/*
 * linux/include/asm-arm/hardware/amba_clcd.h -- Integrator LCD panel.
 *
 * David A Rusling
 *
 * Copyright (C) 2001 ARM Limited
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */
#include <linux/fb.h>
#include <linux/amba/clcd-regs.h>

enum {
        /* individual formats */
        CLCD_CAP_RGB444         = (1 << 0),
        CLCD_CAP_RGB5551        = (1 << 1),
        CLCD_CAP_RGB565         = (1 << 2),
        CLCD_CAP_RGB888         = (1 << 3),
        CLCD_CAP_BGR444         = (1 << 4),
        CLCD_CAP_BGR5551        = (1 << 5),
        CLCD_CAP_BGR565         = (1 << 6),
        CLCD_CAP_BGR888         = (1 << 7),

        /* connection layouts */
        CLCD_CAP_444            = CLCD_CAP_RGB444 | CLCD_CAP_BGR444,
        CLCD_CAP_5551           = CLCD_CAP_RGB5551 | CLCD_CAP_BGR5551,
        CLCD_CAP_565            = CLCD_CAP_RGB565 | CLCD_CAP_BGR565,
        CLCD_CAP_888            = CLCD_CAP_RGB888 | CLCD_CAP_BGR888,

        /* red/blue ordering */
        CLCD_CAP_RGB            = CLCD_CAP_RGB444 | CLCD_CAP_RGB5551 |
                                  CLCD_CAP_RGB565 | CLCD_CAP_RGB888,
        CLCD_CAP_BGR            = CLCD_CAP_BGR444 | CLCD_CAP_BGR5551 |
                                  CLCD_CAP_BGR565 | CLCD_CAP_BGR888,

        CLCD_CAP_ALL            = CLCD_CAP_BGR | CLCD_CAP_RGB,
};

struct backlight_device;

struct clcd_panel {
        struct fb_videomode     mode;
        signed short            width;  /* width in mm */
        signed short            height; /* height in mm */
        u32                     tim2;
        u32                     tim3;
        u32                     cntl;
        u32                     caps;
        unsigned int            bpp:8,
                                fixedtimings:1,
                                grayscale:1;
        unsigned int            connector;
        struct backlight_device *backlight;
        /*
         * If the B/R lines are switched between the CLCD
         * and the panel we need to know this and not try to
         * compensate with the BGR bit in the control register.
         */
        bool                    bgr_connection;
};

struct clcd_regs {
        u32                     tim0;
        u32                     tim1;
        u32                     tim2;
        u32                     tim3;
        u32                     cntl;
        unsigned long           pixclock;
};

struct clcd_fb;

/*
 * the board-type specific routines
 */
struct clcd_board {
        const char *name;

        /*
         * Optional.  Hardware capability flags.
         */
        u32     caps;

        /*
         * Optional.  Check whether the var structure is acceptable
         * for this display.
         */
        int     (*check)(struct clcd_fb *fb, struct fb_var_screeninfo *var);

        /*
         * Compulsory.  Decode fb->fb.var into regs->*.  In the case of
         * fixed timing, set regs->* to the register values required.
         */
        void    (*decode)(struct clcd_fb *fb, struct clcd_regs *regs);

        /*
         * Optional.  Disable any extra display hardware.
         */
        void    (*disable)(struct clcd_fb *);

        /*
         * Optional.  Enable any extra display hardware.
         */
        void    (*enable)(struct clcd_fb *);

        /*
         * Setup platform specific parts of CLCD driver
         */
        int     (*setup)(struct clcd_fb *);

        /*
         * mmap the framebuffer memory
         */
        int     (*mmap)(struct clcd_fb *, struct vm_area_struct *);

        /*
         * Remove platform specific parts of CLCD driver
         */
        void    (*remove)(struct clcd_fb *);
};

struct amba_device;
struct clk;

/**
 * struct clcd_vendor_data - holds hardware (IP-block) vendor-specific
 * variant information
 *
 * @clock_timregs: the CLCD needs to be clocked when accessing the
 * timer registers, or the hardware will hang.
 * @packed_24_bit_pixels: this variant supports 24bit packed pixel data,
 * so that RGB accesses 3 bytes at a time, not just on even 32bit
 * boundaries, packing the pixel data in memory. ST Microelectronics
 * have this.
 * @st_bitmux_control: ST Microelectronics have implemented output
 * bit line multiplexing into the CLCD control register. This indicates
 * that we need to use this.
 * @init_board: custom board init function for this variant
 * @init_panel: custom panel init function for this variant
 */
struct clcd_vendor_data {
        bool    clock_timregs;
        bool    packed_24_bit_pixels;
        bool    st_bitmux_control;
        int     (*init_board)(struct amba_device *adev,
                              struct clcd_board *board);
        int     (*init_panel)(struct clcd_fb *fb,
                              struct device_node *panel);
};

/* this data structure describes each frame buffer device we find */
struct clcd_fb {
        struct fb_info          fb;
        struct amba_device      *dev;
        struct clk              *clk;
        struct clcd_vendor_data *vendor;
        struct clcd_panel       *panel;
        struct clcd_board       *board;
        void                    *board_data;
        void __iomem            *regs;
        u16                     off_ienb;
        u16                     off_cntl;
        u32                     clcd_cntl;
        u32                     cmap[16];
        bool                    clk_enabled;
};

static inline void clcdfb_decode(struct clcd_fb *fb, struct clcd_regs *regs)
{
        struct fb_var_screeninfo *var = &fb->fb.var;
        u32 val, cpl;

        /*
         * Program the CLCD controller registers and start the CLCD
         */
        val = ((var->xres / 16) - 1) << 2;
        val |= (var->hsync_len - 1) << 8;
        val |= (var->right_margin - 1) << 16;
        val |= (var->left_margin - 1) << 24;
        regs->tim0 = val;

        val = var->yres;
        if (fb->panel->cntl & CNTL_LCDDUAL)
                val /= 2;
        val -= 1;
        val |= (var->vsync_len - 1) << 10;
        val |= var->lower_margin << 16;
        val |= var->upper_margin << 24;
        regs->tim1 = val;

        val = fb->panel->tim2;
        val |= var->sync & FB_SYNC_HOR_HIGH_ACT  ? 0 : TIM2_IHS;
        val |= var->sync & FB_SYNC_VERT_HIGH_ACT ? 0 : TIM2_IVS;

        cpl = var->xres_virtual;
        if (fb->panel->cntl & CNTL_LCDTFT)        /* TFT */
                /* / 1 */;
        else if (!var->grayscale)                 /* STN color */
                cpl = cpl * 8 / 3;
        else if (fb->panel->cntl & CNTL_LCDMONO8) /* STN monochrome, 8bit */
                cpl /= 8;
        else                                      /* STN monochrome, 4bit */
                cpl /= 4;

        regs->tim2 = val | ((cpl - 1) << 16);

        regs->tim3 = fb->panel->tim3;

        val = fb->panel->cntl;
        if (var->grayscale)
                val |= CNTL_LCDBW;

        if (fb->panel->caps && fb->board->caps && var->bits_per_pixel >= 16) {
                /*
                 * if board and panel supply capabilities, we can support
                 * changing BGR/RGB depending on supplied parameters. Here
                 * we switch to what the framebuffer is providing if need
                 * be, so if the framebuffer is BGR but the display connection
                 * is RGB (first case) we switch it around. Vice versa mutatis
                 * mutandis if the framebuffer is RGB but the display connection
                 * is BGR, we flip it around.
                 */
                if (var->red.offset == 0)
                        val &= ~CNTL_BGR;
                else
                        val |= CNTL_BGR;
                if (fb->panel->bgr_connection)
                        val ^= CNTL_BGR;
        }

        switch (var->bits_per_pixel) {
        case 1:
                val |= CNTL_LCDBPP1;
                break;
        case 2:
                val |= CNTL_LCDBPP2;
                break;
        case 4:
                val |= CNTL_LCDBPP4;
                break;
        case 8:
                val |= CNTL_LCDBPP8;
                break;
        case 16:
                /*
                 * PL110 cannot choose between 5551 and 565 modes in its
                 * control register.  It is possible to use 565 with
                 * custom external wiring.
                 */
                if (amba_part(fb->dev) == 0x110 ||
                    var->green.length == 5)
                        val |= CNTL_LCDBPP16;
                else if (var->green.length == 6)
                        val |= CNTL_LCDBPP16_565;
                else
                        val |= CNTL_LCDBPP16_444;
                break;
        case 24:
                /* Modified variant supporting 24 bit packed pixels */
                val |= CNTL_ST_LCDBPP24_PACKED;
                break;
        case 32:
                val |= CNTL_LCDBPP24;
                break;
        }

        regs->cntl = val;
        regs->pixclock = var->pixclock;
}

static inline int clcdfb_check(struct clcd_fb *fb, struct fb_var_screeninfo *var)
{
        var->xres_virtual = var->xres = (var->xres + 15) & ~15;
        var->yres_virtual = var->yres = (var->yres + 1) & ~1;

#define CHECK(e,l,h) (var->e < l || var->e > h)
        if (CHECK(right_margin, (5+1), 256) ||  /* back porch */
            CHECK(left_margin, (5+1), 256) ||   /* front porch */
            CHECK(hsync_len, (5+1), 256) ||
            var->xres > 4096 ||
            var->lower_margin > 255 ||          /* back porch */
            var->upper_margin > 255 ||          /* front porch */
            var->vsync_len > 32 ||
            var->yres > 1024)
                return -EINVAL;
#undef CHECK

        /* single panel mode: PCD = max(PCD, 1) */
        /* dual panel mode: PCD = max(PCD, 5) */

        /*
         * You can't change the grayscale setting, and
         * we can only do non-interlaced video.
         */
        if (var->grayscale != fb->fb.var.grayscale ||
            (var->vmode & FB_VMODE_MASK) != FB_VMODE_NONINTERLACED)
                return -EINVAL;

#define CHECK(e) (var->e != fb->fb.var.e)
        if (fb->panel->fixedtimings &&
            (CHECK(xres)                ||
             CHECK(yres)                ||
             CHECK(bits_per_pixel)      ||
             CHECK(pixclock)            ||
             CHECK(left_margin)         ||
             CHECK(right_margin)        ||
             CHECK(upper_margin)        ||
             CHECK(lower_margin)        ||
             CHECK(hsync_len)           ||
             CHECK(vsync_len)           ||
             CHECK(sync)))
                return -EINVAL;
#undef CHECK

        var->nonstd = 0;
        var->accel_flags = 0;

        return 0;
}