/*
 * Copyright (C) 2008
 * Guennadi Liakhovetski, DENX Software Engineering, <lg@denx.de>
 *
 * Copyright 2004-2007 Freescale Semiconductor, 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 version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/fb.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/console.h>
#include <linux/clk.h>
#include <linux/mutex.h>

#include <mach/hardware.h>
#include <mach/ipu.h>
#include <mach/mx3fb.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#define MX3FB_NAME             "mx3_sdc_fb"

#define MX3FB_REG_OFFSET       0xB4

/* SDC Registers */
#define SDC_COM_CONF           (0xB4 - MX3FB_REG_OFFSET)
#define SDC_GW_CTRL            (0xB8 - MX3FB_REG_OFFSET)
#define SDC_FG_POS             (0xBC - MX3FB_REG_OFFSET)
#define SDC_BG_POS             (0xC0 - MX3FB_REG_OFFSET)
#define SDC_CUR_POS            (0xC4 - MX3FB_REG_OFFSET)
#define SDC_PWM_CTRL           (0xC8 - MX3FB_REG_OFFSET)
#define SDC_CUR_MAP            (0xCC - MX3FB_REG_OFFSET)
#define SDC_HOR_CONF           (0xD0 - MX3FB_REG_OFFSET)
#define SDC_VER_CONF           (0xD4 - MX3FB_REG_OFFSET)
#define SDC_SHARP_CONF_1       (0xD8 - MX3FB_REG_OFFSET)
#define SDC_SHARP_CONF_2       (0xDC - MX3FB_REG_OFFSET)

/* Register bits */
#define SDC_COM_TFT_COLOR      0x00000001UL
#define SDC_COM_FG_EN          0x00000010UL
#define SDC_COM_GWSEL          0x00000020UL
#define SDC_COM_GLB_A          0x00000040UL
#define SDC_COM_KEY_COLOR_G    0x00000080UL
#define SDC_COM_BG_EN          0x00000200UL
#define SDC_COM_SHARP          0x00001000UL

#define SDC_V_SYNC_WIDTH_L     0x00000001UL

/* Display Interface registers */
#define DI_DISP_IF_CONF                (0x0124 - MX3FB_REG_OFFSET)
#define DI_DISP_SIG_POL                (0x0128 - MX3FB_REG_OFFSET)
#define DI_SER_DISP1_CONF      (0x012C - MX3FB_REG_OFFSET)
#define DI_SER_DISP2_CONF      (0x0130 - MX3FB_REG_OFFSET)
#define DI_HSP_CLK_PER         (0x0134 - MX3FB_REG_OFFSET)
#define DI_DISP0_TIME_CONF_1   (0x0138 - MX3FB_REG_OFFSET)
#define DI_DISP0_TIME_CONF_2   (0x013C - MX3FB_REG_OFFSET)
#define DI_DISP0_TIME_CONF_3   (0x0140 - MX3FB_REG_OFFSET)
#define DI_DISP1_TIME_CONF_1   (0x0144 - MX3FB_REG_OFFSET)
#define DI_DISP1_TIME_CONF_2   (0x0148 - MX3FB_REG_OFFSET)
#define DI_DISP1_TIME_CONF_3   (0x014C - MX3FB_REG_OFFSET)
#define DI_DISP2_TIME_CONF_1   (0x0150 - MX3FB_REG_OFFSET)
#define DI_DISP2_TIME_CONF_2   (0x0154 - MX3FB_REG_OFFSET)
#define DI_DISP2_TIME_CONF_3   (0x0158 - MX3FB_REG_OFFSET)
#define DI_DISP3_TIME_CONF     (0x015C - MX3FB_REG_OFFSET)
#define DI_DISP0_DB0_MAP       (0x0160 - MX3FB_REG_OFFSET)
#define DI_DISP0_DB1_MAP       (0x0164 - MX3FB_REG_OFFSET)
#define DI_DISP0_DB2_MAP       (0x0168 - MX3FB_REG_OFFSET)
#define DI_DISP0_CB0_MAP       (0x016C - MX3FB_REG_OFFSET)
#define DI_DISP0_CB1_MAP       (0x0170 - MX3FB_REG_OFFSET)
#define DI_DISP0_CB2_MAP       (0x0174 - MX3FB_REG_OFFSET)
#define DI_DISP1_DB0_MAP       (0x0178 - MX3FB_REG_OFFSET)
#define DI_DISP1_DB1_MAP       (0x017C - MX3FB_REG_OFFSET)
#define DI_DISP1_DB2_MAP       (0x0180 - MX3FB_REG_OFFSET)
#define DI_DISP1_CB0_MAP       (0x0184 - MX3FB_REG_OFFSET)
#define DI_DISP1_CB1_MAP       (0x0188 - MX3FB_REG_OFFSET)
#define DI_DISP1_CB2_MAP       (0x018C - MX3FB_REG_OFFSET)
#define DI_DISP2_DB0_MAP       (0x0190 - MX3FB_REG_OFFSET)
#define DI_DISP2_DB1_MAP       (0x0194 - MX3FB_REG_OFFSET)
#define DI_DISP2_DB2_MAP       (0x0198 - MX3FB_REG_OFFSET)
#define DI_DISP2_CB0_MAP       (0x019C - MX3FB_REG_OFFSET)
#define DI_DISP2_CB1_MAP       (0x01A0 - MX3FB_REG_OFFSET)
#define DI_DISP2_CB2_MAP       (0x01A4 - MX3FB_REG_OFFSET)
#define DI_DISP3_B0_MAP                (0x01A8 - MX3FB_REG_OFFSET)
#define DI_DISP3_B1_MAP                (0x01AC - MX3FB_REG_OFFSET)
#define DI_DISP3_B2_MAP                (0x01B0 - MX3FB_REG_OFFSET)
#define DI_DISP_ACC_CC         (0x01B4 - MX3FB_REG_OFFSET)
#define DI_DISP_LLA_CONF       (0x01B8 - MX3FB_REG_OFFSET)
#define DI_DISP_LLA_DATA       (0x01BC - MX3FB_REG_OFFSET)

/* DI_DISP_SIG_POL bits */
#define DI_D3_VSYNC_POL_SHIFT          28
#define DI_D3_HSYNC_POL_SHIFT          27
#define DI_D3_DRDY_SHARP_POL_SHIFT     26
#define DI_D3_CLK_POL_SHIFT            25
#define DI_D3_DATA_POL_SHIFT           24

/* DI_DISP_IF_CONF bits */
#define DI_D3_CLK_IDLE_SHIFT           26
#define DI_D3_CLK_SEL_SHIFT            25
#define DI_D3_DATAMSK_SHIFT            24

enum ipu_panel {
       IPU_PANEL_SHARP_TFT,
       IPU_PANEL_TFT,
};

struct ipu_di_signal_cfg {
       unsigned datamask_en:1;
       unsigned clksel_en:1;
       unsigned clkidle_en:1;
       unsigned data_pol:1;    /* true = inverted */
       unsigned clk_pol:1;     /* true = rising edge */
       unsigned enable_pol:1;
       unsigned Hsync_pol:1;   /* true = active high */
       unsigned Vsync_pol:1;
};

static const struct fb_videomode mx3fb_modedb[] = {
       {
               /* 240x320 @ 60 Hz */
               .name           = "Sharp-QVGA",
               .refresh        = 60,
               .xres           = 240,
               .yres           = 320,
               .pixclock       = 185925,
               .left_margin    = 9,
               .right_margin   = 16,
               .upper_margin   = 7,
               .lower_margin   = 9,
               .hsync_len      = 1,
               .vsync_len      = 1,
               .sync           = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_SHARP_MODE |
                                 FB_SYNC_CLK_INVERT | FB_SYNC_DATA_INVERT |
                                 FB_SYNC_CLK_IDLE_EN,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       }, {
               /* 240x33 @ 60 Hz */
               .name           = "Sharp-CLI",
               .refresh        = 60,
               .xres           = 240,
               .yres           = 33,
               .pixclock       = 185925,
               .left_margin    = 9,
               .right_margin   = 16,
               .upper_margin   = 7,
               .lower_margin   = 9 + 287,
               .hsync_len      = 1,
               .vsync_len      = 1,
               .sync           = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_SHARP_MODE |
                                 FB_SYNC_CLK_INVERT | FB_SYNC_DATA_INVERT |
                                 FB_SYNC_CLK_IDLE_EN,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       }, {
               /* 640x480 @ 60 Hz */
               .name           = "NEC-VGA",
               .refresh        = 60,
               .xres           = 640,
               .yres           = 480,
               .pixclock       = 38255,
               .left_margin    = 144,
               .right_margin   = 0,
               .upper_margin   = 34,
               .lower_margin   = 40,
               .hsync_len      = 1,
               .vsync_len      = 1,
               .sync           = FB_SYNC_VERT_HIGH_ACT | FB_SYNC_OE_ACT_HIGH,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       }, {
               /* NTSC TV output */
               .name           = "TV-NTSC",
               .refresh        = 60,
               .xres           = 640,
               .yres           = 480,
               .pixclock       = 37538,
               .left_margin    = 38,
               .right_margin   = 858 - 640 - 38 - 3,
               .upper_margin   = 36,
               .lower_margin   = 518 - 480 - 36 - 1,
               .hsync_len      = 3,
               .vsync_len      = 1,
               .sync           = 0,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       }, {
               /* PAL TV output */
               .name           = "TV-PAL",
               .refresh        = 50,
               .xres           = 640,
               .yres           = 480,
               .pixclock       = 37538,
               .left_margin    = 38,
               .right_margin   = 960 - 640 - 38 - 32,
               .upper_margin   = 32,
               .lower_margin   = 555 - 480 - 32 - 3,
               .hsync_len      = 32,
               .vsync_len      = 3,
               .sync           = 0,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       }, {
               /* TV output VGA mode, 640x480 @ 65 Hz */
               .name           = "TV-VGA",
               .refresh        = 60,
               .xres           = 640,
               .yres           = 480,
               .pixclock       = 40574,
               .left_margin    = 35,
               .right_margin   = 45,
               .upper_margin   = 9,
               .lower_margin   = 1,
               .hsync_len      = 46,
               .vsync_len      = 5,
               .sync           = 0,
               .vmode          = FB_VMODE_NONINTERLACED,
               .flag           = 0,
       },
};

struct mx3fb_data {
       struct fb_info          *fbi;
       int                     backlight_level;
       void __iomem            *reg_base;
       spinlock_t              lock;
       struct device           *dev;

       uint32_t                h_start_width;
       uint32_t                v_start_width;
};

struct dma_chan_request {
       struct mx3fb_data       *mx3fb;
       enum ipu_channel        id;
};

/* MX3 specific framebuffer information. */
struct mx3fb_info {
       int                             blank;
       enum ipu_channel                ipu_ch;
       uint32_t                        cur_ipu_buf;

       u32                             pseudo_palette[16];

       struct completion               flip_cmpl;
       struct mutex                    mutex;  /* Protects fb-ops */
       struct mx3fb_data               *mx3fb;
       struct idmac_channel            *idmac_channel;
       struct dma_async_tx_descriptor  *txd;
       dma_cookie_t                    cookie;
       struct scatterlist              sg[2];

       u32                             sync;   /* preserve var->sync flags */
};

static void mx3fb_dma_done(void *);

/* Used fb-mode and bpp. Can be set on kernel command line, therefore file-static. */
static const char *fb_mode;
static unsigned long default_bpp = 16;

static u32 mx3fb_read_reg(struct mx3fb_data *mx3fb, unsigned long reg)
{
       return __raw_readl(mx3fb->reg_base + reg);
}

static void mx3fb_write_reg(struct mx3fb_data *mx3fb, u32 value, unsigned long reg)
{
       __raw_writel(value, mx3fb->reg_base + reg);
}

static const uint32_t di_mappings[] = {
       0x1600AAAA, 0x00E05555, 0x00070000, 3,  /* RGB888 */
       0x0005000F, 0x000B000F, 0x0011000F, 1,  /* RGB666 */
       0x0011000F, 0x000B000F, 0x0005000F, 1,  /* BGR666 */
       0x0004003F, 0x000A000F, 0x000F003F, 1   /* RGB565 */
};

static void sdc_fb_init(struct mx3fb_info *fbi)
{
       struct mx3fb_data *mx3fb = fbi->mx3fb;
       uint32_t reg;

       reg = mx3fb_read_reg(mx3fb, SDC_COM_CONF);

       mx3fb_write_reg(mx3fb, reg | SDC_COM_BG_EN, SDC_COM_CONF);
}

/* Returns enabled flag before uninit */
static uint32_t sdc_fb_uninit(struct mx3fb_info *fbi)
{
       struct mx3fb_data *mx3fb = fbi->mx3fb;
       uint32_t reg;

       reg = mx3fb_read_reg(mx3fb, SDC_COM_CONF);

       mx3fb_write_reg(mx3fb, reg & ~SDC_COM_BG_EN, SDC_COM_CONF);

       return reg & SDC_COM_BG_EN;
}

static void sdc_enable_channel(struct mx3fb_info *mx3_fbi)
{
       struct mx3fb_data *mx3fb = mx3_fbi->mx3fb;
       struct idmac_channel *ichan = mx3_fbi->idmac_channel;
       struct dma_chan *dma_chan = &ichan->dma_chan;
       unsigned long flags;
       dma_cookie_t cookie;

       dev_dbg(mx3fb->dev, "mx3fbi %p, desc %p, sg %p\n", mx3_fbi,
               to_tx_desc(mx3_fbi->txd), to_tx_desc(mx3_fbi->txd)->sg);

       /* This enables the channel */
       if (mx3_fbi->cookie < 0) {
               mx3_fbi->txd = dma_chan->device->device_prep_slave_sg(dma_chan,
                     &mx3_fbi->sg[0], 1, DMA_TO_DEVICE, DMA_PREP_INTERRUPT);
               if (!mx3_fbi->txd) {
                       dev_err(mx3fb->dev, "Cannot allocate descriptor on %d\n",
                               dma_chan->chan_id);
                       return;
               }

               mx3_fbi->txd->callback_param    = mx3_fbi->txd;
               mx3_fbi->txd->callback          = mx3fb_dma_done;

               cookie = mx3_fbi->txd->tx_submit(mx3_fbi->txd);
               dev_dbg(mx3fb->dev, "%d: Submit %p #%d [%c]\n", __LINE__,
                      mx3_fbi->txd, cookie, list_empty(&ichan->queue) ? '-' : '+');
       } else {
               if (!mx3_fbi->txd || !mx3_fbi->txd->tx_submit) {
                       dev_err(mx3fb->dev, "Cannot enable channel %d\n",
                               dma_chan->chan_id);
                       return;
               }

               /* Just re-activate the same buffer */
               dma_async_issue_pending(dma_chan);
               cookie = mx3_fbi->cookie;
               dev_dbg(mx3fb->dev, "%d: Re-submit %p #%d [%c]\n", __LINE__,
                      mx3_fbi->txd, cookie, list_empty(&ichan->queue) ? '-' : '+');
       }

       if (cookie >= 0) {
               spin_lock_irqsave(&mx3fb->lock, flags);
               sdc_fb_init(mx3_fbi);
               mx3_fbi->cookie = cookie;
               spin_unlock_irqrestore(&mx3fb->lock, flags);
       }

       /*
        * Attention! Without this msleep the channel keeps generating
        * interrupts. Next sdc_set_brightness() is going to be called
        * from mx3fb_blank().
        */
       msleep(2);
}

static void sdc_disable_channel(struct mx3fb_info *mx3_fbi)
{
       struct mx3fb_data *mx3fb = mx3_fbi->mx3fb;
       uint32_t enabled;
       unsigned long flags;

       spin_lock_irqsave(&mx3fb->lock, flags);

       enabled = sdc_fb_uninit(mx3_fbi);

       spin_unlock_irqrestore(&mx3fb->lock, flags);

       mx3_fbi->txd->chan->device->device_terminate_all(mx3_fbi->txd->chan);
       mx3_fbi->txd = NULL;
       mx3_fbi->cookie = -EINVAL;
}

/**
 * sdc_set_window_pos() - set window position of the respective plane.
 * @mx3fb:     mx3fb context.
 * @channel:   IPU DMAC channel ID.
 * @x_pos:     X coordinate relative to the top left corner to place window at.
 * @y_pos:     Y coordinate relative to the top left corner to place window at.
 * @return:    0 on success or negative error code on failure.
 */
static int sdc_set_window_pos(struct mx3fb_data *mx3fb, enum ipu_channel channel,
                             int16_t x_pos, int16_t y_pos)
{
       x_pos += mx3fb->h_start_width;
       y_pos += mx3fb->v_start_width;

       if (channel != IDMAC_SDC_0)
               return -EINVAL;

       mx3fb_write_reg(mx3fb, (x_pos << 16) | y_pos, SDC_BG_POS);
       return 0;
}

/**
 * sdc_init_panel() - initialize a synchronous LCD panel.
 * @mx3fb:             mx3fb context.
 * @panel:             panel type.
 * @pixel_clk:         desired pixel clock frequency in Hz.
 * @width:             width of panel in pixels.
 * @height:            height of panel in pixels.
 * @pixel_fmt:         pixel format of buffer as FOURCC ASCII code.
 * @h_start_width:     number of pixel clocks between the HSYNC signal pulse
 *                     and the start of valid data.
 * @h_sync_width:      width of the HSYNC signal in units of pixel clocks.
 * @h_end_width:       number of pixel clocks between the end of valid data
 *                     and the HSYNC signal for next line.
 * @v_start_width:     number of lines between the VSYNC signal pulse and the
 *                     start of valid data.
 * @v_sync_width:      width of the VSYNC signal in units of lines
 * @v_end_width:       number of lines between the end of valid data and the
 *                     VSYNC signal for next frame.
 * @sig:               bitfield of signal polarities for LCD interface.
 * @return:            0 on success or negative error code on failure.
 */
static int sdc_init_panel(struct mx3fb_data *mx3fb, enum ipu_panel panel,
                         uint32_t pixel_clk,
                         uint16_t width, uint16_t height,
                         enum pixel_fmt pixel_fmt,
                         uint16_t h_start_width, uint16_t h_sync_width,
                         uint16_t h_end_width, uint16_t v_start_width,
                         uint16_t v_sync_width, uint16_t v_end_width,
                         struct ipu_di_signal_cfg sig)
{
       unsigned long lock_flags;
       uint32_t reg;
       uint32_t old_conf;
       uint32_t div;
       struct clk *ipu_clk;

       dev_dbg(mx3fb->dev, "panel size = %d x %d", width, height);

       if (v_sync_width == 0 || h_sync_width == 0)
               return -EINVAL;

       /* Init panel size and blanking periods */
       reg = ((uint32_t) (h_sync_width - 1) << 26) |
               ((uint32_t) (width + h_start_width + h_end_width - 1) << 16);
       mx3fb_write_reg(mx3fb, reg, SDC_HOR_CONF);

#ifdef DEBUG
       printk(KERN_CONT " hor_conf %x,", reg);
#endif

       reg = ((uint32_t) (v_sync_width - 1) << 26) | SDC_V_SYNC_WIDTH_L |
           ((uint32_t) (height + v_start_width + v_end_width - 1) << 16);
       mx3fb_write_reg(mx3fb, reg, SDC_VER_CONF);

#ifdef DEBUG
       printk(KERN_CONT " ver_conf %x\n", reg);
#endif

       mx3fb->h_start_width = h_start_width;
       mx3fb->v_start_width = v_start_width;

       switch (panel) {
       case IPU_PANEL_SHARP_TFT:
               mx3fb_write_reg(mx3fb, 0x00FD0102L, SDC_SHARP_CONF_1);
               mx3fb_write_reg(mx3fb, 0x00F500F4L, SDC_SHARP_CONF_2);
               mx3fb_write_reg(mx3fb, SDC_COM_SHARP | SDC_COM_TFT_COLOR, SDC_COM_CONF);
               break;
       case IPU_PANEL_TFT:
               mx3fb_write_reg(mx3fb, SDC_COM_TFT_COLOR, SDC_COM_CONF);
               break;
       default:
               return -EINVAL;
       }

       /* Init clocking */

       /*
        * Calculate divider: fractional part is 4 bits so simply multiple by
        * 24 to get fractional part, as long as we stay under ~250MHz and on
        * i.MX31 it (HSP_CLK) is <= 178MHz. Currently 128.267MHz
        */
       dev_dbg(mx3fb->dev, "pixel clk = %d\n", pixel_clk);

       ipu_clk = clk_get(mx3fb->dev, "ipu_clk");
       div = clk_get_rate(ipu_clk) * 16 / pixel_clk;
       clk_put(ipu_clk);

       if (div < 0x40) {       /* Divider less than 4 */
               dev_dbg(mx3fb->dev,
                       "InitPanel() - Pixel clock divider less than 4\n");
               div = 0x40;
       }

       spin_lock_irqsave(&mx3fb->lock, lock_flags);

       /*
        * DISP3_IF_CLK_DOWN_WR is half the divider value and 2 fraction bits
        * fewer. Subtract 1 extra from DISP3_IF_CLK_DOWN_WR based on timing
        * debug. DISP3_IF_CLK_UP_WR is 0
        */
       mx3fb_write_reg(mx3fb, (((div / 8) - 1) << 22) | div, DI_DISP3_TIME_CONF);

       /* DI settings */
       old_conf = mx3fb_read_reg(mx3fb, DI_DISP_IF_CONF) & 0x78FFFFFF;
       old_conf |= sig.datamask_en << DI_D3_DATAMSK_SHIFT |
           sig.clksel_en << DI_D3_CLK_SEL_SHIFT |
           sig.clkidle_en << DI_D3_CLK_IDLE_SHIFT;
       mx3fb_write_reg(mx3fb, old_conf, DI_DISP_IF_CONF);

       old_conf = mx3fb_read_reg(mx3fb, DI_DISP_SIG_POL) & 0xE0FFFFFF;
       old_conf |= sig.data_pol << DI_D3_DATA_POL_SHIFT |
           sig.clk_pol << DI_D3_CLK_POL_SHIFT |
           sig.enable_pol << DI_D3_DRDY_SHARP_POL_SHIFT |
           sig.Hsync_pol << DI_D3_HSYNC_POL_SHIFT |
           sig.Vsync_pol << DI_D3_VSYNC_POL_SHIFT;
       mx3fb_write_reg(mx3fb, old_conf, DI_DISP_SIG_POL);

       switch (pixel_fmt) {
       case IPU_PIX_FMT_RGB24:
               mx3fb_write_reg(mx3fb, di_mappings[0], DI_DISP3_B0_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[1], DI_DISP3_B1_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[2], DI_DISP3_B2_MAP);
               mx3fb_write_reg(mx3fb, mx3fb_read_reg(mx3fb, DI_DISP_ACC_CC) |
                            ((di_mappings[3] - 1) << 12), DI_DISP_ACC_CC);
               break;
       case IPU_PIX_FMT_RGB666:
               mx3fb_write_reg(mx3fb, di_mappings[4], DI_DISP3_B0_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[5], DI_DISP3_B1_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[6], DI_DISP3_B2_MAP);
               mx3fb_write_reg(mx3fb, mx3fb_read_reg(mx3fb, DI_DISP_ACC_CC) |
                            ((di_mappings[7] - 1) << 12), DI_DISP_ACC_CC);
               break;
       case IPU_PIX_FMT_BGR666:
               mx3fb_write_reg(mx3fb, di_mappings[8], DI_DISP3_B0_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[9], DI_DISP3_B1_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[10], DI_DISP3_B2_MAP);
               mx3fb_write_reg(mx3fb, mx3fb_read_reg(mx3fb, DI_DISP_ACC_CC) |
                            ((di_mappings[11] - 1) << 12), DI_DISP_ACC_CC);
               break;
       default:
               mx3fb_write_reg(mx3fb, di_mappings[12], DI_DISP3_B0_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[13], DI_DISP3_B1_MAP);
               mx3fb_write_reg(mx3fb, di_mappings[14], DI_DISP3_B2_MAP);
               mx3fb_write_reg(mx3fb, mx3fb_read_reg(mx3fb, DI_DISP_ACC_CC) |
                            ((di_mappings[15] - 1) << 12), DI_DISP_ACC_CC);
               break;
       }

       spin_unlock_irqrestore(&mx3fb->lock, lock_flags);

       dev_dbg(mx3fb->dev, "DI_DISP_IF_CONF = 0x%08X\n",
               mx3fb_read_reg(mx3fb, DI_DISP_IF_CONF));
       dev_dbg(mx3fb->dev, "DI_DISP_SIG_POL = 0x%08X\n",
               mx3fb_read_reg(mx3fb, DI_DISP_SIG_POL));
       dev_dbg(mx3fb->dev, "DI_DISP3_TIME_CONF = 0x%08X\n",
               mx3fb_read_reg(mx3fb, DI_DISP3_TIME_CONF));

       return 0;
}

/**
 * sdc_set_color_key() - set the transparent color key for SDC graphic plane.
 * @mx3fb:     mx3fb context.
 * @channel:   IPU DMAC channel ID.
 * @enable:    boolean to enable or disable color keyl.
 * @color_key: 24-bit RGB color to use as transparent color key.
 * @return:    0 on success or negative error code on failure.
 */
static int sdc_set_color_key(struct mx3fb_data *mx3fb, enum ipu_channel channel,
                            bool enable, uint32_t color_key)
{
       uint32_t reg, sdc_conf;
       unsigned long lock_flags;

       spin_lock_irqsave(&mx3fb->lock, lock_flags);

       sdc_conf = mx3fb_read_reg(mx3fb, SDC_COM_CONF);
       if (channel == IDMAC_SDC_0)
               sdc_conf &= ~SDC_COM_GWSEL;
       else
               sdc_conf |= SDC_COM_GWSEL;

       if (enable) {
               reg = mx3fb_read_reg(mx3fb, SDC_GW_CTRL) & 0xFF000000L;
               mx3fb_write_reg(mx3fb, reg | (color_key & 0x00FFFFFFL),
                            SDC_GW_CTRL);

               sdc_conf |= SDC_COM_KEY_COLOR_G;
       } else {
               sdc_conf &= ~SDC_COM_KEY_COLOR_G;
       }
       mx3fb_write_reg(mx3fb, sdc_conf, SDC_COM_CONF);

       spin_unlock_irqrestore(&mx3fb->lock, lock_flags);

       return 0;
}

/**
 * sdc_set_global_alpha() - set global alpha blending modes.
 * @mx3fb:     mx3fb context.
 * @enable:    boolean to enable or disable global alpha blending. If disabled,
 *             per pixel blending is used.
 * @alpha:     global alpha value.
 * @return:    0 on success or negative error code on failure.
 */
static int sdc_set_global_alpha(struct mx3fb_data *mx3fb, bool enable, uint8_t alpha)
{
       uint32_t reg;
       unsigned long lock_flags;

       spin_lock_irqsave(&mx3fb->lock, lock_flags);

       if (enable) {
               reg = mx3fb_read_reg(mx3fb, SDC_GW_CTRL) & 0x00FFFFFFL;
               mx3fb_write_reg(mx3fb, reg | ((uint32_t) alpha << 24), SDC_GW_CTRL);

               reg = mx3fb_read_reg(mx3fb, SDC_COM_CONF);
               mx3fb_write_reg(mx3fb, reg | SDC_COM_GLB_A, SDC_COM_CONF);
       } else {
               reg = mx3fb_read_reg(mx3fb, SDC_COM_CONF);
               mx3fb_write_reg(mx3fb, reg & ~SDC_COM_GLB_A, SDC_COM_CONF);
       }

       spin_unlock_irqrestore(&mx3fb->lock, lock_flags);

       return 0;
}

static void sdc_set_brightness(struct mx3fb_data *mx3fb, uint8_t value)
{
       /* This might be board-specific */
       mx3fb_write_reg(mx3fb, 0x03000000UL | value << 16, SDC_PWM_CTRL);
       return;
}

static uint32_t bpp_to_pixfmt(int bpp)
{
       uint32_t pixfmt = 0;
       switch (bpp) {
       case 24:
               pixfmt = IPU_PIX_FMT_BGR24;
               break;
       case 32:
               pixfmt = IPU_PIX_FMT_BGR32;
               break;
       case 16:
               pixfmt = IPU_PIX_FMT_RGB565;
               break;
       }
       return pixfmt;
}

static int mx3fb_blank(int blank, struct fb_info *fbi);
static int mx3fb_map_video_memory(struct fb_info *fbi);
static int mx3fb_unmap_video_memory(struct fb_info *fbi);

/**
 * mx3fb_set_fix() - set fixed framebuffer parameters from variable settings.
 * @info:      framebuffer information pointer
 * @return:    0 on success or negative error code on failure.
 */
static int mx3fb_set_fix(struct fb_info *fbi)
{
       struct fb_fix_screeninfo *fix = &fbi->fix;
       struct fb_var_screeninfo *var = &fbi->var;

       strncpy(fix->id, "DISP3 BG", 8);

       fix->line_length = var->xres_virtual * var->bits_per_pixel / 8;

       fix->type = FB_TYPE_PACKED_PIXELS;
       fix->accel = FB_ACCEL_NONE;
       fix->visual = FB_VISUAL_TRUECOLOR;
       fix->xpanstep = 1;
       fix->ypanstep = 1;

       return 0;
}

static void mx3fb_dma_done(void *arg)
{
       struct idmac_tx_desc *tx_desc = to_tx_desc(arg);
       struct dma_chan *chan = tx_desc->txd.chan;
       struct idmac_channel *ichannel = to_idmac_chan(chan);
       struct mx3fb_data *mx3fb = ichannel->client;
       struct mx3fb_info *mx3_fbi = mx3fb->fbi->par;

       dev_dbg(mx3fb->dev, "irq %d callback\n", ichannel->eof_irq);

       /* We only need one interrupt, it will be re-enabled as needed */
       disable_irq(ichannel->eof_irq);

       complete(&mx3_fbi->flip_cmpl);
}

/**
 * mx3fb_set_par() - set framebuffer parameters and change the operating mode.
 * @fbi:       framebuffer information pointer.
 * @return:    0 on success or negative error code on failure.
 */
static int mx3fb_set_par(struct fb_info *fbi)
{
       u32 mem_len;
       struct ipu_di_signal_cfg sig_cfg;
       enum ipu_panel mode = IPU_PANEL_TFT;
       struct mx3fb_info *mx3_fbi = fbi->par;
       struct mx3fb_data *mx3fb = mx3_fbi->mx3fb;
       struct idmac_channel *ichan = mx3_fbi->idmac_channel;
       struct idmac_video_param *video = &ichan->params.video;
       struct scatterlist *sg = mx3_fbi->sg;
       size_t screen_size;

       dev_dbg(mx3fb->dev, "%s [%c]\n", __func__, list_empty(&ichan->queue) ? '-' : '+');

       mutex_lock(&mx3_fbi->mutex);

       /* Total cleanup */
       if (mx3_fbi->txd)
               sdc_disable_channel(mx3_fbi);

       mx3fb_set_fix(fbi);

       mem_len = fbi->var.yres_virtual * fbi->fix.line_length;
       if (mem_len > fbi->fix.smem_len) {
               if (fbi->fix.smem_start)
                       mx3fb_unmap_video_memory(fbi);

               fbi->fix.smem_len = mem_len;
               if (mx3fb_map_video_memory(fbi) < 0) {
                       mutex_unlock(&mx3_fbi->mutex);
                       return -ENOMEM;
               }
       }

       screen_size = fbi->fix.line_length * fbi->var.yres;

       sg_init_table(&sg[0], 1);
       sg_init_table(&sg[1], 1);

       sg_dma_address(&sg[0])  = fbi->fix.smem_start;
       sg_set_page(&sg[0], virt_to_page(fbi->screen_base),
                   fbi->fix.smem_len,
                   offset_in_page(fbi->screen_base));

       if (mx3_fbi->ipu_ch == IDMAC_SDC_0) {
               memset(&sig_cfg, 0, sizeof(sig_cfg));
               if (fbi->var.sync & FB_SYNC_HOR_HIGH_ACT)
                       sig_cfg.Hsync_pol = true;
               if (fbi->var.sync & FB_SYNC_VERT_HIGH_ACT)
                       sig_cfg.Vsync_pol = true;
               if (fbi->var.sync & FB_SYNC_CLK_INVERT)
                       sig_cfg.clk_pol = true;
               if (fbi->var.sync & FB_SYNC_DATA_INVERT)
                       sig_cfg.data_pol = true;
               if (fbi->var.sync & FB_SYNC_OE_ACT_HIGH)
                       sig_cfg.enable_pol = true;
               if (fbi->var.sync & FB_SYNC_CLK_IDLE_EN)
                       sig_cfg.clkidle_en = true;
               if (fbi->var.sync & FB_SYNC_CLK_SEL_EN)
                       sig_cfg.clksel_en = true;
               if (fbi->var.sync & FB_SYNC_SHARP_MODE)
                       mode = IPU_PANEL_SHARP_TFT;

               dev_dbg(fbi->device, "pixclock = %ul Hz\n",
                       (u32) (PICOS2KHZ(fbi->var.pixclock) * 1000UL));

               if (sdc_init_panel(mx3fb, mode,
                                  (PICOS2KHZ(fbi->var.pixclock)) * 1000UL,
                                  fbi->var.xres, fbi->var.yres,
                                  (fbi->var.sync & FB_SYNC_SWAP_RGB) ?
                                  IPU_PIX_FMT_BGR666 : IPU_PIX_FMT_RGB666,
                                  fbi->var.left_margin,
                                  fbi->var.hsync_len,
                                  fbi->var.right_margin +
                                  fbi->var.hsync_len,
                                  fbi->var.upper_margin,
                                  fbi->var.vsync_len,
                                  fbi->var.lower_margin +
                                  fbi->var.vsync_len, sig_cfg) != 0) {
                       mutex_unlock(&mx3_fbi->mutex);
                       dev_err(fbi->device,
                               "mx3fb: Error initializing panel.\n");
                       return -EINVAL;
               }
       }

       sdc_set_window_pos(mx3fb, mx3_fbi->ipu_ch, 0, 0);

       mx3_fbi->cur_ipu_buf    = 0;

       video->out_pixel_fmt    = bpp_to_pixfmt(fbi->var.bits_per_pixel);
       video->out_width        = fbi->var.xres;
       video->out_height       = fbi->var.yres;
       video->out_stride       = fbi->var.xres_virtual;

       if (mx3_fbi->blank == FB_BLANK_UNBLANK)
               sdc_enable_channel(mx3_fbi);

       mutex_unlock(&mx3_fbi->mutex);

       return 0;
}

/**
 * mx3fb_check_var() - check and adjust framebuffer variable parameters.
 * @var:       framebuffer variable parameters
 * @fbi:       framebuffer information pointer
 */
static int mx3fb_check_var(struct fb_var_screeninfo *var, struct fb_info *fbi)
{
       struct mx3fb_info *mx3_fbi = fbi->par;
       u32 vtotal;
       u32 htotal;

       dev_dbg(fbi->device, "%s\n", __func__);

       if (var->xres_virtual < var->xres)
               var->xres_virtual = var->xres;
       if (var->yres_virtual < var->yres)
               var->yres_virtual = var->yres;

       if ((var->bits_per_pixel != 32) && (var->bits_per_pixel != 24) &&
           (var->bits_per_pixel != 16))
               var->bits_per_pixel = default_bpp;

       switch (var->bits_per_pixel) {
       case 16:
               var->red.length = 5;
               var->red.offset = 11;
               var->red.msb_right = 0;

               var->green.length = 6;
               var->green.offset = 5;
               var->green.msb_right = 0;

               var->blue.length = 5;
               var->blue.offset = 0;
               var->blue.msb_right = 0;

               var->transp.length = 0;
               var->transp.offset = 0;
               var->transp.msb_right = 0;
               break;
       case 24:
               var->red.length = 8;
               var->red.offset = 16;
               var->red.msb_right = 0;

               var->green.length = 8;
               var->green.offset = 8;
               var->green.msb_right = 0;

               var->blue.length = 8;
               var->blue.offset = 0;
               var->blue.msb_right = 0;

               var->transp.length = 0;
               var->transp.offset = 0;
               var->transp.msb_right = 0;
               break;
       case 32:
               var->red.length = 8;
               var->red.offset = 16;
               var->red.msb_right = 0;

               var->green.length = 8;
               var->green.offset = 8;
               var->green.msb_right = 0;

               var->blue.length = 8;
               var->blue.offset = 0;
               var->blue.msb_right = 0;

               var->transp.length = 8;
               var->transp.offset = 24;
               var->transp.msb_right = 0;
               break;
       }

       if (var->pixclock < 1000) {
               htotal = var->xres + var->right_margin + var->hsync_len +
                   var->left_margin;
               vtotal = var->yres + var->lower_margin + var->vsync_len +
                   var->upper_margin;
               var->pixclock = (vtotal * htotal * 6UL) / 100UL;
               var->pixclock = KHZ2PICOS(var->pixclock);
               dev_dbg(fbi->device, "pixclock set for 60Hz refresh = %u ps\n",
                       var->pixclock);
       }

       var->height = -1;
       var->width = -1;
       var->grayscale = 0;

       /* Preserve sync flags */
       var->sync |= mx3_fbi->sync;
       mx3_fbi->sync |= var->sync;

       return 0;
}

static u32 chan_to_field(unsigned int chan, struct fb_bitfield *bf)
{
       chan &= 0xffff;
       chan >>= 16 - bf->length;
       return chan << bf->offset;
}

static int mx3fb_setcolreg(unsigned int regno, unsigned int red,
                          unsigned int green, unsigned int blue,
                          unsigned int trans, struct fb_info *fbi)
{
       struct mx3fb_info *mx3_fbi = fbi->par;
       u32 val;
       int ret = 1;

       dev_dbg(fbi->device, "%s\n", __func__);

       mutex_lock(&mx3_fbi->mutex);
       /*
        * If greyscale is true, then we convert the RGB value
        * to greyscale no matter what visual we are using.
        */
       if (fbi->var.grayscale)
               red = green = blue = (19595 * red + 38470 * green +
                                     7471 * blue) >> 16;
       switch (fbi->fix.visual) {
       case FB_VISUAL_TRUECOLOR:
               /*
                * 16-bit True Colour.  We encode the RGB value
                * according to the RGB bitfield information.
                */
               if (regno < 16) {
                       u32 *pal = fbi->pseudo_palette;

                       val = chan_to_field(red, &fbi->var.red);
                       val |= chan_to_field(green, &fbi->var.green);
                       val |= chan_to_field(blue, &fbi->var.blue);

                       pal[regno] = val;

                       ret = 0;
               }
               break;

       case FB_VISUAL_STATIC_PSEUDOCOLOR:
       case FB_VISUAL_PSEUDOCOLOR:
               break;
       }
       mutex_unlock(&mx3_fbi->mutex);

       return ret;
}

/**
 * mx3fb_blank() - blank the display.
 */
static int mx3fb_blank(int blank, struct fb_info *fbi)
{
       struct mx3fb_info *mx3_fbi = fbi->par;
       struct mx3fb_data *mx3fb = mx3_fbi->mx3fb;

       dev_dbg(fbi->device, "%s\n", __func__);

       dev_dbg(fbi->device, "blank = %d\n", blank);

       if (mx3_fbi->blank == blank)
               return 0;

       mutex_lock(&mx3_fbi->mutex);
       mx3_fbi->blank = blank;

       switch (blank) {
       case FB_BLANK_POWERDOWN:
       case FB_BLANK_VSYNC_SUSPEND:
       case FB_BLANK_HSYNC_SUSPEND:
       case FB_BLANK_NORMAL:
               sdc_disable_channel(mx3_fbi);
               sdc_set_brightness(mx3fb, 0);
               break;
       case FB_BLANK_UNBLANK:
               sdc_enable_channel(mx3_fbi);
               sdc_set_brightness(mx3fb, mx3fb->backlight_level);
               break;
       }
       mutex_unlock(&mx3_fbi->mutex);

       return 0;
}

/**
 * mx3fb_pan_display() - pan or wrap the display
 * @var:       variable screen buffer information.
 * @info:      framebuffer information pointer.
 *
 * We look only at xoffset, yoffset and the FB_VMODE_YWRAP flag
 */
static int mx3fb_pan_display(struct fb_var_screeninfo *var,
                            struct fb_info *fbi)
{
       struct mx3fb_info *mx3_fbi = fbi->par;
       u32 y_bottom;
       unsigned long base;
       off_t offset;
       dma_cookie_t cookie;
       struct scatterlist *sg = mx3_fbi->sg;
       struct dma_chan *dma_chan = &mx3_fbi->idmac_channel->dma_chan;
       struct dma_async_tx_descriptor *txd;
       int ret;

       dev_dbg(fbi->device, "%s [%c]\n", __func__,
               list_empty(&mx3_fbi->idmac_channel->queue) ? '-' : '+');

       if (var->xoffset > 0) {
               dev_dbg(fbi->device, "x panning not supported\n");
               return -EINVAL;
       }

       if (fbi->var.xoffset == var->xoffset &&
           fbi->var.yoffset == var->yoffset)
               return 0;       /* No change, do nothing */

       y_bottom = var->yoffset;

       if (!(var->vmode & FB_VMODE_YWRAP))
               y_bottom += var->yres;

       if (y_bottom > fbi->var.yres_virtual)
               return -EINVAL;

       mutex_lock(&mx3_fbi->mutex);

       offset = (var->yoffset * var->xres_virtual + var->xoffset) *
               (var->bits_per_pixel / 8);
       base = fbi->fix.smem_start + offset;

       dev_dbg(fbi->device, "Updating SDC BG buf %d address=0x%08lX\n",
               mx3_fbi->cur_ipu_buf, base);

       /*
        * We enable the End of Frame interrupt, which will free a tx-descriptor,
        * which we will need for the next device_prep_slave_sg(). The
        * IRQ-handler will disable the IRQ again.
        */
       init_completion(&mx3_fbi->flip_cmpl);
       enable_irq(mx3_fbi->idmac_channel->eof_irq);

       ret = wait_for_completion_timeout(&mx3_fbi->flip_cmpl, HZ / 10);
       if (ret <= 0) {
               mutex_unlock(&mx3_fbi->mutex);
               dev_info(fbi->device, "Panning failed due to %s\n", ret < 0 ?
                        "user interrupt" : "timeout");
               return ret ? : -ETIMEDOUT;
       }

       mx3_fbi->cur_ipu_buf = !mx3_fbi->cur_ipu_buf;

       sg_dma_address(&sg[mx3_fbi->cur_ipu_buf]) = base;
       sg_set_page(&sg[mx3_fbi->cur_ipu_buf],
                   virt_to_page(fbi->screen_base + offset), fbi->fix.smem_len,
                   offset_in_page(fbi->screen_base + offset));

       txd = dma_chan->device->device_prep_slave_sg(dma_chan, sg +
               mx3_fbi->cur_ipu_buf, 1, DMA_TO_DEVICE, DMA_PREP_INTERRUPT);
       if (!txd) {
               dev_err(fbi->device,
                       "Error preparing a DMA transaction descriptor.\n");
               mutex_unlock(&mx3_fbi->mutex);
               return -EIO;
       }

       txd->callback_param     = txd;
       txd->callback           = mx3fb_dma_done;

       /*
        * Emulate original mx3fb behaviour: each new call to idmac_tx_submit()
        * should switch to another buffer
        */
       cookie = txd->tx_submit(txd);
       dev_dbg(fbi->device, "%d: Submit %p #%d\n", __LINE__, txd, cookie);
       if (cookie < 0) {
               dev_err(fbi->device,
                       "Error updating SDC buf %d to address=0x%08lX\n",
                       mx3_fbi->cur_ipu_buf, base);
               mutex_unlock(&mx3_fbi->mutex);
               return -EIO;
       }

       if (mx3_fbi->txd)
               async_tx_ack(mx3_fbi->txd);
       mx3_fbi->txd = txd;

       fbi->var.xoffset = var->xoffset;
       fbi->var.yoffset = var->yoffset;

       if (var->vmode & FB_VMODE_YWRAP)
               fbi->var.vmode |= FB_VMODE_YWRAP;
       else
               fbi->var.vmode &= ~FB_VMODE_YWRAP;

       mutex_unlock(&mx3_fbi->mutex);

       dev_dbg(fbi->device, "Update complete\n");

       return 0;
}

/*
 * This structure contains the pointers to the control functions that are
 * invoked by the core framebuffer driver to perform operations like
 * blitting, rectangle filling, copy regions and cursor definition.
 */
static struct fb_ops mx3fb_ops = {
       .owner = THIS_MODULE,
       .fb_set_par = mx3fb_set_par,
       .fb_check_var = mx3fb_check_var,
       .fb_setcolreg = mx3fb_setcolreg,
       .fb_pan_display = mx3fb_pan_display,
       .fb_fillrect = cfb_fillrect,
       .fb_copyarea = cfb_copyarea,
       .fb_imageblit = cfb_imageblit,
       .fb_blank = mx3fb_blank,
};

#ifdef CONFIG_PM
/*
 * Power management hooks.      Note that we won't be called from IRQ context,
 * unlike the blank functions above, so we may sleep.
 */

/*
 * Suspends the framebuffer and blanks the screen. Power management support
 */
static int mx3fb_suspend(struct platform_device *pdev, pm_message_t state)
{
       struct mx3fb_data *drv_data = platform_get_drvdata(pdev);
       struct mx3fb_info *mx3_fbi = drv_data->fbi->par;

       acquire_console_sem();
       fb_set_suspend(drv_data->fbi, 1);
       release_console_sem();

       if (mx3_fbi->blank == FB_BLANK_UNBLANK) {
               sdc_disable_channel(mx3_fbi);
               sdc_set_brightness(mx3fb, 0);

       }
       return 0;
}

/*
 * Resumes the framebuffer and unblanks the screen. Power management support
 */
static int mx3fb_resume(struct platform_device *pdev)
{
       struct mx3fb_data *drv_data = platform_get_drvdata(pdev);
       struct mx3fb_info *mx3_fbi = drv_data->fbi->par;

       if (mx3_fbi->blank == FB_BLANK_UNBLANK) {
               sdc_enable_channel(mx3_fbi);
               sdc_set_brightness(mx3fb, drv_data->backlight_level);
       }

       acquire_console_sem();
       fb_set_suspend(drv_data->fbi, 0);
       release_console_sem();

       return 0;
}
#else
#define mx3fb_suspend   NULL
#define mx3fb_resume    NULL
#endif

/*
 * Main framebuffer functions
 */

/**
 * mx3fb_map_video_memory() - allocates the DRAM memory for the frame buffer.
 * @fbi:       framebuffer information pointer
 * @return:    Error code indicating success or failure
 *
 * This buffer is remapped into a non-cached, non-buffered, memory region to
 * allow palette and pixel writes to occur without flushing the cache. Once this
 * area is remapped, all virtual memory access to the video memory should occur
 * at the new region.
 */
static int mx3fb_map_video_memory(struct fb_info *fbi)
{
       int retval = 0;
       dma_addr_t addr;

       fbi->screen_base = dma_alloc_writecombine(fbi->device,
                                                 fbi->fix.smem_len,
                                                 &addr, GFP_DMA);

       if (!fbi->screen_base) {
               dev_err(fbi->device, "Cannot allocate %u bytes framebuffer memory\n",
                       fbi->fix.smem_len);
               retval = -EBUSY;
               goto err0;
       }

       fbi->fix.smem_start = addr;

       dev_dbg(fbi->device, "allocated fb @ p=0x%08x, v=0x%p, size=%d.\n",
               (uint32_t) fbi->fix.smem_start, fbi->screen_base, fbi->fix.smem_len);

       fbi->screen_size = fbi->fix.smem_len;

       /* Clear the screen */
       memset((char *)fbi->screen_base, 0, fbi->fix.smem_len);

       return 0;

err0:
       fbi->fix.smem_len = 0;
       fbi->fix.smem_start = 0;
       fbi->screen_base = NULL;
       return retval;
}

/**
 * mx3fb_unmap_video_memory() - de-allocate frame buffer memory.
 * @fbi:       framebuffer information pointer
 * @return:    error code indicating success or failure
 */
static int mx3fb_unmap_video_memory(struct fb_info *fbi)
{
       dma_free_writecombine(fbi->device, fbi->fix.smem_len,
                             fbi->screen_base, fbi->fix.smem_start);

       fbi->screen_base = 0;
       fbi->fix.smem_start = 0;
       fbi->fix.smem_len = 0;
       return 0;
}

/**
 * mx3fb_init_fbinfo() - initialize framebuffer information object.
 * @return:    initialized framebuffer structure.
 */
static struct fb_info *mx3fb_init_fbinfo(struct device *dev, struct fb_ops *ops)
{
       struct fb_info *fbi;
       struct mx3fb_info *mx3fbi;
       int ret;

       /* Allocate sufficient memory for the fb structure */
       fbi = framebuffer_alloc(sizeof(struct mx3fb_info), dev);
       if (!fbi)
               return NULL;

       mx3fbi                  = fbi->par;
       mx3fbi->cookie          = -EINVAL;
       mx3fbi->cur_ipu_buf     = 0;

       fbi->var.activate       = FB_ACTIVATE_NOW;

       fbi->fbops              = ops;
       fbi->flags              = FBINFO_FLAG_DEFAULT;
       fbi->pseudo_palette     = mx3fbi->pseudo_palette;

       mutex_init(&mx3fbi->mutex);

       /* Allocate colormap */
       ret = fb_alloc_cmap(&fbi->cmap, 16, 0);
       if (ret < 0) {
               framebuffer_release(fbi);
               return NULL;
       }

       return fbi;
}

static int init_fb_chan(struct mx3fb_data *mx3fb, struct idmac_channel *ichan)
{
       struct device *dev = mx3fb->dev;
       struct mx3fb_platform_data *mx3fb_pdata = dev->platform_data;
       const char *name = mx3fb_pdata->name;
       unsigned int irq;
       struct fb_info *fbi;
       struct mx3fb_info *mx3fbi;
       const struct fb_videomode *mode;
       int ret, num_modes;

       ichan->client = mx3fb;
       irq = ichan->eof_irq;

       if (ichan->dma_chan.chan_id != IDMAC_SDC_0)
               return -EINVAL;

       fbi = mx3fb_init_fbinfo(dev, &mx3fb_ops);
       if (!fbi)
               return -ENOMEM;

       if (!fb_mode)
               fb_mode = name;

       if (!fb_mode) {
               ret = -EINVAL;
               goto emode;
       }

       if (mx3fb_pdata->mode && mx3fb_pdata->num_modes) {
               mode = mx3fb_pdata->mode;
               num_modes = mx3fb_pdata->num_modes;
       } else {
               mode = mx3fb_modedb;
               num_modes = ARRAY_SIZE(mx3fb_modedb);
       }

       if (!fb_find_mode(&fbi->var, fbi, fb_mode, mode,
                         num_modes, NULL, default_bpp)) {
               ret = -EBUSY;
               goto emode;
       }

       fb_videomode_to_modelist(mode, num_modes, &fbi->modelist);

       /* Default Y virtual size is 2x panel size */
       fbi->var.yres_virtual = fbi->var.yres * 2;

       mx3fb->fbi = fbi;

       /* set Display Interface clock period */
       mx3fb_write_reg(mx3fb, 0x00100010L, DI_HSP_CLK_PER);
       /* Might need to trigger HSP clock change - see 44.3.3.8.5 */

       sdc_set_brightness(mx3fb, 255);
       sdc_set_global_alpha(mx3fb, true, 0xFF);
       sdc_set_color_key(mx3fb, IDMAC_SDC_0, false, 0);

       mx3fbi                  = fbi->par;
       mx3fbi->idmac_channel   = ichan;
       mx3fbi->ipu_ch          = ichan->dma_chan.chan_id;
       mx3fbi->mx3fb           = mx3fb;
       mx3fbi->blank           = FB_BLANK_NORMAL;

       init_completion(&mx3fbi->flip_cmpl);
       disable_irq(ichan->eof_irq);
       dev_dbg(mx3fb->dev, "disabling irq %d\n", ichan->eof_irq);
       ret = mx3fb_set_par(fbi);
       if (ret < 0)
               goto esetpar;

       mx3fb_blank(FB_BLANK_UNBLANK, fbi);

       dev_info(dev, "mx3fb: fb registered, using mode %s\n", fb_mode);

       ret = register_framebuffer(fbi);
       if (ret < 0)
               goto erfb;

       return 0;

erfb:
esetpar:
emode:
       fb_dealloc_cmap(&fbi->cmap);
       framebuffer_release(fbi);

       return ret;
}

static bool chan_filter(struct dma_chan *chan, void *arg)
{
       struct dma_chan_request *rq = arg;
       struct device *dev;
       struct mx3fb_platform_data *mx3fb_pdata;

       if (!rq)
               return false;

       dev = rq->mx3fb->dev;
       mx3fb_pdata = dev->platform_data;

       return rq->id == chan->chan_id &&
               mx3fb_pdata->dma_dev == chan->device->dev;
}

static void release_fbi(struct fb_info *fbi)
{
       mx3fb_unmap_video_memory(fbi);

       fb_dealloc_cmap(&fbi->cmap);

       unregister_framebuffer(fbi);
       framebuffer_release(fbi);
}

static int mx3fb_probe(struct platform_device *pdev)
{
       struct device *dev = &pdev->dev;
       int ret;
       struct resource *sdc_reg;
       struct mx3fb_data *mx3fb;
       dma_cap_mask_t mask;
       struct dma_chan *chan;
       struct dma_chan_request rq;

       /*
        * Display Interface (DI) and Synchronous Display Controller (SDC)
        * registers
        */
       sdc_reg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
       if (!sdc_reg)
               return -EINVAL;

       mx3fb = kzalloc(sizeof(*mx3fb), GFP_KERNEL);
       if (!mx3fb)
               return -ENOMEM;

       spin_lock_init(&mx3fb->lock);

       mx3fb->reg_base = ioremap(sdc_reg->start, resource_size(sdc_reg));
       if (!mx3fb->reg_base) {
               ret = -ENOMEM;
               goto eremap;
       }

       pr_debug("Remapped %x to %x at %p\n", sdc_reg->start, sdc_reg->end,
                mx3fb->reg_base);

       /* IDMAC interface */
       dmaengine_get();

       mx3fb->dev = dev;
       platform_set_drvdata(pdev, mx3fb);

       rq.mx3fb = mx3fb;

       dma_cap_zero(mask);
       dma_cap_set(DMA_SLAVE, mask);
       dma_cap_set(DMA_PRIVATE, mask);
       rq.id = IDMAC_SDC_0;
       chan = dma_request_channel(mask, chan_filter, &rq);
       if (!chan) {
               ret = -EBUSY;
               goto ersdc0;
       }

       ret = init_fb_chan(mx3fb, to_idmac_chan(chan));
       if (ret < 0)
               goto eisdc0;

       mx3fb->backlight_level = 255;

       return 0;

eisdc0:
       dma_release_channel(chan);
ersdc0:
       dmaengine_put();
       iounmap(mx3fb->reg_base);
eremap:
       kfree(mx3fb);
       dev_err(dev, "mx3fb: failed to register fb\n");
       return ret;
}

static int mx3fb_remove(struct platform_device *dev)
{
       struct mx3fb_data *mx3fb = platform_get_drvdata(dev);
       struct fb_info *fbi = mx3fb->fbi;
       struct mx3fb_info *mx3_fbi = fbi->par;
       struct dma_chan *chan;

       chan = &mx3_fbi->idmac_channel->dma_chan;
       release_fbi(fbi);

       dma_release_channel(chan);
       dmaengine_put();

       iounmap(mx3fb->reg_base);
       kfree(mx3fb);
       return 0;
}

static struct platform_driver mx3fb_driver = {
       .driver = {
                  .name = MX3FB_NAME,
       },
       .probe = mx3fb_probe,
       .remove = mx3fb_remove,
       .suspend = mx3fb_suspend,
       .resume = mx3fb_resume,
};

/*
 * Parse user specified options (`video=mx3fb:')
 * example:
 *     video=mx3fb:bpp=16
 */
static int mx3fb_setup(void)
{
#ifndef MODULE
       char *opt, *options = NULL;

       if (fb_get_options("mx3fb", &options))
               return -ENODEV;

       if (!options || !*options)
               return 0;

       while ((opt = strsep(&options, ",")) != NULL) {
               if (!*opt)
                       continue;
               if (!strncmp(opt, "bpp=", 4))
                       default_bpp = simple_strtoul(opt + 4, NULL, 0);
               else
                       fb_mode = opt;
       }
#endif

       return 0;
}

static int __init mx3fb_init(void)
{
       int ret = mx3fb_setup();

       if (ret < 0)
               return ret;

       ret = platform_driver_register(&mx3fb_driver);
       return ret;
}

static void __exit mx3fb_exit(void)
{
       platform_driver_unregister(&mx3fb_driver);
}

module_init(mx3fb_init);
module_exit(mx3fb_exit);

MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MX3 framebuffer driver");
MODULE_ALIAS("platform:" MX3FB_NAME);
MODULE_LICENSE("GPL v2");