/* linux/drivers/video/sm501fb.c
 *
 * Copyright (c) 2006 Simtec Electronics
 *      Vincent Sanders <vince@simtec.co.uk>
 *      Ben Dooks <ben@simtec.co.uk>
 *
 * 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.
 *
 * Framebuffer driver for the Silicon Motion SM501
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/vmalloc.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/workqueue.h>
#include <linux/wait.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/console.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/div64.h>

#ifdef CONFIG_PM
#include <linux/pm.h>
#endif

#include <linux/sm501.h>
#include <linux/sm501-regs.h>

#define NR_PALETTE      256

enum sm501_controller {
        HEAD_CRT        = 0,
        HEAD_PANEL      = 1,
};

/* SM501 memory address.
 *
 * This structure is used to track memory usage within the SM501 framebuffer
 * allocation. The sm_addr field is stored as an offset as it is often used
 * against both the physical and mapped addresses.
 */
struct sm501_mem {
        unsigned long    size;
        unsigned long    sm_addr;       /* offset from base of sm501 fb. */
        void __iomem    *k_addr;
};

/* private data that is shared between all frambuffers* */
struct sm501fb_info {
        struct device           *dev;
        struct fb_info          *fb[2];         /* fb info for both heads */
        struct resource         *fbmem_res;     /* framebuffer resource */
        struct resource         *regs_res;      /* registers resource */
        struct sm501_platdata_fb *pdata;        /* our platform data */

        unsigned long            pm_crt_ctrl;   /* pm: crt ctrl save */

        int                      irq;
        int                      swap_endian;   /* set to swap rgb=>bgr */
        void __iomem            *regs;          /* remapped registers */
        void __iomem            *fbmem;         /* remapped framebuffer */
        size_t                   fbmem_len;     /* length of remapped region */
};

/* per-framebuffer private data */
struct sm501fb_par {
        u32                      pseudo_palette[16];

        enum sm501_controller    head;
        struct sm501_mem         cursor;
        struct sm501_mem         screen;
        struct fb_ops            ops;

        void                    *store_fb;
        void                    *store_cursor;
        void __iomem            *cursor_regs;
        struct sm501fb_info     *info;
};

/* Helper functions */

static inline int h_total(struct fb_var_screeninfo *var)
{
        return var->xres + var->left_margin +
                var->right_margin + var->hsync_len;
}

static inline int v_total(struct fb_var_screeninfo *var)
{
        return var->yres + var->upper_margin +
                var->lower_margin + var->vsync_len;
}

/* sm501fb_sync_regs()
 *
 * This call is mainly for PCI bus systems where we need to
 * ensure that any writes to the bus are completed before the
 * next phase, or after completing a function.
*/

static inline void sm501fb_sync_regs(struct sm501fb_info *info)
{
        readl(info->regs);
}

/* sm501_alloc_mem
 *
 * This is an attempt to lay out memory for the two framebuffers and
 * everything else
 *
 * |fbmem_res->start                                           fbmem_res->end|
 * |                                                                         |
 * |fb[0].fix.smem_start    |         |fb[1].fix.smem_start    |     2K      |
 * |-> fb[0].fix.smem_len <-| spare   |-> fb[1].fix.smem_len <-|-> cursors <-|
 *
 * The "spare" space is for the 2d engine data
 * the fixed is space for the cursors (2x1Kbyte)
 *
 * we need to allocate memory for the 2D acceleration engine
 * command list and the data for the engine to deal with.
 *
 * - all allocations must be 128bit aligned
 * - cursors are 64x64x2 bits (1Kbyte)
 *
 */

#define SM501_MEMF_CURSOR               (1)
#define SM501_MEMF_PANEL                (2)
#define SM501_MEMF_CRT                  (4)
#define SM501_MEMF_ACCEL                (8)

static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
                           unsigned int why, size_t size)
{
        struct sm501fb_par *par;
        struct fb_info *fbi;
        unsigned int ptr;
        unsigned int end;

        switch (why) {
        case SM501_MEMF_CURSOR:
                ptr = inf->fbmem_len - size;
                inf->fbmem_len = ptr;   /* adjust available memory. */
                break;

        case SM501_MEMF_PANEL:
                if (size > inf->fbmem_len)
                        return -ENOMEM;

                ptr = inf->fbmem_len - size;
                fbi = inf->fb[HEAD_CRT];

                /* round down, some programs such as directfb do not draw
                 * 0,0 correctly unless the start is aligned to a page start.
                 */

                if (ptr > 0)
                        ptr &= ~(PAGE_SIZE - 1);

                if (fbi && ptr < fbi->fix.smem_len)
                        return -ENOMEM;

                break;

        case SM501_MEMF_CRT:
                ptr = 0;

                /* check to see if we have panel memory allocated
                 * which would put an limit on available memory. */

                fbi = inf->fb[HEAD_PANEL];
                if (fbi) {
                        par = fbi->par;
                        end = par->screen.k_addr ? par->screen.sm_addr : inf->fbmem_len;
                } else
                        end = inf->fbmem_len;

                if ((ptr + size) > end)
                        return -ENOMEM;

                break;

        case SM501_MEMF_ACCEL:
                fbi = inf->fb[HEAD_CRT];
                ptr = fbi ? fbi->fix.smem_len : 0;

                fbi = inf->fb[HEAD_PANEL];
                if (fbi) {
                        par = fbi->par;
                        end = par->screen.sm_addr;
                } else
                        end = inf->fbmem_len;

                if ((ptr + size) > end)
                        return -ENOMEM;

                break;

        default:
                return -EINVAL;
        }

        mem->size    = size;
        mem->sm_addr = ptr;
        mem->k_addr  = inf->fbmem + ptr;

        dev_dbg(inf->dev, "%s: result %08lx, %p - %u, %zd\n",
                __func__, mem->sm_addr, mem->k_addr, why, size);

        return 0;
}

/* sm501fb_ps_to_hz
 *
 * Converts a period in picoseconds to Hz.
 *
 * Note, we try to keep this in Hz to minimise rounding with
 * the limited PLL settings on the SM501.
*/

static unsigned long sm501fb_ps_to_hz(unsigned long psvalue)
{
        unsigned long long numerator=1000000000000ULL;

        /* 10^12 / picosecond period gives frequency in Hz */
        do_div(numerator, psvalue);
        return (unsigned long)numerator;
}

/* sm501fb_hz_to_ps is identical to the oposite transform */

#define sm501fb_hz_to_ps(x) sm501fb_ps_to_hz(x)

/* sm501fb_setup_gamma
 *
 * Programs a linear 1.0 gamma ramp in case the gamma
 * correction is enabled without programming anything else.
*/

static void sm501fb_setup_gamma(struct sm501fb_info *fbi,
                                unsigned long palette)
{
        unsigned long value = 0;
        int offset;

        /* set gamma values */
        for (offset = 0; offset < 256 * 4; offset += 4) {
                writel(value, fbi->regs + palette + offset);
                value += 0x010101;      /* Advance RGB by 1,1,1.*/
        }
}

/* sm501fb_check_var
 *
 * check common variables for both panel and crt
*/

static int sm501fb_check_var(struct fb_var_screeninfo *var,
                             struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *sm  = par->info;
        unsigned long tmp;

        /* check we can fit these values into the registers */

        if (var->hsync_len > 255 || var->vsync_len > 63)
                return -EINVAL;

        /* hdisplay end and hsync start */
        if ((var->xres + var->right_margin) > 4096)
                return -EINVAL;

        /* vdisplay end and vsync start */
        if ((var->yres + var->lower_margin) > 2048)
                return -EINVAL;

        /* hard limits of device */

        if (h_total(var) > 4096 || v_total(var) > 2048)
                return -EINVAL;

        /* check our line length is going to be 128 bit aligned */

        tmp = (var->xres * var->bits_per_pixel) / 8;
        if ((tmp & 15) != 0)
                return -EINVAL;

        /* check the virtual size */

        if (var->xres_virtual > 4096 || var->yres_virtual > 2048)
                return -EINVAL;

        /* can cope with 8,16 or 32bpp */

        if (var->bits_per_pixel <= 8)
                var->bits_per_pixel = 8;
        else if (var->bits_per_pixel <= 16)
                var->bits_per_pixel = 16;
        else if (var->bits_per_pixel == 24)
                var->bits_per_pixel = 32;

        /* set r/g/b positions and validate bpp */
        switch(var->bits_per_pixel) {
        case 8:
                var->red.length         = var->bits_per_pixel;
                var->red.offset         = 0;
                var->green.length       = var->bits_per_pixel;
                var->green.offset       = 0;
                var->blue.length        = var->bits_per_pixel;
                var->blue.offset        = 0;
                var->transp.length      = 0;
                var->transp.offset      = 0;

                break;

        case 16:
                if (sm->pdata->flags & SM501_FBPD_SWAP_FB_ENDIAN) {
                        var->blue.offset        = 11;
                        var->green.offset       = 5;
                        var->red.offset         = 0;
                } else {
                        var->red.offset         = 11;
                        var->green.offset       = 5;
                        var->blue.offset        = 0;
                }
                var->transp.offset      = 0;

                var->red.length         = 5;
                var->green.length       = 6;
                var->blue.length        = 5;
                var->transp.length      = 0;
                break;

        case 32:
                if (sm->pdata->flags & SM501_FBPD_SWAP_FB_ENDIAN) {
                        var->transp.offset      = 0;
                        var->red.offset         = 8;
                        var->green.offset       = 16;
                        var->blue.offset        = 24;
                } else {
                        var->transp.offset      = 24;
                        var->red.offset         = 16;
                        var->green.offset       = 8;
                        var->blue.offset        = 0;
                }

                var->red.length         = 8;
                var->green.length       = 8;
                var->blue.length        = 8;
                var->transp.length      = 0;
                break;

        default:
                return -EINVAL;
        }

        return 0;
}

/*
 * sm501fb_check_var_crt():
 *
 * check the parameters for the CRT head, and either bring them
 * back into range, or return -EINVAL.
*/

static int sm501fb_check_var_crt(struct fb_var_screeninfo *var,
                                 struct fb_info *info)
{
        return sm501fb_check_var(var, info);
}

/* sm501fb_check_var_pnl():
 *
 * check the parameters for the CRT head, and either bring them
 * back into range, or return -EINVAL.
*/

static int sm501fb_check_var_pnl(struct fb_var_screeninfo *var,
                                 struct fb_info *info)
{
        return sm501fb_check_var(var, info);
}

/* sm501fb_set_par_common
 *
 * set common registers for framebuffers
*/

static int sm501fb_set_par_common(struct fb_info *info,
                                  struct fb_var_screeninfo *var)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        unsigned long pixclock;      /* pixelclock in Hz */
        unsigned long sm501pixclock; /* pixelclock the 501 can achive in Hz */
        unsigned int mem_type;
        unsigned int clock_type;
        unsigned int head_addr;

        dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n",
                __func__, var->xres, var->yres, var->bits_per_pixel,
                var->xres_virtual, var->yres_virtual);

        switch (par->head) {
        case HEAD_CRT:
                mem_type = SM501_MEMF_CRT;
                clock_type = SM501_CLOCK_V2XCLK;
                head_addr = SM501_DC_CRT_FB_ADDR;
                break;

        case HEAD_PANEL:
                mem_type = SM501_MEMF_PANEL;
                clock_type = SM501_CLOCK_P2XCLK;
                head_addr = SM501_DC_PANEL_FB_ADDR;
                break;

        default:
                mem_type = 0;           /* stop compiler warnings */
                head_addr = 0;
                clock_type = 0;
        }

        switch (var->bits_per_pixel) {
        case 8:
                info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
                break;

        case 16:
                info->fix.visual = FB_VISUAL_TRUECOLOR;
                break;

        case 32:
                info->fix.visual = FB_VISUAL_TRUECOLOR;
                break;
        }

        /* allocate fb memory within 501 */
        info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8;
        info->fix.smem_len    = info->fix.line_length * var->yres_virtual;

        dev_dbg(fbi->dev, "%s: line length = %u\n", __func__,
                info->fix.line_length);

        if (sm501_alloc_mem(fbi, &par->screen, mem_type,
                            info->fix.smem_len)) {
                dev_err(fbi->dev, "no memory available\n");
                return -ENOMEM;
        }

        info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr;

        info->screen_base = fbi->fbmem + par->screen.sm_addr;
        info->screen_size = info->fix.smem_len;

        /* set start of framebuffer to the screen */

        writel(par->screen.sm_addr | SM501_ADDR_FLIP, fbi->regs + head_addr);

        /* program CRT clock  */

        pixclock = sm501fb_ps_to_hz(var->pixclock);

        sm501pixclock = sm501_set_clock(fbi->dev->parent, clock_type,
                                        pixclock);

        /* update fb layer with actual clock used */
        var->pixclock = sm501fb_hz_to_ps(sm501pixclock);

        dev_dbg(fbi->dev, "%s: pixclock(ps) = %u, pixclock(Hz)  = %lu, "
               "sm501pixclock = %lu,  error = %ld%%\n",
               __func__, var->pixclock, pixclock, sm501pixclock,
               ((pixclock - sm501pixclock)*100)/pixclock);

        return 0;
}

/* sm501fb_set_par_geometry
 *
 * set the geometry registers for specified framebuffer.
*/

static void sm501fb_set_par_geometry(struct fb_info *info,
                                     struct fb_var_screeninfo *var)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        void __iomem *base = fbi->regs;
        unsigned long reg;

        if (par->head == HEAD_CRT)
                base += SM501_DC_CRT_H_TOT;
        else
                base += SM501_DC_PANEL_H_TOT;

        /* set framebuffer width and display width */

        reg = info->fix.line_length;
        reg |= ((var->xres * var->bits_per_pixel)/8) << 16;

        writel(reg, fbi->regs + (par->head == HEAD_CRT ?
                    SM501_DC_CRT_FB_OFFSET :  SM501_DC_PANEL_FB_OFFSET));

        /* program horizontal total */

        reg  = (h_total(var) - 1) << 16;
        reg |= (var->xres - 1);

        writel(reg, base + SM501_OFF_DC_H_TOT);

        /* program horizontal sync */

        reg  = var->hsync_len << 16;
        reg |= var->xres + var->right_margin - 1;

        writel(reg, base + SM501_OFF_DC_H_SYNC);

        /* program vertical total */

        reg  = (v_total(var) - 1) << 16;
        reg |= (var->yres - 1);

        writel(reg, base + SM501_OFF_DC_V_TOT);

        /* program vertical sync */
        reg  = var->vsync_len << 16;
        reg |= var->yres + var->lower_margin - 1;

        writel(reg, base + SM501_OFF_DC_V_SYNC);
}

/* sm501fb_pan_crt
 *
 * pan the CRT display output within an virtual framebuffer
*/

static int sm501fb_pan_crt(struct fb_var_screeninfo *var,
                           struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        unsigned int bytes_pixel = var->bits_per_pixel / 8;
        unsigned long reg;
        unsigned long xoffs;

        xoffs = var->xoffset * bytes_pixel;

        reg = readl(fbi->regs + SM501_DC_CRT_CONTROL);

        reg &= ~SM501_DC_CRT_CONTROL_PIXEL_MASK;
        reg |= ((xoffs & 15) / bytes_pixel) << 4;
        writel(reg, fbi->regs + SM501_DC_CRT_CONTROL);

        reg = (par->screen.sm_addr + xoffs +
               var->yoffset * info->fix.line_length);
        writel(reg | SM501_ADDR_FLIP, fbi->regs + SM501_DC_CRT_FB_ADDR);

        sm501fb_sync_regs(fbi);
        return 0;
}

/* sm501fb_pan_pnl
 *
 * pan the panel display output within an virtual framebuffer
*/

static int sm501fb_pan_pnl(struct fb_var_screeninfo *var,
                           struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        unsigned long reg;

        reg = var->xoffset | (var->xres_virtual << 16);
        writel(reg, fbi->regs + SM501_DC_PANEL_FB_WIDTH);

        reg = var->yoffset | (var->yres_virtual << 16);
        writel(reg, fbi->regs + SM501_DC_PANEL_FB_HEIGHT);

        sm501fb_sync_regs(fbi);
        return 0;
}

/* sm501fb_set_par_crt
 *
 * Set the CRT video mode from the fb_info structure
*/

static int sm501fb_set_par_crt(struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        struct fb_var_screeninfo *var = &info->var;
        unsigned long control;       /* control register */
        int ret;

        /* activate new configuration */

        dev_dbg(fbi->dev, "%s(%p)\n", __func__, info);

        /* enable CRT DAC - note 0 is on!*/
        sm501_misc_control(fbi->dev->parent, 0, SM501_MISC_DAC_POWER);

        control = readl(fbi->regs + SM501_DC_CRT_CONTROL);

        control &= (SM501_DC_CRT_CONTROL_PIXEL_MASK |
                    SM501_DC_CRT_CONTROL_GAMMA |
                    SM501_DC_CRT_CONTROL_BLANK |
                    SM501_DC_CRT_CONTROL_SEL |
                    SM501_DC_CRT_CONTROL_CP |
                    SM501_DC_CRT_CONTROL_TVP);

        /* set the sync polarities before we check data source  */

        if ((var->sync & FB_SYNC_HOR_HIGH_ACT) == 0)
                control |= SM501_DC_CRT_CONTROL_HSP;

        if ((var->sync & FB_SYNC_VERT_HIGH_ACT) == 0)
                control |= SM501_DC_CRT_CONTROL_VSP;

        if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) {
                /* the head is displaying panel data... */

                sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0);
                goto out_update;
        }

        ret = sm501fb_set_par_common(info, var);
        if (ret) {
                dev_err(fbi->dev, "failed to set common parameters\n");
                return ret;
        }

        sm501fb_pan_crt(var, info);
        sm501fb_set_par_geometry(info, var);

        control |= SM501_FIFO_3;        /* fill if >3 free slots */

        switch(var->bits_per_pixel) {
        case 8:
                control |= SM501_DC_CRT_CONTROL_8BPP;
                break;

        case 16:
                control |= SM501_DC_CRT_CONTROL_16BPP;
                sm501fb_setup_gamma(fbi, SM501_DC_CRT_PALETTE);
                break;

        case 32:
                control |= SM501_DC_CRT_CONTROL_32BPP;
                sm501fb_setup_gamma(fbi, SM501_DC_CRT_PALETTE);
                break;

        default:
                BUG();
        }

        control |= SM501_DC_CRT_CONTROL_SEL;    /* CRT displays CRT data */
        control |= SM501_DC_CRT_CONTROL_TE;     /* enable CRT timing */
        control |= SM501_DC_CRT_CONTROL_ENABLE; /* enable CRT plane */

 out_update:
        dev_dbg(fbi->dev, "new control is %08lx\n", control);

        writel(control, fbi->regs + SM501_DC_CRT_CONTROL);
        sm501fb_sync_regs(fbi);

        return 0;
}

static void sm501fb_panel_power(struct sm501fb_info *fbi, int to)
{
        unsigned long control;
        void __iomem *ctrl_reg = fbi->regs + SM501_DC_PANEL_CONTROL;
        struct sm501_platdata_fbsub *pd = fbi->pdata->fb_pnl;

        control = readl(ctrl_reg);

        if (to && (control & SM501_DC_PANEL_CONTROL_VDD) == 0) {
                /* enable panel power */

                control |= SM501_DC_PANEL_CONTROL_VDD;  /* FPVDDEN */
                writel(control, ctrl_reg);
                sm501fb_sync_regs(fbi);
                mdelay(10);

                control |= SM501_DC_PANEL_CONTROL_DATA; /* DATA */
                writel(control, ctrl_reg);
                sm501fb_sync_regs(fbi);
                mdelay(10);

                /* VBIASEN */

                if (!(pd->flags & SM501FB_FLAG_PANEL_NO_VBIASEN)) {
                        if (pd->flags & SM501FB_FLAG_PANEL_INV_VBIASEN)
                                control &= ~SM501_DC_PANEL_CONTROL_BIAS;
                        else
                                control |= SM501_DC_PANEL_CONTROL_BIAS;

                        writel(control, ctrl_reg);
                        sm501fb_sync_regs(fbi);
                        mdelay(10);
                }

                if (!(pd->flags & SM501FB_FLAG_PANEL_NO_FPEN)) {
                        if (pd->flags & SM501FB_FLAG_PANEL_INV_FPEN)
                                control &= ~SM501_DC_PANEL_CONTROL_FPEN;
                        else
                                control |= SM501_DC_PANEL_CONTROL_FPEN;

                        writel(control, ctrl_reg);
                        sm501fb_sync_regs(fbi);
                        mdelay(10);
                }
        } else if (!to && (control & SM501_DC_PANEL_CONTROL_VDD) != 0) {
                /* disable panel power */
                if (!(pd->flags & SM501FB_FLAG_PANEL_NO_FPEN)) {
                        if (pd->flags & SM501FB_FLAG_PANEL_INV_FPEN)
                                control |= SM501_DC_PANEL_CONTROL_FPEN;
                        else
                                control &= ~SM501_DC_PANEL_CONTROL_FPEN;

                        writel(control, ctrl_reg);
                        sm501fb_sync_regs(fbi);
                        mdelay(10);
                }

                if (!(pd->flags & SM501FB_FLAG_PANEL_NO_VBIASEN)) {
                        if (pd->flags & SM501FB_FLAG_PANEL_INV_VBIASEN)
                                control |= SM501_DC_PANEL_CONTROL_BIAS;
                        else
                                control &= ~SM501_DC_PANEL_CONTROL_BIAS;

                        writel(control, ctrl_reg);
                        sm501fb_sync_regs(fbi);
                        mdelay(10);
                }

                control &= ~SM501_DC_PANEL_CONTROL_DATA;
                writel(control, ctrl_reg);
                sm501fb_sync_regs(fbi);
                mdelay(10);

                control &= ~SM501_DC_PANEL_CONTROL_VDD;
                writel(control, ctrl_reg);
                sm501fb_sync_regs(fbi);
                mdelay(10);
        }

        sm501fb_sync_regs(fbi);
}

/* sm501fb_set_par_pnl
 *
 * Set the panel video mode from the fb_info structure
*/

static int sm501fb_set_par_pnl(struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        struct fb_var_screeninfo *var = &info->var;
        unsigned long control;
        unsigned long reg;
        int ret;

        dev_dbg(fbi->dev, "%s(%p)\n", __func__, info);

        /* activate this new configuration */

        ret = sm501fb_set_par_common(info, var);
        if (ret)
                return ret;

        sm501fb_pan_pnl(var, info);
        sm501fb_set_par_geometry(info, var);

        /* update control register */

        control = readl(fbi->regs + SM501_DC_PANEL_CONTROL);
        control &= (SM501_DC_PANEL_CONTROL_GAMMA |
                    SM501_DC_PANEL_CONTROL_VDD  |
                    SM501_DC_PANEL_CONTROL_DATA |
                    SM501_DC_PANEL_CONTROL_BIAS |
                    SM501_DC_PANEL_CONTROL_FPEN |
                    SM501_DC_PANEL_CONTROL_CP |
                    SM501_DC_PANEL_CONTROL_CK |
                    SM501_DC_PANEL_CONTROL_HP |
                    SM501_DC_PANEL_CONTROL_VP |
                    SM501_DC_PANEL_CONTROL_HPD |
                    SM501_DC_PANEL_CONTROL_VPD);

        control |= SM501_FIFO_3;        /* fill if >3 free slots */

        switch(var->bits_per_pixel) {
        case 8:
                control |= SM501_DC_PANEL_CONTROL_8BPP;
                break;

        case 16:
                control |= SM501_DC_PANEL_CONTROL_16BPP;
                sm501fb_setup_gamma(fbi, SM501_DC_PANEL_PALETTE);
                break;

        case 32:
                control |= SM501_DC_PANEL_CONTROL_32BPP;
                sm501fb_setup_gamma(fbi, SM501_DC_PANEL_PALETTE);
                break;

        default:
                BUG();
        }

        writel(0x0, fbi->regs + SM501_DC_PANEL_PANNING_CONTROL);

        /* panel plane top left and bottom right location */

        writel(0x00, fbi->regs + SM501_DC_PANEL_TL_LOC);

        reg  = var->xres - 1;
        reg |= (var->yres - 1) << 16;

        writel(reg, fbi->regs + SM501_DC_PANEL_BR_LOC);

        /* program panel control register */

        control |= SM501_DC_PANEL_CONTROL_TE;   /* enable PANEL timing */
        control |= SM501_DC_PANEL_CONTROL_EN;   /* enable PANEL gfx plane */

        if ((var->sync & FB_SYNC_HOR_HIGH_ACT) == 0)
                control |= SM501_DC_PANEL_CONTROL_HSP;

        if ((var->sync & FB_SYNC_VERT_HIGH_ACT) == 0)
                control |= SM501_DC_PANEL_CONTROL_VSP;

        writel(control, fbi->regs + SM501_DC_PANEL_CONTROL);
        sm501fb_sync_regs(fbi);

        /* ensure the panel interface is not tristated at this point */

        sm501_modify_reg(fbi->dev->parent, SM501_SYSTEM_CONTROL,
                         0, SM501_SYSCTRL_PANEL_TRISTATE);

        /* power the panel up */
        sm501fb_panel_power(fbi, 1);
        return 0;
}


/* chan_to_field
 *
 * convert a colour value into a field position
 *
 * from pxafb.c
*/

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

/* sm501fb_setcolreg
 *
 * set the colour mapping for modes that support palettised data
*/

static int sm501fb_setcolreg(unsigned regno,
                             unsigned red, unsigned green, unsigned blue,
                             unsigned transp, struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        void __iomem *base = fbi->regs;
        unsigned int val;

        if (par->head == HEAD_CRT)
                base += SM501_DC_CRT_PALETTE;
        else
                base += SM501_DC_PANEL_PALETTE;

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

                if (regno < 16) {
                        u32 *pal = par->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 < 256) {
                        val = (red >> 8) << 16;
                        val |= (green >> 8) << 8;
                        val |= blue >> 8;

                        writel(val, base + (regno * 4));
                }

                break;

        default:
                return 1;   /* unknown type */
        }

        return 0;
}

/* sm501fb_blank_pnl
 *
 * Blank or un-blank the panel interface
*/

static int sm501fb_blank_pnl(int blank_mode, struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;

        dev_dbg(fbi->dev, "%s(mode=%d, %p)\n", __func__, blank_mode, info);

        switch (blank_mode) {
        case FB_BLANK_POWERDOWN:
                sm501fb_panel_power(fbi, 0);
                break;

        case FB_BLANK_UNBLANK:
                sm501fb_panel_power(fbi, 1);
                break;

        case FB_BLANK_NORMAL:
        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
        default:
                return 1;
        }

        return 0;
}

/* sm501fb_blank_crt
 *
 * Blank or un-blank the crt interface
*/

static int sm501fb_blank_crt(int blank_mode, struct fb_info *info)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        unsigned long ctrl;

        dev_dbg(fbi->dev, "%s(mode=%d, %p)\n", __func__, blank_mode, info);

        ctrl = readl(fbi->regs + SM501_DC_CRT_CONTROL);

        switch (blank_mode) {
        case FB_BLANK_POWERDOWN:
                ctrl &= ~SM501_DC_CRT_CONTROL_ENABLE;
                sm501_misc_control(fbi->dev->parent, SM501_MISC_DAC_POWER, 0);

        case FB_BLANK_NORMAL:
                ctrl |= SM501_DC_CRT_CONTROL_BLANK;
                break;

        case FB_BLANK_UNBLANK:
                ctrl &= ~SM501_DC_CRT_CONTROL_BLANK;
                ctrl |=  SM501_DC_CRT_CONTROL_ENABLE;
                sm501_misc_control(fbi->dev->parent, 0, SM501_MISC_DAC_POWER);
                break;

        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
        default:
                return 1;

        }

        writel(ctrl, fbi->regs + SM501_DC_CRT_CONTROL);
        sm501fb_sync_regs(fbi);

        return 0;
}

/* sm501fb_cursor
 *
 * set or change the hardware cursor parameters
*/

static int sm501fb_cursor(struct fb_info *info, struct fb_cursor *cursor)
{
        struct sm501fb_par  *par = info->par;
        struct sm501fb_info *fbi = par->info;
        void __iomem *base = fbi->regs;
        unsigned long hwc_addr;
        unsigned long fg, bg;

        dev_dbg(fbi->dev, "%s(%p,%p)\n", __func__, info, cursor);

        if (par->head == HEAD_CRT)
                base += SM501_DC_CRT_HWC_BASE;
        else
                base += SM501_DC_PANEL_HWC_BASE;

        /* check not being asked to exceed capabilities */

        if (cursor->image.width > 64)
                return -EINVAL;

        if (cursor->image.height > 64)
                return -EINVAL;

        if (cursor->image.depth > 1)
                return -EINVAL;

        hwc_addr = readl(base + SM501_OFF_HWC_ADDR);

        if (cursor->enable)
                writel(hwc_addr | SM501_HWC_EN, base + SM501_OFF_HWC_ADDR);
        else
                writel(hwc_addr & ~SM501_HWC_EN, base + SM501_OFF_HWC_ADDR);

        /* set data */
        if (cursor->set & FB_CUR_SETPOS) {
                unsigned int x = cursor->image.dx;
                unsigned int y = cursor->image.dy;

                if (x >= 2048 || y >= 2048 )
                        return -EINVAL;

                dev_dbg(fbi->dev, "set position %d,%d\n", x, y);

                //y += cursor->image.height;

                writel(x | (y << 16), base + SM501_OFF_HWC_LOC);
        }

        if (cursor->set & FB_CUR_SETCMAP) {
                unsigned int bg_col = cursor->image.bg_color;
                unsigned int fg_col = cursor->image.fg_color;

                dev_dbg(fbi->dev, "%s: update cmap (%08x,%08x)\n",
                        __func__, bg_col, fg_col);

                bg = ((info->cmap.red[bg_col] & 0xF8) << 8) |
                        ((info->cmap.green[bg_col] & 0xFC) << 3) |
                        ((info->cmap.blue[bg_col] & 0xF8) >> 3);

                fg = ((info->cmap.red[fg_col] & 0xF8) << 8) |
                        ((info->cmap.green[fg_col] & 0xFC) << 3) |
                        ((info->cmap.blue[fg_col] & 0xF8) >> 3);

                dev_dbg(fbi->dev, "fgcol %08lx, bgcol %08lx\n", fg, bg);

                writel(bg, base + SM501_OFF_HWC_COLOR_1_2);
                writel(fg, base + SM501_OFF_HWC_COLOR_3);
        }

        if (cursor->set & FB_CUR_SETSIZE ||
            cursor->set & (FB_CUR_SETIMAGE | FB_CUR_SETSHAPE)) {
                /* SM501 cursor is a two bpp 64x64 bitmap this routine
                 * clears it to transparent then combines the cursor
                 * shape plane with the colour plane to set the
                 * cursor */
                int x, y;
                const unsigned char *pcol = cursor->image.data;
                const unsigned char *pmsk = cursor->mask;
                void __iomem   *dst = par->cursor.k_addr;
                unsigned char  dcol = 0;
                unsigned char  dmsk = 0;
                unsigned int   op;

                dev_dbg(fbi->dev, "%s: setting shape (%d,%d)\n",
                        __func__, cursor->image.width, cursor->image.height);

                for (op = 0; op < (64*64*2)/8; op+=4)
                        writel(0x0, dst + op);

                for (y = 0; y < cursor->image.height; y++) {
                        for (x = 0; x < cursor->image.width; x++) {
                                if ((x % 8) == 0) {
                                        dcol = *pcol++;
                                        dmsk = *pmsk++;
                                } else {
                                        dcol >>= 1;
                                        dmsk >>= 1;
                                }

                                if (dmsk & 1) {
                                        op = (dcol & 1) ? 1 : 3;
                                        op <<= ((x % 4) * 2);

                                        op |= readb(dst + (x / 4));
                                        writeb(op, dst + (x / 4));
                                }
                        }
                        dst += (64*2)/8;
                }
        }

        sm501fb_sync_regs(fbi); /* ensure cursor data flushed */
        return 0;
}

/* sm501fb_crtsrc_show
 *
 * device attribute code to show where the crt output is sourced from
*/

static ssize_t sm501fb_crtsrc_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
{
        struct sm501fb_info *info = dev_get_drvdata(dev);
        unsigned long ctrl;

        ctrl = readl(info->regs + SM501_DC_CRT_CONTROL);
        ctrl &= SM501_DC_CRT_CONTROL_SEL;

        return snprintf(buf, PAGE_SIZE, "%s\n", ctrl ? "crt" : "panel");
}

/* sm501fb_crtsrc_show
 *
 * device attribute code to set where the crt output is sourced from
*/

static ssize_t sm501fb_crtsrc_store(struct device *dev,
                                struct device_attribute *attr,
                                const char *buf, size_t len)
{
        struct sm501fb_info *info = dev_get_drvdata(dev);
        enum sm501_controller head;
        unsigned long ctrl;

        if (len < 1)
                return -EINVAL;

        if (strnicmp(buf, "crt", 3) == 0)
                head = HEAD_CRT;
        else if (strnicmp(buf, "panel", 5) == 0)
                head = HEAD_PANEL;
        else
                return -EINVAL;

        dev_info(dev, "setting crt source to head %d\n", head);

        ctrl = readl(info->regs + SM501_DC_CRT_CONTROL);

        if (head == HEAD_CRT) {
                ctrl |= SM501_DC_CRT_CONTROL_SEL;
                ctrl |= SM501_DC_CRT_CONTROL_ENABLE;
                ctrl |= SM501_DC_CRT_CONTROL_TE;
        } else {
                ctrl &= ~SM501_DC_CRT_CONTROL_SEL;
                ctrl &= ~SM501_DC_CRT_CONTROL_ENABLE;
                ctrl &= ~SM501_DC_CRT_CONTROL_TE;
        }

        writel(ctrl, info->regs + SM501_DC_CRT_CONTROL);
        sm501fb_sync_regs(info);

        return len;
}

/* Prepare the device_attr for registration with sysfs later */
static DEVICE_ATTR(crt_src, 0666, sm501fb_crtsrc_show, sm501fb_crtsrc_store);

/* sm501fb_show_regs
 *
 * show the primary sm501 registers
*/
static int sm501fb_show_regs(struct sm501fb_info *info, char *ptr,
                             unsigned int start, unsigned int len)
{
        void __iomem *mem = info->regs;
        char *buf = ptr;
        unsigned int reg;

        for (reg = start; reg < (len + start); reg += 4)
                ptr += sprintf(ptr, "%08x = %08x\n", reg, readl(mem + reg));

        return ptr - buf;
}

/* sm501fb_debug_show_crt
 *
 * show the crt control and cursor registers
*/

static ssize_t sm501fb_debug_show_crt(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct sm501fb_info *info = dev_get_drvdata(dev);
        char *ptr = buf;

        ptr += sm501fb_show_regs(info, ptr, SM501_DC_CRT_CONTROL, 0x40);
        ptr += sm501fb_show_regs(info, ptr, SM501_DC_CRT_HWC_BASE, 0x10);

        return ptr - buf;
}

static DEVICE_ATTR(fbregs_crt, 0444, sm501fb_debug_show_crt, NULL);

/* sm501fb_debug_show_pnl
 *
 * show the panel control and cursor registers
*/

static ssize_t sm501fb_debug_show_pnl(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct sm501fb_info *info = dev_get_drvdata(dev);
        char *ptr = buf;

        ptr += sm501fb_show_regs(info, ptr, 0x0, 0x40);
        ptr += sm501fb_show_regs(info, ptr, SM501_DC_PANEL_HWC_BASE, 0x10);

        return ptr - buf;
}

static DEVICE_ATTR(fbregs_pnl, 0444, sm501fb_debug_show_pnl, NULL);

/* framebuffer ops */

static struct fb_ops sm501fb_ops_crt = {
        .owner          = THIS_MODULE,
        .fb_check_var   = sm501fb_check_var_crt,
        .fb_set_par     = sm501fb_set_par_crt,
        .fb_blank       = sm501fb_blank_crt,
        .fb_setcolreg   = sm501fb_setcolreg,
        .fb_pan_display = sm501fb_pan_crt,
        .fb_cursor      = sm501fb_cursor,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

static struct fb_ops sm501fb_ops_pnl = {
        .owner          = THIS_MODULE,
        .fb_check_var   = sm501fb_check_var_pnl,
        .fb_set_par     = sm501fb_set_par_pnl,
        .fb_pan_display = sm501fb_pan_pnl,
        .fb_blank       = sm501fb_blank_pnl,
        .fb_setcolreg   = sm501fb_setcolreg,
        .fb_cursor      = sm501fb_cursor,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

/* sm501_init_cursor
 *
 * initialise hw cursor parameters
*/

static int sm501_init_cursor(struct fb_info *fbi, unsigned int reg_base)
{
        struct sm501fb_par *par;
        struct sm501fb_info *info;
        int ret;

        if (fbi == NULL)
                return 0;

        par = fbi->par;
        info = par->info;

        par->cursor_regs = info->regs + reg_base;

        ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024);
        if (ret < 0)
                return ret;

        /* initialise the colour registers */

        writel(par->cursor.sm_addr, par->cursor_regs + SM501_OFF_HWC_ADDR);

        writel(0x00, par->cursor_regs + SM501_OFF_HWC_LOC);
        writel(0x00, par->cursor_regs + SM501_OFF_HWC_COLOR_1_2);
        writel(0x00, par->cursor_regs + SM501_OFF_HWC_COLOR_3);
        sm501fb_sync_regs(info);

        return 0;
}

/* sm501fb_info_start
 *
 * fills the par structure claiming resources and remapping etc.
*/

static int sm501fb_start(struct sm501fb_info *info,
                         struct platform_device *pdev)
{
        struct resource *res;
        struct device *dev = &pdev->dev;
        int k;
        int ret;

        info->irq = ret = platform_get_irq(pdev, 0);
        if (ret < 0) {
                /* we currently do not use the IRQ */
                dev_warn(dev, "no irq for device\n");
        }

        /* allocate, reserve and remap resources for registers */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (res == NULL) {
                dev_err(dev, "no resource definition for registers\n");
                ret = -ENOENT;
                goto err_release;
        }

        info->regs_res = request_mem_region(res->start,
                                            res->end - res->start,
                                            pdev->name);

        if (info->regs_res == NULL) {
                dev_err(dev, "cannot claim registers\n");
                ret = -ENXIO;
                goto err_release;
        }

        info->regs = ioremap(res->start, (res->end - res->start)+1);
        if (info->regs == NULL) {
                dev_err(dev, "cannot remap registers\n");
                ret = -ENXIO;
                goto err_regs_res;
        }

        /* allocate, reserve resources for framebuffer */
        res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
        if (res == NULL) {
                dev_err(dev, "no memory resource defined\n");
                ret = -ENXIO;
                goto err_regs_map;
        }

        info->fbmem_res = request_mem_region(res->start,
                                             (res->end - res->start)+1,
                                             pdev->name);
        if (info->fbmem_res == NULL) {
                dev_err(dev, "cannot claim framebuffer\n");
                ret = -ENXIO;
                goto err_regs_map;
        }

        info->fbmem = ioremap(res->start, (res->end - res->start)+1);
        if (info->fbmem == NULL) {
                dev_err(dev, "cannot remap framebuffer\n");
                goto err_mem_res;
        }

        info->fbmem_len = (res->end - res->start)+1;

        /* clear framebuffer memory - avoids garbage data on unused fb */
        memset(info->fbmem, 0, info->fbmem_len);

        /* clear palette ram - undefined at power on */
        for (k = 0; k < (256 * 3); k++)
                writel(0, info->regs + SM501_DC_PANEL_PALETTE + (k * 4));

        /* enable display controller */
        sm501_unit_power(dev->parent, SM501_GATE_DISPLAY, 1);

        /* setup cursors */

        sm501_init_cursor(info->fb[HEAD_CRT], SM501_DC_CRT_HWC_ADDR);
        sm501_init_cursor(info->fb[HEAD_PANEL], SM501_DC_PANEL_HWC_ADDR);

        return 0; /* everything is setup */

 err_mem_res:
        release_resource(info->fbmem_res);
        kfree(info->fbmem_res);

 err_regs_map:
        iounmap(info->regs);

 err_regs_res:
        release_resource(info->regs_res);
        kfree(info->regs_res);

 err_release:
        return ret;
}

static void sm501fb_stop(struct sm501fb_info *info)
{
        /* disable display controller */
        sm501_unit_power(info->dev->parent, SM501_GATE_DISPLAY, 0);

        iounmap(info->fbmem);
        release_resource(info->fbmem_res);
        kfree(info->fbmem_res);

        iounmap(info->regs);
        release_resource(info->regs_res);
        kfree(info->regs_res);
}

static int sm501fb_init_fb(struct fb_info *fb,
                           enum sm501_controller head,
                           const char *fbname)
{
        struct sm501_platdata_fbsub *pd;
        struct sm501fb_par *par = fb->par;
        struct sm501fb_info *info = par->info;
        unsigned long ctrl;
        unsigned int enable;
        int ret;

        switch (head) {
        case HEAD_CRT:
                pd = info->pdata->fb_crt;
                ctrl = readl(info->regs + SM501_DC_CRT_CONTROL);
                enable = (ctrl & SM501_DC_CRT_CONTROL_ENABLE) ? 1 : 0;

                /* ensure we set the correct source register */
                if (info->pdata->fb_route != SM501_FB_CRT_PANEL) {
                        ctrl |= SM501_DC_CRT_CONTROL_SEL;
                        writel(ctrl, info->regs + SM501_DC_CRT_CONTROL);
                }

                break;

        case HEAD_PANEL:
                pd = info->pdata->fb_pnl;
                ctrl = readl(info->regs + SM501_DC_PANEL_CONTROL);
                enable = (ctrl & SM501_DC_PANEL_CONTROL_EN) ? 1 : 0;
                break;

        default:
                pd = NULL;              /* stop compiler warnings */
                ctrl = 0;
                enable = 0;
                BUG();
        }

        dev_info(info->dev, "fb %s %sabled at start\n",
                 fbname, enable ? "en" : "dis");

        /* check to see if our routing allows this */

        if (head == HEAD_CRT && info->pdata->fb_route == SM501_FB_CRT_PANEL) {
                ctrl &= ~SM501_DC_CRT_CONTROL_SEL;
                writel(ctrl, info->regs + SM501_DC_CRT_CONTROL);
                enable = 0;
        }

        strlcpy(fb->fix.id, fbname, sizeof(fb->fix.id));

        memcpy(&par->ops,
               (head == HEAD_CRT) ? &sm501fb_ops_crt : &sm501fb_ops_pnl,
               sizeof(struct fb_ops));

        /* update ops dependant on what we've been passed */

        if ((pd->flags & SM501FB_FLAG_USE_HWCURSOR) == 0)
                par->ops.fb_cursor = NULL;

        fb->fbops = &par->ops;
        fb->flags = FBINFO_FLAG_DEFAULT |
                FBINFO_HWACCEL_XPAN | FBINFO_HWACCEL_YPAN;

        /* fixed data */

        fb->fix.type            = FB_TYPE_PACKED_PIXELS;
        fb->fix.type_aux        = 0;
        fb->fix.xpanstep        = 1;
        fb->fix.ypanstep        = 1;
        fb->fix.ywrapstep       = 0;
        fb->fix.accel           = FB_ACCEL_NONE;

        /* screenmode */

        fb->var.nonstd          = 0;
        fb->var.activate        = FB_ACTIVATE_NOW;
        fb->var.accel_flags     = 0;
        fb->var.vmode           = FB_VMODE_NONINTERLACED;
        fb->var.bits_per_pixel  = 16;

        if (enable && (pd->flags & SM501FB_FLAG_USE_INIT_MODE) && 0) {
                /* TODO read the mode from the current display */

        } else {
                if (pd->def_mode) {
                        dev_info(info->dev, "using supplied mode\n");
                        fb_videomode_to_var(&fb->var, pd->def_mode);

                        fb->var.bits_per_pixel = pd->def_bpp ? pd->def_bpp : 8;
                        fb->var.xres_virtual = fb->var.xres;
                        fb->var.yres_virtual = fb->var.yres;
                } else {
                        ret = fb_find_mode(&fb->var, fb,
                                           NULL, NULL, 0, NULL, 8);

                        if (ret == 0 || ret == 4) {
                                dev_err(info->dev,
                                        "failed to get initial mode\n");
                                return -EINVAL;
                        }
                }
        }

        /* initialise and set the palette */
        if (fb_alloc_cmap(&fb->cmap, NR_PALETTE, 0)) {
                dev_err(info->dev, "failed to allocate cmap memory\n");
                return -ENOMEM;
        }
        fb_set_cmap(&fb->cmap, fb);

        ret = (fb->fbops->fb_check_var)(&fb->var, fb);
        if (ret)
                dev_err(info->dev, "check_var() failed on initial setup?\n");

        /* ensure we've activated our new configuration */
        (fb->fbops->fb_set_par)(fb);

        return 0;
}

/* default platform data if none is supplied (ie, PCI device) */

static struct sm501_platdata_fbsub sm501fb_pdata_crt = {
        .flags          = (SM501FB_FLAG_USE_INIT_MODE |
                           SM501FB_FLAG_USE_HWCURSOR |
                           SM501FB_FLAG_USE_HWACCEL |
                           SM501FB_FLAG_DISABLE_AT_EXIT),

};

static struct sm501_platdata_fbsub sm501fb_pdata_pnl = {
        .flags          = (SM501FB_FLAG_USE_INIT_MODE |
                           SM501FB_FLAG_USE_HWCURSOR |
                           SM501FB_FLAG_USE_HWACCEL |
                           SM501FB_FLAG_DISABLE_AT_EXIT),
};

static struct sm501_platdata_fb sm501fb_def_pdata = {
        .fb_route               = SM501_FB_OWN,
        .fb_crt                 = &sm501fb_pdata_crt,
        .fb_pnl                 = &sm501fb_pdata_pnl,
};

static char driver_name_crt[] = "sm501fb-crt";
static char driver_name_pnl[] = "sm501fb-panel";

static int __devinit sm501fb_probe_one(struct sm501fb_info *info,
                                       enum sm501_controller head)
{
        unsigned char *name = (head == HEAD_CRT) ? "crt" : "panel";
        struct sm501_platdata_fbsub *pd;
        struct sm501fb_par *par;
        struct fb_info *fbi;

        pd = (head == HEAD_CRT) ? info->pdata->fb_crt : info->pdata->fb_pnl;

        /* Do not initialise if we've not been given any platform data */
        if (pd == NULL) {
                dev_info(info->dev, "no data for fb %s (disabled)\n", name);
                return 0;
        }

        fbi = framebuffer_alloc(sizeof(struct sm501fb_par), info->dev);
        if (fbi == NULL) {
                dev_err(info->dev, "cannot allocate %s framebuffer\n", name);
                return -ENOMEM;
        }

        par = fbi->par;
        par->info = info;
        par->head = head;
        fbi->pseudo_palette = &par->pseudo_palette;

        info->fb[head] = fbi;

        return 0;
}

/* Free up anything allocated by sm501fb_init_fb */

static void sm501_free_init_fb(struct sm501fb_info *info,
                                enum sm501_controller head)
{
        struct fb_info *fbi = info->fb[head];

        fb_dealloc_cmap(&fbi->cmap);
}

static int __devinit sm501fb_start_one(struct sm501fb_info *info,
                                       enum sm501_controller head,
                                       const char *drvname)
{
        struct fb_info *fbi = info->fb[head];
        int ret;

        if (!fbi)
                return 0;

        ret = sm501fb_init_fb(info->fb[head], head, drvname);
        if (ret) {
                dev_err(info->dev, "cannot initialise fb %s\n", drvname);
                return ret;
        }

        ret = register_framebuffer(info->fb[head]);
        if (ret) {
                dev_err(info->dev, "failed to register fb %s\n", drvname);
                sm501_free_init_fb(info, head);
                return ret;
        }

        dev_info(info->dev, "fb%d: %s frame buffer\n", fbi->node, fbi->fix.id);

        return 0;
}

static int __devinit sm501fb_probe(struct platform_device *pdev)
{
        struct sm501fb_info *info;
        struct device *dev = &pdev->dev;
        int ret;

        /* allocate our framebuffers */

        info = kzalloc(sizeof(struct sm501fb_info), GFP_KERNEL);
        if (!info) {
                dev_err(dev, "failed to allocate state\n");
                return -ENOMEM;
        }

        info->dev = dev = &pdev->dev;
        platform_set_drvdata(pdev, info);

        if (dev->parent->platform_data) {
                struct sm501_platdata *pd = dev->parent->platform_data;
                info->pdata = pd->fb;
        }

        if (info->pdata == NULL) {
                dev_info(dev, "using default configuration data\n");
                info->pdata = &sm501fb_def_pdata;
        }

        /* probe for the presence of each panel */

        ret = sm501fb_probe_one(info, HEAD_CRT);
        if (ret < 0) {
                dev_err(dev, "failed to probe CRT\n");
                goto err_alloc;
        }

        ret = sm501fb_probe_one(info, HEAD_PANEL);
        if (ret < 0) {
                dev_err(dev, "failed to probe PANEL\n");
                goto err_probed_crt;
        }

        if (info->fb[HEAD_PANEL] == NULL &&
            info->fb[HEAD_CRT] == NULL) {
                dev_err(dev, "no framebuffers found\n");
                goto err_alloc;
        }

        /* get the resources for both of the framebuffers */

        ret = sm501fb_start(info, pdev);
        if (ret) {
                dev_err(dev, "cannot initialise SM501\n");
                goto err_probed_panel;
        }

        ret = sm501fb_start_one(info, HEAD_CRT, driver_name_crt);
        if (ret) {
                dev_err(dev, "failed to start CRT\n");
                goto err_started;
        }

        ret = sm501fb_start_one(info, HEAD_PANEL, driver_name_pnl);
        if (ret) {
                dev_err(dev, "failed to start Panel\n");
                goto err_started_crt;
        }

        /* create device files */

        ret = device_create_file(dev, &dev_attr_crt_src);
        if (ret)
                goto err_started_panel;

        ret = device_create_file(dev, &dev_attr_fbregs_pnl);
        if (ret)
                goto err_attached_crtsrc_file;

        ret = device_create_file(dev, &dev_attr_fbregs_crt);
        if (ret)
                goto err_attached_pnlregs_file;

        /* we registered, return ok */
        return 0;

err_attached_pnlregs_file:
        device_remove_file(dev, &dev_attr_fbregs_pnl);

err_attached_crtsrc_file:
        device_remove_file(dev, &dev_attr_crt_src);

err_started_panel:
        unregister_framebuffer(info->fb[HEAD_PANEL]);
        sm501_free_init_fb(info, HEAD_PANEL);

err_started_crt:
        unregister_framebuffer(info->fb[HEAD_CRT]);
        sm501_free_init_fb(info, HEAD_CRT);

err_started:
        sm501fb_stop(info);

err_probed_panel:
        framebuffer_release(info->fb[HEAD_PANEL]);

err_probed_crt:
        framebuffer_release(info->fb[HEAD_CRT]);

err_alloc:
        kfree(info);

        return ret;
}


/*
 *  Cleanup
 */
static int sm501fb_remove(struct platform_device *pdev)
{
        struct sm501fb_info *info = platform_get_drvdata(pdev);
        struct fb_info     *fbinfo_crt = info->fb[0];
        struct fb_info     *fbinfo_pnl = info->fb[1];

        device_remove_file(&pdev->dev, &dev_attr_fbregs_crt);
        device_remove_file(&pdev->dev, &dev_attr_fbregs_pnl);
        device_remove_file(&pdev->dev, &dev_attr_crt_src);

        sm501_free_init_fb(info, HEAD_CRT);
        sm501_free_init_fb(info, HEAD_PANEL);

        unregister_framebuffer(fbinfo_crt);
        unregister_framebuffer(fbinfo_pnl);

        sm501fb_stop(info);
        kfree(info);

        framebuffer_release(fbinfo_pnl);
        framebuffer_release(fbinfo_crt);

        return 0;
}

#ifdef CONFIG_PM

static int sm501fb_suspend_fb(struct sm501fb_info *info,
                              enum sm501_controller head)
{
        struct fb_info *fbi = info->fb[head];
        struct sm501fb_par *par = fbi->par;

        if (par->screen.size == 0)
                return 0;

        /* blank the relevant interface to ensure unit power minimised */
        (par->ops.fb_blank)(FB_BLANK_POWERDOWN, fbi);

        /* tell console/fb driver we are suspending */

        acquire_console_sem();
        fb_set_suspend(fbi, 1);
        release_console_sem();

        /* backup copies in case chip is powered down over suspend */

        par->store_fb = vmalloc(par->screen.size);
        if (par->store_fb == NULL) {
                dev_err(info->dev, "no memory to store screen\n");
                return -ENOMEM;
        }

        par->store_cursor = vmalloc(par->cursor.size);
        if (par->store_cursor == NULL) {
                dev_err(info->dev, "no memory to store cursor\n");
                goto err_nocursor;
        }

        dev_dbg(info->dev, "suspending screen to %p\n", par->store_fb);
        dev_dbg(info->dev, "suspending cursor to %p\n", par->store_cursor);

        memcpy_fromio(par->store_fb, par->screen.k_addr, par->screen.size);
        memcpy_fromio(par->store_cursor, par->cursor.k_addr, par->cursor.size);

        return 0;

 err_nocursor:
        vfree(par->store_fb);
        par->store_fb = NULL;

        return -ENOMEM;
}

static void sm501fb_resume_fb(struct sm501fb_info *info,
                              enum sm501_controller head)
{
        struct fb_info *fbi = info->fb[head];
        struct sm501fb_par *par = fbi->par;

        if (par->screen.size == 0)
                return;

        /* re-activate the configuration */

        (par->ops.fb_set_par)(fbi);

        /* restore the data */

        dev_dbg(info->dev, "restoring screen from %p\n", par->store_fb);
        dev_dbg(info->dev, "restoring cursor from %p\n", par->store_cursor);

        if (par->store_fb)
                memcpy_toio(par->screen.k_addr, par->store_fb,
                            par->screen.size);

        if (par->store_cursor)
                memcpy_toio(par->cursor.k_addr, par->store_cursor,
                            par->cursor.size);

        acquire_console_sem();
        fb_set_suspend(fbi, 0);
        release_console_sem();

        vfree(par->store_fb);
        vfree(par->store_cursor);
}


/* suspend and resume support */

static int sm501fb_suspend(struct platform_device *pdev, pm_message_t state)
{
        struct sm501fb_info *info = platform_get_drvdata(pdev);

        /* store crt control to resume with */
        info->pm_crt_ctrl = readl(info->regs + SM501_DC_CRT_CONTROL);

        sm501fb_suspend_fb(info, HEAD_CRT);
        sm501fb_suspend_fb(info, HEAD_PANEL);

        /* turn off the clocks, in case the device is not powered down */
        sm501_unit_power(info->dev->parent, SM501_GATE_DISPLAY, 0);

        return 0;
}

#define SM501_CRT_CTRL_SAVE (SM501_DC_CRT_CONTROL_TVP |        \
                             SM501_DC_CRT_CONTROL_SEL)


static int sm501fb_resume(struct platform_device *pdev)
{
        struct sm501fb_info *info = platform_get_drvdata(pdev);
        unsigned long crt_ctrl;

        sm501_unit_power(info->dev->parent, SM501_GATE_DISPLAY, 1);

        /* restore the items we want to be saved for crt control */

        crt_ctrl = readl(info->regs + SM501_DC_CRT_CONTROL);
        crt_ctrl &= ~SM501_CRT_CTRL_SAVE;
        crt_ctrl |= info->pm_crt_ctrl & SM501_CRT_CTRL_SAVE;
        writel(crt_ctrl, info->regs + SM501_DC_CRT_CONTROL);

        sm501fb_resume_fb(info, HEAD_CRT);
        sm501fb_resume_fb(info, HEAD_PANEL);

        return 0;
}

#else
#define sm501fb_suspend NULL
#define sm501fb_resume  NULL
#endif

static struct platform_driver sm501fb_driver = {
        .probe          = sm501fb_probe,
        .remove         = sm501fb_remove,
        .suspend        = sm501fb_suspend,
        .resume         = sm501fb_resume,
        .driver         = {
                .name   = "sm501-fb",
                .owner  = THIS_MODULE,
        },
};

static int __devinit sm501fb_init(void)
{
        return platform_driver_register(&sm501fb_driver);
}

static void __exit sm501fb_cleanup(void)
{
        platform_driver_unregister(&sm501fb_driver);
}

module_init(sm501fb_init);
module_exit(sm501fb_cleanup);

MODULE_AUTHOR("Ben Dooks, Vincent Sanders");
MODULE_DESCRIPTION("SM501 Framebuffer driver");
MODULE_LICENSE("GPL v2");