/*
 *	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