From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 drivers/video/fbdev/mxsfb.c | 1019 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1019 insertions(+)
 create mode 100644 drivers/video/fbdev/mxsfb.c

(limited to 'drivers/video/fbdev/mxsfb.c')

diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c
new file mode 100644
index 000000000..0f64165b0
--- /dev/null
+++ b/drivers/video/fbdev/mxsfb.c
@@ -0,0 +1,1019 @@
+/*
+ * Copyright (C) 2010 Juergen Beisert, Pengutronix
+ *
+ * This code is based on:
+ * Author: Vitaly Wool <vital@embeddedalley.com>
+ *
+ * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#define DRIVER_NAME "mxsfb"
+
+/**
+ * @file
+ * @brief LCDIF driver for i.MX23 and i.MX28
+ *
+ * The LCDIF support four modes of operation
+ * - MPU interface (to drive smart displays) -> not supported yet
+ * - VSYNC interface (like MPU interface plus Vsync) -> not supported yet
+ * - Dotclock interface (to drive LC displays with RGB data and sync signals)
+ * - DVI (to drive ITU-R BT656)  -> not supported yet
+ *
+ * This driver depends on a correct setup of the pins used for this purpose
+ * (platform specific).
+ *
+ * For the developer: Don't forget to set the data bus width to the display
+ * in the imx_fb_videomode structure. You will else end up with ugly colours.
+ * If you fight against jitter you can vary the clock delay. This is a feature
+ * of the i.MX28 and you can vary it between 2 ns ... 8 ns in 2 ns steps. Give
+ * the required value in the imx_fb_videomode structure.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/fb.h>
+#include <linux/regulator/consumer.h>
+#include <video/of_display_timing.h>
+#include <video/of_videomode.h>
+#include <video/videomode.h>
+
+#define REG_SET	4
+#define REG_CLR	8
+
+#define LCDC_CTRL			0x00
+#define LCDC_CTRL1			0x10
+#define LCDC_V4_CTRL2			0x20
+#define LCDC_V3_TRANSFER_COUNT		0x20
+#define LCDC_V4_TRANSFER_COUNT		0x30
+#define LCDC_V4_CUR_BUF			0x40
+#define LCDC_V4_NEXT_BUF		0x50
+#define LCDC_V3_CUR_BUF			0x30
+#define LCDC_V3_NEXT_BUF		0x40
+#define LCDC_TIMING			0x60
+#define LCDC_VDCTRL0			0x70
+#define LCDC_VDCTRL1			0x80
+#define LCDC_VDCTRL2			0x90
+#define LCDC_VDCTRL3			0xa0
+#define LCDC_VDCTRL4			0xb0
+#define LCDC_DVICTRL0			0xc0
+#define LCDC_DVICTRL1			0xd0
+#define LCDC_DVICTRL2			0xe0
+#define LCDC_DVICTRL3			0xf0
+#define LCDC_DVICTRL4			0x100
+#define LCDC_V4_DATA			0x180
+#define LCDC_V3_DATA			0x1b0
+#define LCDC_V4_DEBUG0			0x1d0
+#define LCDC_V3_DEBUG0			0x1f0
+
+#define CTRL_SFTRST			(1 << 31)
+#define CTRL_CLKGATE			(1 << 30)
+#define CTRL_BYPASS_COUNT		(1 << 19)
+#define CTRL_VSYNC_MODE			(1 << 18)
+#define CTRL_DOTCLK_MODE		(1 << 17)
+#define CTRL_DATA_SELECT		(1 << 16)
+#define CTRL_SET_BUS_WIDTH(x)		(((x) & 0x3) << 10)
+#define CTRL_GET_BUS_WIDTH(x)		(((x) >> 10) & 0x3)
+#define CTRL_SET_WORD_LENGTH(x)		(((x) & 0x3) << 8)
+#define CTRL_GET_WORD_LENGTH(x)		(((x) >> 8) & 0x3)
+#define CTRL_MASTER			(1 << 5)
+#define CTRL_DF16			(1 << 3)
+#define CTRL_DF18			(1 << 2)
+#define CTRL_DF24			(1 << 1)
+#define CTRL_RUN			(1 << 0)
+
+#define CTRL1_FIFO_CLEAR		(1 << 21)
+#define CTRL1_SET_BYTE_PACKAGING(x)	(((x) & 0xf) << 16)
+#define CTRL1_GET_BYTE_PACKAGING(x)	(((x) >> 16) & 0xf)
+
+#define TRANSFER_COUNT_SET_VCOUNT(x)	(((x) & 0xffff) << 16)
+#define TRANSFER_COUNT_GET_VCOUNT(x)	(((x) >> 16) & 0xffff)
+#define TRANSFER_COUNT_SET_HCOUNT(x)	((x) & 0xffff)
+#define TRANSFER_COUNT_GET_HCOUNT(x)	((x) & 0xffff)
+
+
+#define VDCTRL0_ENABLE_PRESENT		(1 << 28)
+#define VDCTRL0_VSYNC_ACT_HIGH		(1 << 27)
+#define VDCTRL0_HSYNC_ACT_HIGH		(1 << 26)
+#define VDCTRL0_DOTCLK_ACT_FALLING	(1 << 25)
+#define VDCTRL0_ENABLE_ACT_HIGH		(1 << 24)
+#define VDCTRL0_VSYNC_PERIOD_UNIT	(1 << 21)
+#define VDCTRL0_VSYNC_PULSE_WIDTH_UNIT	(1 << 20)
+#define VDCTRL0_HALF_LINE		(1 << 19)
+#define VDCTRL0_HALF_LINE_MODE		(1 << 18)
+#define VDCTRL0_SET_VSYNC_PULSE_WIDTH(x) ((x) & 0x3ffff)
+#define VDCTRL0_GET_VSYNC_PULSE_WIDTH(x) ((x) & 0x3ffff)
+
+#define VDCTRL2_SET_HSYNC_PERIOD(x)	((x) & 0x3ffff)
+#define VDCTRL2_GET_HSYNC_PERIOD(x)	((x) & 0x3ffff)
+
+#define VDCTRL3_MUX_SYNC_SIGNALS	(1 << 29)
+#define VDCTRL3_VSYNC_ONLY		(1 << 28)
+#define SET_HOR_WAIT_CNT(x)		(((x) & 0xfff) << 16)
+#define GET_HOR_WAIT_CNT(x)		(((x) >> 16) & 0xfff)
+#define SET_VERT_WAIT_CNT(x)		((x) & 0xffff)
+#define GET_VERT_WAIT_CNT(x)		((x) & 0xffff)
+
+#define VDCTRL4_SET_DOTCLK_DLY(x)	(((x) & 0x7) << 29) /* v4 only */
+#define VDCTRL4_GET_DOTCLK_DLY(x)	(((x) >> 29) & 0x7) /* v4 only */
+#define VDCTRL4_SYNC_SIGNALS_ON		(1 << 18)
+#define SET_DOTCLK_H_VALID_DATA_CNT(x)	((x) & 0x3ffff)
+
+#define DEBUG0_HSYNC			(1 < 26)
+#define DEBUG0_VSYNC			(1 < 25)
+
+#define MIN_XRES			120
+#define MIN_YRES			120
+
+#define RED 0
+#define GREEN 1
+#define BLUE 2
+#define TRANSP 3
+
+#define STMLCDIF_8BIT  1 /** pixel data bus to the display is of 8 bit width */
+#define STMLCDIF_16BIT 0 /** pixel data bus to the display is of 16 bit width */
+#define STMLCDIF_18BIT 2 /** pixel data bus to the display is of 18 bit width */
+#define STMLCDIF_24BIT 3 /** pixel data bus to the display is of 24 bit width */
+
+#define MXSFB_SYNC_DATA_ENABLE_HIGH_ACT	(1 << 6)
+#define MXSFB_SYNC_DOTCLK_FALLING_ACT	(1 << 7) /* negtive edge sampling */
+
+enum mxsfb_devtype {
+	MXSFB_V3,
+	MXSFB_V4,
+};
+
+/* CPU dependent register offsets */
+struct mxsfb_devdata {
+	unsigned transfer_count;
+	unsigned cur_buf;
+	unsigned next_buf;
+	unsigned debug0;
+	unsigned hs_wdth_mask;
+	unsigned hs_wdth_shift;
+	unsigned ipversion;
+};
+
+struct mxsfb_info {
+	struct fb_info fb_info;
+	struct platform_device *pdev;
+	struct clk *clk;
+	struct clk *clk_axi;
+	struct clk *clk_disp_axi;
+	void __iomem *base;	/* registers */
+	unsigned allocated_size;
+	int enabled;
+	unsigned ld_intf_width;
+	unsigned dotclk_delay;
+	const struct mxsfb_devdata *devdata;
+	u32 sync;
+	struct regulator *reg_lcd;
+};
+
+#define mxsfb_is_v3(host) (host->devdata->ipversion == 3)
+#define mxsfb_is_v4(host) (host->devdata->ipversion == 4)
+
+static const struct mxsfb_devdata mxsfb_devdata[] = {
+	[MXSFB_V3] = {
+		.transfer_count = LCDC_V3_TRANSFER_COUNT,
+		.cur_buf = LCDC_V3_CUR_BUF,
+		.next_buf = LCDC_V3_NEXT_BUF,
+		.debug0 = LCDC_V3_DEBUG0,
+		.hs_wdth_mask = 0xff,
+		.hs_wdth_shift = 24,
+		.ipversion = 3,
+	},
+	[MXSFB_V4] = {
+		.transfer_count = LCDC_V4_TRANSFER_COUNT,
+		.cur_buf = LCDC_V4_CUR_BUF,
+		.next_buf = LCDC_V4_NEXT_BUF,
+		.debug0 = LCDC_V4_DEBUG0,
+		.hs_wdth_mask = 0x3fff,
+		.hs_wdth_shift = 18,
+		.ipversion = 4,
+	},
+};
+
+#define to_imxfb_host(x) (container_of(x, struct mxsfb_info, fb_info))
+
+/* mask and shift depends on architecture */
+static inline u32 set_hsync_pulse_width(struct mxsfb_info *host, unsigned val)
+{
+	return (val & host->devdata->hs_wdth_mask) <<
+		host->devdata->hs_wdth_shift;
+}
+
+static inline u32 get_hsync_pulse_width(struct mxsfb_info *host, unsigned val)
+{
+	return (val >> host->devdata->hs_wdth_shift) &
+		host->devdata->hs_wdth_mask;
+}
+
+static const struct fb_bitfield def_rgb565[] = {
+	[RED] = {
+		.offset = 11,
+		.length = 5,
+	},
+	[GREEN] = {
+		.offset = 5,
+		.length = 6,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 5,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+static const struct fb_bitfield def_rgb888[] = {
+	[RED] = {
+		.offset = 16,
+		.length = 8,
+	},
+	[GREEN] = {
+		.offset = 8,
+		.length = 8,
+	},
+	[BLUE] = {
+		.offset = 0,
+		.length = 8,
+	},
+	[TRANSP] = {	/* no support for transparency */
+		.length = 0,
+	}
+};
+
+static inline unsigned chan_to_field(unsigned chan, struct fb_bitfield *bf)
+{
+	chan &= 0xffff;
+	chan >>= 16 - bf->length;
+	return chan << bf->offset;
+}
+
+static int mxsfb_check_var(struct fb_var_screeninfo *var,
+		struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	const struct fb_bitfield *rgb = NULL;
+
+	if (var->xres < MIN_XRES)
+		var->xres = MIN_XRES;
+	if (var->yres < MIN_YRES)
+		var->yres = MIN_YRES;
+
+	var->xres_virtual = var->xres;
+
+	var->yres_virtual = var->yres;
+
+	switch (var->bits_per_pixel) {
+	case 16:
+		/* always expect RGB 565 */
+		rgb = def_rgb565;
+		break;
+	case 32:
+		switch (host->ld_intf_width) {
+		case STMLCDIF_8BIT:
+			pr_debug("Unsupported LCD bus width mapping\n");
+			break;
+		case STMLCDIF_16BIT:
+		case STMLCDIF_18BIT:
+		case STMLCDIF_24BIT:
+			/* real 24 bit */
+			rgb = def_rgb888;
+			break;
+		}
+		break;
+	default:
+		pr_err("Unsupported colour depth: %u\n", var->bits_per_pixel);
+		return -EINVAL;
+	}
+
+	/*
+	 * Copy the RGB parameters for this display
+	 * from the machine specific parameters.
+	 */
+	var->red    = rgb[RED];
+	var->green  = rgb[GREEN];
+	var->blue   = rgb[BLUE];
+	var->transp = rgb[TRANSP];
+
+	return 0;
+}
+
+static inline void mxsfb_enable_axi_clk(struct mxsfb_info *host)
+{
+	if (host->clk_axi)
+		clk_prepare_enable(host->clk_axi);
+}
+
+static inline void mxsfb_disable_axi_clk(struct mxsfb_info *host)
+{
+	if (host->clk_axi)
+		clk_disable_unprepare(host->clk_axi);
+}
+
+static void mxsfb_enable_controller(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	u32 reg;
+	int ret;
+
+	dev_dbg(&host->pdev->dev, "%s\n", __func__);
+
+	if (host->reg_lcd) {
+		ret = regulator_enable(host->reg_lcd);
+		if (ret) {
+			dev_err(&host->pdev->dev,
+				"lcd regulator enable failed:	%d\n", ret);
+			return;
+		}
+	}
+
+	if (host->clk_disp_axi)
+		clk_prepare_enable(host->clk_disp_axi);
+	clk_prepare_enable(host->clk);
+	clk_set_rate(host->clk, PICOS2KHZ(fb_info->var.pixclock) * 1000U);
+
+	mxsfb_enable_axi_clk(host);
+
+	/* if it was disabled, re-enable the mode again */
+	writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_SET);
+
+	/* enable the SYNC signals first, then the DMA engine */
+	reg = readl(host->base + LCDC_VDCTRL4);
+	reg |= VDCTRL4_SYNC_SIGNALS_ON;
+	writel(reg, host->base + LCDC_VDCTRL4);
+
+	writel(CTRL_RUN, host->base + LCDC_CTRL + REG_SET);
+
+	host->enabled = 1;
+}
+
+static void mxsfb_disable_controller(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	unsigned loop;
+	u32 reg;
+	int ret;
+
+	dev_dbg(&host->pdev->dev, "%s\n", __func__);
+
+	/*
+	 * Even if we disable the controller here, it will still continue
+	 * until its FIFOs are running out of data
+	 */
+	writel(CTRL_DOTCLK_MODE, host->base + LCDC_CTRL + REG_CLR);
+
+	loop = 1000;
+	while (loop) {
+		reg = readl(host->base + LCDC_CTRL);
+		if (!(reg & CTRL_RUN))
+			break;
+		loop--;
+	}
+
+	reg = readl(host->base + LCDC_VDCTRL4);
+	writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);
+
+	mxsfb_disable_axi_clk(host);
+
+	clk_disable_unprepare(host->clk);
+	if (host->clk_disp_axi)
+		clk_disable_unprepare(host->clk_disp_axi);
+
+	host->enabled = 0;
+
+	if (host->reg_lcd) {
+		ret = regulator_disable(host->reg_lcd);
+		if (ret)
+			dev_err(&host->pdev->dev,
+				"lcd regulator disable failed: %d\n", ret);
+	}
+}
+
+static int mxsfb_set_par(struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	u32 ctrl, vdctrl0, vdctrl4;
+	int line_size, fb_size;
+	int reenable = 0;
+
+	line_size =  fb_info->var.xres * (fb_info->var.bits_per_pixel >> 3);
+	fb_size = fb_info->var.yres_virtual * line_size;
+
+	if (fb_size > fb_info->fix.smem_len)
+		return -ENOMEM;
+
+	fb_info->fix.line_length = line_size;
+
+	/*
+	 * It seems, you can't re-program the controller if it is still running.
+	 * This may lead into shifted pictures (FIFO issue?).
+	 * So, first stop the controller and drain its FIFOs
+	 */
+	if (host->enabled) {
+		reenable = 1;
+		mxsfb_disable_controller(fb_info);
+	}
+
+	mxsfb_enable_axi_clk(host);
+
+	/* clear the FIFOs */
+	writel(CTRL1_FIFO_CLEAR, host->base + LCDC_CTRL1 + REG_SET);
+
+	ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER |
+		CTRL_SET_BUS_WIDTH(host->ld_intf_width);
+
+	switch (fb_info->var.bits_per_pixel) {
+	case 16:
+		dev_dbg(&host->pdev->dev, "Setting up RGB565 mode\n");
+		ctrl |= CTRL_SET_WORD_LENGTH(0);
+		writel(CTRL1_SET_BYTE_PACKAGING(0xf), host->base + LCDC_CTRL1);
+		break;
+	case 32:
+		dev_dbg(&host->pdev->dev, "Setting up RGB888/666 mode\n");
+		ctrl |= CTRL_SET_WORD_LENGTH(3);
+		switch (host->ld_intf_width) {
+		case STMLCDIF_8BIT:
+			mxsfb_disable_axi_clk(host);
+			dev_err(&host->pdev->dev,
+					"Unsupported LCD bus width mapping\n");
+			return -EINVAL;
+		case STMLCDIF_16BIT:
+		case STMLCDIF_18BIT:
+		case STMLCDIF_24BIT:
+			/* real 24 bit */
+			break;
+		}
+		/* do not use packed pixels = one pixel per word instead */
+		writel(CTRL1_SET_BYTE_PACKAGING(0x7), host->base + LCDC_CTRL1);
+		break;
+	default:
+		mxsfb_disable_axi_clk(host);
+		dev_err(&host->pdev->dev, "Unhandled color depth of %u\n",
+				fb_info->var.bits_per_pixel);
+		return -EINVAL;
+	}
+
+	writel(ctrl, host->base + LCDC_CTRL);
+
+	writel(TRANSFER_COUNT_SET_VCOUNT(fb_info->var.yres) |
+			TRANSFER_COUNT_SET_HCOUNT(fb_info->var.xres),
+			host->base + host->devdata->transfer_count);
+
+	vdctrl0 = VDCTRL0_ENABLE_PRESENT |	/* always in DOTCLOCK mode */
+		VDCTRL0_VSYNC_PERIOD_UNIT |
+		VDCTRL0_VSYNC_PULSE_WIDTH_UNIT |
+		VDCTRL0_SET_VSYNC_PULSE_WIDTH(fb_info->var.vsync_len);
+	if (fb_info->var.sync & FB_SYNC_HOR_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_HSYNC_ACT_HIGH;
+	if (fb_info->var.sync & FB_SYNC_VERT_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_VSYNC_ACT_HIGH;
+	if (host->sync & MXSFB_SYNC_DATA_ENABLE_HIGH_ACT)
+		vdctrl0 |= VDCTRL0_ENABLE_ACT_HIGH;
+	if (host->sync & MXSFB_SYNC_DOTCLK_FALLING_ACT)
+		vdctrl0 |= VDCTRL0_DOTCLK_ACT_FALLING;
+
+	writel(vdctrl0, host->base + LCDC_VDCTRL0);
+
+	/* frame length in lines */
+	writel(fb_info->var.upper_margin + fb_info->var.vsync_len +
+		fb_info->var.lower_margin + fb_info->var.yres,
+		host->base + LCDC_VDCTRL1);
+
+	/* line length in units of clocks or pixels */
+	writel(set_hsync_pulse_width(host, fb_info->var.hsync_len) |
+		VDCTRL2_SET_HSYNC_PERIOD(fb_info->var.left_margin +
+		fb_info->var.hsync_len + fb_info->var.right_margin +
+		fb_info->var.xres),
+		host->base + LCDC_VDCTRL2);
+
+	writel(SET_HOR_WAIT_CNT(fb_info->var.left_margin +
+		fb_info->var.hsync_len) |
+		SET_VERT_WAIT_CNT(fb_info->var.upper_margin +
+			fb_info->var.vsync_len),
+		host->base + LCDC_VDCTRL3);
+
+	vdctrl4 = SET_DOTCLK_H_VALID_DATA_CNT(fb_info->var.xres);
+	if (mxsfb_is_v4(host))
+		vdctrl4 |= VDCTRL4_SET_DOTCLK_DLY(host->dotclk_delay);
+	writel(vdctrl4, host->base + LCDC_VDCTRL4);
+
+	writel(fb_info->fix.smem_start +
+			fb_info->fix.line_length * fb_info->var.yoffset,
+			host->base + host->devdata->next_buf);
+
+	mxsfb_disable_axi_clk(host);
+
+	if (reenable)
+		mxsfb_enable_controller(fb_info);
+
+	return 0;
+}
+
+static int mxsfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+		u_int transp, struct fb_info *fb_info)
+{
+	unsigned int val;
+	int ret = -EINVAL;
+
+	/*
+	 * If greyscale is true, then we convert the RGB value
+	 * to greyscale no matter what visual we are using.
+	 */
+	if (fb_info->var.grayscale)
+		red = green = blue = (19595 * red + 38470 * green +
+					7471 * blue) >> 16;
+
+	switch (fb_info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		/*
+		 * 12 or 16-bit True Colour.  We encode the RGB value
+		 * according to the RGB bitfield information.
+		 */
+		if (regno < 16) {
+			u32 *pal = fb_info->pseudo_palette;
+
+			val  = chan_to_field(red, &fb_info->var.red);
+			val |= chan_to_field(green, &fb_info->var.green);
+			val |= chan_to_field(blue, &fb_info->var.blue);
+
+			pal[regno] = val;
+			ret = 0;
+		}
+		break;
+
+	case FB_VISUAL_STATIC_PSEUDOCOLOR:
+	case FB_VISUAL_PSEUDOCOLOR:
+		break;
+	}
+
+	return ret;
+}
+
+static int mxsfb_blank(int blank, struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+
+	switch (blank) {
+	case FB_BLANK_POWERDOWN:
+	case FB_BLANK_VSYNC_SUSPEND:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_NORMAL:
+		if (host->enabled)
+			mxsfb_disable_controller(fb_info);
+		break;
+
+	case FB_BLANK_UNBLANK:
+		if (!host->enabled)
+			mxsfb_enable_controller(fb_info);
+		break;
+	}
+	return 0;
+}
+
+static int mxsfb_pan_display(struct fb_var_screeninfo *var,
+		struct fb_info *fb_info)
+{
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+	unsigned offset;
+
+	if (var->xoffset != 0)
+		return -EINVAL;
+
+	offset = fb_info->fix.line_length * var->yoffset;
+
+	mxsfb_enable_axi_clk(host);
+
+	/* update on next VSYNC */
+	writel(fb_info->fix.smem_start + offset,
+			host->base + host->devdata->next_buf);
+
+	mxsfb_disable_axi_clk(host);
+
+	return 0;
+}
+
+static struct fb_ops mxsfb_ops = {
+	.owner = THIS_MODULE,
+	.fb_check_var = mxsfb_check_var,
+	.fb_set_par = mxsfb_set_par,
+	.fb_setcolreg = mxsfb_setcolreg,
+	.fb_blank = mxsfb_blank,
+	.fb_pan_display = mxsfb_pan_display,
+	.fb_fillrect = cfb_fillrect,
+	.fb_copyarea = cfb_copyarea,
+	.fb_imageblit = cfb_imageblit,
+};
+
+static int mxsfb_restore_mode(struct mxsfb_info *host,
+			struct fb_videomode *vmode)
+{
+	struct fb_info *fb_info = &host->fb_info;
+	unsigned line_count;
+	unsigned period;
+	unsigned long pa, fbsize;
+	int bits_per_pixel, ofs, ret = 0;
+	u32 transfer_count, vdctrl0, vdctrl2, vdctrl3, vdctrl4, ctrl;
+
+	mxsfb_enable_axi_clk(host);
+
+	/* Only restore the mode when the controller is running */
+	ctrl = readl(host->base + LCDC_CTRL);
+	if (!(ctrl & CTRL_RUN)) {
+		ret = -EINVAL;
+		goto err;
+	}
+
+	vdctrl0 = readl(host->base + LCDC_VDCTRL0);
+	vdctrl2 = readl(host->base + LCDC_VDCTRL2);
+	vdctrl3 = readl(host->base + LCDC_VDCTRL3);
+	vdctrl4 = readl(host->base + LCDC_VDCTRL4);
+
+	transfer_count = readl(host->base + host->devdata->transfer_count);
+
+	vmode->xres = TRANSFER_COUNT_GET_HCOUNT(transfer_count);
+	vmode->yres = TRANSFER_COUNT_GET_VCOUNT(transfer_count);
+
+	switch (CTRL_GET_WORD_LENGTH(ctrl)) {
+	case 0:
+		bits_per_pixel = 16;
+		break;
+	case 3:
+		bits_per_pixel = 32;
+		break;
+	case 1:
+	default:
+		ret = -EINVAL;
+		goto err;
+	}
+
+	fb_info->var.bits_per_pixel = bits_per_pixel;
+
+	vmode->pixclock = KHZ2PICOS(clk_get_rate(host->clk) / 1000U);
+	vmode->hsync_len = get_hsync_pulse_width(host, vdctrl2);
+	vmode->left_margin = GET_HOR_WAIT_CNT(vdctrl3) - vmode->hsync_len;
+	vmode->right_margin = VDCTRL2_GET_HSYNC_PERIOD(vdctrl2) -
+		vmode->hsync_len - vmode->left_margin - vmode->xres;
+	vmode->vsync_len = VDCTRL0_GET_VSYNC_PULSE_WIDTH(vdctrl0);
+	period = readl(host->base + LCDC_VDCTRL1);
+	vmode->upper_margin = GET_VERT_WAIT_CNT(vdctrl3) - vmode->vsync_len;
+	vmode->lower_margin = period - vmode->vsync_len -
+		vmode->upper_margin - vmode->yres;
+
+	vmode->vmode = FB_VMODE_NONINTERLACED;
+
+	vmode->sync = 0;
+	if (vdctrl0 & VDCTRL0_HSYNC_ACT_HIGH)
+		vmode->sync |= FB_SYNC_HOR_HIGH_ACT;
+	if (vdctrl0 & VDCTRL0_VSYNC_ACT_HIGH)
+		vmode->sync |= FB_SYNC_VERT_HIGH_ACT;
+
+	pr_debug("Reconstructed video mode:\n");
+	pr_debug("%dx%d, hsync: %u left: %u, right: %u, vsync: %u, upper: %u, lower: %u\n",
+		vmode->xres, vmode->yres, vmode->hsync_len, vmode->left_margin,
+		vmode->right_margin, vmode->vsync_len, vmode->upper_margin,
+		vmode->lower_margin);
+	pr_debug("pixclk: %ldkHz\n", PICOS2KHZ(vmode->pixclock));
+
+	host->ld_intf_width = CTRL_GET_BUS_WIDTH(ctrl);
+	host->dotclk_delay = VDCTRL4_GET_DOTCLK_DLY(vdctrl4);
+
+	fb_info->fix.line_length = vmode->xres * (bits_per_pixel >> 3);
+
+	pa = readl(host->base + host->devdata->cur_buf);
+	fbsize = fb_info->fix.line_length * vmode->yres;
+	if (pa < fb_info->fix.smem_start) {
+		ret = -EINVAL;
+		goto err;
+	}
+	if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len) {
+		ret = -EINVAL;
+		goto err;
+	}
+	ofs = pa - fb_info->fix.smem_start;
+	if (ofs) {
+		memmove(fb_info->screen_base, fb_info->screen_base + ofs, fbsize);
+		writel(fb_info->fix.smem_start, host->base + host->devdata->next_buf);
+	}
+
+	line_count = fb_info->fix.smem_len / fb_info->fix.line_length;
+	fb_info->fix.ypanstep = 1;
+
+	clk_prepare_enable(host->clk);
+	host->enabled = 1;
+
+err:
+	if (ret)
+		mxsfb_disable_axi_clk(host);
+
+	return ret;
+}
+
+static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,
+				struct fb_videomode *vmode)
+{
+	struct fb_info *fb_info = &host->fb_info;
+	struct fb_var_screeninfo *var = &fb_info->var;
+	struct device *dev = &host->pdev->dev;
+	struct device_node *np = host->pdev->dev.of_node;
+	struct device_node *display_np;
+	struct videomode vm;
+	u32 width;
+	int ret;
+
+	display_np = of_parse_phandle(np, "display", 0);
+	if (!display_np) {
+		dev_err(dev, "failed to find display phandle\n");
+		return -ENOENT;
+	}
+
+	ret = of_property_read_u32(display_np, "bus-width", &width);
+	if (ret < 0) {
+		dev_err(dev, "failed to get property bus-width\n");
+		goto put_display_node;
+	}
+
+	switch (width) {
+	case 8:
+		host->ld_intf_width = STMLCDIF_8BIT;
+		break;
+	case 16:
+		host->ld_intf_width = STMLCDIF_16BIT;
+		break;
+	case 18:
+		host->ld_intf_width = STMLCDIF_18BIT;
+		break;
+	case 24:
+		host->ld_intf_width = STMLCDIF_24BIT;
+		break;
+	default:
+		dev_err(dev, "invalid bus-width value\n");
+		ret = -EINVAL;
+		goto put_display_node;
+	}
+
+	ret = of_property_read_u32(display_np, "bits-per-pixel",
+				   &var->bits_per_pixel);
+	if (ret < 0) {
+		dev_err(dev, "failed to get property bits-per-pixel\n");
+		goto put_display_node;
+	}
+
+	ret = of_get_videomode(display_np, &vm, OF_USE_NATIVE_MODE);
+	if (ret) {
+		dev_err(dev, "failed to get videomode from DT\n");
+		goto put_display_node;
+	}
+
+	ret = fb_videomode_from_videomode(&vm, vmode);
+	if (ret < 0)
+		goto put_display_node;
+
+	if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+		host->sync |= MXSFB_SYNC_DATA_ENABLE_HIGH_ACT;
+	if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+		host->sync |= MXSFB_SYNC_DOTCLK_FALLING_ACT;
+
+put_display_node:
+	of_node_put(display_np);
+	return ret;
+}
+
+static int mxsfb_init_fbinfo(struct mxsfb_info *host,
+			struct fb_videomode *vmode)
+{
+	int ret;
+	struct fb_info *fb_info = &host->fb_info;
+	struct fb_var_screeninfo *var = &fb_info->var;
+	dma_addr_t fb_phys;
+	void *fb_virt;
+	unsigned fb_size;
+
+	fb_info->fbops = &mxsfb_ops;
+	fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_READS_FAST;
+	strlcpy(fb_info->fix.id, "mxs", sizeof(fb_info->fix.id));
+	fb_info->fix.type = FB_TYPE_PACKED_PIXELS;
+	fb_info->fix.ypanstep = 1;
+	fb_info->fix.visual = FB_VISUAL_TRUECOLOR,
+	fb_info->fix.accel = FB_ACCEL_NONE;
+
+	ret = mxsfb_init_fbinfo_dt(host, vmode);
+	if (ret)
+		return ret;
+
+	var->nonstd = 0;
+	var->activate = FB_ACTIVATE_NOW;
+	var->accel_flags = 0;
+	var->vmode = FB_VMODE_NONINTERLACED;
+
+	/* Memory allocation for framebuffer */
+	fb_size = SZ_2M;
+	fb_virt = alloc_pages_exact(fb_size, GFP_DMA);
+	if (!fb_virt)
+		return -ENOMEM;
+
+	fb_phys = virt_to_phys(fb_virt);
+
+	fb_info->fix.smem_start = fb_phys;
+	fb_info->screen_base = fb_virt;
+	fb_info->screen_size = fb_info->fix.smem_len = fb_size;
+
+	if (mxsfb_restore_mode(host, vmode))
+		memset(fb_virt, 0, fb_size);
+
+	return 0;
+}
+
+static void mxsfb_free_videomem(struct mxsfb_info *host)
+{
+	struct fb_info *fb_info = &host->fb_info;
+
+	free_pages_exact(fb_info->screen_base, fb_info->fix.smem_len);
+}
+
+static struct platform_device_id mxsfb_devtype[] = {
+	{
+		.name = "imx23-fb",
+		.driver_data = MXSFB_V3,
+	}, {
+		.name = "imx28-fb",
+		.driver_data = MXSFB_V4,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(platform, mxsfb_devtype);
+
+static const struct of_device_id mxsfb_dt_ids[] = {
+	{ .compatible = "fsl,imx23-lcdif", .data = &mxsfb_devtype[0], },
+	{ .compatible = "fsl,imx28-lcdif", .data = &mxsfb_devtype[1], },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxsfb_dt_ids);
+
+static int mxsfb_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id =
+			of_match_device(mxsfb_dt_ids, &pdev->dev);
+	struct resource *res;
+	struct mxsfb_info *host;
+	struct fb_info *fb_info;
+	struct fb_videomode *mode;
+	int ret;
+
+	if (of_id)
+		pdev->id_entry = of_id->data;
+
+	fb_info = framebuffer_alloc(sizeof(struct mxsfb_info), &pdev->dev);
+	if (!fb_info) {
+		dev_err(&pdev->dev, "Failed to allocate fbdev\n");
+		return -ENOMEM;
+	}
+
+	mode = devm_kzalloc(&pdev->dev, sizeof(struct fb_videomode),
+			GFP_KERNEL);
+	if (mode == NULL)
+		return -ENOMEM;
+
+	host = to_imxfb_host(fb_info);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	host->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(host->base)) {
+		ret = PTR_ERR(host->base);
+		goto fb_release;
+	}
+
+	host->pdev = pdev;
+	platform_set_drvdata(pdev, host);
+
+	host->devdata = &mxsfb_devdata[pdev->id_entry->driver_data];
+
+	host->clk = devm_clk_get(&host->pdev->dev, NULL);
+	if (IS_ERR(host->clk)) {
+		ret = PTR_ERR(host->clk);
+		goto fb_release;
+	}
+
+	host->clk_axi = devm_clk_get(&host->pdev->dev, "axi");
+	if (IS_ERR(host->clk_axi))
+		host->clk_axi = NULL;
+
+	host->clk_disp_axi = devm_clk_get(&host->pdev->dev, "disp_axi");
+	if (IS_ERR(host->clk_disp_axi))
+		host->clk_disp_axi = NULL;
+
+	host->reg_lcd = devm_regulator_get(&pdev->dev, "lcd");
+	if (IS_ERR(host->reg_lcd))
+		host->reg_lcd = NULL;
+
+	fb_info->pseudo_palette = devm_kzalloc(&pdev->dev, sizeof(u32) * 16,
+					       GFP_KERNEL);
+	if (!fb_info->pseudo_palette) {
+		ret = -ENOMEM;
+		goto fb_release;
+	}
+
+	ret = mxsfb_init_fbinfo(host, mode);
+	if (ret != 0)
+		goto fb_release;
+
+	fb_videomode_to_var(&fb_info->var, mode);
+
+	/* init the color fields */
+	mxsfb_check_var(&fb_info->var, fb_info);
+
+	platform_set_drvdata(pdev, fb_info);
+
+	ret = register_framebuffer(fb_info);
+	if (ret != 0) {
+		dev_err(&pdev->dev,"Failed to register framebuffer\n");
+		goto fb_destroy;
+	}
+
+	if (!host->enabled) {
+		mxsfb_enable_axi_clk(host);
+		writel(0, host->base + LCDC_CTRL);
+		mxsfb_disable_axi_clk(host);
+		mxsfb_set_par(fb_info);
+		mxsfb_enable_controller(fb_info);
+	}
+
+	dev_info(&pdev->dev, "initialized\n");
+
+	return 0;
+
+fb_destroy:
+	if (host->enabled)
+		clk_disable_unprepare(host->clk);
+fb_release:
+	framebuffer_release(fb_info);
+
+	return ret;
+}
+
+static int mxsfb_remove(struct platform_device *pdev)
+{
+	struct fb_info *fb_info = platform_get_drvdata(pdev);
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+
+	if (host->enabled)
+		mxsfb_disable_controller(fb_info);
+
+	unregister_framebuffer(fb_info);
+	mxsfb_free_videomem(host);
+
+	framebuffer_release(fb_info);
+
+	return 0;
+}
+
+static void mxsfb_shutdown(struct platform_device *pdev)
+{
+	struct fb_info *fb_info = platform_get_drvdata(pdev);
+	struct mxsfb_info *host = to_imxfb_host(fb_info);
+
+	mxsfb_enable_axi_clk(host);
+
+	/*
+	 * Force stop the LCD controller as keeping it running during reboot
+	 * might interfere with the BootROM's boot mode pads sampling.
+	 */
+	writel(CTRL_RUN, host->base + LCDC_CTRL + REG_CLR);
+
+	mxsfb_disable_axi_clk(host);
+}
+
+static struct platform_driver mxsfb_driver = {
+	.probe = mxsfb_probe,
+	.remove = mxsfb_remove,
+	.shutdown = mxsfb_shutdown,
+	.id_table = mxsfb_devtype,
+	.driver = {
+		   .name = DRIVER_NAME,
+		   .of_match_table = mxsfb_dt_ids,
+	},
+};
+
+module_platform_driver(mxsfb_driver);
+
+MODULE_DESCRIPTION("Freescale mxs framebuffer driver");
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_LICENSE("GPL");
-- 
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