drivers/gpu/drm/sti/sti_vtg.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) STMicroelectronics SA 2014
  * Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
  *          Fabien Dessenne <fabien.dessenne@st.com>
  *          Vincent Abriou <vincent.abriou@st.com>
  *          for STMicroelectronics.
  */

 #include <linux/module.h>
 #include <linux/notifier.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>

 #include <drm/drmP.h>

 #include "sti_drv.h"
 #include "sti_vtg.h"

 #define VTG_MODE_MASTER         0

 /* registers offset */
 #define VTG_MODE            0x0000
 #define VTG_CLKLN           0x0008
 #define VTG_HLFLN           0x000C
 #define VTG_DRST_AUTOC      0x0010
 #define VTG_VID_TFO         0x0040
 #define VTG_VID_TFS         0x0044
 #define VTG_VID_BFO         0x0048
 #define VTG_VID_BFS         0x004C

 #define VTG_HOST_ITS        0x0078
 #define VTG_HOST_ITS_BCLR   0x007C
 #define VTG_HOST_ITM_BCLR   0x0088
 #define VTG_HOST_ITM_BSET   0x008C

 #define VTG_H_HD_1          0x00C0
 #define VTG_TOP_V_VD_1      0x00C4
 #define VTG_BOT_V_VD_1      0x00C8
 #define VTG_TOP_V_HD_1      0x00CC
 #define VTG_BOT_V_HD_1      0x00D0

 #define VTG_H_HD_2          0x00E0
 #define VTG_TOP_V_VD_2      0x00E4
 #define VTG_BOT_V_VD_2      0x00E8
 #define VTG_TOP_V_HD_2      0x00EC
 #define VTG_BOT_V_HD_2      0x00F0

 #define VTG_H_HD_3          0x0100
 #define VTG_TOP_V_VD_3      0x0104
 #define VTG_BOT_V_VD_3      0x0108
 #define VTG_TOP_V_HD_3      0x010C
 #define VTG_BOT_V_HD_3      0x0110

 #define VTG_H_HD_4          0x0120
 #define VTG_TOP_V_VD_4      0x0124
 #define VTG_BOT_V_VD_4      0x0128
 #define VTG_TOP_V_HD_4      0x012c
 #define VTG_BOT_V_HD_4      0x0130

 #define VTG_IRQ_BOTTOM      BIT(0)
 #define VTG_IRQ_TOP         BIT(1)
 #define VTG_IRQ_MASK        (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)

 /* Delay introduced by the HDMI in nb of pixel */
 #define HDMI_DELAY          (5)

 /* Delay introduced by the DVO in nb of pixel */
 #define DVO_DELAY           (7)

 /* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
 #define AWG_DELAY_HD        (-9)
 #define AWG_DELAY_ED        (-8)
 #define AWG_DELAY_SD        (-7)

 /*
  * STI VTG register offset structure
  *
  *@h_hd:     stores the VTG_H_HD_x     register offset
  *@top_v_vd: stores the VTG_TOP_V_VD_x register offset
  *@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
  *@top_v_hd: stores the VTG_TOP_V_HD_x register offset
  *@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
  */
 struct sti_vtg_regs_offs {
 	u32 h_hd;
 	u32 top_v_vd;
 	u32 bot_v_vd;
 	u32 top_v_hd;
 	u32 bot_v_hd;
 };

 #define VTG_MAX_SYNC_OUTPUT 4
 static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
 	{ VTG_H_HD_1,
 	  VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
 	{ VTG_H_HD_2,
 	  VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
 	{ VTG_H_HD_3,
 	  VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
 	{ VTG_H_HD_4,
 	  VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
 };

 /*
  * STI VTG synchronisation parameters structure
  *
  *@hsync: sample number falling and rising edge
  *@vsync_line_top: vertical top field line number falling and rising edge
  *@vsync_line_bot: vertical bottom field line number falling and rising edge
  *@vsync_off_top: vertical top field sample number rising and falling edge
  *@vsync_off_bot: vertical bottom field sample number rising and falling edge
  */
 struct sti_vtg_sync_params {
 	u32 hsync;
 	u32 vsync_line_top;
 	u32 vsync_line_bot;
 	u32 vsync_off_top;
 	u32 vsync_off_bot;
 };

 /**
  * STI VTG structure
  *
  * @regs: register mapping
  * @sync_params: synchronisation parameters used to generate timings
  * @irq: VTG irq
  * @irq_status: store the IRQ status value
  * @notifier_list: notifier callback
  * @crtc: the CRTC for vblank event
  */
 struct sti_vtg {
 	void __iomem *regs;
 	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
 	int irq;
 	u32 irq_status;
 	struct raw_notifier_head notifier_list;
 	struct drm_crtc *crtc;
 };

 struct sti_vtg *of_vtg_find(struct device_node *np)
 {
 	struct platform_device *pdev;

 	pdev = of_find_device_by_node(np);
 	if (!pdev)
 		return NULL;

 	return (struct sti_vtg *)platform_get_drvdata(pdev);
 }

 static void vtg_reset(struct sti_vtg *vtg)
 {
 	writel(1, vtg->regs + VTG_DRST_AUTOC);
 }

 static void vtg_set_output_window(void __iomem *regs,
 				  const struct drm_display_mode *mode)
 {
 	u32 video_top_field_start;
 	u32 video_top_field_stop;
 	u32 video_bottom_field_start;
 	u32 video_bottom_field_stop;
 	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
 	u32 ystart = sti_vtg_get_line_number(*mode, 0);
 	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
 	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);

 	/* Set output window to fit the display mode selected */
 	video_top_field_start = (ystart << 16) | xstart;
 	video_top_field_stop = (ystop << 16) | xstop;

 	/* Only progressive supported for now */
 	video_bottom_field_start = video_top_field_start;
 	video_bottom_field_stop = video_top_field_stop;

 	writel(video_top_field_start, regs + VTG_VID_TFO);
 	writel(video_top_field_stop, regs + VTG_VID_TFS);
 	writel(video_bottom_field_start, regs + VTG_VID_BFO);
 	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
 }

 static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
 				    int delay,
 				    const struct drm_display_mode *mode)
 {
 	long clocksperline, start, stop;
 	u32 risesync_top, fallsync_top;
 	u32 risesync_offs_top, fallsync_offs_top;

 	clocksperline = mode->htotal;

 	/* Get the hsync position */
 	start = 0;
 	stop = mode->hsync_end - mode->hsync_start;

 	start += delay;
 	stop  += delay;

 	if (start < 0)
 		start += clocksperline;
 	else if (start >= clocksperline)
 		start -= clocksperline;

 	if (stop < 0)
 		stop += clocksperline;
 	else if (stop >= clocksperline)
 		stop -= clocksperline;

 	sync->hsync = (stop << 16) | start;

 	/* Get the vsync position */
 	if (delay >= 0) {
 		risesync_top = 1;
 		fallsync_top = risesync_top;
 		fallsync_top += mode->vsync_end - mode->vsync_start;

 		fallsync_offs_top = (u32)delay;
 		risesync_offs_top = (u32)delay;
 	} else {
 		risesync_top = mode->vtotal;
 		fallsync_top = mode->vsync_end - mode->vsync_start;

 		fallsync_offs_top = clocksperline + delay;
 		risesync_offs_top = clocksperline + delay;
 	}

 	sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
 	sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;

 	/* Only progressive supported for now */
 	sync->vsync_line_bot = sync->vsync_line_top;
 	sync->vsync_off_bot = sync->vsync_off_top;
 }

 static void vtg_set_mode(struct sti_vtg *vtg,
 			 int type,
 			 struct sti_vtg_sync_params *sync,
 			 const struct drm_display_mode *mode)
 {
 	unsigned int i;

 	/* Set the number of clock cycles per line */
 	writel(mode->htotal, vtg->regs + VTG_CLKLN);

 	/* Set Half Line Per Field (only progressive supported for now) */
 	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);

 	/* Program output window */
 	vtg_set_output_window(vtg->regs, mode);

 	/* Set hsync and vsync position for HDMI */
 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);

 	/* Set hsync and vsync position for HD DCS */
 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);

 	/* Set hsync and vsync position for HDF */
 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);

 	/* Set hsync and vsync position for DVO */
 	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);

 	/* Progam the syncs outputs */
 	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
 		writel(sync[i].hsync,
 		       vtg->regs + vtg_regs_offs[i].h_hd);
 		writel(sync[i].vsync_line_top,
 		       vtg->regs + vtg_regs_offs[i].top_v_vd);
 		writel(sync[i].vsync_line_bot,
 		       vtg->regs + vtg_regs_offs[i].bot_v_vd);
 		writel(sync[i].vsync_off_top,
 		       vtg->regs + vtg_regs_offs[i].top_v_hd);
 		writel(sync[i].vsync_off_bot,
 		       vtg->regs + vtg_regs_offs[i].bot_v_hd);
 	}

 	/* mode */
 	writel(type, vtg->regs + VTG_MODE);
 }

 static void vtg_enable_irq(struct sti_vtg *vtg)
 {
 	/* clear interrupt status and mask */
 	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
 	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
 	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
 }

 void sti_vtg_set_config(struct sti_vtg *vtg,
 		const struct drm_display_mode *mode)
 {
 	/* write configuration */
 	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);

 	vtg_reset(vtg);

 	vtg_enable_irq(vtg);
 }

 /**
  * sti_vtg_get_line_number
  *
  * @mode: display mode to be used
  * @y:    line
  *
  * Return the line number according to the display mode taking
  * into account the Sync and Back Porch information.
  * Video frame line numbers start at 1, y starts at 0.
  * In interlaced modes the start line is the field line number of the odd
  * field, but y is still defined as a progressive frame.
  */
 u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
 {
 	u32 start_line = mode.vtotal - mode.vsync_start + 1;

 	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
 		start_line *= 2;

 	return start_line + y;
 }

 /**
  * sti_vtg_get_pixel_number
  *
  * @mode: display mode to be used
  * @x:    row
  *
  * Return the pixel number according to the display mode taking
  * into account the Sync and Back Porch information.
  * Pixels are counted from 0.
  */
 u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
 {
 	return mode.htotal - mode.hsync_start + x;
 }

 int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
 			    struct drm_crtc *crtc)
 {
 	vtg->crtc = crtc;
 	return raw_notifier_chain_register(&vtg->notifier_list, nb);
 }

 int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
 {
 	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
 }

 static irqreturn_t vtg_irq_thread(int irq, void *arg)
 {
 	struct sti_vtg *vtg = arg;
 	u32 event;

 	event = (vtg->irq_status & VTG_IRQ_TOP) ?
 		VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;

 	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);

 	return IRQ_HANDLED;
 }

 static irqreturn_t vtg_irq(int irq, void *arg)
 {
 	struct sti_vtg *vtg = arg;

 	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);

 	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);

 	/* force sync bus write */
 	readl(vtg->regs + VTG_HOST_ITS);

 	return IRQ_WAKE_THREAD;
 }

 static int vtg_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct sti_vtg *vtg;
 	struct resource *res;
 	int ret;

 	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
 	if (!vtg)
 		return -ENOMEM;

 	/* Get Memory ressources */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		DRM_ERROR("Get memory resource failed\n");
 		return -ENOMEM;
 	}
 	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
 	if (!vtg->regs) {
 		DRM_ERROR("failed to remap I/O memory\n");
 		return -ENOMEM;
 	}

 	vtg->irq = platform_get_irq(pdev, 0);
 	if (vtg->irq < 0) {
 		DRM_ERROR("Failed to get VTG interrupt\n");
 		return vtg->irq;
 	}

 	RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);

 	ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
 					vtg_irq_thread, IRQF_ONESHOT,
 					dev_name(dev), vtg);
 	if (ret < 0) {
 		DRM_ERROR("Failed to register VTG interrupt\n");
 		return ret;
 	}

 	platform_set_drvdata(pdev, vtg);

 	DRM_INFO("%s %s\n", __func__, dev_name(dev));

 	return 0;
 }

 static const struct of_device_id vtg_of_match[] = {
 	{ .compatible = "st,vtg", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, vtg_of_match);

 struct platform_driver sti_vtg_driver = {
 	.driver = {
 		.name = "sti-vtg",
 		.owner = THIS_MODULE,
 		.of_match_table = vtg_of_match,
 	},
 	.probe	= vtg_probe,
 };

 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) STMicroelectronics SA 2014
	* Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
	* Fabien Dessenne <fabien.dessenne@st.com>
	* Vincent Abriou <vincent.abriou@st.com>
	* for STMicroelectronics.
	*/

	#include <linux/module.h>
	#include <linux/notifier.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>

	#include <drm/drmP.h>

	#include "sti_drv.h"
	#include "sti_vtg.h"

	#define VTG_MODE_MASTER 0

	/* registers offset */
	#define VTG_MODE 0x0000
	#define VTG_CLKLN 0x0008
	#define VTG_HLFLN 0x000C
	#define VTG_DRST_AUTOC 0x0010
	#define VTG_VID_TFO 0x0040
	#define VTG_VID_TFS 0x0044
	#define VTG_VID_BFO 0x0048
	#define VTG_VID_BFS 0x004C

	#define VTG_HOST_ITS 0x0078
	#define VTG_HOST_ITS_BCLR 0x007C
	#define VTG_HOST_ITM_BCLR 0x0088
	#define VTG_HOST_ITM_BSET 0x008C

	#define VTG_H_HD_1 0x00C0
	#define VTG_TOP_V_VD_1 0x00C4
	#define VTG_BOT_V_VD_1 0x00C8
	#define VTG_TOP_V_HD_1 0x00CC
	#define VTG_BOT_V_HD_1 0x00D0

	#define VTG_H_HD_2 0x00E0
	#define VTG_TOP_V_VD_2 0x00E4
	#define VTG_BOT_V_VD_2 0x00E8
	#define VTG_TOP_V_HD_2 0x00EC
	#define VTG_BOT_V_HD_2 0x00F0

	#define VTG_H_HD_3 0x0100
	#define VTG_TOP_V_VD_3 0x0104
	#define VTG_BOT_V_VD_3 0x0108
	#define VTG_TOP_V_HD_3 0x010C
	#define VTG_BOT_V_HD_3 0x0110

	#define VTG_H_HD_4 0x0120
	#define VTG_TOP_V_VD_4 0x0124
	#define VTG_BOT_V_VD_4 0x0128
	#define VTG_TOP_V_HD_4 0x012c
	#define VTG_BOT_V_HD_4 0x0130

	#define VTG_IRQ_BOTTOM BIT(0)
	#define VTG_IRQ_TOP BIT(1)
	#define VTG_IRQ_MASK (VTG_IRQ_TOP \| VTG_IRQ_BOTTOM)

	/* Delay introduced by the HDMI in nb of pixel */
	#define HDMI_DELAY (5)

	/* Delay introduced by the DVO in nb of pixel */
	#define DVO_DELAY (7)

	/* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
	#define AWG_DELAY_HD (-9)
	#define AWG_DELAY_ED (-8)
	#define AWG_DELAY_SD (-7)

	/*
	* STI VTG register offset structure
	*
	*@h_hd: stores the VTG_H_HD_x register offset
	*@top_v_vd: stores the VTG_TOP_V_VD_x register offset
	*@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
	*@top_v_hd: stores the VTG_TOP_V_HD_x register offset
	*@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
	*/
	struct sti_vtg_regs_offs {
	u32 h_hd;
	u32 top_v_vd;
	u32 bot_v_vd;
	u32 top_v_hd;
	u32 bot_v_hd;
	};

	#define VTG_MAX_SYNC_OUTPUT 4
	static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
	{ VTG_H_HD_1,
	VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
	{ VTG_H_HD_2,
	VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
	{ VTG_H_HD_3,
	VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
	{ VTG_H_HD_4,
	VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
	};

	/*
	* STI VTG synchronisation parameters structure
	*
	*@hsync: sample number falling and rising edge
	*@vsync_line_top: vertical top field line number falling and rising edge
	*@vsync_line_bot: vertical bottom field line number falling and rising edge
	*@vsync_off_top: vertical top field sample number rising and falling edge
	*@vsync_off_bot: vertical bottom field sample number rising and falling edge
	*/
	struct sti_vtg_sync_params {
	u32 hsync;
	u32 vsync_line_top;
	u32 vsync_line_bot;
	u32 vsync_off_top;
	u32 vsync_off_bot;
	};

	/**
	* STI VTG structure
	*
	* @regs: register mapping
	* @sync_params: synchronisation parameters used to generate timings
	* @irq: VTG irq
	* @irq_status: store the IRQ status value
	* @notifier_list: notifier callback
	* @crtc: the CRTC for vblank event
	*/
	struct sti_vtg {
	void __iomem *regs;
	struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
	int irq;
	u32 irq_status;
	struct raw_notifier_head notifier_list;
	struct drm_crtc *crtc;
	};

	struct sti_vtg of_vtg_find(struct device_node np)
	{
	struct platform_device *pdev;

	pdev = of_find_device_by_node(np);
	if (!pdev)
	return NULL;

	return (struct sti_vtg *)platform_get_drvdata(pdev);
	}

	static void vtg_reset(struct sti_vtg *vtg)
	{
	writel(1, vtg->regs + VTG_DRST_AUTOC);
	}

	static void vtg_set_output_window(void __iomem *regs,
	const struct drm_display_mode *mode)
	{
	u32 video_top_field_start;
	u32 video_top_field_stop;
	u32 video_bottom_field_start;
	u32 video_bottom_field_stop;
	u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
	u32 ystart = sti_vtg_get_line_number(*mode, 0);
	u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
	u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);

	/* Set output window to fit the display mode selected */
	video_top_field_start = (ystart << 16) \| xstart;
	video_top_field_stop = (ystop << 16) \| xstop;

	/* Only progressive supported for now */
	video_bottom_field_start = video_top_field_start;
	video_bottom_field_stop = video_top_field_stop;

	writel(video_top_field_start, regs + VTG_VID_TFO);
	writel(video_top_field_stop, regs + VTG_VID_TFS);
	writel(video_bottom_field_start, regs + VTG_VID_BFO);
	writel(video_bottom_field_stop, regs + VTG_VID_BFS);
	}

	static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
	int delay,
	const struct drm_display_mode *mode)
	{
	long clocksperline, start, stop;
	u32 risesync_top, fallsync_top;
	u32 risesync_offs_top, fallsync_offs_top;

	clocksperline = mode->htotal;

	/* Get the hsync position */
	start = 0;
	stop = mode->hsync_end - mode->hsync_start;

	start += delay;
	stop += delay;

	if (start < 0)
	start += clocksperline;
	else if (start >= clocksperline)
	start -= clocksperline;

	if (stop < 0)
	stop += clocksperline;
	else if (stop >= clocksperline)
	stop -= clocksperline;

	sync->hsync = (stop << 16) \| start;

	/* Get the vsync position */
	if (delay >= 0) {
	risesync_top = 1;
	fallsync_top = risesync_top;
	fallsync_top += mode->vsync_end - mode->vsync_start;

	fallsync_offs_top = (u32)delay;
	risesync_offs_top = (u32)delay;
	} else {
	risesync_top = mode->vtotal;
	fallsync_top = mode->vsync_end - mode->vsync_start;

	fallsync_offs_top = clocksperline + delay;
	risesync_offs_top = clocksperline + delay;
	}

	sync->vsync_line_top = (fallsync_top << 16) \| risesync_top;
	sync->vsync_off_top = (fallsync_offs_top << 16) \| risesync_offs_top;

	/* Only progressive supported for now */
	sync->vsync_line_bot = sync->vsync_line_top;
	sync->vsync_off_bot = sync->vsync_off_top;
	}

	static void vtg_set_mode(struct sti_vtg *vtg,
	int type,
	struct sti_vtg_sync_params *sync,
	const struct drm_display_mode *mode)
	{
	unsigned int i;

	/* Set the number of clock cycles per line */
	writel(mode->htotal, vtg->regs + VTG_CLKLN);

	/* Set Half Line Per Field (only progressive supported for now) */
	writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);

	/* Program output window */
	vtg_set_output_window(vtg->regs, mode);

	/* Set hsync and vsync position for HDMI */
	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);

	/* Set hsync and vsync position for HD DCS */
	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);

	/* Set hsync and vsync position for HDF */
	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);

	/* Set hsync and vsync position for DVO */
	vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);

	/* Progam the syncs outputs */
	for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
	writel(sync[i].hsync,
	vtg->regs + vtg_regs_offs[i].h_hd);
	writel(sync[i].vsync_line_top,
	vtg->regs + vtg_regs_offs[i].top_v_vd);
	writel(sync[i].vsync_line_bot,
	vtg->regs + vtg_regs_offs[i].bot_v_vd);
	writel(sync[i].vsync_off_top,
	vtg->regs + vtg_regs_offs[i].top_v_hd);
	writel(sync[i].vsync_off_bot,
	vtg->regs + vtg_regs_offs[i].bot_v_hd);
	}

	/* mode */
	writel(type, vtg->regs + VTG_MODE);
	}

	static void vtg_enable_irq(struct sti_vtg *vtg)
	{
	/* clear interrupt status and mask */
	writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
	writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
	writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
	}

	void sti_vtg_set_config(struct sti_vtg *vtg,
	const struct drm_display_mode *mode)
	{
	/* write configuration */
	vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);

	vtg_reset(vtg);

	vtg_enable_irq(vtg);
	}

	/**
	* sti_vtg_get_line_number
	*
	* @mode: display mode to be used
	* @y: line
	*
	* Return the line number according to the display mode taking
	* into account the Sync and Back Porch information.
	* Video frame line numbers start at 1, y starts at 0.
	* In interlaced modes the start line is the field line number of the odd
	* field, but y is still defined as a progressive frame.
	*/
	u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
	{
	u32 start_line = mode.vtotal - mode.vsync_start + 1;

	if (mode.flags & DRM_MODE_FLAG_INTERLACE)
	start_line *= 2;

	return start_line + y;
	}

	/**
	* sti_vtg_get_pixel_number
	*
	* @mode: display mode to be used
	* @x: row
	*
	* Return the pixel number according to the display mode taking
	* into account the Sync and Back Porch information.
	* Pixels are counted from 0.
	*/
	u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
	{
	return mode.htotal - mode.hsync_start + x;
	}

	int sti_vtg_register_client(struct sti_vtg vtg, struct notifier_block nb,
	struct drm_crtc *crtc)
	{
	vtg->crtc = crtc;
	return raw_notifier_chain_register(&vtg->notifier_list, nb);
	}

	int sti_vtg_unregister_client(struct sti_vtg vtg, struct notifier_block nb)
	{
	return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
	}

	static irqreturn_t vtg_irq_thread(int irq, void *arg)
	{
	struct sti_vtg *vtg = arg;
	u32 event;

	event = (vtg->irq_status & VTG_IRQ_TOP) ?
	VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;

	raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);

	return IRQ_HANDLED;
	}

	static irqreturn_t vtg_irq(int irq, void *arg)
	{
	struct sti_vtg *vtg = arg;

	vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);

	writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);

	/* force sync bus write */
	readl(vtg->regs + VTG_HOST_ITS);

	return IRQ_WAKE_THREAD;
	}

	static int vtg_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct sti_vtg *vtg;
	struct resource *res;
	int ret;

	vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
	if (!vtg)
	return -ENOMEM;

	/* Get Memory ressources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	DRM_ERROR("Get memory resource failed\n");
	return -ENOMEM;
	}
	vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
	if (!vtg->regs) {
	DRM_ERROR("failed to remap I/O memory\n");
	return -ENOMEM;
	}

	vtg->irq = platform_get_irq(pdev, 0);
	if (vtg->irq < 0) {
	DRM_ERROR("Failed to get VTG interrupt\n");
	return vtg->irq;
	}

	RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);

	ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
	vtg_irq_thread, IRQF_ONESHOT,
	dev_name(dev), vtg);
	if (ret < 0) {
	DRM_ERROR("Failed to register VTG interrupt\n");
	return ret;
	}

	platform_set_drvdata(pdev, vtg);

	DRM_INFO("%s %s\n", __func__, dev_name(dev));

	return 0;
	}

	static const struct of_device_id vtg_of_match[] = {
	{ .compatible = "st,vtg", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, vtg_of_match);

	struct platform_driver sti_vtg_driver = {
	.driver = {
	.name = "sti-vtg",
	.owner = THIS_MODULE,
	.of_match_table = vtg_of_match,
	},
	.probe = vtg_probe,
	};

	MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
	MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
	MODULE_LICENSE("GPL");