drivers/gpu/drm/mxsfb/mxsfb_crtc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (C) 2016 Marek Vasut <marex@denx.de>
  *
  * This code is based on drivers/video/fbdev/mxsfb.c :
  * Copyright (C) 2010 Juergen Beisert, Pengutronix
  * Copyright (C) 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
  * Copyright (C) 2008 Embedded Alley Solutions, Inc All Rights Reserved.
  */

 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_fb_cma_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 <linux/clk.h>
 #include <linux/iopoll.h>
 #include <linux/of_graph.h>
 #include <linux/platform_data/simplefb.h>
 #include <video/videomode.h>

 #include "mxsfb_drv.h"
 #include "mxsfb_regs.h"

 #define MXS_SET_ADDR		0x4
 #define MXS_CLR_ADDR		0x8
 #define MODULE_CLKGATE		BIT(30)
 #define MODULE_SFTRST		BIT(31)
 /* 1 second delay should be plenty of time for block reset */
 #define RESET_TIMEOUT		1000000

 static u32 set_hsync_pulse_width(struct mxsfb_drm_private *mxsfb, u32 val)
 {
 	return (val & mxsfb->devdata->hs_wdth_mask) <<
 		mxsfb->devdata->hs_wdth_shift;
 }

 /* Setup the MXSFB registers for decoding the pixels out of the framebuffer */
 static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
 	struct drm_device *drm = crtc->dev;
 	const u32 format = crtc->primary->state->fb->format->format;
 	u32 ctrl, ctrl1;

 	ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER;

 	/*
 	 * WARNING: The bus width, CTRL_SET_BUS_WIDTH(), is configured to
 	 * match the selected mode here. This differs from the original
 	 * MXSFB driver, which had the option to configure the bus width
 	 * to arbitrary value. This limitation should not pose an issue.
 	 */

 	/* CTRL1 contains IRQ config and status bits, preserve those. */
 	ctrl1 = readl(mxsfb->base + LCDC_CTRL1);
 	ctrl1 &= CTRL1_CUR_FRAME_DONE_IRQ_EN | CTRL1_CUR_FRAME_DONE_IRQ;

 	switch (format) {
 	case DRM_FORMAT_RGB565:
 		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
 		ctrl |= CTRL_SET_WORD_LENGTH(0);
 		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0xf);
 		break;
 	case DRM_FORMAT_XRGB8888:
 		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
 		ctrl |= CTRL_SET_WORD_LENGTH(3);
 		/* Do not use packed pixels = one pixel per word instead. */
 		ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0x7);
 		break;
 	default:
 		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
 		return -EINVAL;
 	}

 	writel(ctrl1, mxsfb->base + LCDC_CTRL1);
 	writel(ctrl, mxsfb->base + LCDC_CTRL);

 	return 0;
 }

 static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
 	struct drm_device *drm = crtc->dev;
 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
 	u32 reg;

 	reg = readl(mxsfb->base + LCDC_CTRL);

 	if (mxsfb->connector.display_info.num_bus_formats)
 		bus_format = mxsfb->connector.display_info.bus_formats[0];

 	reg &= ~CTRL_BUS_WIDTH_MASK;
 	switch (bus_format) {
 	case MEDIA_BUS_FMT_RGB565_1X16:
 		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_16BIT);
 		break;
 	case MEDIA_BUS_FMT_RGB666_1X18:
 		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_18BIT);
 		break;
 	case MEDIA_BUS_FMT_RGB888_1X24:
 		reg |= CTRL_SET_BUS_WIDTH(STMLCDIF_24BIT);
 		break;
 	default:
 		dev_err(drm->dev, "Unknown media bus format %d\n", bus_format);
 		break;
 	}
 	writel(reg, mxsfb->base + LCDC_CTRL);
 }

 static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
 {
 	u32 reg;

 	if (mxsfb->clk_disp_axi)
 		clk_prepare_enable(mxsfb->clk_disp_axi);
 	clk_prepare_enable(mxsfb->clk);

 	/* If it was disabled, re-enable the mode again */
 	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);

 	/* Enable the SYNC signals first, then the DMA engine */
 	reg = readl(mxsfb->base + LCDC_VDCTRL4);
 	reg |= VDCTRL4_SYNC_SIGNALS_ON;
 	writel(reg, mxsfb->base + LCDC_VDCTRL4);

 	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
 }

 static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
 {
 	u32 reg;

 	/*
 	 * Even if we disable the controller here, it will still continue
 	 * until its FIFOs are running out of data
 	 */
 	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_CLR);

 	readl_poll_timeout(mxsfb->base + LCDC_CTRL, reg, !(reg & CTRL_RUN),
 			   0, 1000);

 	reg = readl(mxsfb->base + LCDC_VDCTRL4);
 	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
 	writel(reg, mxsfb->base + LCDC_VDCTRL4);

 	clk_disable_unprepare(mxsfb->clk);
 	if (mxsfb->clk_disp_axi)
 		clk_disable_unprepare(mxsfb->clk_disp_axi);
 }

 /*
  * Clear the bit and poll it cleared.  This is usually called with
  * a reset address and mask being either SFTRST(bit 31) or CLKGATE
  * (bit 30).
  */
 static int clear_poll_bit(void __iomem *addr, u32 mask)
 {
 	u32 reg;

 	writel(mask, addr + MXS_CLR_ADDR);
 	return readl_poll_timeout(addr, reg, !(reg & mask), 0, RESET_TIMEOUT);
 }

 static int mxsfb_reset_block(void __iomem *reset_addr)
 {
 	int ret;

 	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
 	if (ret)
 		return ret;

 	writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR);

 	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
 	if (ret)
 		return ret;

 	return clear_poll_bit(reset_addr, MODULE_CLKGATE);
 }

 static dma_addr_t mxsfb_get_fb_paddr(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_framebuffer *fb = mxsfb->pipe.plane.state->fb;
 	struct drm_gem_cma_object *gem;

 	if (!fb)
 		return 0;

 	gem = drm_fb_cma_get_gem_obj(fb, 0);
 	if (!gem)
 		return 0;

 	return gem->paddr;
 }

 static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
 {
 	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
 	const u32 bus_flags = mxsfb->connector.display_info.bus_flags;
 	u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
 	int err;

 	/*
 	 * It seems, you can't re-program the controller if it is still
 	 * running. This may lead to shifted pictures (FIFO issue?), so
 	 * first stop the controller and drain its FIFOs.
 	 */

 	/* Mandatory eLCDIF reset as per the Reference Manual */
 	err = mxsfb_reset_block(mxsfb->base);
 	if (err)
 		return;

 	/* Clear the FIFOs */
 	writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET);

 	err = mxsfb_set_pixel_fmt(mxsfb);
 	if (err)
 		return;

 	clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);

 	writel(TRANSFER_COUNT_SET_VCOUNT(m->crtc_vdisplay) |
 	       TRANSFER_COUNT_SET_HCOUNT(m->crtc_hdisplay),
 	       mxsfb->base + mxsfb->devdata->transfer_count);

 	vsync_pulse_len = m->crtc_vsync_end - m->crtc_vsync_start;

 	vdctrl0 = VDCTRL0_ENABLE_PRESENT |	/* Always in DOTCLOCK mode */
 		  VDCTRL0_VSYNC_PERIOD_UNIT |
 		  VDCTRL0_VSYNC_PULSE_WIDTH_UNIT |
 		  VDCTRL0_SET_VSYNC_PULSE_WIDTH(vsync_pulse_len);
 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
 		vdctrl0 |= VDCTRL0_HSYNC_ACT_HIGH;
 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
 		vdctrl0 |= VDCTRL0_VSYNC_ACT_HIGH;
 	/* Make sure Data Enable is high active by default */
 	if (!(bus_flags & DRM_BUS_FLAG_DE_LOW))
 		vdctrl0 |= VDCTRL0_ENABLE_ACT_HIGH;
 	/*
 	 * DRM_BUS_FLAG_PIXDATA_DRIVE_ defines are controller centric,
 	 * controllers VDCTRL0_DOTCLK is display centric.
 	 * Drive on positive edge       -> display samples on falling edge
 	 * DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE -> VDCTRL0_DOTCLK_ACT_FALLING
 	 */
 	if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE)
 		vdctrl0 |= VDCTRL0_DOTCLK_ACT_FALLING;

 	writel(vdctrl0, mxsfb->base + LCDC_VDCTRL0);

 	mxsfb_set_bus_fmt(mxsfb);

 	/* Frame length in lines. */
 	writel(m->crtc_vtotal, mxsfb->base + LCDC_VDCTRL1);

 	/* Line length in units of clocks or pixels. */
 	hsync_pulse_len = m->crtc_hsync_end - m->crtc_hsync_start;
 	writel(set_hsync_pulse_width(mxsfb, hsync_pulse_len) |
 	       VDCTRL2_SET_HSYNC_PERIOD(m->crtc_htotal),
 	       mxsfb->base + LCDC_VDCTRL2);

 	writel(SET_HOR_WAIT_CNT(m->crtc_htotal - m->crtc_hsync_start) |
 	       SET_VERT_WAIT_CNT(m->crtc_vtotal - m->crtc_vsync_start),
 	       mxsfb->base + LCDC_VDCTRL3);

 	writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay),
 	       mxsfb->base + LCDC_VDCTRL4);
 }

 void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
 {
 	dma_addr_t paddr;

 	mxsfb_enable_axi_clk(mxsfb);
 	mxsfb_crtc_mode_set_nofb(mxsfb);

 	/* Write cur_buf as well to avoid an initial corrupt frame */
 	paddr = mxsfb_get_fb_paddr(mxsfb);
 	if (paddr) {
 		writel(paddr, mxsfb->base + mxsfb->devdata->cur_buf);
 		writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
 	}

 	mxsfb_enable_controller(mxsfb);
 }

 void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb)
 {
 	mxsfb_disable_controller(mxsfb);
 	mxsfb_disable_axi_clk(mxsfb);
 }

 void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
 			       struct drm_plane_state *state)
 {
 	struct drm_simple_display_pipe *pipe = &mxsfb->pipe;
 	struct drm_crtc *crtc = &pipe->crtc;
 	struct drm_pending_vblank_event *event;
 	dma_addr_t paddr;

 	spin_lock_irq(&crtc->dev->event_lock);
 	event = crtc->state->event;
 	if (event) {
 		crtc->state->event = NULL;

 		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);

 	paddr = mxsfb_get_fb_paddr(mxsfb);
 	if (paddr) {
 		mxsfb_enable_axi_clk(mxsfb);
 		writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
 		mxsfb_disable_axi_clk(mxsfb);
 	}
 }
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (C) 2016 Marek Vasut <marex@denx.de>
	*
	* This code is based on drivers/video/fbdev/mxsfb.c :
	* Copyright (C) 2010 Juergen Beisert, Pengutronix
	* Copyright (C) 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
	* Copyright (C) 2008 Embedded Alley Solutions, Inc All Rights Reserved.
	*/

	#include <drm/drmP.h>
	#include <drm/drm_atomic_helper.h>
	#include <drm/drm_crtc.h>
	#include <drm/drm_fb_helper.h>
	#include <drm/drm_fb_cma_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 <linux/clk.h>
	#include <linux/iopoll.h>
	#include <linux/of_graph.h>
	#include <linux/platform_data/simplefb.h>
	#include <video/videomode.h>

	#include "mxsfb_drv.h"
	#include "mxsfb_regs.h"

	#define MXS_SET_ADDR 0x4
	#define MXS_CLR_ADDR 0x8
	#define MODULE_CLKGATE BIT(30)
	#define MODULE_SFTRST BIT(31)
	/* 1 second delay should be plenty of time for block reset */
	#define RESET_TIMEOUT 1000000

	static u32 set_hsync_pulse_width(struct mxsfb_drm_private *mxsfb, u32 val)
	{
	return (val & mxsfb->devdata->hs_wdth_mask) <<
	mxsfb->devdata->hs_wdth_shift;
	}

	/* Setup the MXSFB registers for decoding the pixels out of the framebuffer */
	static int mxsfb_set_pixel_fmt(struct mxsfb_drm_private *mxsfb)
	{
	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
	struct drm_device *drm = crtc->dev;
	const u32 format = crtc->primary->state->fb->format->format;
	u32 ctrl, ctrl1;

	ctrl = CTRL_BYPASS_COUNT \| CTRL_MASTER;

	/*
	* WARNING: The bus width, CTRL_SET_BUS_WIDTH(), is configured to
	* match the selected mode here. This differs from the original
	* MXSFB driver, which had the option to configure the bus width
	* to arbitrary value. This limitation should not pose an issue.
	*/

	/* CTRL1 contains IRQ config and status bits, preserve those. */
	ctrl1 = readl(mxsfb->base + LCDC_CTRL1);
	ctrl1 &= CTRL1_CUR_FRAME_DONE_IRQ_EN \| CTRL1_CUR_FRAME_DONE_IRQ;

	switch (format) {
	case DRM_FORMAT_RGB565:
	dev_dbg(drm->dev, "Setting up RGB565 mode\n");
	ctrl \|= CTRL_SET_WORD_LENGTH(0);
	ctrl1 \|= CTRL1_SET_BYTE_PACKAGING(0xf);
	break;
	case DRM_FORMAT_XRGB8888:
	dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
	ctrl \|= CTRL_SET_WORD_LENGTH(3);
	/* Do not use packed pixels = one pixel per word instead. */
	ctrl1 \|= CTRL1_SET_BYTE_PACKAGING(0x7);
	break;
	default:
	dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
	return -EINVAL;
	}

	writel(ctrl1, mxsfb->base + LCDC_CTRL1);
	writel(ctrl, mxsfb->base + LCDC_CTRL);

	return 0;
	}

	static void mxsfb_set_bus_fmt(struct mxsfb_drm_private *mxsfb)
	{
	struct drm_crtc *crtc = &mxsfb->pipe.crtc;
	struct drm_device *drm = crtc->dev;
	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
	u32 reg;

	reg = readl(mxsfb->base + LCDC_CTRL);

	if (mxsfb->connector.display_info.num_bus_formats)
	bus_format = mxsfb->connector.display_info.bus_formats[0];

	reg &= ~CTRL_BUS_WIDTH_MASK;
	switch (bus_format) {
	case MEDIA_BUS_FMT_RGB565_1X16:
	reg \|= CTRL_SET_BUS_WIDTH(STMLCDIF_16BIT);
	break;
	case MEDIA_BUS_FMT_RGB666_1X18:
	reg \|= CTRL_SET_BUS_WIDTH(STMLCDIF_18BIT);
	break;
	case MEDIA_BUS_FMT_RGB888_1X24:
	reg \|= CTRL_SET_BUS_WIDTH(STMLCDIF_24BIT);
	break;
	default:
	dev_err(drm->dev, "Unknown media bus format %d\n", bus_format);
	break;
	}
	writel(reg, mxsfb->base + LCDC_CTRL);
	}

	static void mxsfb_enable_controller(struct mxsfb_drm_private *mxsfb)
	{
	u32 reg;

	if (mxsfb->clk_disp_axi)
	clk_prepare_enable(mxsfb->clk_disp_axi);
	clk_prepare_enable(mxsfb->clk);

	/* If it was disabled, re-enable the mode again */
	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_SET);

	/* Enable the SYNC signals first, then the DMA engine */
	reg = readl(mxsfb->base + LCDC_VDCTRL4);
	reg \|= VDCTRL4_SYNC_SIGNALS_ON;
	writel(reg, mxsfb->base + LCDC_VDCTRL4);

	writel(CTRL_RUN, mxsfb->base + LCDC_CTRL + REG_SET);
	}

	static void mxsfb_disable_controller(struct mxsfb_drm_private *mxsfb)
	{
	u32 reg;

	/*
	* Even if we disable the controller here, it will still continue
	* until its FIFOs are running out of data
	*/
	writel(CTRL_DOTCLK_MODE, mxsfb->base + LCDC_CTRL + REG_CLR);

	readl_poll_timeout(mxsfb->base + LCDC_CTRL, reg, !(reg & CTRL_RUN),
	0, 1000);

	reg = readl(mxsfb->base + LCDC_VDCTRL4);
	reg &= ~VDCTRL4_SYNC_SIGNALS_ON;
	writel(reg, mxsfb->base + LCDC_VDCTRL4);

	clk_disable_unprepare(mxsfb->clk);
	if (mxsfb->clk_disp_axi)
	clk_disable_unprepare(mxsfb->clk_disp_axi);
	}

	/*
	* Clear the bit and poll it cleared. This is usually called with
	* a reset address and mask being either SFTRST(bit 31) or CLKGATE
	* (bit 30).
	*/
	static int clear_poll_bit(void __iomem *addr, u32 mask)
	{
	u32 reg;

	writel(mask, addr + MXS_CLR_ADDR);
	return readl_poll_timeout(addr, reg, !(reg & mask), 0, RESET_TIMEOUT);
	}

	static int mxsfb_reset_block(void __iomem *reset_addr)
	{
	int ret;

	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
	if (ret)
	return ret;

	writel(MODULE_CLKGATE, reset_addr + MXS_CLR_ADDR);

	ret = clear_poll_bit(reset_addr, MODULE_SFTRST);
	if (ret)
	return ret;

	return clear_poll_bit(reset_addr, MODULE_CLKGATE);
	}

	static dma_addr_t mxsfb_get_fb_paddr(struct mxsfb_drm_private *mxsfb)
	{
	struct drm_framebuffer *fb = mxsfb->pipe.plane.state->fb;
	struct drm_gem_cma_object *gem;

	if (!fb)
	return 0;

	gem = drm_fb_cma_get_gem_obj(fb, 0);
	if (!gem)
	return 0;

	return gem->paddr;
	}

	static void mxsfb_crtc_mode_set_nofb(struct mxsfb_drm_private *mxsfb)
	{
	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
	const u32 bus_flags = mxsfb->connector.display_info.bus_flags;
	u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
	int err;

	/*
	* It seems, you can't re-program the controller if it is still
	* running. This may lead to shifted pictures (FIFO issue?), so
	* first stop the controller and drain its FIFOs.
	*/

	/* Mandatory eLCDIF reset as per the Reference Manual */
	err = mxsfb_reset_block(mxsfb->base);
	if (err)
	return;

	/* Clear the FIFOs */
	writel(CTRL1_FIFO_CLEAR, mxsfb->base + LCDC_CTRL1 + REG_SET);

	err = mxsfb_set_pixel_fmt(mxsfb);
	if (err)
	return;

	clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);

	writel(TRANSFER_COUNT_SET_VCOUNT(m->crtc_vdisplay) \|
	TRANSFER_COUNT_SET_HCOUNT(m->crtc_hdisplay),
	mxsfb->base + mxsfb->devdata->transfer_count);

	vsync_pulse_len = m->crtc_vsync_end - m->crtc_vsync_start;

	vdctrl0 = VDCTRL0_ENABLE_PRESENT \| /* Always in DOTCLOCK mode */
	VDCTRL0_VSYNC_PERIOD_UNIT \|
	VDCTRL0_VSYNC_PULSE_WIDTH_UNIT \|
	VDCTRL0_SET_VSYNC_PULSE_WIDTH(vsync_pulse_len);
	if (m->flags & DRM_MODE_FLAG_PHSYNC)
	vdctrl0 \|= VDCTRL0_HSYNC_ACT_HIGH;
	if (m->flags & DRM_MODE_FLAG_PVSYNC)
	vdctrl0 \|= VDCTRL0_VSYNC_ACT_HIGH;
	/* Make sure Data Enable is high active by default */
	if (!(bus_flags & DRM_BUS_FLAG_DE_LOW))
	vdctrl0 \|= VDCTRL0_ENABLE_ACT_HIGH;
	/*
	* DRM_BUS_FLAG_PIXDATA_DRIVE_ defines are controller centric,
	* controllers VDCTRL0_DOTCLK is display centric.
	* Drive on positive edge -> display samples on falling edge
	* DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE -> VDCTRL0_DOTCLK_ACT_FALLING
	*/
	if (bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE)
	vdctrl0 \|= VDCTRL0_DOTCLK_ACT_FALLING;

	writel(vdctrl0, mxsfb->base + LCDC_VDCTRL0);

	mxsfb_set_bus_fmt(mxsfb);

	/* Frame length in lines. */
	writel(m->crtc_vtotal, mxsfb->base + LCDC_VDCTRL1);

	/* Line length in units of clocks or pixels. */
	hsync_pulse_len = m->crtc_hsync_end - m->crtc_hsync_start;
	writel(set_hsync_pulse_width(mxsfb, hsync_pulse_len) \|
	VDCTRL2_SET_HSYNC_PERIOD(m->crtc_htotal),
	mxsfb->base + LCDC_VDCTRL2);

	writel(SET_HOR_WAIT_CNT(m->crtc_htotal - m->crtc_hsync_start) \|
	SET_VERT_WAIT_CNT(m->crtc_vtotal - m->crtc_vsync_start),
	mxsfb->base + LCDC_VDCTRL3);

	writel(SET_DOTCLK_H_VALID_DATA_CNT(m->hdisplay),
	mxsfb->base + LCDC_VDCTRL4);
	}

	void mxsfb_crtc_enable(struct mxsfb_drm_private *mxsfb)
	{
	dma_addr_t paddr;

	mxsfb_enable_axi_clk(mxsfb);
	mxsfb_crtc_mode_set_nofb(mxsfb);

	/* Write cur_buf as well to avoid an initial corrupt frame */
	paddr = mxsfb_get_fb_paddr(mxsfb);
	if (paddr) {
	writel(paddr, mxsfb->base + mxsfb->devdata->cur_buf);
	writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
	}

	mxsfb_enable_controller(mxsfb);
	}

	void mxsfb_crtc_disable(struct mxsfb_drm_private *mxsfb)
	{
	mxsfb_disable_controller(mxsfb);
	mxsfb_disable_axi_clk(mxsfb);
	}

	void mxsfb_plane_atomic_update(struct mxsfb_drm_private *mxsfb,
	struct drm_plane_state *state)
	{
	struct drm_simple_display_pipe *pipe = &mxsfb->pipe;
	struct drm_crtc *crtc = &pipe->crtc;
	struct drm_pending_vblank_event *event;
	dma_addr_t paddr;

	spin_lock_irq(&crtc->dev->event_lock);
	event = crtc->state->event;
	if (event) {
	crtc->state->event = NULL;

	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);

	paddr = mxsfb_get_fb_paddr(mxsfb);
	if (paddr) {
	mxsfb_enable_axi_clk(mxsfb);
	writel(paddr, mxsfb->base + mxsfb->devdata->next_buf);
	mxsfb_disable_axi_clk(mxsfb);
	}
	}