/*
 * linux/drivers/video/pxa168fb.c -- Marvell PXA168 LCD Controller
 *
 *  Copyright (C) 2008 Marvell International Ltd.
 *  All rights reserved.
 *
 *  2009-02-16  adapted from original version for PXA168/910
 *              Jun Nie <njun@marvell.com>
 *
 * 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.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.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/io.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/uaccess.h>
#include <video/pxa168fb.h>

#include "pxa168fb.h"

#define DEFAULT_REFRESH         60      /* Hz */

static int determine_best_pix_fmt(struct fb_var_screeninfo *var)
{
        /*
         * Pseudocolor mode?
         */
        if (var->bits_per_pixel == 8)
                return PIX_FMT_PSEUDOCOLOR;

        /*
         * Check for 565/1555.
         */
        if (var->bits_per_pixel == 16 && var->red.length <= 5 &&
            var->green.length <= 6 && var->blue.length <= 5) {
                if (var->transp.length == 0) {
                        if (var->red.offset >= var->blue.offset)
                                return PIX_FMT_RGB565;
                        else
                                return PIX_FMT_BGR565;
                }

                if (var->transp.length == 1 && var->green.length <= 5) {
                        if (var->red.offset >= var->blue.offset)
                                return PIX_FMT_RGB1555;
                        else
                                return PIX_FMT_BGR1555;
                }

                /* fall through */
        }

        /*
         * Check for 888/A888.
         */
        if (var->bits_per_pixel <= 32 && var->red.length <= 8 &&
            var->green.length <= 8 && var->blue.length <= 8) {
                if (var->bits_per_pixel == 24 && var->transp.length == 0) {
                        if (var->red.offset >= var->blue.offset)
                                return PIX_FMT_RGB888PACK;
                        else
                                return PIX_FMT_BGR888PACK;
                }

                if (var->bits_per_pixel == 32 && var->transp.length == 8) {
                        if (var->red.offset >= var->blue.offset)
                                return PIX_FMT_RGBA888;
                        else
                                return PIX_FMT_BGRA888;
                } else {
                        if (var->red.offset >= var->blue.offset)
                                return PIX_FMT_RGB888UNPACK;
                        else
                                return PIX_FMT_BGR888UNPACK;
                }

                /* fall through */
        }

        return -EINVAL;
}

static void set_pix_fmt(struct fb_var_screeninfo *var, int pix_fmt)
{
        switch (pix_fmt) {
        case PIX_FMT_RGB565:
                var->bits_per_pixel = 16;
                var->red.offset = 11;    var->red.length = 5;
                var->green.offset = 5;   var->green.length = 6;
                var->blue.offset = 0;    var->blue.length = 5;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
        case PIX_FMT_BGR565:
                var->bits_per_pixel = 16;
                var->red.offset = 0;     var->red.length = 5;
                var->green.offset = 5;   var->green.length = 6;
                var->blue.offset = 11;   var->blue.length = 5;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
        case PIX_FMT_RGB1555:
                var->bits_per_pixel = 16;
                var->red.offset = 10;    var->red.length = 5;
                var->green.offset = 5;   var->green.length = 5;
                var->blue.offset = 0;    var->blue.length = 5;
                var->transp.offset = 15; var->transp.length = 1;
                break;
        case PIX_FMT_BGR1555:
                var->bits_per_pixel = 16;
                var->red.offset = 0;     var->red.length = 5;
                var->green.offset = 5;   var->green.length = 5;
                var->blue.offset = 10;   var->blue.length = 5;
                var->transp.offset = 15; var->transp.length = 1;
                break;
        case PIX_FMT_RGB888PACK:
                var->bits_per_pixel = 24;
                var->red.offset = 16;    var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 0;    var->blue.length = 8;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
        case PIX_FMT_BGR888PACK:
                var->bits_per_pixel = 24;
                var->red.offset = 0;     var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 16;   var->blue.length = 8;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
        case PIX_FMT_RGBA888:
                var->bits_per_pixel = 32;
                var->red.offset = 16;    var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 0;    var->blue.length = 8;
                var->transp.offset = 24; var->transp.length = 8;
                break;
        case PIX_FMT_BGRA888:
                var->bits_per_pixel = 32;
                var->red.offset = 0;     var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 16;   var->blue.length = 8;
                var->transp.offset = 24; var->transp.length = 8;
                break;
        case PIX_FMT_PSEUDOCOLOR:
                var->bits_per_pixel = 8;
                var->red.offset = 0;     var->red.length = 8;
                var->green.offset = 0;   var->green.length = 8;
                var->blue.offset = 0;    var->blue.length = 8;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
        }
}

static void set_mode(struct pxa168fb_info *fbi, struct fb_var_screeninfo *var,
                     struct fb_videomode *mode, int pix_fmt, int ystretch)
{
        struct fb_info *info = fbi->info;

        set_pix_fmt(var, pix_fmt);

        var->xres = mode->xres;
        var->yres = mode->yres;
        var->xres_virtual = max(var->xres, var->xres_virtual);
        if (ystretch)
                var->yres_virtual = info->fix.smem_len /
                        (var->xres_virtual * (var->bits_per_pixel >> 3));
        else
                var->yres_virtual = max(var->yres, var->yres_virtual);
        var->grayscale = 0;
        var->accel_flags = FB_ACCEL_NONE;
        var->pixclock = mode->pixclock;
        var->left_margin = mode->left_margin;
        var->right_margin = mode->right_margin;
        var->upper_margin = mode->upper_margin;
        var->lower_margin = mode->lower_margin;
        var->hsync_len = mode->hsync_len;
        var->vsync_len = mode->vsync_len;
        var->sync = mode->sync;
        var->vmode = FB_VMODE_NONINTERLACED;
        var->rotate = FB_ROTATE_UR;
}

static int pxa168fb_check_var(struct fb_var_screeninfo *var,
                              struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;
        int pix_fmt;

        /*
         * Determine which pixel format we're going to use.
         */
        pix_fmt = determine_best_pix_fmt(var);
        if (pix_fmt < 0)
                return pix_fmt;
        set_pix_fmt(var, pix_fmt);
        fbi->pix_fmt = pix_fmt;

        /*
         * Basic geometry sanity checks.
         */
        if (var->xoffset + var->xres > var->xres_virtual)
                return -EINVAL;
        if (var->yoffset + var->yres > var->yres_virtual)
                return -EINVAL;
        if (var->xres + var->right_margin +
            var->hsync_len + var->left_margin > 2048)
                return -EINVAL;
        if (var->yres + var->lower_margin +
            var->vsync_len + var->upper_margin > 2048)
                return -EINVAL;

        /*
         * Check size of framebuffer.
         */
        if (var->xres_virtual * var->yres_virtual *
            (var->bits_per_pixel >> 3) > info->fix.smem_len)
                return -EINVAL;

        return 0;
}

/*
 * The hardware clock divider has an integer and a fractional
 * stage:
 *
 *      clk2 = clk_in / integer_divider
 *      clk_out = clk2 * (1 - (fractional_divider >> 12))
 *
 * Calculate integer and fractional divider for given clk_in
 * and clk_out.
 */
static void set_clock_divider(struct pxa168fb_info *fbi,
                              const struct fb_videomode *m)
{
        int divider_int;
        int needed_pixclk;
        u64 div_result;
        u32 x = 0;

        /*
         * Notice: The field pixclock is used by linux fb
         * is in pixel second. E.g. struct fb_videomode &
         * struct fb_var_screeninfo
         */

        /*
         * Check input values.
         */
        if (!m || !m->pixclock || !m->refresh) {
                dev_err(fbi->dev, "Input refresh or pixclock is wrong.\n");
                return;
        }

        /*
         * Using PLL/AXI clock.
         */
        x = 0x80000000;

        /*
         * Calc divider according to refresh rate.
         */
        div_result = 1000000000000ll;
        do_div(div_result, m->pixclock);
        needed_pixclk = (u32)div_result;

        divider_int = clk_get_rate(fbi->clk) / needed_pixclk;

        /* check whether divisor is too small. */
        if (divider_int < 2) {
                dev_warn(fbi->dev, "Warning: clock source is too slow."
                                "Try smaller resolution\n");
                divider_int = 2;
        }

        /*
         * Set setting to reg.
         */
        x |= divider_int;
        writel(x, fbi->reg_base + LCD_CFG_SCLK_DIV);
}

static void set_dma_control0(struct pxa168fb_info *fbi)
{
        u32 x;

        /*
         * Set bit to enable graphics DMA.
         */
        x = readl(fbi->reg_base + LCD_SPU_DMA_CTRL0);
        x &= ~CFG_GRA_ENA_MASK;
        x |= fbi->active ? CFG_GRA_ENA(1) : CFG_GRA_ENA(0);

        /*
         * If we are in a pseudo-color mode, we need to enable
         * palette lookup.
         */
        if (fbi->pix_fmt == PIX_FMT_PSEUDOCOLOR)
                x |= 0x10000000;

        /*
         * Configure hardware pixel format.
         */
        x &= ~(0xF << 16);
        x |= (fbi->pix_fmt >> 1) << 16;

        /*
         * Check red and blue pixel swap.
         * 1. source data swap
         * 2. panel output data swap
         */
        x &= ~(1 << 12);
        x |= ((fbi->pix_fmt & 1) ^ (fbi->panel_rbswap)) << 12;

        writel(x, fbi->reg_base + LCD_SPU_DMA_CTRL0);
}

static void set_dma_control1(struct pxa168fb_info *fbi, int sync)
{
        u32 x;

        /*
         * Configure default bits: vsync triggers DMA, gated clock
         * enable, power save enable, configure alpha registers to
         * display 100% graphics, and set pixel command.
         */
        x = readl(fbi->reg_base + LCD_SPU_DMA_CTRL1);
        x |= 0x2032ff81;

        /*
         * We trigger DMA on the falling edge of vsync if vsync is
         * active low, or on the rising edge if vsync is active high.
         */
        if (!(sync & FB_SYNC_VERT_HIGH_ACT))
                x |= 0x08000000;

        writel(x, fbi->reg_base + LCD_SPU_DMA_CTRL1);
}

static void set_graphics_start(struct fb_info *info, int xoffset, int yoffset)
{
        struct pxa168fb_info *fbi = info->par;
        struct fb_var_screeninfo *var = &info->var;
        int pixel_offset;
        unsigned long addr;

        pixel_offset = (yoffset * var->xres_virtual) + xoffset;

        addr = fbi->fb_start_dma + (pixel_offset * (var->bits_per_pixel >> 3));
        writel(addr, fbi->reg_base + LCD_CFG_GRA_START_ADDR0);
}

static void set_dumb_panel_control(struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;
        struct pxa168fb_mach_info *mi = fbi->dev->platform_data;
        u32 x;

        /*
         * Preserve enable flag.
         */
        x = readl(fbi->reg_base + LCD_SPU_DUMB_CTRL) & 0x00000001;

        x |= (fbi->is_blanked ? 0x7 : mi->dumb_mode) << 28;
        x |= mi->gpio_output_data << 20;
        x |= mi->gpio_output_mask << 12;
        x |= mi->panel_rgb_reverse_lanes ? 0x00000080 : 0;
        x |= mi->invert_composite_blank ? 0x00000040 : 0;
        x |= (info->var.sync & FB_SYNC_COMP_HIGH_ACT) ? 0x00000020 : 0;
        x |= mi->invert_pix_val_ena ? 0x00000010 : 0;
        x |= (info->var.sync & FB_SYNC_VERT_HIGH_ACT) ? 0 : 0x00000008;
        x |= (info->var.sync & FB_SYNC_HOR_HIGH_ACT) ? 0 : 0x00000004;
        x |= mi->invert_pixclock ? 0x00000002 : 0;

        writel(x, fbi->reg_base + LCD_SPU_DUMB_CTRL);
}

static void set_dumb_screen_dimensions(struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;
        struct fb_var_screeninfo *v = &info->var;
        int x;
        int y;

        x = v->xres + v->right_margin + v->hsync_len + v->left_margin;
        y = v->yres + v->lower_margin + v->vsync_len + v->upper_margin;

        writel((y << 16) | x, fbi->reg_base + LCD_SPUT_V_H_TOTAL);
}

static int pxa168fb_set_par(struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;
        struct fb_var_screeninfo *var = &info->var;
        struct fb_videomode mode;
        u32 x;
        struct pxa168fb_mach_info *mi;

        mi = fbi->dev->platform_data;

        /*
         * Set additional mode info.
         */
        if (fbi->pix_fmt == PIX_FMT_PSEUDOCOLOR)
                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
        else
                info->fix.visual = FB_VISUAL_TRUECOLOR;
        info->fix.line_length = var->xres_virtual * var->bits_per_pixel / 8;
        info->fix.ypanstep = var->yres;

        /*
         * Disable panel output while we setup the display.
         */
        x = readl(fbi->reg_base + LCD_SPU_DUMB_CTRL);
        writel(x & ~1, fbi->reg_base + LCD_SPU_DUMB_CTRL);

        /*
         * Configure global panel parameters.
         */
        writel((var->yres << 16) | var->xres,
                fbi->reg_base + LCD_SPU_V_H_ACTIVE);

        /*
         * convet var to video mode
         */
        fb_var_to_videomode(&mode, &info->var);

        /* Calculate clock divisor. */
        set_clock_divider(fbi, &mode);

        /* Configure dma ctrl regs. */
        set_dma_control0(fbi);
        set_dma_control1(fbi, info->var.sync);

        /*
         * Configure graphics DMA parameters.
         */
        x = readl(fbi->reg_base + LCD_CFG_GRA_PITCH);
        x = (x & ~0xFFFF) | ((var->xres_virtual * var->bits_per_pixel) >> 3);
        writel(x, fbi->reg_base + LCD_CFG_GRA_PITCH);
        writel((var->yres << 16) | var->xres,
                fbi->reg_base + LCD_SPU_GRA_HPXL_VLN);
        writel((var->yres << 16) | var->xres,
                fbi->reg_base + LCD_SPU_GZM_HPXL_VLN);

        /*
         * Configure dumb panel ctrl regs & timings.
         */
        set_dumb_panel_control(info);
        set_dumb_screen_dimensions(info);

        writel((var->left_margin << 16) | var->right_margin,
                        fbi->reg_base + LCD_SPU_H_PORCH);
        writel((var->upper_margin << 16) | var->lower_margin,
                        fbi->reg_base + LCD_SPU_V_PORCH);

        /*
         * Re-enable panel output.
         */
        x = readl(fbi->reg_base + LCD_SPU_DUMB_CTRL);
        writel(x | 1, fbi->reg_base + LCD_SPU_DUMB_CTRL);

        return 0;
}

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

static u32 to_rgb(u16 red, u16 green, u16 blue)
{
        red >>= 8;
        green >>= 8;
        blue >>= 8;

        return (red << 16) | (green << 8) | blue;
}

static int
pxa168fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
                 unsigned int blue, unsigned int trans, struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;
        u32 val;

        if (info->var.grayscale)
                red = green = blue = (19595 * red + 38470 * green +
                                        7471 * blue) >> 16;

        if (info->fix.visual == FB_VISUAL_TRUECOLOR && regno < 16) {
                val =  chan_to_field(red,   &info->var.red);
                val |= chan_to_field(green, &info->var.green);
                val |= chan_to_field(blue , &info->var.blue);
                fbi->pseudo_palette[regno] = val;
        }

        if (info->fix.visual == FB_VISUAL_PSEUDOCOLOR && regno < 256) {
                val = to_rgb(red, green, blue);
                writel(val, fbi->reg_base + LCD_SPU_SRAM_WRDAT);
                writel(0x8300 | regno, fbi->reg_base + LCD_SPU_SRAM_CTRL);
        }

        return 0;
}

static int pxa168fb_blank(int blank, struct fb_info *info)
{
        struct pxa168fb_info *fbi = info->par;

        fbi->is_blanked = (blank == FB_BLANK_UNBLANK) ? 0 : 1;
        set_dumb_panel_control(info);

        return 0;
}

static int pxa168fb_pan_display(struct fb_var_screeninfo *var,
                                struct fb_info *info)
{
        set_graphics_start(info, var->xoffset, var->yoffset);

        return 0;
}

static irqreturn_t pxa168fb_handle_irq(int irq, void *dev_id)
{
        struct pxa168fb_info *fbi = dev_id;
        u32 isr = readl(fbi->reg_base + SPU_IRQ_ISR);

        if ((isr & GRA_FRAME_IRQ0_ENA_MASK)) {

                writel(isr & (~GRA_FRAME_IRQ0_ENA_MASK),
                        fbi->reg_base + SPU_IRQ_ISR);

                return IRQ_HANDLED;
        }
        return IRQ_NONE;
}

static struct fb_ops pxa168fb_ops = {
        .owner          = THIS_MODULE,
        .fb_check_var   = pxa168fb_check_var,
        .fb_set_par     = pxa168fb_set_par,
        .fb_setcolreg   = pxa168fb_setcolreg,
        .fb_blank       = pxa168fb_blank,
        .fb_pan_display = pxa168fb_pan_display,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

static int pxa168fb_init_mode(struct fb_info *info,
                              struct pxa168fb_mach_info *mi)
{
        struct pxa168fb_info *fbi = info->par;
        struct fb_var_screeninfo *var = &info->var;
        int ret = 0;
        u32 total_w, total_h, refresh;
        u64 div_result;
        const struct fb_videomode *m;

        /*
         * Set default value
         */
        refresh = DEFAULT_REFRESH;

        /* try to find best video mode. */
        m = fb_find_best_mode(&info->var, &info->modelist);
        if (m)
                fb_videomode_to_var(&info->var, m);

        /* Init settings. */
        var->xres_virtual = var->xres;
        var->yres_virtual = info->fix.smem_len /
                (var->xres_virtual * (var->bits_per_pixel >> 3));
        dev_dbg(fbi->dev, "pxa168fb: find best mode: res = %dx%d\n",
                                var->xres, var->yres);

        /* correct pixclock. */
        total_w = var->xres + var->left_margin + var->right_margin +
                  var->hsync_len;
        total_h = var->yres + var->upper_margin + var->lower_margin +
                  var->vsync_len;

        div_result = 1000000000000ll;
        do_div(div_result, total_w * total_h * refresh);
        var->pixclock = (u32)div_result;

        return ret;
}

static int pxa168fb_probe(struct platform_device *pdev)
{
        struct pxa168fb_mach_info *mi;
        struct fb_info *info = 0;
        struct pxa168fb_info *fbi = 0;
        struct resource *res;
        struct clk *clk;
        int irq, ret;

        mi = pdev->dev.platform_data;
        if (mi == NULL) {
                dev_err(&pdev->dev, "no platform data defined\n");
                return -EINVAL;
        }

        clk = clk_get(&pdev->dev, "LCDCLK");
        if (IS_ERR(clk)) {
                dev_err(&pdev->dev, "unable to get LCDCLK");
                return PTR_ERR(clk);
        }

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
                dev_err(&pdev->dev, "no IO memory defined\n");
                ret = -ENOENT;
                goto failed_put_clk;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_err(&pdev->dev, "no IRQ defined\n");
                ret = -ENOENT;
                goto failed_put_clk;
        }

        info = framebuffer_alloc(sizeof(struct pxa168fb_info), &pdev->dev);
        if (info == NULL) {
                ret = -ENOMEM;
                goto failed_put_clk;
        }

        /* Initialize private data */
        fbi = info->par;
        fbi->info = info;
        fbi->clk = clk;
        fbi->dev = info->dev = &pdev->dev;
        fbi->panel_rbswap = mi->panel_rbswap;
        fbi->is_blanked = 0;
        fbi->active = mi->active;

        /*
         * Initialise static fb parameters.
         */
        info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK |
                      FBINFO_HWACCEL_XPAN | FBINFO_HWACCEL_YPAN;
        info->node = -1;
        strlcpy(info->fix.id, mi->id, 16);
        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.mmio_start = res->start;
        info->fix.mmio_len = resource_size(res);
        info->fix.accel = FB_ACCEL_NONE;
        info->fbops = &pxa168fb_ops;
        info->pseudo_palette = fbi->pseudo_palette;

        /*
         * Map LCD controller registers.
         */
        fbi->reg_base = devm_ioremap_nocache(&pdev->dev, res->start,
                                             resource_size(res));
        if (fbi->reg_base == NULL) {
                ret = -ENOMEM;
                goto failed_free_info;
        }

        /*
         * Allocate framebuffer memory.
         */
        info->fix.smem_len = PAGE_ALIGN(DEFAULT_FB_SIZE);

        info->screen_base = dma_alloc_writecombine(fbi->dev, info->fix.smem_len,
                                                &fbi->fb_start_dma, GFP_KERNEL);
        if (info->screen_base == NULL) {
                ret = -ENOMEM;
                goto failed_free_info;
        }

        info->fix.smem_start = (unsigned long)fbi->fb_start_dma;
        set_graphics_start(info, 0, 0);

        /*
         * Set video mode according to platform data.
         */
        set_mode(fbi, &info->var, mi->modes, mi->pix_fmt, 1);

        fb_videomode_to_modelist(mi->modes, mi->num_modes, &info->modelist);

        /*
         * init video mode data.
         */
        pxa168fb_init_mode(info, mi);

        /*
         * Fill in sane defaults.
         */
        ret = pxa168fb_check_var(&info->var, info);
        if (ret)
                goto failed_free_fbmem;

        /*
         * enable controller clock
         */
        clk_enable(fbi->clk);

        pxa168fb_set_par(info);

        /*
         * Configure default register values.
         */
        writel(0, fbi->reg_base + LCD_SPU_BLANKCOLOR);
        writel(mi->io_pin_allocation_mode, fbi->reg_base + SPU_IOPAD_CONTROL);
        writel(0, fbi->reg_base + LCD_CFG_GRA_START_ADDR1);
        writel(0, fbi->reg_base + LCD_SPU_GRA_OVSA_HPXL_VLN);
        writel(0, fbi->reg_base + LCD_SPU_SRAM_PARA0);
        writel(CFG_CSB_256x32(0x1)|CFG_CSB_256x24(0x1)|CFG_CSB_256x8(0x1),
                fbi->reg_base + LCD_SPU_SRAM_PARA1);

        /*
         * Allocate color map.
         */
        if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
                ret = -ENOMEM;
                goto failed_free_clk;
        }

        /*
         * Register irq handler.
         */
        ret = devm_request_irq(&pdev->dev, irq, pxa168fb_handle_irq,
                               IRQF_SHARED, info->fix.id, fbi);
        if (ret < 0) {
                dev_err(&pdev->dev, "unable to request IRQ\n");
                ret = -ENXIO;
                goto failed_free_cmap;
        }

        /*
         * Enable GFX interrupt
         */
        writel(GRA_FRAME_IRQ0_ENA(0x1), fbi->reg_base + SPU_IRQ_ENA);

        /*
         * Register framebuffer.
         */
        ret = register_framebuffer(info);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to register pxa168-fb: %d\n", ret);
                ret = -ENXIO;
                goto failed_free_cmap;
        }

        platform_set_drvdata(pdev, fbi);
        return 0;

failed_free_cmap:
        fb_dealloc_cmap(&info->cmap);
failed_free_clk:
        clk_disable(fbi->clk);
failed_free_fbmem:
        dma_free_coherent(fbi->dev, info->fix.smem_len,
                        info->screen_base, fbi->fb_start_dma);
failed_free_info:
        kfree(info);
failed_put_clk:
        clk_put(clk);

        dev_err(&pdev->dev, "frame buffer device init failed with %d\n", ret);
        return ret;
}

static int pxa168fb_remove(struct platform_device *pdev)
{
        struct pxa168fb_info *fbi = platform_get_drvdata(pdev);
        struct fb_info *info;
        int irq;
        unsigned int data;

        if (!fbi)
                return 0;

        /* disable DMA transfer */
        data = readl(fbi->reg_base + LCD_SPU_DMA_CTRL0);
        data &= ~CFG_GRA_ENA_MASK;
        writel(data, fbi->reg_base + LCD_SPU_DMA_CTRL0);

        info = fbi->info;

        unregister_framebuffer(info);

        writel(GRA_FRAME_IRQ0_ENA(0x0), fbi->reg_base + SPU_IRQ_ENA);

        if (info->cmap.len)
                fb_dealloc_cmap(&info->cmap);

        irq = platform_get_irq(pdev, 0);

        dma_free_writecombine(fbi->dev, PAGE_ALIGN(info->fix.smem_len),
                                info->screen_base, info->fix.smem_start);

        clk_disable(fbi->clk);
        clk_put(fbi->clk);

        framebuffer_release(info);

        return 0;
}

static struct platform_driver pxa168fb_driver = {
        .driver         = {
                .name   = "pxa168-fb",
                .owner  = THIS_MODULE,
        },
        .probe          = pxa168fb_probe,
        .remove         = pxa168fb_remove,
};

module_platform_driver(pxa168fb_driver);

MODULE_AUTHOR("Lennert Buytenhek <buytenh@marvell.com> "
              "Green Wan <gwan@marvell.com>");
MODULE_DESCRIPTION("Framebuffer driver for PXA168/910");
MODULE_LICENSE("GPL");