Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / video / fbdev / mxsfb.c
diff --git a/kernel/drivers/video/fbdev/mxsfb.c b/kernel/drivers/video/fbdev/mxsfb.c
new file mode 100644 (file)
index 0000000..0f64165
--- /dev/null
@@ -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");