Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

[mirror_ubuntu-bionic-kernel.git] / drivers / video / imxfb.c

/*
 *  Freescale i.MX Frame Buffer device driver
 *
 *  Copyright (C) 2004 Sascha Hauer, Pengutronix
 *   Based on acornfb.c Copyright (C) Russell King.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 * Please direct your questions and comments on this driver to the following
 * email address:
 *
 *      linux-arm-kernel@lists.arm.linux.org.uk
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/cpufreq.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/math64.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <video/of_display_timing.h>
#include <video/of_videomode.h>
#include <video/videomode.h>

#include <linux/platform_data/video-imxfb.h>

/*
 * Complain if VAR is out of range.
 */
#define DEBUG_VAR 1

#if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) || \
        (defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE) && \
                defined(CONFIG_FB_IMX_MODULE))
#define PWMR_BACKLIGHT_AVAILABLE
#endif

#define DRIVER_NAME "imx-fb"

#define LCDC_SSA        0x00

#define LCDC_SIZE       0x04
#define SIZE_XMAX(x)    ((((x) >> 4) & 0x3f) << 20)

#define YMAX_MASK_IMX1  0x1ff
#define YMAX_MASK_IMX21 0x3ff

#define LCDC_VPW        0x08
#define VPW_VPW(x)      ((x) & 0x3ff)

#define LCDC_CPOS       0x0C
#define CPOS_CC1        (1<<31)
#define CPOS_CC0        (1<<30)
#define CPOS_OP         (1<<28)
#define CPOS_CXP(x)     (((x) & 3ff) << 16)

#define LCDC_LCWHB      0x10
#define LCWHB_BK_EN     (1<<31)
#define LCWHB_CW(w)     (((w) & 0x1f) << 24)
#define LCWHB_CH(h)     (((h) & 0x1f) << 16)
#define LCWHB_BD(x)     ((x) & 0xff)

#define LCDC_LCHCC      0x14

#define LCDC_PCR        0x18

#define LCDC_HCR        0x1C
#define HCR_H_WIDTH(x)  (((x) & 0x3f) << 26)
#define HCR_H_WAIT_1(x) (((x) & 0xff) << 8)
#define HCR_H_WAIT_2(x) ((x) & 0xff)

#define LCDC_VCR        0x20
#define VCR_V_WIDTH(x)  (((x) & 0x3f) << 26)
#define VCR_V_WAIT_1(x) (((x) & 0xff) << 8)
#define VCR_V_WAIT_2(x) ((x) & 0xff)

#define LCDC_POS        0x24
#define POS_POS(x)      ((x) & 1f)

#define LCDC_LSCR1      0x28
/* bit fields in imxfb.h */

#define LCDC_PWMR       0x2C
/* bit fields in imxfb.h */

#define LCDC_DMACR      0x30
/* bit fields in imxfb.h */

#define LCDC_RMCR       0x34

#define RMCR_LCDC_EN_MX1        (1<<1)

#define RMCR_SELF_REF   (1<<0)

#define LCDC_LCDICR     0x38
#define LCDICR_INT_SYN  (1<<2)
#define LCDICR_INT_CON  (1)

#define LCDC_LCDISR     0x40
#define LCDISR_UDR_ERR  (1<<3)
#define LCDISR_ERR_RES  (1<<2)
#define LCDISR_EOF      (1<<1)
#define LCDISR_BOF      (1<<0)

#define IMXFB_LSCR1_DEFAULT 0x00120300

/* Used fb-mode. Can be set on kernel command line, therefore file-static. */
static const char *fb_mode;

/*
 * These are the bitfields for each
 * display depth that we support.
 */
struct imxfb_rgb {
        struct fb_bitfield      red;
        struct fb_bitfield      green;
        struct fb_bitfield      blue;
        struct fb_bitfield      transp;
};

enum imxfb_type {
        IMX1_FB,
        IMX21_FB,
};

struct imxfb_info {
        struct platform_device  *pdev;
        void __iomem            *regs;
        struct clk              *clk_ipg;
        struct clk              *clk_ahb;
        struct clk              *clk_per;
        enum imxfb_type         devtype;
        bool                    enabled;

        /*
         * These are the addresses we mapped
         * the framebuffer memory region to.
         */
        dma_addr_t              map_dma;
        u_char                  *map_cpu;
        u_int                   map_size;

        u_char                  *screen_cpu;
        dma_addr_t              screen_dma;
        u_int                   palette_size;

        dma_addr_t              dbar1;
        dma_addr_t              dbar2;

        u_int                   pcr;
        u_int                   pwmr;
        u_int                   lscr1;
        u_int                   dmacr;
        u_int                   cmap_inverse:1,
                                cmap_static:1,
                                unused:30;

        struct imx_fb_videomode *mode;
        int                     num_modes;
#ifdef PWMR_BACKLIGHT_AVAILABLE
        struct backlight_device *bl;
#endif

        void (*lcd_power)(int);
        void (*backlight_power)(int);
};

static struct platform_device_id imxfb_devtype[] = {
        {
                .name = "imx1-fb",
                .driver_data = IMX1_FB,
        }, {
                .name = "imx21-fb",
                .driver_data = IMX21_FB,
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(platform, imxfb_devtype);

static struct of_device_id imxfb_of_dev_id[] = {
        {
                .compatible = "fsl,imx1-fb",
                .data = &imxfb_devtype[IMX1_FB],
        }, {
                .compatible = "fsl,imx21-fb",
                .data = &imxfb_devtype[IMX21_FB],
        }, {
                /* sentinel */
        }
};
MODULE_DEVICE_TABLE(of, imxfb_of_dev_id);

static inline int is_imx1_fb(struct imxfb_info *fbi)
{
        return fbi->devtype == IMX1_FB;
}

#define IMX_NAME        "IMX"

/*
 * Minimum X and Y resolutions
 */
#define MIN_XRES        64
#define MIN_YRES        64

/* Actually this really is 18bit support, the lowest 2 bits of each colour
 * are unused in hardware. We claim to have 24bit support to make software
 * like X work, which does not support 18bit.
 */
static struct imxfb_rgb def_rgb_18 = {
        .red    = {.offset = 16, .length = 8,},
        .green  = {.offset = 8, .length = 8,},
        .blue   = {.offset = 0, .length = 8,},
        .transp = {.offset = 0, .length = 0,},
};

static struct imxfb_rgb def_rgb_16_tft = {
        .red    = {.offset = 11, .length = 5,},
        .green  = {.offset = 5, .length = 6,},
        .blue   = {.offset = 0, .length = 5,},
        .transp = {.offset = 0, .length = 0,},
};

static struct imxfb_rgb def_rgb_16_stn = {
        .red    = {.offset = 8, .length = 4,},
        .green  = {.offset = 4, .length = 4,},
        .blue   = {.offset = 0, .length = 4,},
        .transp = {.offset = 0, .length = 0,},
};

static struct imxfb_rgb def_rgb_8 = {
        .red    = {.offset = 0, .length = 8,},
        .green  = {.offset = 0, .length = 8,},
        .blue   = {.offset = 0, .length = 8,},
        .transp = {.offset = 0, .length = 0,},
};

static int imxfb_activate_var(struct fb_var_screeninfo *var,
                struct fb_info *info);

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

static int imxfb_setpalettereg(u_int regno, u_int red, u_int green, u_int blue,
                u_int trans, struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;
        u_int val, ret = 1;

#define CNVT_TOHW(val,width) ((((val)<<(width))+0x7FFF-(val))>>16)
        if (regno < fbi->palette_size) {
                val = (CNVT_TOHW(red, 4) << 8) |
                      (CNVT_TOHW(green,4) << 4) |
                      CNVT_TOHW(blue,  4);

                writel(val, fbi->regs + 0x800 + (regno << 2));
                ret = 0;
        }
        return ret;
}

static int imxfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                   u_int trans, struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;
        unsigned int val;
        int ret = 1;

        /*
         * If inverse mode was selected, invert all the colours
         * rather than the register number.  The register number
         * is what you poke into the framebuffer to produce the
         * colour you requested.
         */
        if (fbi->cmap_inverse) {
                red   = 0xffff - red;
                green = 0xffff - green;
                blue  = 0xffff - blue;
        }

        /*
         * If greyscale is true, then we convert the RGB value
         * to greyscale no mater what visual we are using.
         */
        if (info->var.grayscale)
                red = green = blue = (19595 * red + 38470 * green +
                                        7471 * blue) >> 16;

        switch (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 = info->pseudo_palette;

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

                        pal[regno] = val;
                        ret = 0;
                }
                break;

        case FB_VISUAL_STATIC_PSEUDOCOLOR:
        case FB_VISUAL_PSEUDOCOLOR:
                ret = imxfb_setpalettereg(regno, red, green, blue, trans, info);
                break;
        }

        return ret;
}

static const struct imx_fb_videomode *imxfb_find_mode(struct imxfb_info *fbi)
{
        struct imx_fb_videomode *m;
        int i;

        if (!fb_mode)
                return &fbi->mode[0];

        for (i = 0, m = &fbi->mode[0]; i < fbi->num_modes; i++, m++) {
                if (!strcmp(m->mode.name, fb_mode))
                        return m;
        }
        return NULL;
}

/*
 *  imxfb_check_var():
 *    Round up in the following order: bits_per_pixel, xres,
 *    yres, xres_virtual, yres_virtual, xoffset, yoffset, grayscale,
 *    bitfields, horizontal timing, vertical timing.
 */
static int imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;
        struct imxfb_rgb *rgb;
        const struct imx_fb_videomode *imxfb_mode;
        unsigned long lcd_clk;
        unsigned long long tmp;
        u32 pcr = 0;

        if (var->xres < MIN_XRES)
                var->xres = MIN_XRES;
        if (var->yres < MIN_YRES)
                var->yres = MIN_YRES;

        imxfb_mode = imxfb_find_mode(fbi);
        if (!imxfb_mode)
                return -EINVAL;

        var->xres               = imxfb_mode->mode.xres;
        var->yres               = imxfb_mode->mode.yres;
        var->bits_per_pixel     = imxfb_mode->bpp;
        var->pixclock           = imxfb_mode->mode.pixclock;
        var->hsync_len          = imxfb_mode->mode.hsync_len;
        var->left_margin        = imxfb_mode->mode.left_margin;
        var->right_margin       = imxfb_mode->mode.right_margin;
        var->vsync_len          = imxfb_mode->mode.vsync_len;
        var->upper_margin       = imxfb_mode->mode.upper_margin;
        var->lower_margin       = imxfb_mode->mode.lower_margin;
        var->sync               = imxfb_mode->mode.sync;
        var->xres_virtual       = max(var->xres_virtual, var->xres);
        var->yres_virtual       = max(var->yres_virtual, var->yres);

        pr_debug("var->bits_per_pixel=%d\n", var->bits_per_pixel);

        lcd_clk = clk_get_rate(fbi->clk_per);

        tmp = var->pixclock * (unsigned long long)lcd_clk;

        do_div(tmp, 1000000);

        if (do_div(tmp, 1000000) > 500000)
                tmp++;

        pcr = (unsigned int)tmp;

        if (--pcr > 0x3F) {
                pcr = 0x3F;
                printk(KERN_WARNING "Must limit pixel clock to %luHz\n",
                                lcd_clk / pcr);
        }

        switch (var->bits_per_pixel) {
        case 32:
                pcr |= PCR_BPIX_18;
                rgb = &def_rgb_18;
                break;
        case 16:
        default:
                if (is_imx1_fb(fbi))
                        pcr |= PCR_BPIX_12;
                else
                        pcr |= PCR_BPIX_16;

                if (imxfb_mode->pcr & PCR_TFT)
                        rgb = &def_rgb_16_tft;
                else
                        rgb = &def_rgb_16_stn;
                break;
        case 8:
                pcr |= PCR_BPIX_8;
                rgb = &def_rgb_8;
                break;
        }

        /* add sync polarities */
        pcr |= imxfb_mode->pcr & ~(0x3f | (7 << 25));

        fbi->pcr = pcr;

        /*
         * 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;

        pr_debug("RGBT length = %d:%d:%d:%d\n",
                var->red.length, var->green.length, var->blue.length,
                var->transp.length);

        pr_debug("RGBT offset = %d:%d:%d:%d\n",
                var->red.offset, var->green.offset, var->blue.offset,
                var->transp.offset);

        return 0;
}

/*
 * imxfb_set_par():
 *      Set the user defined part of the display for the specified console
 */
static int imxfb_set_par(struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;
        struct fb_var_screeninfo *var = &info->var;

        if (var->bits_per_pixel == 16 || var->bits_per_pixel == 32)
                info->fix.visual = FB_VISUAL_TRUECOLOR;
        else if (!fbi->cmap_static)
                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        else {
                /*
                 * Some people have weird ideas about wanting static
                 * pseudocolor maps.  I suspect their user space
                 * applications are broken.
                 */
                info->fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
        }

        info->fix.line_length = var->xres_virtual * var->bits_per_pixel / 8;
        fbi->palette_size = var->bits_per_pixel == 8 ? 256 : 16;

        imxfb_activate_var(var, info);

        return 0;
}

#ifdef PWMR_BACKLIGHT_AVAILABLE
static int imxfb_bl_get_brightness(struct backlight_device *bl)
{
        struct imxfb_info *fbi = bl_get_data(bl);

        return readl(fbi->regs + LCDC_PWMR) & 0xFF;
}

static int imxfb_bl_update_status(struct backlight_device *bl)
{
        struct imxfb_info *fbi = bl_get_data(bl);
        int brightness = bl->props.brightness;

        if (!fbi->pwmr)
                return 0;

        if (bl->props.power != FB_BLANK_UNBLANK)
                brightness = 0;
        if (bl->props.fb_blank != FB_BLANK_UNBLANK)
                brightness = 0;

        fbi->pwmr = (fbi->pwmr & ~0xFF) | brightness;

        if (bl->props.fb_blank != FB_BLANK_UNBLANK) {
                clk_prepare_enable(fbi->clk_ipg);
                clk_prepare_enable(fbi->clk_ahb);
                clk_prepare_enable(fbi->clk_per);
        }
        writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
        if (bl->props.fb_blank != FB_BLANK_UNBLANK) {
                clk_disable_unprepare(fbi->clk_per);
                clk_disable_unprepare(fbi->clk_ahb);
                clk_disable_unprepare(fbi->clk_ipg);
        }

        return 0;
}

static const struct backlight_ops imxfb_lcdc_bl_ops = {
        .update_status = imxfb_bl_update_status,
        .get_brightness = imxfb_bl_get_brightness,
};

static void imxfb_init_backlight(struct imxfb_info *fbi)
{
        struct backlight_properties props;
        struct backlight_device *bl;

        if (fbi->bl)
                return;

        memset(&props, 0, sizeof(struct backlight_properties));
        props.max_brightness = 0xff;
        props.type = BACKLIGHT_RAW;
        writel(fbi->pwmr, fbi->regs + LCDC_PWMR);

        bl = backlight_device_register("imxfb-bl", &fbi->pdev->dev, fbi,
                                       &imxfb_lcdc_bl_ops, &props);
        if (IS_ERR(bl)) {
                dev_err(&fbi->pdev->dev, "error %ld on backlight register\n",
                                PTR_ERR(bl));
                return;
        }

        fbi->bl = bl;
        bl->props.power = FB_BLANK_UNBLANK;
        bl->props.fb_blank = FB_BLANK_UNBLANK;
        bl->props.brightness = imxfb_bl_get_brightness(bl);
}

static void imxfb_exit_backlight(struct imxfb_info *fbi)
{
        if (fbi->bl)
                backlight_device_unregister(fbi->bl);
}
#endif

static void imxfb_enable_controller(struct imxfb_info *fbi)
{

        if (fbi->enabled)
                return;

        pr_debug("Enabling LCD controller\n");

        writel(fbi->screen_dma, fbi->regs + LCDC_SSA);

        /* panning offset 0 (0 pixel offset)        */
        writel(0x00000000, fbi->regs + LCDC_POS);

        /* disable hardware cursor */
        writel(readl(fbi->regs + LCDC_CPOS) & ~(CPOS_CC0 | CPOS_CC1),
                fbi->regs + LCDC_CPOS);

        /*
         * RMCR_LCDC_EN_MX1 is present on i.MX1 only, but doesn't hurt
         * on other SoCs
         */
        writel(RMCR_LCDC_EN_MX1, fbi->regs + LCDC_RMCR);

        clk_prepare_enable(fbi->clk_ipg);
        clk_prepare_enable(fbi->clk_ahb);
        clk_prepare_enable(fbi->clk_per);
        fbi->enabled = true;

        if (fbi->backlight_power)
                fbi->backlight_power(1);
        if (fbi->lcd_power)
                fbi->lcd_power(1);
}

static void imxfb_disable_controller(struct imxfb_info *fbi)
{
        if (!fbi->enabled)
                return;

        pr_debug("Disabling LCD controller\n");

        if (fbi->backlight_power)
                fbi->backlight_power(0);
        if (fbi->lcd_power)
                fbi->lcd_power(0);

        clk_disable_unprepare(fbi->clk_per);
        clk_disable_unprepare(fbi->clk_ipg);
        clk_disable_unprepare(fbi->clk_ahb);
        fbi->enabled = false;

        writel(0, fbi->regs + LCDC_RMCR);
}

static int imxfb_blank(int blank, struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;

        pr_debug("imxfb_blank: blank=%d\n", blank);

        switch (blank) {
        case FB_BLANK_POWERDOWN:
        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
        case FB_BLANK_NORMAL:
                imxfb_disable_controller(fbi);
                break;

        case FB_BLANK_UNBLANK:
                imxfb_enable_controller(fbi);
                break;
        }
        return 0;
}

static struct fb_ops imxfb_ops = {
        .owner          = THIS_MODULE,
        .fb_check_var   = imxfb_check_var,
        .fb_set_par     = imxfb_set_par,
        .fb_setcolreg   = imxfb_setcolreg,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
        .fb_blank       = imxfb_blank,
};

/*
 * imxfb_activate_var():
 *      Configures LCD Controller based on entries in var parameter.  Settings are
 *      only written to the controller if changes were made.
 */
static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        struct imxfb_info *fbi = info->par;
        u32 ymax_mask = is_imx1_fb(fbi) ? YMAX_MASK_IMX1 : YMAX_MASK_IMX21;

        pr_debug("var: xres=%d hslen=%d lm=%d rm=%d\n",
                var->xres, var->hsync_len,
                var->left_margin, var->right_margin);
        pr_debug("var: yres=%d vslen=%d um=%d bm=%d\n",
                var->yres, var->vsync_len,
                var->upper_margin, var->lower_margin);

#if DEBUG_VAR
        if (var->xres < 16        || var->xres > 1024)
                printk(KERN_ERR "%s: invalid xres %d\n",
                        info->fix.id, var->xres);
        if (var->hsync_len < 1    || var->hsync_len > 64)
                printk(KERN_ERR "%s: invalid hsync_len %d\n",
                        info->fix.id, var->hsync_len);
        if (var->left_margin > 255)
                printk(KERN_ERR "%s: invalid left_margin %d\n",
                        info->fix.id, var->left_margin);
        if (var->right_margin > 255)
                printk(KERN_ERR "%s: invalid right_margin %d\n",
                        info->fix.id, var->right_margin);
        if (var->yres < 1 || var->yres > ymax_mask)
                printk(KERN_ERR "%s: invalid yres %d\n",
                        info->fix.id, var->yres);
        if (var->vsync_len > 100)
                printk(KERN_ERR "%s: invalid vsync_len %d\n",
                        info->fix.id, var->vsync_len);
        if (var->upper_margin > 63)
                printk(KERN_ERR "%s: invalid upper_margin %d\n",
                        info->fix.id, var->upper_margin);
        if (var->lower_margin > 255)
                printk(KERN_ERR "%s: invalid lower_margin %d\n",
                        info->fix.id, var->lower_margin);
#endif

        /* physical screen start address            */
        writel(VPW_VPW(var->xres * var->bits_per_pixel / 8 / 4),
                fbi->regs + LCDC_VPW);

        writel(HCR_H_WIDTH(var->hsync_len - 1) |
                HCR_H_WAIT_1(var->right_margin - 1) |
                HCR_H_WAIT_2(var->left_margin - 3),
                fbi->regs + LCDC_HCR);

        writel(VCR_V_WIDTH(var->vsync_len) |
                VCR_V_WAIT_1(var->lower_margin) |
                VCR_V_WAIT_2(var->upper_margin),
                fbi->regs + LCDC_VCR);

        writel(SIZE_XMAX(var->xres) | (var->yres & ymax_mask),
                        fbi->regs + LCDC_SIZE);

        writel(fbi->pcr, fbi->regs + LCDC_PCR);
#ifndef PWMR_BACKLIGHT_AVAILABLE
        if (fbi->pwmr)
                writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
#endif
        writel(fbi->lscr1, fbi->regs + LCDC_LSCR1);

        /* dmacr = 0 is no valid value, as we need DMA control marks. */
        if (fbi->dmacr)
                writel(fbi->dmacr, fbi->regs + LCDC_DMACR);

        return 0;
}

#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.
 */
static int imxfb_suspend(struct platform_device *dev, pm_message_t state)
{
        struct fb_info *info = platform_get_drvdata(dev);
        struct imxfb_info *fbi = info->par;

        pr_debug("%s\n", __func__);

        imxfb_disable_controller(fbi);
        return 0;
}

static int imxfb_resume(struct platform_device *dev)
{
        struct fb_info *info = platform_get_drvdata(dev);
        struct imxfb_info *fbi = info->par;

        pr_debug("%s\n", __func__);

        imxfb_enable_controller(fbi);
        return 0;
}
#else
#define imxfb_suspend   NULL
#define imxfb_resume    NULL
#endif

static int imxfb_init_fbinfo(struct platform_device *pdev)
{
        struct imx_fb_platform_data *pdata = dev_get_platdata(&pdev->dev);
        struct fb_info *info = dev_get_drvdata(&pdev->dev);
        struct imxfb_info *fbi = info->par;
        struct device_node *np;

        pr_debug("%s\n",__func__);

        info->pseudo_palette = kmalloc(sizeof(u32) * 16, GFP_KERNEL);
        if (!info->pseudo_palette)
                return -ENOMEM;

        memset(fbi, 0, sizeof(struct imxfb_info));

        fbi->devtype = pdev->id_entry->driver_data;

        strlcpy(info->fix.id, IMX_NAME, sizeof(info->fix.id));

        info->fix.type                  = FB_TYPE_PACKED_PIXELS;
        info->fix.type_aux              = 0;
        info->fix.xpanstep              = 0;
        info->fix.ypanstep              = 0;
        info->fix.ywrapstep             = 0;
        info->fix.accel                 = FB_ACCEL_NONE;

        info->var.nonstd                = 0;
        info->var.activate              = FB_ACTIVATE_NOW;
        info->var.height                = -1;
        info->var.width = -1;
        info->var.accel_flags           = 0;
        info->var.vmode                 = FB_VMODE_NONINTERLACED;

        info->fbops                     = &imxfb_ops;
        info->flags                     = FBINFO_FLAG_DEFAULT |
                                          FBINFO_READS_FAST;
        if (pdata) {
                info->var.grayscale             = pdata->cmap_greyscale;
                fbi->cmap_inverse               = pdata->cmap_inverse;
                fbi->cmap_static                = pdata->cmap_static;
                fbi->lscr1                      = pdata->lscr1;
                fbi->dmacr                      = pdata->dmacr;
                fbi->pwmr                       = pdata->pwmr;
                fbi->lcd_power                  = pdata->lcd_power;
                fbi->backlight_power            = pdata->backlight_power;
        } else {
                np = pdev->dev.of_node;
                info->var.grayscale = of_property_read_bool(np,
                                                "cmap-greyscale");
                fbi->cmap_inverse = of_property_read_bool(np, "cmap-inverse");
                fbi->cmap_static = of_property_read_bool(np, "cmap-static");

                fbi->lscr1 = IMXFB_LSCR1_DEFAULT;
                of_property_read_u32(np, "fsl,lscr1", &fbi->lscr1);

                of_property_read_u32(np, "fsl,dmacr", &fbi->dmacr);

                /* These two function pointers could be used by some specific
                 * platforms. */
                fbi->lcd_power = NULL;
                fbi->backlight_power = NULL;
        }

        return 0;
}

static int imxfb_of_read_mode(struct device *dev, struct device_node *np,
                struct imx_fb_videomode *imxfb_mode)
{
        int ret;
        struct fb_videomode *of_mode = &imxfb_mode->mode;
        u32 bpp;
        u32 pcr;

        ret = of_property_read_string(np, "model", &of_mode->name);
        if (ret)
                of_mode->name = NULL;

        ret = of_get_fb_videomode(np, of_mode, OF_USE_NATIVE_MODE);
        if (ret) {
                dev_err(dev, "Failed to get videomode from DT\n");
                return ret;
        }

        ret = of_property_read_u32(np, "bits-per-pixel", &bpp);
        ret |= of_property_read_u32(np, "fsl,pcr", &pcr);

        if (ret) {
                dev_err(dev, "Failed to read bpp and pcr from DT\n");
                return -EINVAL;
        }

        if (bpp < 1 || bpp > 255) {
                dev_err(dev, "Bits per pixel have to be between 1 and 255\n");
                return -EINVAL;
        }

        imxfb_mode->bpp = bpp;
        imxfb_mode->pcr = pcr;

        return 0;
}

static int imxfb_probe(struct platform_device *pdev)
{
        struct imxfb_info *fbi;
        struct fb_info *info;
        struct imx_fb_platform_data *pdata;
        struct resource *res;
        struct imx_fb_videomode *m;
        const struct of_device_id *of_id;
        int ret, i;
        int bytes_per_pixel;

        dev_info(&pdev->dev, "i.MX Framebuffer driver\n");

        of_id = of_match_device(imxfb_of_dev_id, &pdev->dev);
        if (of_id)
                pdev->id_entry = of_id->data;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;

        pdata = dev_get_platdata(&pdev->dev);

        info = framebuffer_alloc(sizeof(struct imxfb_info), &pdev->dev);
        if (!info)
                return -ENOMEM;

        fbi = info->par;

        platform_set_drvdata(pdev, info);

        ret = imxfb_init_fbinfo(pdev);
        if (ret < 0)
                goto failed_init;

        if (pdata) {
                if (!fb_mode)
                        fb_mode = pdata->mode[0].mode.name;

                fbi->mode = pdata->mode;
                fbi->num_modes = pdata->num_modes;
        } else {
                struct device_node *display_np;
                fb_mode = NULL;

                display_np = of_parse_phandle(pdev->dev.of_node, "display", 0);
                if (!display_np) {
                        dev_err(&pdev->dev, "No display defined in devicetree\n");
                        ret = -EINVAL;
                        goto failed_of_parse;
                }

                /*
                 * imxfb does not support more modes, we choose only the native
                 * mode.
                 */
                fbi->num_modes = 1;

                fbi->mode = devm_kzalloc(&pdev->dev,
                                sizeof(struct imx_fb_videomode), GFP_KERNEL);
                if (!fbi->mode) {
                        ret = -ENOMEM;
                        goto failed_of_parse;
                }

                ret = imxfb_of_read_mode(&pdev->dev, display_np, fbi->mode);
                if (ret)
                        goto failed_of_parse;
        }

        /* Calculate maximum bytes used per pixel. In most cases this should
         * be the same as m->bpp/8 */
        m = &fbi->mode[0];
        bytes_per_pixel = (m->bpp + 7) / 8;
        for (i = 0; i < fbi->num_modes; i++, m++)
                info->fix.smem_len = max_t(size_t, info->fix.smem_len,
                                m->mode.xres * m->mode.yres * bytes_per_pixel);

        res = request_mem_region(res->start, resource_size(res),
                                DRIVER_NAME);
        if (!res) {
                ret = -EBUSY;
                goto failed_req;
        }

        fbi->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
        if (IS_ERR(fbi->clk_ipg)) {
                ret = PTR_ERR(fbi->clk_ipg);
                goto failed_getclock;
        }

        fbi->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
        if (IS_ERR(fbi->clk_ahb)) {
                ret = PTR_ERR(fbi->clk_ahb);
                goto failed_getclock;
        }

        fbi->clk_per = devm_clk_get(&pdev->dev, "per");
        if (IS_ERR(fbi->clk_per)) {
                ret = PTR_ERR(fbi->clk_per);
                goto failed_getclock;
        }

        fbi->regs = ioremap(res->start, resource_size(res));
        if (fbi->regs == NULL) {
                dev_err(&pdev->dev, "Cannot map frame buffer registers\n");
                ret = -ENOMEM;
                goto failed_ioremap;
        }

        /* Seems not being used by anyone, so no support for oftree */
        if (!pdata || !pdata->fixed_screen_cpu) {
                fbi->map_size = PAGE_ALIGN(info->fix.smem_len);
                fbi->map_cpu = dma_alloc_writecombine(&pdev->dev,
                                fbi->map_size, &fbi->map_dma, GFP_KERNEL);

                if (!fbi->map_cpu) {
                        dev_err(&pdev->dev, "Failed to allocate video RAM: %d\n", ret);
                        ret = -ENOMEM;
                        goto failed_map;
                }

                info->screen_base = fbi->map_cpu;
                fbi->screen_cpu = fbi->map_cpu;
                fbi->screen_dma = fbi->map_dma;
                info->fix.smem_start = fbi->screen_dma;
        } else {
                /* Fixed framebuffer mapping enables location of the screen in eSRAM */
                fbi->map_cpu = pdata->fixed_screen_cpu;
                fbi->map_dma = pdata->fixed_screen_dma;
                info->screen_base = fbi->map_cpu;
                fbi->screen_cpu = fbi->map_cpu;
                fbi->screen_dma = fbi->map_dma;
                info->fix.smem_start = fbi->screen_dma;
        }

        if (pdata && pdata->init) {
                ret = pdata->init(fbi->pdev);
                if (ret)
                        goto failed_platform_init;
        }


        INIT_LIST_HEAD(&info->modelist);
        for (i = 0; i < fbi->num_modes; i++)
                fb_add_videomode(&fbi->mode[i].mode, &info->modelist);

        /*
         * This makes sure that our colour bitfield
         * descriptors are correctly initialised.
         */
        imxfb_check_var(&info->var, info);

        ret = fb_alloc_cmap(&info->cmap, 1 << info->var.bits_per_pixel, 0);
        if (ret < 0)
                goto failed_cmap;

        imxfb_set_par(info);
        ret = register_framebuffer(info);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to register framebuffer\n");
                goto failed_register;
        }

        imxfb_enable_controller(fbi);
        fbi->pdev = pdev;
#ifdef PWMR_BACKLIGHT_AVAILABLE
        imxfb_init_backlight(fbi);
#endif

        return 0;

failed_register:
        fb_dealloc_cmap(&info->cmap);
failed_cmap:
        if (pdata && pdata->exit)
                pdata->exit(fbi->pdev);
failed_platform_init:
        if (pdata && !pdata->fixed_screen_cpu)
                dma_free_writecombine(&pdev->dev,fbi->map_size,fbi->map_cpu,
                        fbi->map_dma);
failed_map:
        iounmap(fbi->regs);
failed_ioremap:
failed_getclock:
        release_mem_region(res->start, resource_size(res));
failed_req:
failed_of_parse:
        kfree(info->pseudo_palette);
failed_init:
        framebuffer_release(info);
        return ret;
}

static int imxfb_remove(struct platform_device *pdev)
{
        struct imx_fb_platform_data *pdata;
        struct fb_info *info = platform_get_drvdata(pdev);
        struct imxfb_info *fbi = info->par;
        struct resource *res;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

        imxfb_disable_controller(fbi);

#ifdef PWMR_BACKLIGHT_AVAILABLE
        imxfb_exit_backlight(fbi);
#endif
        unregister_framebuffer(info);

        pdata = dev_get_platdata(&pdev->dev);
        if (pdata && pdata->exit)
                pdata->exit(fbi->pdev);

        fb_dealloc_cmap(&info->cmap);
        kfree(info->pseudo_palette);
        framebuffer_release(info);

        iounmap(fbi->regs);
        release_mem_region(res->start, resource_size(res));

        return 0;
}

static void imxfb_shutdown(struct platform_device *dev)
{
        struct fb_info *info = platform_get_drvdata(dev);
        struct imxfb_info *fbi = info->par;
        imxfb_disable_controller(fbi);
}

static struct platform_driver imxfb_driver = {
        .suspend        = imxfb_suspend,
        .resume         = imxfb_resume,
        .remove         = imxfb_remove,
        .shutdown       = imxfb_shutdown,
        .driver         = {
                .name   = DRIVER_NAME,
                .of_match_table = imxfb_of_dev_id,
        },
        .id_table       = imxfb_devtype,
};

static int imxfb_setup(void)
{
#ifndef MODULE
        char *opt, *options = NULL;

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

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

        while ((opt = strsep(&options, ",")) != NULL) {
                if (!*opt)
                        continue;
                else
                        fb_mode = opt;
        }
#endif
        return 0;
}

static int __init imxfb_init(void)
{
        int ret = imxfb_setup();

        if (ret < 0)
                return ret;

        return platform_driver_probe(&imxfb_driver, imxfb_probe);
}

static void __exit imxfb_cleanup(void)
{
        platform_driver_unregister(&imxfb_driver);
}

module_init(imxfb_init);
module_exit(imxfb_cleanup);

MODULE_DESCRIPTION("Freescale i.MX framebuffer driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");