omapfb: Create new header file for omapfb DSS implementation

[linux-2.6/btrfs-unstable.git] / drivers / video / fbdev / s3c-fb.c

/* linux/drivers/video/s3c-fb.c
 *
 * Copyright 2008 Openmoko Inc.
 * Copyright 2008-2010 Simtec Electronics
 *      Ben Dooks <ben@simtec.co.uk>
 *      http://armlinux.simtec.co.uk/
 *
 * Samsung SoC Framebuffer driver
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/fb.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/pm_runtime.h>
#include <linux/platform_data/video_s3c.h>

#include <video/samsung_fimd.h>

/* This driver will export a number of framebuffer interfaces depending
 * on the configuration passed in via the platform data. Each fb instance
 * maps to a hardware window. Currently there is no support for runtime
 * setting of the alpha-blending functions that each window has, so only
 * window 0 is actually useful.
 *
 * Window 0 is treated specially, it is used for the basis of the LCD
 * output timings and as the control for the output power-down state.
*/

/* note, the previous use of <mach/regs-fb.h> to get platform specific data
 * has been replaced by using the platform device name to pick the correct
 * configuration data for the system.
*/

#ifdef CONFIG_FB_S3C_DEBUG_REGWRITE
#undef writel
#define writel(v, r) do { \
        pr_debug("%s: %08x => %p\n", __func__, (unsigned int)v, r); \
        __raw_writel(v, r); \
} while (0)
#endif /* FB_S3C_DEBUG_REGWRITE */

/* irq_flags bits */
#define S3C_FB_VSYNC_IRQ_EN     0

#define VSYNC_TIMEOUT_MSEC 50

struct s3c_fb;

#define VALID_BPP(x) (1 << ((x) - 1))

#define OSD_BASE(win, variant) ((variant).osd + ((win) * (variant).osd_stride))
#define VIDOSD_A(win, variant) (OSD_BASE(win, variant) + 0x00)
#define VIDOSD_B(win, variant) (OSD_BASE(win, variant) + 0x04)
#define VIDOSD_C(win, variant) (OSD_BASE(win, variant) + 0x08)
#define VIDOSD_D(win, variant) (OSD_BASE(win, variant) + 0x0C)

/**
 * struct s3c_fb_variant - fb variant information
 * @is_2443: Set if S3C2443/S3C2416 style hardware.
 * @nr_windows: The number of windows.
 * @vidtcon: The base for the VIDTCONx registers
 * @wincon: The base for the WINxCON registers.
 * @winmap: The base for the WINxMAP registers.
 * @keycon: The abse for the WxKEYCON registers.
 * @buf_start: Offset of buffer start registers.
 * @buf_size: Offset of buffer size registers.
 * @buf_end: Offset of buffer end registers.
 * @osd: The base for the OSD registers.
 * @palette: Address of palette memory, or 0 if none.
 * @has_prtcon: Set if has PRTCON register.
 * @has_shadowcon: Set if has SHADOWCON register.
 * @has_blendcon: Set if has BLENDCON register.
 * @has_clksel: Set if VIDCON0 register has CLKSEL bit.
 * @has_fixvclk: Set if VIDCON1 register has FIXVCLK bits.
 */
struct s3c_fb_variant {
        unsigned int    is_2443:1;
        unsigned short  nr_windows;
        unsigned int    vidtcon;
        unsigned short  wincon;
        unsigned short  winmap;
        unsigned short  keycon;
        unsigned short  buf_start;
        unsigned short  buf_end;
        unsigned short  buf_size;
        unsigned short  osd;
        unsigned short  osd_stride;
        unsigned short  palette[S3C_FB_MAX_WIN];

        unsigned int    has_prtcon:1;
        unsigned int    has_shadowcon:1;
        unsigned int    has_blendcon:1;
        unsigned int    has_clksel:1;
        unsigned int    has_fixvclk:1;
};

/**
 * struct s3c_fb_win_variant
 * @has_osd_c: Set if has OSD C register.
 * @has_osd_d: Set if has OSD D register.
 * @has_osd_alpha: Set if can change alpha transparency for a window.
 * @palette_sz: Size of palette in entries.
 * @palette_16bpp: Set if palette is 16bits wide.
 * @osd_size_off: If != 0, supports setting up OSD for a window; the appropriate
 *                register is located at the given offset from OSD_BASE.
 * @valid_bpp: 1 bit per BPP setting to show valid bits-per-pixel.
 *
 * valid_bpp bit x is set if (x+1)BPP is supported.
 */
struct s3c_fb_win_variant {
        unsigned int    has_osd_c:1;
        unsigned int    has_osd_d:1;
        unsigned int    has_osd_alpha:1;
        unsigned int    palette_16bpp:1;
        unsigned short  osd_size_off;
        unsigned short  palette_sz;
        u32             valid_bpp;
};

/**
 * struct s3c_fb_driverdata - per-device type driver data for init time.
 * @variant: The variant information for this driver.
 * @win: The window information for each window.
 */
struct s3c_fb_driverdata {
        struct s3c_fb_variant   variant;
        struct s3c_fb_win_variant *win[S3C_FB_MAX_WIN];
};

/**
 * struct s3c_fb_palette - palette information
 * @r: Red bitfield.
 * @g: Green bitfield.
 * @b: Blue bitfield.
 * @a: Alpha bitfield.
 */
struct s3c_fb_palette {
        struct fb_bitfield      r;
        struct fb_bitfield      g;
        struct fb_bitfield      b;
        struct fb_bitfield      a;
};

/**
 * struct s3c_fb_win - per window private data for each framebuffer.
 * @windata: The platform data supplied for the window configuration.
 * @parent: The hardware that this window is part of.
 * @fbinfo: Pointer pack to the framebuffer info for this window.
 * @varint: The variant information for this window.
 * @palette_buffer: Buffer/cache to hold palette entries.
 * @pseudo_palette: For use in TRUECOLOUR modes for entries 0..15/
 * @index: The window number of this window.
 * @palette: The bitfields for changing r/g/b into a hardware palette entry.
 */
struct s3c_fb_win {
        struct s3c_fb_pd_win    *windata;
        struct s3c_fb           *parent;
        struct fb_info          *fbinfo;
        struct s3c_fb_palette    palette;
        struct s3c_fb_win_variant variant;

        u32                     *palette_buffer;
        u32                      pseudo_palette[16];
        unsigned int             index;
};

/**
 * struct s3c_fb_vsync - vsync information
 * @wait:       a queue for processes waiting for vsync
 * @count:      vsync interrupt count
 */
struct s3c_fb_vsync {
        wait_queue_head_t       wait;
        unsigned int            count;
};

/**
 * struct s3c_fb - overall hardware state of the hardware
 * @slock: The spinlock protection for this data structure.
 * @dev: The device that we bound to, for printing, etc.
 * @bus_clk: The clk (hclk) feeding our interface and possibly pixclk.
 * @lcd_clk: The clk (sclk) feeding pixclk.
 * @regs: The mapped hardware registers.
 * @variant: Variant information for this hardware.
 * @enabled: A bitmask of enabled hardware windows.
 * @output_on: Flag if the physical output is enabled.
 * @pdata: The platform configuration data passed with the device.
 * @windows: The hardware windows that have been claimed.
 * @irq_no: IRQ line number
 * @irq_flags: irq flags
 * @vsync_info: VSYNC-related information (count, queues...)
 */
struct s3c_fb {
        spinlock_t              slock;
        struct device           *dev;
        struct clk              *bus_clk;
        struct clk              *lcd_clk;
        void __iomem            *regs;
        struct s3c_fb_variant    variant;

        unsigned char            enabled;
        bool                     output_on;

        struct s3c_fb_platdata  *pdata;
        struct s3c_fb_win       *windows[S3C_FB_MAX_WIN];

        int                      irq_no;
        unsigned long            irq_flags;
        struct s3c_fb_vsync      vsync_info;
};

/**
 * s3c_fb_validate_win_bpp - validate the bits-per-pixel for this mode.
 * @win: The device window.
 * @bpp: The bit depth.
 */
static bool s3c_fb_validate_win_bpp(struct s3c_fb_win *win, unsigned int bpp)
{
        return win->variant.valid_bpp & VALID_BPP(bpp);
}

/**
 * s3c_fb_check_var() - framebuffer layer request to verify a given mode.
 * @var: The screen information to verify.
 * @info: The framebuffer device.
 *
 * Framebuffer layer call to verify the given information and allow us to
 * update various information depending on the hardware capabilities.
 */
static int s3c_fb_check_var(struct fb_var_screeninfo *var,
                            struct fb_info *info)
{
        struct s3c_fb_win *win = info->par;
        struct s3c_fb *sfb = win->parent;

        dev_dbg(sfb->dev, "checking parameters\n");

        var->xres_virtual = max(var->xres_virtual, var->xres);
        var->yres_virtual = max(var->yres_virtual, var->yres);

        if (!s3c_fb_validate_win_bpp(win, var->bits_per_pixel)) {
                dev_dbg(sfb->dev, "win %d: unsupported bpp %d\n",
                        win->index, var->bits_per_pixel);
                return -EINVAL;
        }

        /* always ensure these are zero, for drop through cases below */
        var->transp.offset = 0;
        var->transp.length = 0;

        switch (var->bits_per_pixel) {
        case 1:
        case 2:
        case 4:
        case 8:
                if (sfb->variant.palette[win->index] != 0) {
                        /* non palletised, A:1,R:2,G:3,B:2 mode */
                        var->red.offset         = 5;
                        var->green.offset       = 2;
                        var->blue.offset        = 0;
                        var->red.length         = 2;
                        var->green.length       = 3;
                        var->blue.length        = 2;
                        var->transp.offset      = 7;
                        var->transp.length      = 1;
                } else {
                        var->red.offset = 0;
                        var->red.length = var->bits_per_pixel;
                        var->green      = var->red;
                        var->blue       = var->red;
                }
                break;

        case 19:
                /* 666 with one bit alpha/transparency */
                var->transp.offset      = 18;
                var->transp.length      = 1;
                /* drop through */
        case 18:
                var->bits_per_pixel     = 32;

                /* 666 format */
                var->red.offset         = 12;
                var->green.offset       = 6;
                var->blue.offset        = 0;
                var->red.length         = 6;
                var->green.length       = 6;
                var->blue.length        = 6;
                break;

        case 16:
                /* 16 bpp, 565 format */
                var->red.offset         = 11;
                var->green.offset       = 5;
                var->blue.offset        = 0;
                var->red.length         = 5;
                var->green.length       = 6;
                var->blue.length        = 5;
                break;

        case 32:
        case 28:
        case 25:
                var->transp.length      = var->bits_per_pixel - 24;
                var->transp.offset      = 24;
                /* drop through */
        case 24:
                /* our 24bpp is unpacked, so 32bpp */
                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;
                break;

        default:
                dev_err(sfb->dev, "invalid bpp\n");
                return -EINVAL;
        }

        dev_dbg(sfb->dev, "%s: verified parameters\n", __func__);
        return 0;
}

/**
 * s3c_fb_calc_pixclk() - calculate the divider to create the pixel clock.
 * @sfb: The hardware state.
 * @pixclock: The pixel clock wanted, in picoseconds.
 *
 * Given the specified pixel clock, work out the necessary divider to get
 * close to the output frequency.
 */
static int s3c_fb_calc_pixclk(struct s3c_fb *sfb, unsigned int pixclk)
{
        unsigned long clk;
        unsigned long long tmp;
        unsigned int result;

        if (sfb->variant.has_clksel)
                clk = clk_get_rate(sfb->bus_clk);
        else
                clk = clk_get_rate(sfb->lcd_clk);

        tmp = (unsigned long long)clk;
        tmp *= pixclk;

        do_div(tmp, 1000000000UL);
        result = (unsigned int)tmp / 1000;

        dev_dbg(sfb->dev, "pixclk=%u, clk=%lu, div=%d (%lu)\n",
                pixclk, clk, result, result ? clk / result : clk);

        return result;
}

/**
 * s3c_fb_align_word() - align pixel count to word boundary
 * @bpp: The number of bits per pixel
 * @pix: The value to be aligned.
 *
 * Align the given pixel count so that it will start on an 32bit word
 * boundary.
 */
static int s3c_fb_align_word(unsigned int bpp, unsigned int pix)
{
        int pix_per_word;

        if (bpp > 16)
                return pix;

        pix_per_word = (8 * 32) / bpp;
        return ALIGN(pix, pix_per_word);
}

/**
 * vidosd_set_size() - set OSD size for a window
 *
 * @win: the window to set OSD size for
 * @size: OSD size register value
 */
static void vidosd_set_size(struct s3c_fb_win *win, u32 size)
{
        struct s3c_fb *sfb = win->parent;

        /* OSD can be set up if osd_size_off != 0 for this window */
        if (win->variant.osd_size_off)
                writel(size, sfb->regs + OSD_BASE(win->index, sfb->variant)
                                + win->variant.osd_size_off);
}

/**
 * vidosd_set_alpha() - set alpha transparency for a window
 *
 * @win: the window to set OSD size for
 * @alpha: alpha register value
 */
static void vidosd_set_alpha(struct s3c_fb_win *win, u32 alpha)
{
        struct s3c_fb *sfb = win->parent;

        if (win->variant.has_osd_alpha)
                writel(alpha, sfb->regs + VIDOSD_C(win->index, sfb->variant));
}

/**
 * shadow_protect_win() - disable updating values from shadow registers at vsync
 *
 * @win: window to protect registers for
 * @protect: 1 to protect (disable updates)
 */
static void shadow_protect_win(struct s3c_fb_win *win, bool protect)
{
        struct s3c_fb *sfb = win->parent;
        u32 reg;

        if (protect) {
                if (sfb->variant.has_prtcon) {
                        writel(PRTCON_PROTECT, sfb->regs + PRTCON);
                } else if (sfb->variant.has_shadowcon) {
                        reg = readl(sfb->regs + SHADOWCON);
                        writel(reg | SHADOWCON_WINx_PROTECT(win->index),
                                sfb->regs + SHADOWCON);
                }
        } else {
                if (sfb->variant.has_prtcon) {
                        writel(0, sfb->regs + PRTCON);
                } else if (sfb->variant.has_shadowcon) {
                        reg = readl(sfb->regs + SHADOWCON);
                        writel(reg & ~SHADOWCON_WINx_PROTECT(win->index),
                                sfb->regs + SHADOWCON);
                }
        }
}

/**
 * s3c_fb_enable() - Set the state of the main LCD output
 * @sfb: The main framebuffer state.
 * @enable: The state to set.
 */
static void s3c_fb_enable(struct s3c_fb *sfb, int enable)
{
        u32 vidcon0 = readl(sfb->regs + VIDCON0);

        if (enable && !sfb->output_on)
                pm_runtime_get_sync(sfb->dev);

        if (enable) {
                vidcon0 |= VIDCON0_ENVID | VIDCON0_ENVID_F;
        } else {
                /* see the note in the framebuffer datasheet about
                 * why you cannot take both of these bits down at the
                 * same time. */

                if (vidcon0 & VIDCON0_ENVID) {
                        vidcon0 |= VIDCON0_ENVID;
                        vidcon0 &= ~VIDCON0_ENVID_F;
                }
        }

        writel(vidcon0, sfb->regs + VIDCON0);

        if (!enable && sfb->output_on)
                pm_runtime_put_sync(sfb->dev);

        sfb->output_on = enable;
}

/**
 * s3c_fb_set_par() - framebuffer request to set new framebuffer state.
 * @info: The framebuffer to change.
 *
 * Framebuffer layer request to set a new mode for the specified framebuffer
 */
static int s3c_fb_set_par(struct fb_info *info)
{
        struct fb_var_screeninfo *var = &info->var;
        struct s3c_fb_win *win = info->par;
        struct s3c_fb *sfb = win->parent;
        void __iomem *regs = sfb->regs;
        void __iomem *buf = regs;
        int win_no = win->index;
        u32 alpha = 0;
        u32 data;
        u32 pagewidth;

        dev_dbg(sfb->dev, "setting framebuffer parameters\n");

        pm_runtime_get_sync(sfb->dev);

        shadow_protect_win(win, 1);

        switch (var->bits_per_pixel) {
        case 32:
        case 24:
        case 16:
        case 12:
                info->fix.visual = FB_VISUAL_TRUECOLOR;
                break;
        case 8:
                if (win->variant.palette_sz >= 256)
                        info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
                else
                        info->fix.visual = FB_VISUAL_TRUECOLOR;
                break;
        case 1:
                info->fix.visual = FB_VISUAL_MONO01;
                break;
        default:
                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
                break;
        }

        info->fix.line_length = (var->xres_virtual * var->bits_per_pixel) / 8;

        info->fix.xpanstep = info->var.xres_virtual > info->var.xres ? 1 : 0;
        info->fix.ypanstep = info->var.yres_virtual > info->var.yres ? 1 : 0;

        /* disable the window whilst we update it */
        writel(0, regs + WINCON(win_no));

        if (!sfb->output_on)
                s3c_fb_enable(sfb, 1);

        /* write the buffer address */

        /* start and end registers stride is 8 */
        buf = regs + win_no * 8;

        writel(info->fix.smem_start, buf + sfb->variant.buf_start);

        data = info->fix.smem_start + info->fix.line_length * var->yres;
        writel(data, buf + sfb->variant.buf_end);

        pagewidth = (var->xres * var->bits_per_pixel) >> 3;
        data = VIDW_BUF_SIZE_OFFSET(info->fix.line_length - pagewidth) |
               VIDW_BUF_SIZE_PAGEWIDTH(pagewidth) |
               VIDW_BUF_SIZE_OFFSET_E(info->fix.line_length - pagewidth) |
               VIDW_BUF_SIZE_PAGEWIDTH_E(pagewidth);
        writel(data, regs + sfb->variant.buf_size + (win_no * 4));

        /* write 'OSD' registers to control position of framebuffer */

        data = VIDOSDxA_TOPLEFT_X(0) | VIDOSDxA_TOPLEFT_Y(0) |
               VIDOSDxA_TOPLEFT_X_E(0) | VIDOSDxA_TOPLEFT_Y_E(0);
        writel(data, regs + VIDOSD_A(win_no, sfb->variant));

        data = VIDOSDxB_BOTRIGHT_X(s3c_fb_align_word(var->bits_per_pixel,
                                                     var->xres - 1)) |
               VIDOSDxB_BOTRIGHT_Y(var->yres - 1) |
               VIDOSDxB_BOTRIGHT_X_E(s3c_fb_align_word(var->bits_per_pixel,
                                                     var->xres - 1)) |
               VIDOSDxB_BOTRIGHT_Y_E(var->yres - 1);

        writel(data, regs + VIDOSD_B(win_no, sfb->variant));

        data = var->xres * var->yres;

        alpha = VIDISD14C_ALPHA1_R(0xf) |
                VIDISD14C_ALPHA1_G(0xf) |
                VIDISD14C_ALPHA1_B(0xf);

        vidosd_set_alpha(win, alpha);
        vidosd_set_size(win, data);

        /* Enable DMA channel for this window */
        if (sfb->variant.has_shadowcon) {
                data = readl(sfb->regs + SHADOWCON);
                data |= SHADOWCON_CHx_ENABLE(win_no);
                writel(data, sfb->regs + SHADOWCON);
        }

        data = WINCONx_ENWIN;
        sfb->enabled |= (1 << win->index);

        /* note, since we have to round up the bits-per-pixel, we end up
         * relying on the bitfield information for r/g/b/a to work out
         * exactly which mode of operation is intended. */

        switch (var->bits_per_pixel) {
        case 1:
                data |= WINCON0_BPPMODE_1BPP;
                data |= WINCONx_BITSWP;
                data |= WINCONx_BURSTLEN_4WORD;
                break;
        case 2:
                data |= WINCON0_BPPMODE_2BPP;
                data |= WINCONx_BITSWP;
                data |= WINCONx_BURSTLEN_8WORD;
                break;
        case 4:
                data |= WINCON0_BPPMODE_4BPP;
                data |= WINCONx_BITSWP;
                data |= WINCONx_BURSTLEN_8WORD;
                break;
        case 8:
                if (var->transp.length != 0)
                        data |= WINCON1_BPPMODE_8BPP_1232;
                else
                        data |= WINCON0_BPPMODE_8BPP_PALETTE;
                data |= WINCONx_BURSTLEN_8WORD;
                data |= WINCONx_BYTSWP;
                break;
        case 16:
                if (var->transp.length != 0)
                        data |= WINCON1_BPPMODE_16BPP_A1555;
                else
                        data |= WINCON0_BPPMODE_16BPP_565;
                data |= WINCONx_HAWSWP;
                data |= WINCONx_BURSTLEN_16WORD;
                break;
        case 24:
        case 32:
                if (var->red.length == 6) {
                        if (var->transp.length != 0)
                                data |= WINCON1_BPPMODE_19BPP_A1666;
                        else
                                data |= WINCON1_BPPMODE_18BPP_666;
                } else if (var->transp.length == 1)
                        data |= WINCON1_BPPMODE_25BPP_A1888
                                | WINCON1_BLD_PIX;
                else if ((var->transp.length == 4) ||
                        (var->transp.length == 8))
                        data |= WINCON1_BPPMODE_28BPP_A4888
                                | WINCON1_BLD_PIX | WINCON1_ALPHA_SEL;
                else
                        data |= WINCON0_BPPMODE_24BPP_888;

                data |= WINCONx_WSWP;
                data |= WINCONx_BURSTLEN_16WORD;
                break;
        }

        /* Enable the colour keying for the window below this one */
        if (win_no > 0) {
                u32 keycon0_data = 0, keycon1_data = 0;
                void __iomem *keycon = regs + sfb->variant.keycon;

                keycon0_data = ~(WxKEYCON0_KEYBL_EN |
                                WxKEYCON0_KEYEN_F |
                                WxKEYCON0_DIRCON) | WxKEYCON0_COMPKEY(0);

                keycon1_data = WxKEYCON1_COLVAL(0xffffff);

                keycon += (win_no - 1) * 8;

                writel(keycon0_data, keycon + WKEYCON0);
                writel(keycon1_data, keycon + WKEYCON1);
        }

        writel(data, regs + sfb->variant.wincon + (win_no * 4));
        writel(0x0, regs + sfb->variant.winmap + (win_no * 4));

        /* Set alpha value width */
        if (sfb->variant.has_blendcon) {
                data = readl(sfb->regs + BLENDCON);
                data &= ~BLENDCON_NEW_MASK;
                if (var->transp.length > 4)
                        data |= BLENDCON_NEW_8BIT_ALPHA_VALUE;
                else
                        data |= BLENDCON_NEW_4BIT_ALPHA_VALUE;
                writel(data, sfb->regs + BLENDCON);
        }

        shadow_protect_win(win, 0);

        pm_runtime_put_sync(sfb->dev);

        return 0;
}

/**
 * s3c_fb_update_palette() - set or schedule a palette update.
 * @sfb: The hardware information.
 * @win: The window being updated.
 * @reg: The palette index being changed.
 * @value: The computed palette value.
 *
 * Change the value of a palette register, either by directly writing to
 * the palette (this requires the palette RAM to be disconnected from the
 * hardware whilst this is in progress) or schedule the update for later.
 *
 * At the moment, since we have no VSYNC interrupt support, we simply set
 * the palette entry directly.
 */
static void s3c_fb_update_palette(struct s3c_fb *sfb,
                                  struct s3c_fb_win *win,
                                  unsigned int reg,
                                  u32 value)
{
        void __iomem *palreg;
        u32 palcon;

        palreg = sfb->regs + sfb->variant.palette[win->index];

        dev_dbg(sfb->dev, "%s: win %d, reg %d (%p): %08x\n",
                __func__, win->index, reg, palreg, value);

        win->palette_buffer[reg] = value;

        palcon = readl(sfb->regs + WPALCON);
        writel(palcon | WPALCON_PAL_UPDATE, sfb->regs + WPALCON);

        if (win->variant.palette_16bpp)
                writew(value, palreg + (reg * 2));
        else
                writel(value, palreg + (reg * 4));

        writel(palcon, sfb->regs + WPALCON);
}

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

/**
 * s3c_fb_setcolreg() - framebuffer layer request to change palette.
 * @regno: The palette index to change.
 * @red: The red field for the palette data.
 * @green: The green field for the palette data.
 * @blue: The blue field for the palette data.
 * @trans: The transparency (alpha) field for the palette data.
 * @info: The framebuffer being changed.
 */
static int s3c_fb_setcolreg(unsigned regno,
                            unsigned red, unsigned green, unsigned blue,
                            unsigned transp, struct fb_info *info)
{
        struct s3c_fb_win *win = info->par;
        struct s3c_fb *sfb = win->parent;
        unsigned int val;

        dev_dbg(sfb->dev, "%s: win %d: %d => rgb=%d/%d/%d\n",
                __func__, win->index, regno, red, green, blue);

        pm_runtime_get_sync(sfb->dev);

        switch (info->fix.visual) {
        case FB_VISUAL_TRUECOLOR:
                /* true-colour, use pseudo-palette */

                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;
                }
                break;

        case FB_VISUAL_PSEUDOCOLOR:
                if (regno < win->variant.palette_sz) {
                        val  = chan_to_field(red, &win->palette.r);
                        val |= chan_to_field(green, &win->palette.g);
                        val |= chan_to_field(blue, &win->palette.b);

                        s3c_fb_update_palette(sfb, win, regno, val);
                }

                break;

        default:
                pm_runtime_put_sync(sfb->dev);
                return 1;       /* unknown type */
        }

        pm_runtime_put_sync(sfb->dev);
        return 0;
}

/**
 * s3c_fb_blank() - blank or unblank the given window
 * @blank_mode: The blank state from FB_BLANK_*
 * @info: The framebuffer to blank.
 *
 * Framebuffer layer request to change the power state.
 */
static int s3c_fb_blank(int blank_mode, struct fb_info *info)
{
        struct s3c_fb_win *win = info->par;
        struct s3c_fb *sfb = win->parent;
        unsigned int index = win->index;
        u32 wincon;
        u32 output_on = sfb->output_on;

        dev_dbg(sfb->dev, "blank mode %d\n", blank_mode);

        pm_runtime_get_sync(sfb->dev);

        wincon = readl(sfb->regs + sfb->variant.wincon + (index * 4));

        switch (blank_mode) {
        case FB_BLANK_POWERDOWN:
                wincon &= ~WINCONx_ENWIN;
                sfb->enabled &= ~(1 << index);
                /* fall through to FB_BLANK_NORMAL */

        case FB_BLANK_NORMAL:
                /* disable the DMA and display 0x0 (black) */
                shadow_protect_win(win, 1);
                writel(WINxMAP_MAP | WINxMAP_MAP_COLOUR(0x0),
                       sfb->regs + sfb->variant.winmap + (index * 4));
                shadow_protect_win(win, 0);
                break;

        case FB_BLANK_UNBLANK:
                shadow_protect_win(win, 1);
                writel(0x0, sfb->regs + sfb->variant.winmap + (index * 4));
                shadow_protect_win(win, 0);
                wincon |= WINCONx_ENWIN;
                sfb->enabled |= (1 << index);
                break;

        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
        default:
                pm_runtime_put_sync(sfb->dev);
                return 1;
        }

        shadow_protect_win(win, 1);
        writel(wincon, sfb->regs + sfb->variant.wincon + (index * 4));

        /* Check the enabled state to see if we need to be running the
         * main LCD interface, as if there are no active windows then
         * it is highly likely that we also do not need to output
         * anything.
         */
        s3c_fb_enable(sfb, sfb->enabled ? 1 : 0);
        shadow_protect_win(win, 0);

        pm_runtime_put_sync(sfb->dev);

        return output_on == sfb->output_on;
}

/**
 * s3c_fb_pan_display() - Pan the display.
 *
 * Note that the offsets can be written to the device at any time, as their
 * values are latched at each vsync automatically. This also means that only
 * the last call to this function will have any effect on next vsync, but
 * there is no need to sleep waiting for it to prevent tearing.
 *
 * @var: The screen information to verify.
 * @info: The framebuffer device.
 */
static int s3c_fb_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info)
{
        struct s3c_fb_win *win  = info->par;
        struct s3c_fb *sfb      = win->parent;
        void __iomem *buf       = sfb->regs + win->index * 8;
        unsigned int start_boff, end_boff;

        pm_runtime_get_sync(sfb->dev);

        /* Offset in bytes to the start of the displayed area */
        start_boff = var->yoffset * info->fix.line_length;
        /* X offset depends on the current bpp */
        if (info->var.bits_per_pixel >= 8) {
                start_boff += var->xoffset * (info->var.bits_per_pixel >> 3);
        } else {
                switch (info->var.bits_per_pixel) {
                case 4:
                        start_boff += var->xoffset >> 1;
                        break;
                case 2:
                        start_boff += var->xoffset >> 2;
                        break;
                case 1:
                        start_boff += var->xoffset >> 3;
                        break;
                default:
                        dev_err(sfb->dev, "invalid bpp\n");
                        pm_runtime_put_sync(sfb->dev);
                        return -EINVAL;
                }
        }
        /* Offset in bytes to the end of the displayed area */
        end_boff = start_boff + info->var.yres * info->fix.line_length;

        /* Temporarily turn off per-vsync update from shadow registers until
         * both start and end addresses are updated to prevent corruption */
        shadow_protect_win(win, 1);

        writel(info->fix.smem_start + start_boff, buf + sfb->variant.buf_start);
        writel(info->fix.smem_start + end_boff, buf + sfb->variant.buf_end);

        shadow_protect_win(win, 0);

        pm_runtime_put_sync(sfb->dev);
        return 0;
}

/**
 * s3c_fb_enable_irq() - enable framebuffer interrupts
 * @sfb: main hardware state
 */
static void s3c_fb_enable_irq(struct s3c_fb *sfb)
{
        void __iomem *regs = sfb->regs;
        u32 irq_ctrl_reg;

        if (!test_and_set_bit(S3C_FB_VSYNC_IRQ_EN, &sfb->irq_flags)) {
                /* IRQ disabled, enable it */
                irq_ctrl_reg = readl(regs + VIDINTCON0);

                irq_ctrl_reg |= VIDINTCON0_INT_ENABLE;
                irq_ctrl_reg |= VIDINTCON0_INT_FRAME;

                irq_ctrl_reg &= ~VIDINTCON0_FRAMESEL0_MASK;
                irq_ctrl_reg |= VIDINTCON0_FRAMESEL0_VSYNC;
                irq_ctrl_reg &= ~VIDINTCON0_FRAMESEL1_MASK;
                irq_ctrl_reg |= VIDINTCON0_FRAMESEL1_NONE;

                writel(irq_ctrl_reg, regs + VIDINTCON0);
        }
}

/**
 * s3c_fb_disable_irq() - disable framebuffer interrupts
 * @sfb: main hardware state
 */
static void s3c_fb_disable_irq(struct s3c_fb *sfb)
{
        void __iomem *regs = sfb->regs;
        u32 irq_ctrl_reg;

        if (test_and_clear_bit(S3C_FB_VSYNC_IRQ_EN, &sfb->irq_flags)) {
                /* IRQ enabled, disable it */
                irq_ctrl_reg = readl(regs + VIDINTCON0);

                irq_ctrl_reg &= ~VIDINTCON0_INT_FRAME;
                irq_ctrl_reg &= ~VIDINTCON0_INT_ENABLE;

                writel(irq_ctrl_reg, regs + VIDINTCON0);
        }
}

static irqreturn_t s3c_fb_irq(int irq, void *dev_id)
{
        struct s3c_fb *sfb = dev_id;
        void __iomem  *regs = sfb->regs;
        u32 irq_sts_reg;

        spin_lock(&sfb->slock);

        irq_sts_reg = readl(regs + VIDINTCON1);

        if (irq_sts_reg & VIDINTCON1_INT_FRAME) {

                /* VSYNC interrupt, accept it */
                writel(VIDINTCON1_INT_FRAME, regs + VIDINTCON1);

                sfb->vsync_info.count++;
                wake_up_interruptible(&sfb->vsync_info.wait);
        }

        /* We only support waiting for VSYNC for now, so it's safe
         * to always disable irqs here.
         */
        s3c_fb_disable_irq(sfb);

        spin_unlock(&sfb->slock);
        return IRQ_HANDLED;
}

/**
 * s3c_fb_wait_for_vsync() - sleep until next VSYNC interrupt or timeout
 * @sfb: main hardware state
 * @crtc: head index.
 */
static int s3c_fb_wait_for_vsync(struct s3c_fb *sfb, u32 crtc)
{
        unsigned long count;
        int ret;

        if (crtc != 0)
                return -ENODEV;

        pm_runtime_get_sync(sfb->dev);

        count = sfb->vsync_info.count;
        s3c_fb_enable_irq(sfb);
        ret = wait_event_interruptible_timeout(sfb->vsync_info.wait,
                                       count != sfb->vsync_info.count,
                                       msecs_to_jiffies(VSYNC_TIMEOUT_MSEC));

        pm_runtime_put_sync(sfb->dev);

        if (ret == 0)
                return -ETIMEDOUT;

        return 0;
}

static int s3c_fb_ioctl(struct fb_info *info, unsigned int cmd,
                        unsigned long arg)
{
        struct s3c_fb_win *win = info->par;
        struct s3c_fb *sfb = win->parent;
        int ret;
        u32 crtc;

        switch (cmd) {
        case FBIO_WAITFORVSYNC:
                if (get_user(crtc, (u32 __user *)arg)) {
                        ret = -EFAULT;
                        break;
                }

                ret = s3c_fb_wait_for_vsync(sfb, crtc);
                break;
        default:
                ret = -ENOTTY;
        }

        return ret;
}

static struct fb_ops s3c_fb_ops = {
        .owner          = THIS_MODULE,
        .fb_check_var   = s3c_fb_check_var,
        .fb_set_par     = s3c_fb_set_par,
        .fb_blank       = s3c_fb_blank,
        .fb_setcolreg   = s3c_fb_setcolreg,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
        .fb_pan_display = s3c_fb_pan_display,
        .fb_ioctl       = s3c_fb_ioctl,
};

/**
 * s3c_fb_missing_pixclock() - calculates pixel clock
 * @mode: The video mode to change.
 *
 * Calculate the pixel clock when none has been given through platform data.
 */
static void s3c_fb_missing_pixclock(struct fb_videomode *mode)
{
        u64 pixclk = 1000000000000ULL;
        u32 div;

        div  = mode->left_margin + mode->hsync_len + mode->right_margin +
               mode->xres;
        div *= mode->upper_margin + mode->vsync_len + mode->lower_margin +
               mode->yres;
        div *= mode->refresh ? : 60;

        do_div(pixclk, div);

        mode->pixclock = pixclk;
}

/**
 * s3c_fb_alloc_memory() - allocate display memory for framebuffer window
 * @sfb: The base resources for the hardware.
 * @win: The window to initialise memory for.
 *
 * Allocate memory for the given framebuffer.
 */
static int s3c_fb_alloc_memory(struct s3c_fb *sfb, struct s3c_fb_win *win)
{
        struct s3c_fb_pd_win *windata = win->windata;
        unsigned int real_size, virt_size, size;
        struct fb_info *fbi = win->fbinfo;
        dma_addr_t map_dma;

        dev_dbg(sfb->dev, "allocating memory for display\n");

        real_size = windata->xres * windata->yres;
        virt_size = windata->virtual_x * windata->virtual_y;

        dev_dbg(sfb->dev, "real_size=%u (%u.%u), virt_size=%u (%u.%u)\n",
                real_size, windata->xres, windata->yres,
                virt_size, windata->virtual_x, windata->virtual_y);

        size = (real_size > virt_size) ? real_size : virt_size;
        size *= (windata->max_bpp > 16) ? 32 : windata->max_bpp;
        size /= 8;

        fbi->fix.smem_len = size;
        size = PAGE_ALIGN(size);

        dev_dbg(sfb->dev, "want %u bytes for window\n", size);

        fbi->screen_base = dma_alloc_wc(sfb->dev, size, &map_dma, GFP_KERNEL);
        if (!fbi->screen_base)
                return -ENOMEM;

        dev_dbg(sfb->dev, "mapped %x to %p\n",
                (unsigned int)map_dma, fbi->screen_base);

        memset(fbi->screen_base, 0x0, size);
        fbi->fix.smem_start = map_dma;

        return 0;
}

/**
 * s3c_fb_free_memory() - free the display memory for the given window
 * @sfb: The base resources for the hardware.
 * @win: The window to free the display memory for.
 *
 * Free the display memory allocated by s3c_fb_alloc_memory().
 */
static void s3c_fb_free_memory(struct s3c_fb *sfb, struct s3c_fb_win *win)
{
        struct fb_info *fbi = win->fbinfo;

        if (fbi->screen_base)
                dma_free_wc(sfb->dev, PAGE_ALIGN(fbi->fix.smem_len),
                            fbi->screen_base, fbi->fix.smem_start);
}

/**
 * s3c_fb_release_win() - release resources for a framebuffer window.
 * @win: The window to cleanup the resources for.
 *
 * Release the resources that where claimed for the hardware window,
 * such as the framebuffer instance and any memory claimed for it.
 */
static void s3c_fb_release_win(struct s3c_fb *sfb, struct s3c_fb_win *win)
{
        u32 data;

        if (win->fbinfo) {
                if (sfb->variant.has_shadowcon) {
                        data = readl(sfb->regs + SHADOWCON);
                        data &= ~SHADOWCON_CHx_ENABLE(win->index);
                        data &= ~SHADOWCON_CHx_LOCAL_ENABLE(win->index);
                        writel(data, sfb->regs + SHADOWCON);
                }
                unregister_framebuffer(win->fbinfo);
                if (win->fbinfo->cmap.len)
                        fb_dealloc_cmap(&win->fbinfo->cmap);
                s3c_fb_free_memory(sfb, win);
                framebuffer_release(win->fbinfo);
        }
}

/**
 * s3c_fb_probe_win() - register an hardware window
 * @sfb: The base resources for the hardware
 * @variant: The variant information for this window.
 * @res: Pointer to where to place the resultant window.
 *
 * Allocate and do the basic initialisation for one of the hardware's graphics
 * windows.
 */
static int s3c_fb_probe_win(struct s3c_fb *sfb, unsigned int win_no,
                            struct s3c_fb_win_variant *variant,
                            struct s3c_fb_win **res)
{
        struct fb_var_screeninfo *var;
        struct fb_videomode initmode;
        struct s3c_fb_pd_win *windata;
        struct s3c_fb_win *win;
        struct fb_info *fbinfo;
        int palette_size;
        int ret;

        dev_dbg(sfb->dev, "probing window %d, variant %p\n", win_no, variant);

        init_waitqueue_head(&sfb->vsync_info.wait);

        palette_size = variant->palette_sz * 4;

        fbinfo = framebuffer_alloc(sizeof(struct s3c_fb_win) +
                                   palette_size * sizeof(u32), sfb->dev);
        if (!fbinfo) {
                dev_err(sfb->dev, "failed to allocate framebuffer\n");
                return -ENOENT;
        }

        windata = sfb->pdata->win[win_no];
        initmode = *sfb->pdata->vtiming;

        WARN_ON(windata->max_bpp == 0);
        WARN_ON(windata->xres == 0);
        WARN_ON(windata->yres == 0);

        win = fbinfo->par;
        *res = win;
        var = &fbinfo->var;
        win->variant = *variant;
        win->fbinfo = fbinfo;
        win->parent = sfb;
        win->windata = windata;
        win->index = win_no;
        win->palette_buffer = (u32 *)(win + 1);

        ret = s3c_fb_alloc_memory(sfb, win);
        if (ret) {
                dev_err(sfb->dev, "failed to allocate display memory\n");
                return ret;
        }

        /* setup the r/b/g positions for the window's palette */
        if (win->variant.palette_16bpp) {
                /* Set RGB 5:6:5 as default */
                win->palette.r.offset = 11;
                win->palette.r.length = 5;
                win->palette.g.offset = 5;
                win->palette.g.length = 6;
                win->palette.b.offset = 0;
                win->palette.b.length = 5;

        } else {
                /* Set 8bpp or 8bpp and 1bit alpha */
                win->palette.r.offset = 16;
                win->palette.r.length = 8;
                win->palette.g.offset = 8;
                win->palette.g.length = 8;
                win->palette.b.offset = 0;
                win->palette.b.length = 8;
        }

        /* setup the initial video mode from the window */
        initmode.xres = windata->xres;
        initmode.yres = windata->yres;
        fb_videomode_to_var(&fbinfo->var, &initmode);

        fbinfo->fix.type        = FB_TYPE_PACKED_PIXELS;
        fbinfo->fix.accel       = FB_ACCEL_NONE;
        fbinfo->var.activate    = FB_ACTIVATE_NOW;
        fbinfo->var.vmode       = FB_VMODE_NONINTERLACED;
        fbinfo->var.bits_per_pixel = windata->default_bpp;
        fbinfo->fbops           = &s3c_fb_ops;
        fbinfo->flags           = FBINFO_FLAG_DEFAULT;
        fbinfo->pseudo_palette  = &win->pseudo_palette;

        /* prepare to actually start the framebuffer */

        ret = s3c_fb_check_var(&fbinfo->var, fbinfo);
        if (ret < 0) {
                dev_err(sfb->dev, "check_var failed on initial video params\n");
                return ret;
        }

        /* create initial colour map */

        ret = fb_alloc_cmap(&fbinfo->cmap, win->variant.palette_sz, 1);
        if (ret == 0)
                fb_set_cmap(&fbinfo->cmap, fbinfo);
        else
                dev_err(sfb->dev, "failed to allocate fb cmap\n");

        s3c_fb_set_par(fbinfo);

        dev_dbg(sfb->dev, "about to register framebuffer\n");

        /* run the check_var and set_par on our configuration. */

        ret = register_framebuffer(fbinfo);
        if (ret < 0) {
                dev_err(sfb->dev, "failed to register framebuffer\n");
                return ret;
        }

        dev_info(sfb->dev, "window %d: fb %s\n", win_no, fbinfo->fix.id);

        return 0;
}

/**
 * s3c_fb_set_rgb_timing() - set video timing for rgb interface.
 * @sfb: The base resources for the hardware.
 *
 * Set horizontal and vertical lcd rgb interface timing.
 */
static void s3c_fb_set_rgb_timing(struct s3c_fb *sfb)
{
        struct fb_videomode *vmode = sfb->pdata->vtiming;
        void __iomem *regs = sfb->regs;
        int clkdiv;
        u32 data;

        if (!vmode->pixclock)
                s3c_fb_missing_pixclock(vmode);

        clkdiv = s3c_fb_calc_pixclk(sfb, vmode->pixclock);

        data = sfb->pdata->vidcon0;
        data &= ~(VIDCON0_CLKVAL_F_MASK | VIDCON0_CLKDIR);

        if (clkdiv > 1)
                data |= VIDCON0_CLKVAL_F(clkdiv-1) | VIDCON0_CLKDIR;
        else
                data &= ~VIDCON0_CLKDIR;        /* 1:1 clock */

        if (sfb->variant.is_2443)
                data |= (1 << 5);
        writel(data, regs + VIDCON0);

        data = VIDTCON0_VBPD(vmode->upper_margin - 1) |
               VIDTCON0_VFPD(vmode->lower_margin - 1) |
               VIDTCON0_VSPW(vmode->vsync_len - 1);
        writel(data, regs + sfb->variant.vidtcon);

        data = VIDTCON1_HBPD(vmode->left_margin - 1) |
               VIDTCON1_HFPD(vmode->right_margin - 1) |
               VIDTCON1_HSPW(vmode->hsync_len - 1);
        writel(data, regs + sfb->variant.vidtcon + 4);

        data = VIDTCON2_LINEVAL(vmode->yres - 1) |
               VIDTCON2_HOZVAL(vmode->xres - 1) |
               VIDTCON2_LINEVAL_E(vmode->yres - 1) |
               VIDTCON2_HOZVAL_E(vmode->xres - 1);
        writel(data, regs + sfb->variant.vidtcon + 8);
}

/**
 * s3c_fb_clear_win() - clear hardware window registers.
 * @sfb: The base resources for the hardware.
 * @win: The window to process.
 *
 * Reset the specific window registers to a known state.
 */
static void s3c_fb_clear_win(struct s3c_fb *sfb, int win)
{
        void __iomem *regs = sfb->regs;
        u32 reg;

        writel(0, regs + sfb->variant.wincon + (win * 4));
        writel(0, regs + VIDOSD_A(win, sfb->variant));
        writel(0, regs + VIDOSD_B(win, sfb->variant));
        writel(0, regs + VIDOSD_C(win, sfb->variant));

        if (sfb->variant.has_shadowcon) {
                reg = readl(sfb->regs + SHADOWCON);
                reg &= ~(SHADOWCON_WINx_PROTECT(win) |
                        SHADOWCON_CHx_ENABLE(win) |
                        SHADOWCON_CHx_LOCAL_ENABLE(win));
                writel(reg, sfb->regs + SHADOWCON);
        }
}

static int s3c_fb_probe(struct platform_device *pdev)
{
        const struct platform_device_id *platid;
        struct s3c_fb_driverdata *fbdrv;
        struct device *dev = &pdev->dev;
        struct s3c_fb_platdata *pd;
        struct s3c_fb *sfb;
        struct resource *res;
        int win;
        int ret = 0;
        u32 reg;

        platid = platform_get_device_id(pdev);
        fbdrv = (struct s3c_fb_driverdata *)platid->driver_data;

        if (fbdrv->variant.nr_windows > S3C_FB_MAX_WIN) {
                dev_err(dev, "too many windows, cannot attach\n");
                return -EINVAL;
        }

        pd = dev_get_platdata(&pdev->dev);
        if (!pd) {
                dev_err(dev, "no platform data specified\n");
                return -EINVAL;
        }

        sfb = devm_kzalloc(dev, sizeof(struct s3c_fb), GFP_KERNEL);
        if (!sfb) {
                dev_err(dev, "no memory for framebuffers\n");
                return -ENOMEM;
        }

        dev_dbg(dev, "allocate new framebuffer %p\n", sfb);

        sfb->dev = dev;
        sfb->pdata = pd;
        sfb->variant = fbdrv->variant;

        spin_lock_init(&sfb->slock);

        sfb->bus_clk = devm_clk_get(dev, "lcd");
        if (IS_ERR(sfb->bus_clk)) {
                dev_err(dev, "failed to get bus clock\n");
                return PTR_ERR(sfb->bus_clk);
        }

        clk_prepare_enable(sfb->bus_clk);

        if (!sfb->variant.has_clksel) {
                sfb->lcd_clk = devm_clk_get(dev, "sclk_fimd");
                if (IS_ERR(sfb->lcd_clk)) {
                        dev_err(dev, "failed to get lcd clock\n");
                        ret = PTR_ERR(sfb->lcd_clk);
                        goto err_bus_clk;
                }

                clk_prepare_enable(sfb->lcd_clk);
        }

        pm_runtime_enable(sfb->dev);

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        sfb->regs = devm_ioremap_resource(dev, res);
        if (IS_ERR(sfb->regs)) {
                ret = PTR_ERR(sfb->regs);
                goto err_lcd_clk;
        }

        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
        if (!res) {
                dev_err(dev, "failed to acquire irq resource\n");
                ret = -ENOENT;
                goto err_lcd_clk;
        }
        sfb->irq_no = res->start;
        ret = devm_request_irq(dev, sfb->irq_no, s3c_fb_irq,
                          0, "s3c_fb", sfb);
        if (ret) {
                dev_err(dev, "irq request failed\n");
                goto err_lcd_clk;
        }

        dev_dbg(dev, "got resources (regs %p), probing windows\n", sfb->regs);

        platform_set_drvdata(pdev, sfb);
        pm_runtime_get_sync(sfb->dev);

        /* setup gpio and output polarity controls */

        pd->setup_gpio();

        writel(pd->vidcon1, sfb->regs + VIDCON1);

        /* set video clock running at under-run */
        if (sfb->variant.has_fixvclk) {
                reg = readl(sfb->regs + VIDCON1);
                reg &= ~VIDCON1_VCLK_MASK;
                reg |= VIDCON1_VCLK_RUN;
                writel(reg, sfb->regs + VIDCON1);
        }

        /* zero all windows before we do anything */

        for (win = 0; win < fbdrv->variant.nr_windows; win++)
                s3c_fb_clear_win(sfb, win);

        /* initialise colour key controls */
        for (win = 0; win < (fbdrv->variant.nr_windows - 1); win++) {
                void __iomem *regs = sfb->regs + sfb->variant.keycon;

                regs += (win * 8);
                writel(0xffffff, regs + WKEYCON0);
                writel(0xffffff, regs + WKEYCON1);
        }

        s3c_fb_set_rgb_timing(sfb);

        /* we have the register setup, start allocating framebuffers */

        for (win = 0; win < fbdrv->variant.nr_windows; win++) {
                if (!pd->win[win])
                        continue;

                ret = s3c_fb_probe_win(sfb, win, fbdrv->win[win],
                                       &sfb->windows[win]);
                if (ret < 0) {
                        dev_err(dev, "failed to create window %d\n", win);
                        for (; win >= 0; win--)
                                s3c_fb_release_win(sfb, sfb->windows[win]);
                        goto err_pm_runtime;
                }
        }

        platform_set_drvdata(pdev, sfb);
        pm_runtime_put_sync(sfb->dev);

        return 0;

err_pm_runtime:
        pm_runtime_put_sync(sfb->dev);

err_lcd_clk:
        pm_runtime_disable(sfb->dev);

        if (!sfb->variant.has_clksel)
                clk_disable_unprepare(sfb->lcd_clk);

err_bus_clk:
        clk_disable_unprepare(sfb->bus_clk);

        return ret;
}

/**
 * s3c_fb_remove() - Cleanup on module finalisation
 * @pdev: The platform device we are bound to.
 *
 * Shutdown and then release all the resources that the driver allocated
 * on initialisation.
 */
static int s3c_fb_remove(struct platform_device *pdev)
{
        struct s3c_fb *sfb = platform_get_drvdata(pdev);
        int win;

        pm_runtime_get_sync(sfb->dev);

        for (win = 0; win < S3C_FB_MAX_WIN; win++)
                if (sfb->windows[win])
                        s3c_fb_release_win(sfb, sfb->windows[win]);

        if (!sfb->variant.has_clksel)
                clk_disable_unprepare(sfb->lcd_clk);

        clk_disable_unprepare(sfb->bus_clk);

        pm_runtime_put_sync(sfb->dev);
        pm_runtime_disable(sfb->dev);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int s3c_fb_suspend(struct device *dev)
{
        struct s3c_fb *sfb = dev_get_drvdata(dev);
        struct s3c_fb_win *win;
        int win_no;

        pm_runtime_get_sync(sfb->dev);

        for (win_no = S3C_FB_MAX_WIN - 1; win_no >= 0; win_no--) {
                win = sfb->windows[win_no];
                if (!win)
                        continue;

                /* use the blank function to push into power-down */
                s3c_fb_blank(FB_BLANK_POWERDOWN, win->fbinfo);
        }

        if (!sfb->variant.has_clksel)
                clk_disable_unprepare(sfb->lcd_clk);

        clk_disable_unprepare(sfb->bus_clk);

        pm_runtime_put_sync(sfb->dev);

        return 0;
}

static int s3c_fb_resume(struct device *dev)
{
        struct s3c_fb *sfb = dev_get_drvdata(dev);
        struct s3c_fb_platdata *pd = sfb->pdata;
        struct s3c_fb_win *win;
        int win_no;
        u32 reg;

        pm_runtime_get_sync(sfb->dev);

        clk_prepare_enable(sfb->bus_clk);

        if (!sfb->variant.has_clksel)
                clk_prepare_enable(sfb->lcd_clk);

        /* setup gpio and output polarity controls */
        pd->setup_gpio();
        writel(pd->vidcon1, sfb->regs + VIDCON1);

        /* set video clock running at under-run */
        if (sfb->variant.has_fixvclk) {
                reg = readl(sfb->regs + VIDCON1);
                reg &= ~VIDCON1_VCLK_MASK;
                reg |= VIDCON1_VCLK_RUN;
                writel(reg, sfb->regs + VIDCON1);
        }

        /* zero all windows before we do anything */
        for (win_no = 0; win_no < sfb->variant.nr_windows; win_no++)
                s3c_fb_clear_win(sfb, win_no);

        for (win_no = 0; win_no < sfb->variant.nr_windows - 1; win_no++) {
                void __iomem *regs = sfb->regs + sfb->variant.keycon;
                win = sfb->windows[win_no];
                if (!win)
                        continue;

                shadow_protect_win(win, 1);
                regs += (win_no * 8);
                writel(0xffffff, regs + WKEYCON0);
                writel(0xffffff, regs + WKEYCON1);
                shadow_protect_win(win, 0);
        }

        s3c_fb_set_rgb_timing(sfb);

        /* restore framebuffers */
        for (win_no = 0; win_no < S3C_FB_MAX_WIN; win_no++) {
                win = sfb->windows[win_no];
                if (!win)
                        continue;

                dev_dbg(dev, "resuming window %d\n", win_no);
                s3c_fb_set_par(win->fbinfo);
        }

        pm_runtime_put_sync(sfb->dev);

        return 0;
}
#endif

#ifdef CONFIG_PM
static int s3c_fb_runtime_suspend(struct device *dev)
{
        struct s3c_fb *sfb = dev_get_drvdata(dev);

        if (!sfb->variant.has_clksel)
                clk_disable_unprepare(sfb->lcd_clk);

        clk_disable_unprepare(sfb->bus_clk);

        return 0;
}

static int s3c_fb_runtime_resume(struct device *dev)
{
        struct s3c_fb *sfb = dev_get_drvdata(dev);
        struct s3c_fb_platdata *pd = sfb->pdata;

        clk_prepare_enable(sfb->bus_clk);

        if (!sfb->variant.has_clksel)
                clk_prepare_enable(sfb->lcd_clk);

        /* setup gpio and output polarity controls */
        pd->setup_gpio();
        writel(pd->vidcon1, sfb->regs + VIDCON1);

        return 0;
}
#endif

#define VALID_BPP124 (VALID_BPP(1) | VALID_BPP(2) | VALID_BPP(4))
#define VALID_BPP1248 (VALID_BPP124 | VALID_BPP(8))

static struct s3c_fb_win_variant s3c_fb_data_64xx_wins[] = {
        [0] = {
                .has_osd_c      = 1,
                .osd_size_off   = 0x8,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(24)),
        },
        [1] = {
                .has_osd_c      = 1,
                .has_osd_d      = 1,
                .osd_size_off   = 0xc,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(28)),
        },
        [2] = {
                .has_osd_c      = 1,
                .has_osd_d      = 1,
                .osd_size_off   = 0xc,
                .has_osd_alpha  = 1,
                .palette_sz     = 16,
                .palette_16bpp  = 1,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(28)),
        },
        [3] = {
                .has_osd_c      = 1,
                .has_osd_alpha  = 1,
                .palette_sz     = 16,
                .palette_16bpp  = 1,
                .valid_bpp      = (VALID_BPP124  | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(28)),
        },
        [4] = {
                .has_osd_c      = 1,
                .has_osd_alpha  = 1,
                .palette_sz     = 4,
                .palette_16bpp  = 1,
                .valid_bpp      = (VALID_BPP(1) | VALID_BPP(2) |
                                   VALID_BPP(16) | VALID_BPP(18) |
                                   VALID_BPP(19) | VALID_BPP(24) |
                                   VALID_BPP(25) | VALID_BPP(28)),
        },
};

static struct s3c_fb_win_variant s3c_fb_data_s5p_wins[] = {
        [0] = {
                .has_osd_c      = 1,
                .osd_size_off   = 0x8,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(13) |
                                   VALID_BPP(15) | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(32)),
        },
        [1] = {
                .has_osd_c      = 1,
                .has_osd_d      = 1,
                .osd_size_off   = 0xc,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(13) |
                                   VALID_BPP(15) | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(32)),
        },
        [2] = {
                .has_osd_c      = 1,
                .has_osd_d      = 1,
                .osd_size_off   = 0xc,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(13) |
                                   VALID_BPP(15) | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(32)),
        },
        [3] = {
                .has_osd_c      = 1,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(13) |
                                   VALID_BPP(15) | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(32)),
        },
        [4] = {
                .has_osd_c      = 1,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(13) |
                                   VALID_BPP(15) | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(32)),
        },
};

static struct s3c_fb_driverdata s3c_fb_data_64xx = {
        .variant = {
                .nr_windows     = 5,
                .vidtcon        = VIDTCON0,
                .wincon         = WINCON(0),
                .winmap         = WINxMAP(0),
                .keycon         = WKEYCON,
                .osd            = VIDOSD_BASE,
                .osd_stride     = 16,
                .buf_start      = VIDW_BUF_START(0),
                .buf_size       = VIDW_BUF_SIZE(0),
                .buf_end        = VIDW_BUF_END(0),

                .palette = {
                        [0] = 0x400,
                        [1] = 0x800,
                        [2] = 0x300,
                        [3] = 0x320,
                        [4] = 0x340,
                },

                .has_prtcon     = 1,
                .has_clksel     = 1,
        },
        .win[0] = &s3c_fb_data_64xx_wins[0],
        .win[1] = &s3c_fb_data_64xx_wins[1],
        .win[2] = &s3c_fb_data_64xx_wins[2],
        .win[3] = &s3c_fb_data_64xx_wins[3],
        .win[4] = &s3c_fb_data_64xx_wins[4],
};

static struct s3c_fb_driverdata s3c_fb_data_s5pv210 = {
        .variant = {
                .nr_windows     = 5,
                .vidtcon        = VIDTCON0,
                .wincon         = WINCON(0),
                .winmap         = WINxMAP(0),
                .keycon         = WKEYCON,
                .osd            = VIDOSD_BASE,
                .osd_stride     = 16,
                .buf_start      = VIDW_BUF_START(0),
                .buf_size       = VIDW_BUF_SIZE(0),
                .buf_end        = VIDW_BUF_END(0),

                .palette = {
                        [0] = 0x2400,
                        [1] = 0x2800,
                        [2] = 0x2c00,
                        [3] = 0x3000,
                        [4] = 0x3400,
                },

                .has_shadowcon  = 1,
                .has_blendcon   = 1,
                .has_clksel     = 1,
                .has_fixvclk    = 1,
        },
        .win[0] = &s3c_fb_data_s5p_wins[0],
        .win[1] = &s3c_fb_data_s5p_wins[1],
        .win[2] = &s3c_fb_data_s5p_wins[2],
        .win[3] = &s3c_fb_data_s5p_wins[3],
        .win[4] = &s3c_fb_data_s5p_wins[4],
};

static struct s3c_fb_driverdata s3c_fb_data_exynos4 = {
        .variant = {
                .nr_windows     = 5,
                .vidtcon        = VIDTCON0,
                .wincon         = WINCON(0),
                .winmap         = WINxMAP(0),
                .keycon         = WKEYCON,
                .osd            = VIDOSD_BASE,
                .osd_stride     = 16,
                .buf_start      = VIDW_BUF_START(0),
                .buf_size       = VIDW_BUF_SIZE(0),
                .buf_end        = VIDW_BUF_END(0),

                .palette = {
                        [0] = 0x2400,
                        [1] = 0x2800,
                        [2] = 0x2c00,
                        [3] = 0x3000,
                        [4] = 0x3400,
                },

                .has_shadowcon  = 1,
                .has_blendcon   = 1,
                .has_fixvclk    = 1,
        },
        .win[0] = &s3c_fb_data_s5p_wins[0],
        .win[1] = &s3c_fb_data_s5p_wins[1],
        .win[2] = &s3c_fb_data_s5p_wins[2],
        .win[3] = &s3c_fb_data_s5p_wins[3],
        .win[4] = &s3c_fb_data_s5p_wins[4],
};

static struct s3c_fb_driverdata s3c_fb_data_exynos5 = {
        .variant = {
                .nr_windows     = 5,
                .vidtcon        = FIMD_V8_VIDTCON0,
                .wincon         = WINCON(0),
                .winmap         = WINxMAP(0),
                .keycon         = WKEYCON,
                .osd            = VIDOSD_BASE,
                .osd_stride     = 16,
                .buf_start      = VIDW_BUF_START(0),
                .buf_size       = VIDW_BUF_SIZE(0),
                .buf_end        = VIDW_BUF_END(0),

                .palette = {
                        [0] = 0x2400,
                        [1] = 0x2800,
                        [2] = 0x2c00,
                        [3] = 0x3000,
                        [4] = 0x3400,
                },
                .has_shadowcon  = 1,
                .has_blendcon   = 1,
                .has_fixvclk    = 1,
        },
        .win[0] = &s3c_fb_data_s5p_wins[0],
        .win[1] = &s3c_fb_data_s5p_wins[1],
        .win[2] = &s3c_fb_data_s5p_wins[2],
        .win[3] = &s3c_fb_data_s5p_wins[3],
        .win[4] = &s3c_fb_data_s5p_wins[4],
};

/* S3C2443/S3C2416 style hardware */
static struct s3c_fb_driverdata s3c_fb_data_s3c2443 = {
        .variant = {
                .nr_windows     = 2,
                .is_2443        = 1,

                .vidtcon        = 0x08,
                .wincon         = 0x14,
                .winmap         = 0xd0,
                .keycon         = 0xb0,
                .osd            = 0x28,
                .osd_stride     = 12,
                .buf_start      = 0x64,
                .buf_size       = 0x94,
                .buf_end        = 0x7c,

                .palette = {
                        [0] = 0x400,
                        [1] = 0x800,
                },
                .has_clksel     = 1,
        },
        .win[0] = &(struct s3c_fb_win_variant) {
                .palette_sz     = 256,
                .valid_bpp      = VALID_BPP1248 | VALID_BPP(16) | VALID_BPP(24),
        },
        .win[1] = &(struct s3c_fb_win_variant) {
                .has_osd_c      = 1,
                .has_osd_alpha  = 1,
                .palette_sz     = 256,
                .valid_bpp      = (VALID_BPP1248 | VALID_BPP(16) |
                                   VALID_BPP(18) | VALID_BPP(19) |
                                   VALID_BPP(24) | VALID_BPP(25) |
                                   VALID_BPP(28)),
        },
};

static const struct platform_device_id s3c_fb_driver_ids[] = {
        {
                .name           = "s3c-fb",
                .driver_data    = (unsigned long)&s3c_fb_data_64xx,
        }, {
                .name           = "s5pv210-fb",
                .driver_data    = (unsigned long)&s3c_fb_data_s5pv210,
        }, {
                .name           = "exynos4-fb",
                .driver_data    = (unsigned long)&s3c_fb_data_exynos4,
        }, {
                .name           = "exynos5-fb",
                .driver_data    = (unsigned long)&s3c_fb_data_exynos5,
        }, {
                .name           = "s3c2443-fb",
                .driver_data    = (unsigned long)&s3c_fb_data_s3c2443,
        },
        {},
};
MODULE_DEVICE_TABLE(platform, s3c_fb_driver_ids);

static const struct dev_pm_ops s3cfb_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(s3c_fb_suspend, s3c_fb_resume)
        SET_RUNTIME_PM_OPS(s3c_fb_runtime_suspend, s3c_fb_runtime_resume,
                           NULL)
};

static struct platform_driver s3c_fb_driver = {
        .probe          = s3c_fb_probe,
        .remove         = s3c_fb_remove,
        .id_table       = s3c_fb_driver_ids,
        .driver         = {
                .name   = "s3c-fb",
                .pm     = &s3cfb_pm_ops,
        },
};

module_platform_driver(s3c_fb_driver);

MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
MODULE_DESCRIPTION("Samsung S3C SoC Framebuffer driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c-fb");