primary) {
		DRM_ERROR("Can not create primary plane\n");
		return -EINVAL;
	}

	drm_plane_create_zpos_immutable_property(primary, 0);

	ret = drm_crtc_init_with_planes(ddev, crtc, primary, NULL,
					&ltdc_crtc_funcs, NULL);
	if (ret) {
		DRM_ERROR("Can not initialize CRTC\n");
		goto cleanup;
	}

	drm_crtc_helper_add(crtc, &ltdc_crtc_helper_funcs);

	drm_mode_crtc_set_gamma_size(crtc, CLUT_SIZE);
	drm_crtc_enable_color_mgmt(crtc, 0, false, CLUT_SIZE);

	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, i);
		if (!overlay) {
			ret = -ENOMEM;
			DRM_ERROR("Can not create overlay plane %d\n", i);
			goto cleanup;
		}
		drm_plane_create_zpos_immutable_property(overlay, i);
	}

	return 0;

cleanup:
	ltdc_plane_destroy_all(ddev);
	return ret;
}

static void ltdc_encoder_disable(struct drm_encoder *encoder)
{
	struct drm_device *ddev = encoder->dev;
	struct ltdc_device *ldev = ddev->dev_private;

	DRM_DEBUG_DRIVER("\n");

	/* Disable LTDC */
	regmap_clear_bits(ldev->regmap, LTDC_GCR, GCR_LTDCEN);

	/* Set to sleep state the pinctrl whatever type of encoder */
	pinctrl_pm_select_sleep_state(ddev->dev);
}

static void ltdc_encoder_enable(struct drm_encoder *encoder)
{
	struct drm_device *ddev = encoder->dev;
	struct ltdc_device *ldev = ddev->dev_private;

	DRM_DEBUG_DRIVER("\n");

	/* Enable LTDC */
	regmap_set_bits(ldev->regmap, LTDC_GCR, GCR_LTDCEN);
}

static void ltdc_encoder_mode_set(struct drm_encoder *encoder,
				  struct drm_display_mode *mode,
				  struct drm_display_mode *adjusted_mode)
{
	struct drm_device *ddev = encoder->dev;

	DRM_DEBUG_DRIVER("\n");

	/*
	 * Set to default state the pinctrl only with DPI type.
	 * Others types like DSI, don't need pinctrl due to
	 * internal bridge (the signals do not come out of the chipset).
	 */
	if (encoder->encoder_type == DRM_MODE_ENCODER_DPI)
		pinctrl_pm_select_default_state(ddev->dev);
}

static const struct drm_encoder_helper_funcs ltdc_encoder_helper_funcs = {
	.disable = ltdc_encoder_disable,
	.enable = ltdc_encoder_enable,
	.mode_set = ltdc_encoder_mode_set,
};

static int ltdc_encoder_init(struct drm_device *ddev, struct drm_bridge *bridge)
{
	struct drm_encoder *encoder;
	int ret;

	encoder = devm_kzalloc(ddev->dev, sizeof(*encoder), GFP_KERNEL);
	if (!encoder)
		return -ENOMEM;

	encoder->possible_crtcs = CRTC_MASK;
	encoder->possible_clones = 0;	/* No cloning support */

	drm_simple_encoder_init(ddev, encoder, DRM_MODE_ENCODER_DPI);

	drm_encoder_helper_add(encoder, &ltdc_encoder_helper_funcs);

	ret = drm_bridge_attach(encoder, bridge, NULL, 0);
	if (ret) {
		if (ret != -EPROBE_DEFER)
			drm_encoder_cleanup(encoder);
		return ret;
	}

	DRM_DEBUG_DRIVER("Bridge encoder:%d created\n", encoder->base.id);

	return 0;
}

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 & the number of layers
	 * must not exceed LTDC_MAX_LAYER
	 */
	regmap_read(ldev->regmap, LTDC_LCR, &lcr);

	ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);

	/* set data bus width */
	regmap_read(ldev->regmap, LTDC_GC2R, &gc2r);
	bus_width_log2 = (gc2r & GC2R_BW) >> 4;
	ldev->caps.bus_width = 8 << bus_width_log2;
	regmap_read(ldev->regmap, LTDC_IDR, &ldev->caps.hw_version);

	switch (ldev->caps.hw_version) {
	case HWVER_10200:
	case HWVER_10300:
		ldev->caps.layer_ofs = LAY_OFS_0;
		ldev->caps.layer_regs = ltdc_layer_regs_a0;
		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a0;
		ldev->caps.pix_fmt_drm = ltdc_drm_fmt_a0;
		ldev->caps.pix_fmt_nb = ARRAY_SIZE(ltdc_drm_fmt_a0);
		ldev->caps.pix_fmt_flex = false;
		/*
		 * Hw older versions support non-alpha color formats derived
		 * from native alpha color formats only on the primary layer.
		 * For instance, RG16 native format without alpha works fine
		 * on 2nd layer but XR24 (derived color format from AR24)
		 * does not work on 2nd layer.
		 */
		ldev->caps.non_alpha_only_l1 = true;
		ldev->caps.pad_max_freq_hz = 90000000;
		if (ldev->caps.hw_version == HWVER_10200)
			ldev->caps.pad_max_freq_hz = 65000000;
		ldev->caps.nb_irq = 2;
		ldev->caps.ycbcr_input = false;
		ldev->caps.ycbcr_output = false;
		ldev->caps.plane_reg_shadow = false;
		break;
	case HWVER_20101:
		ldev->caps.layer_ofs = LAY_OFS_0;
		ldev->caps.layer_regs = ltdc_layer_regs_a1;
		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a1;
		ldev->caps.pix_fmt_drm = ltdc_drm_fmt_a1;
		ldev->caps.pix_fmt_nb = ARRAY_SIZE(ltdc_drm_fmt_a1);
		ldev->caps.pix_fmt_flex = false;
		ldev->caps.non_alpha_only_l1 = false;
		ldev->caps.pad_max_freq_hz = 150000000;
		ldev->caps.nb_irq = 4;
		ldev->caps.ycbcr_input = false;
		ldev->caps.ycbcr_output = false;
		ldev->caps.plane_reg_shadow = false;
		break;
	case HWVER_40100:
		ldev->caps.layer_ofs = LAY_OFS_1;
		ldev->caps.layer_regs = ltdc_layer_regs_a2;
		ldev->caps.pix_fmt_hw = ltdc_pix_fmt_a2;
		ldev->caps.pix_fmt_drm = ltdc_drm_fmt_a2;
		ldev->caps.pix_fmt_nb = ARRAY_SIZE(ltdc_drm_fmt_a2);
		ldev->caps.pix_fmt_flex = true;
		ldev->caps.non_alpha_only_l1 = false;
		ldev->caps.pad_max_freq_hz = 90000000;
		ldev->caps.nb_irq = 2;
		ldev->caps.ycbcr_input = true;
		ldev->caps.ycbcr_output = true;
		ldev->caps.plane_reg_shadow = true;
		break;
	default:
		return -ENODEV;
	}

	return 0;
}

void ltdc_suspend(struct drm_device *ddev)
{
	struct ltdc_device *ldev = ddev->dev_private;

	DRM_DEBUG_DRIVER("\n");
	clk_disable_unprepare(ldev->pixel_clk);
}

int ltdc_resume(struct drm_device *ddev)
{
	struct ltdc_device *ldev = ddev->dev_private;
	int ret;

	DRM_DEBUG_DRIVER("\n");

	ret = clk_prepare_enable(ldev->pixel_clk);
	if (ret) {
		DRM_ERROR("failed to enable pixel clock (%d)\n", ret);
		return ret;
	}

	return 0;
}

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_bridge *bridge;
	struct drm_panel *panel;
	struct drm_crtc *crtc;
	struct reset_control *rstc;
	struct resource *res;
	int irq, i, nb_endpoints;
	int ret = -ENODEV;

	DRM_DEBUG_DRIVER("\n");

	/* Get number of endpoints */
	nb_endpoints = of_graph_get_endpoint_count(np);
	if (!nb_endpoints)
		return -ENODEV;

	ldev->pixel_clk = devm_clk_get(dev, "lcd");
	if (IS_ERR(ldev->pixel_clk)) {
		if (PTR_ERR(ldev->pixel_clk) != -EPROBE_DEFER)
			DRM_ERROR("Unable to get lcd clock\n");
		return PTR_ERR(ldev->pixel_clk);
	}

	if (clk_prepare_enable(ldev->pixel_clk)) {
		DRM_ERROR("Unable to prepare pixel clock\n");
		return -ENODEV;
	}

	/* Get endpoints if any */
	for (i = 0; i < nb_endpoints; i++) {
		ret = drm_of_find_panel_or_bridge(np, 0, i, &panel, &bridge);

		/*
		 * If at least one endpoint is -ENODEV, continue probing,
		 * else if at least one endpoint returned an error
		 * (ie -EPROBE_DEFER) then stop probing.
		 */
		if (ret == -ENODEV)
			continue;
		else if (ret)
			goto err;

		if (panel) {
			bridge = drm_panel_bridge_add_typed(panel,
							    DRM_MODE_CONNECTOR_DPI);
			if (IS_ERR(bridge)) {
				DRM_ERROR("panel-bridge endpoint %d\n", i);
				ret = PTR_ERR(bridge);
				goto err;
			}
		}

		if (bridge) {
			ret = ltdc_encoder_init(ddev, bridge);
			if (ret) {
				if (ret != -EPROBE_DEFER)
					DRM_ERROR("init encoder endpoint %d\n", i);
				goto err;
			}
		}
	}

	rstc = devm_reset_control_get_exclusive(dev, NULL);

	mutex_init(&ldev->err_lock);

	if (!IS_ERR(rstc)) {
		reset_control_assert(rstc);
		usleep_range(10, 20);
		reset_control_deassert(rstc);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ldev->regs = devm_ioremap_resource(dev, res);
	if (IS_ERR(ldev->regs)) {
		DRM_ERROR("Unable to get ltdc registers\n");
		ret = PTR_ERR(ldev->regs);
		goto err;
	}

	ldev->regmap = devm_regmap_init_mmio(&pdev->dev, ldev->regs, &stm32_ltdc_regmap_cfg);
	if (IS_ERR(ldev->regmap)) {
		DRM_ERROR("Unable to regmap ltdc registers\n");
		ret = PTR_ERR(ldev->regmap);
		goto err;
	}

	/* Disable interrupts */
	regmap_clear_bits(ldev->regmap, 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);
		goto err;
	}

	DRM_DEBUG_DRIVER("ltdc hw version 0x%08x\n", ldev->caps.hw_version);

	for (i = 0; i < ldev->caps.nb_irq; i++) {
		irq = platform_get_irq(pdev, i);
		if (irq < 0) {
			ret = irq;
			goto err;
		}

		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");
			goto err;
		}

	}

	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;
	}

	clk_disable_unprepare(ldev->pixel_clk);

	pinctrl_pm_select_sleep_state(ddev->dev);

	pm_runtime_enable(ddev->dev);

	return 0;
err:
	for (i = 0; i < nb_endpoints; i++)
		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);

	clk_disable_unprepare(ldev->pixel_clk);

	return ret;
}

void ltdc_unload(struct drm_device *ddev)
{
	struct device *dev = ddev->dev;
	int nb_endpoints, i;

	DRM_DEBUG_DRIVER("\n");

	nb_endpoints = of_graph_get_endpoint_count(dev->of_node);

	for (i = 0; i < nb_endpoints; i++)
		drm_of_panel_bridge_remove(ddev->dev->of_node, 0, i);

	pm_runtime_disable(ddev->dev);
}

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");