/*
 *      linux/drivers/video/pmag-aa-fb.c
 *      Copyright 2002 Karsten Merker <merker@debian.org>
 *
 *      PMAG-AA TurboChannel framebuffer card support ... derived from
 *      pmag-ba-fb.c, which is Copyright (C) 1999, 2000, 2001 by
 *      Michael Engel <engel@unix-ag.org>, Karsten Merker <merker@debian.org>
 *      and Harald Koerfgen <hkoerfg@web.de>, which itself is derived from
 *      "HP300 Topcat framebuffer support (derived from macfb of all things)
 *      Phil Blundell <philb@gnu.org> 1998"
 *
 *      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.
 *
 *      2002-09-28  Karsten Merker <merker@linuxtag.org>
 *              Version 0.01: First try to get a PMAG-AA running.
 *
 *      2003-02-24  Thiemo Seufer  <seufer@csv.ica.uni-stuttgart.de>
 *              Version 0.02: Major code cleanup.
 *
 *      2003-09-21  Thiemo Seufer  <seufer@csv.ica.uni-stuttgart.de>
 *              Hardware cursor support.
 */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <linux/console.h>

#include <asm/bootinfo.h>
#include <asm/dec/machtype.h>
#include <asm/dec/tc.h>

#include <video/fbcon.h>
#include <video/fbcon-cfb8.h>

#include "bt455.h"
#include "bt431.h"

/* Version information */
#define DRIVER_VERSION "0.02"
#define DRIVER_AUTHOR "Karsten Merker <merker@linuxtag.org>"
#define DRIVER_DESCRIPTION "PMAG-AA Framebuffer Driver"

/* Prototypes */
static int aafb_set_var(struct fb_var_screeninfo *var, int con,
                        struct fb_info *info);

/*
 * Bt455 RAM DAC register base offset (rel. to TC slot base address).
 */
#define PMAG_AA_BT455_OFFSET            0x100000

/*
 * Bt431 cursor generator offset (rel. to TC slot base address).
 */
#define PMAG_AA_BT431_OFFSET            0x180000

/*
 * Begin of PMAG-AA framebuffer memory relative to TC slot address,
 * resolution is 1280x1024x1 (8 bits deep, but only LSB is used).
 */
#define PMAG_AA_ONBOARD_FBMEM_OFFSET    0x200000

struct aafb_cursor {
        struct timer_list timer;
        int enable;
        int on;
        int vbl_cnt;
        int blink_rate;
        u16 x, y, width, height;
};

#define CURSOR_TIMER_FREQ       (HZ / 50)
#define CURSOR_BLINK_RATE       (20)
#define CURSOR_DRAW_DELAY       (2)

struct aafb_info {
        struct fb_info info;
        struct display disp;
        struct aafb_cursor cursor;
        struct bt455_regs *bt455;
        struct bt431_regs *bt431;
        unsigned long fb_start;
        unsigned long fb_size;
        unsigned long fb_line_length;
};

/*
 * Max 3 TURBOchannel slots -> max 3 PMAG-AA.
 */
static struct aafb_info my_fb_info[3];

static struct aafb_par {
} current_par;

static int currcon = -1;

static void aafb_set_cursor(struct aafb_info *info, int on)
{
        struct aafb_cursor *c = &info->cursor;

        if (on) {
                bt431_position_cursor(info->bt431, c->x, c->y);
                bt431_enable_cursor(info->bt431);
        } else
                bt431_erase_cursor(info->bt431);
}

static void aafbcon_cursor(struct display *disp, int mode, int x, int y)
{
        struct aafb_info *info = (struct aafb_info *)disp->fb_info;
        struct aafb_cursor *c = &info->cursor;

        x *= fontwidth(disp);
        y *= fontheight(disp);

        if (c->x == x && c->y == y && (mode == CM_ERASE) == !c->enable)
                return;

        c->enable = 0;
        if (c->on)
                aafb_set_cursor(info, 0);
        c->x = x - disp->var.xoffset;
        c->y = y - disp->var.yoffset;

        switch (mode) {
                case CM_ERASE:
                        c->on = 0;
                        break;
                case CM_DRAW:
                case CM_MOVE:
                        if (c->on)
                                aafb_set_cursor(info, c->on);
                        else
                                c->vbl_cnt = CURSOR_DRAW_DELAY;
                        c->enable = 1;
                        break;
        }
}

static int aafbcon_set_font(struct display *disp, int width, int height)
{
        struct aafb_info *info = (struct aafb_info *)disp->fb_info;
        struct aafb_cursor *c = &info->cursor;
        u8 fgc = ~attr_bgcol_ec(disp, disp->conp, &info->info);

        if (width > 64 || height > 64 || width < 0 || height < 0)
                return -EINVAL;

        c->height = height;
        c->width = width;

        bt431_set_font(info->bt431, fgc, width, height);

        return 1;
}

static void aafb_cursor_timer_handler(unsigned long data)
{
        struct aafb_info *info = (struct aafb_info *)data;
        struct aafb_cursor *c = &info->cursor;

        if (!c->enable)
                goto out;

        if (c->vbl_cnt && --c->vbl_cnt == 0) {
                c->on ^= 1;
                aafb_set_cursor(info, c->on);
                c->vbl_cnt = c->blink_rate;
        }

out:
        c->timer.expires = jiffies + CURSOR_TIMER_FREQ;
        add_timer(&c->timer);
}

static void __init aafb_cursor_init(struct aafb_info *info)
{
        struct aafb_cursor *c = &info->cursor;

        c->enable = 1;
        c->on = 1;
        c->x = c->y = 0;
        c->width = c->height = 0;
        c->vbl_cnt = CURSOR_DRAW_DELAY;
        c->blink_rate = CURSOR_BLINK_RATE;

        init_timer(&c->timer);
        c->timer.data = (unsigned long)info;
        c->timer.function = aafb_cursor_timer_handler;
        mod_timer(&c->timer, jiffies + CURSOR_TIMER_FREQ);
}

static void __exit aafb_cursor_exit(struct aafb_info *info)
{
        struct aafb_cursor *c = &info->cursor;

        del_timer_sync(&c->timer);
}

static struct display_switch aafb_switch8 = {
        .setup = fbcon_cfb8_setup,
        .bmove = fbcon_cfb8_bmove,
        .clear = fbcon_cfb8_clear,
        .putc = fbcon_cfb8_putc,
        .putcs = fbcon_cfb8_putcs,
        .revc = fbcon_cfb8_revc,
        .cursor = aafbcon_cursor,
        .set_font = aafbcon_set_font,
        .clear_margins = fbcon_cfb8_clear_margins,
        .fontwidthmask = FONTWIDTH(4)|FONTWIDTH(8)|FONTWIDTH(12)|FONTWIDTH(16)
};

static void aafb_get_par(struct aafb_par *par)
{
        *par = current_par;
}

static int aafb_get_fix(struct fb_fix_screeninfo *fix, int con,
                        struct fb_info *info)
{
        struct aafb_info *ip = (struct aafb_info *)info;

        memset(fix, 0, sizeof(struct fb_fix_screeninfo));
        strcpy(fix->id, "PMAG-AA");
        fix->smem_start = ip->fb_start;
        fix->smem_len = ip->fb_size;
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->ypanstep = 1;
        fix->ywrapstep = 1;
        fix->visual = FB_VISUAL_MONO10;
        fix->line_length = 1280;
        fix->accel = FB_ACCEL_NONE;

        return 0;
}

static void aafb_set_disp(struct display *disp, int con,
                          struct aafb_info *info)
{
        struct fb_fix_screeninfo fix;

        disp->fb_info = &info->info;
        aafb_set_var(&disp->var, con, &info->info);
        if (disp->conp && disp->conp->vc_sw && disp->conp->vc_sw->con_cursor)
                disp->conp->vc_sw->con_cursor(disp->conp, CM_ERASE);
        disp->dispsw = &aafb_switch8;
        disp->dispsw_data = 0;

        aafb_get_fix(&fix, con, &info->info);
        disp->screen_base = (u8 *) fix.smem_start;
        disp->visual = fix.visual;
        disp->type = fix.type;
        disp->type_aux = fix.type_aux;
        disp->ypanstep = fix.ypanstep;
        disp->ywrapstep = fix.ywrapstep;
        disp->line_length = fix.line_length;
        disp->next_line = 2048;
        disp->can_soft_blank = 1;
        disp->inverse = 0;
        disp->scrollmode = SCROLL_YREDRAW;

        aafbcon_set_font(disp, fontwidth(disp), fontheight(disp));
}

static int aafb_get_cmap(struct fb_cmap *cmap, int kspc, int con,
                         struct fb_info *info)
{
        static u16 color[2] = {0x0000, 0x000f};
        static struct fb_cmap aafb_cmap = {0, 2, color, color, color, NULL};

        fb_copy_cmap(&aafb_cmap, cmap, kspc ? 0 : 2);
        return 0;
}

static int aafb_set_cmap(struct fb_cmap *cmap, int kspc, int con,
                         struct fb_info *info)
{
        u16 color[2] = {0x0000, 0x000f};

        if (cmap->start == 0
            && cmap->len == 2
            && memcmp(cmap->red, color, sizeof(color)) == 0
            && memcmp(cmap->green, color, sizeof(color)) == 0
            && memcmp(cmap->blue, color, sizeof(color)) == 0
            && cmap->transp == NULL)
                return 0;
        else
                return -EINVAL;
}

static int aafb_ioctl(struct fb_info *info, u32 cmd, unsigned long arg)
{
        /* TODO: Not yet implemented */
        return -ENOIOCTLCMD;
}

static int aafb_switch(int con, struct fb_info *info)
{
        struct aafb_info *ip = (struct aafb_info *)info;
        struct display *old = (currcon < 0) ? &ip->disp : (fb_display + currcon);
        struct display *new = (con < 0) ? &ip->disp : (fb_display + con);

        if (old->conp && old->conp->vc_sw && old->conp->vc_sw->con_cursor)
                old->conp->vc_sw->con_cursor(old->conp, CM_ERASE);

        /* Set the current console. */
        currcon = con;
        aafb_set_disp(new, con, ip);

        return 0;
}

static void aafb_encode_var(struct fb_var_screeninfo *var,
                            struct aafb_par *par)
{
        var->xres = 1280;
        var->yres = 1024;
        var->xres_virtual = 2048;
        var->yres_virtual = 1024;
        var->xoffset = 0;
        var->yoffset = 0;
        var->bits_per_pixel = 8;
        var->grayscale = 1;
        var->red.offset = 0;
        var->red.length = 0;
        var->red.msb_right = 0;
        var->green.offset = 0;
        var->green.length = 1;
        var->green.msb_right = 0;
        var->blue.offset = 0;
        var->blue.length = 0;
        var->blue.msb_right = 0;
        var->transp.offset = 0;
        var->transp.length = 0;
        var->transp.msb_right = 0;
        var->nonstd = 0;
        var->activate &= ~FB_ACTIVATE_MASK & FB_ACTIVATE_NOW;
        var->accel_flags = 0;
        var->sync = FB_SYNC_ON_GREEN;
        var->vmode &= ~FB_VMODE_MASK & FB_VMODE_NONINTERLACED;
}

static int aafb_get_var(struct fb_var_screeninfo *var, int con,
                        struct fb_info *info)
{
        if (con < 0) {
                struct aafb_par par;

                memset(var, 0, sizeof(struct fb_var_screeninfo));
                aafb_get_par(&par);
                aafb_encode_var(var, &par);
        } else
                *var = info->var;

        return 0;
}

static int aafb_set_var(struct fb_var_screeninfo *var, int con,
                        struct fb_info *info)
{
        struct aafb_par par;

        aafb_get_par(&par);
        aafb_encode_var(var, &par);
        info->var = *var;

        return 0;
}

static int aafb_update_var(int con, struct fb_info *info)
{
        struct aafb_info *ip = (struct aafb_info *)info;
        struct display *disp = (con < 0) ? &ip->disp : (fb_display + con);

        if (con == currcon)
                aafbcon_cursor(disp, CM_ERASE, ip->cursor.x, ip->cursor.y);

        return 0;
}

/* 0 unblanks, any other blanks. */

static void aafb_blank(int blank, struct fb_info *info)
{
        struct aafb_info *ip = (struct aafb_info *)info;
        u8 val = blank ? 0x00 : 0x0f;

        bt455_write_cmap_entry(ip->bt455, 1, val, val, val);
        aafbcon_cursor(&ip->disp, CM_ERASE, ip->cursor.x, ip->cursor.y);
}

static struct fb_ops aafb_ops = {
        .owner = THIS_MODULE,
        .fb_get_fix = aafb_get_fix,
        .fb_get_var = aafb_get_var,
        .fb_set_var = aafb_set_var,
        .fb_get_cmap = aafb_get_cmap,
        .fb_set_cmap = aafb_set_cmap,
        .fb_ioctl = aafb_ioctl
};

static int __init init_one(int slot)
{
        unsigned long base_addr = CKSEG1ADDR(get_tc_base_addr(slot));
        struct aafb_info *ip = &my_fb_info[slot];

        memset(ip, 0, sizeof(struct aafb_info));

        /*
         * Framebuffer display memory base address and friends.
         */
        ip->bt455 = (struct bt455_regs *) (base_addr + PMAG_AA_BT455_OFFSET);
        ip->bt431 = (struct bt431_regs *) (base_addr + PMAG_AA_BT431_OFFSET);
        ip->fb_start = base_addr + PMAG_AA_ONBOARD_FBMEM_OFFSET;
        ip->fb_size = 2048 * 1024; /* fb_fix_screeninfo.smem_length
                                      seems to be physical */
        ip->fb_line_length = 2048;

        /*
         * Let there be consoles..
         */
        strcpy(ip->info.modename, "PMAG-AA");
        ip->info.node = -1;
        ip->info.flags = FBINFO_FLAG_DEFAULT;
        ip->info.fbops = &aafb_ops;
        ip->info.disp = &ip->disp;
        ip->info.changevar = NULL;
        ip->info.switch_con = &aafb_switch;
        ip->info.updatevar = &aafb_update_var;
        ip->info.blank = &aafb_blank;

        aafb_set_disp(&ip->disp, currcon, ip);

        /*
         * Configure the RAM DACs.
         */
        bt455_erase_cursor(ip->bt455);

        /* Init colormap. */
        bt455_write_cmap_entry(ip->bt455, 0, 0x00, 0x00, 0x00);
        bt455_write_cmap_entry(ip->bt455, 1, 0x0f, 0x0f, 0x0f);

        /* Init hardware cursor. */
        bt431_init_cursor(ip->bt431);
        aafb_cursor_init(ip);

        /* Clear the screen. */
        memset ((void *)ip->fb_start, 0, ip->fb_size);

        if (register_framebuffer(&ip->info) < 0)
                return -EINVAL;

        printk(KERN_INFO "fb%d: %s frame buffer in TC slot %d\n",
               GET_FB_IDX(ip->info.node), ip->info.modename, slot);

        return 0;
}

static int __exit exit_one(int slot)
{
        struct aafb_info *ip = &my_fb_info[slot];

        if (unregister_framebuffer(&ip->info) < 0)
                return -EINVAL;

        return 0;
}

/*
 * Initialise the framebuffer.
 */
int __init pmagaafb_init(void)
{
        int sid;
        int found = 0;

        while ((sid = search_tc_card("PMAG-AA")) >= 0) {
                found = 1;
                claim_tc_card(sid);
                init_one(sid);
        }

        return found ? 0 : -ENXIO;
}

static void __exit pmagaafb_exit(void)
{
        int sid;

        while ((sid = search_tc_card("PMAG-AA")) >= 0) {
                exit_one(sid);
                release_tc_card(sid);
        }
}

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
MODULE_LICENSE("GPL");
#ifdef MODULE
module_init(pmagaafb_init);
module_exit(pmagaafb_exit);
#endif