/* cg6.c: CGSIX (GX, GXplus, TGX) frame buffer driver
 *
 * Copyright (C) 2003, 2006 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1996,1998 Jakub Jelinek (jj@ultra.linux.cz)
 * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
 *
 * Driver layout based loosely on tgafb.c, see that file for credits.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/fb.h>
#include <linux/mm.h>
#include <linux/of_device.h>

#include <asm/io.h>
#include <asm/fbio.h>

#include "sbuslib.h"

/*
 * Local functions.
 */

static int cg6_setcolreg(unsigned, unsigned, unsigned, unsigned,
			 unsigned, struct fb_info *);
static int cg6_blank(int, struct fb_info *);

static void cg6_imageblit(struct fb_info *, const struct fb_image *);
static void cg6_fillrect(struct fb_info *, const struct fb_fillrect *);
static void cg6_copyarea(struct fb_info *info, const struct fb_copyarea *area);
static int cg6_sync(struct fb_info *);
static int cg6_mmap(struct fb_info *, struct vm_area_struct *);
static int cg6_ioctl(struct fb_info *, unsigned int, unsigned long);
static int cg6_pan_display(struct fb_var_screeninfo *, struct fb_info *);

/*
 *  Frame buffer operations
 */

static struct fb_ops cg6_ops = {
	.owner			= THIS_MODULE,
	.fb_setcolreg		= cg6_setcolreg,
	.fb_blank		= cg6_blank,
	.fb_pan_display		= cg6_pan_display,
	.fb_fillrect		= cg6_fillrect,
	.fb_copyarea		= cg6_copyarea,
	.fb_imageblit		= cg6_imageblit,
	.fb_sync		= cg6_sync,
	.fb_mmap		= cg6_mmap,
	.fb_ioctl		= cg6_ioctl,
#ifdef CONFIG_COMPAT
	.fb_compat_ioctl	= sbusfb_compat_ioctl,
#endif
};

/* Offset of interesting structures in the OBIO space */
/*
 * Brooktree is the video dac and is funny to program on the cg6.
 * (it's even funnier on the cg3)
 * The FBC could be the frame buffer control
 * The FHC could is the frame buffer hardware control.
 */
#define CG6_ROM_OFFSET			0x0UL
#define CG6_BROOKTREE_OFFSET		0x200000UL
#define CG6_DHC_OFFSET			0x240000UL
#define CG6_ALT_OFFSET			0x280000UL
#define CG6_FHC_OFFSET			0x300000UL
#define CG6_THC_OFFSET			0x301000UL
#define CG6_FBC_OFFSET			0x700000UL
#define CG6_TEC_OFFSET			0x701000UL
#define CG6_RAM_OFFSET			0x800000UL

/* FHC definitions */
#define CG6_FHC_FBID_SHIFT		24
#define CG6_FHC_FBID_MASK		255
#define CG6_FHC_REV_SHIFT		20
#define CG6_FHC_REV_MASK		15
#define CG6_FHC_FROP_DISABLE		(1 << 19)
#define CG6_FHC_ROW_DISABLE		(1 << 18)
#define CG6_FHC_SRC_DISABLE		(1 << 17)
#define CG6_FHC_DST_DISABLE		(1 << 16)
#define CG6_FHC_RESET			(1 << 15)
#define CG6_FHC_LITTLE_ENDIAN		(1 << 13)
#define CG6_FHC_RES_MASK		(3 << 11)
#define CG6_FHC_1024			(0 << 11)
#define CG6_FHC_1152			(1 << 11)
#define CG6_FHC_1280			(2 << 11)
#define CG6_FHC_1600			(3 << 11)
#define CG6_FHC_CPU_MASK		(3 << 9)
#define CG6_FHC_CPU_SPARC		(0 << 9)
#define CG6_FHC_CPU_68020		(1 << 9)
#define CG6_FHC_CPU_386			(2 << 9)
#define CG6_FHC_TEST			(1 << 8)
#define CG6_FHC_TEST_X_SHIFT		4
#define CG6_FHC_TEST_X_MASK		15
#define CG6_FHC_TEST_Y_SHIFT		0
#define CG6_FHC_TEST_Y_MASK		15

/* FBC mode definitions */
#define CG6_FBC_BLIT_IGNORE		0x00000000
#define CG6_FBC_BLIT_NOSRC		0x00100000
#define CG6_FBC_BLIT_SRC		0x00200000
#define CG6_FBC_BLIT_ILLEGAL		0x00300000
#define CG6_FBC_BLIT_MASK		0x00300000

#define CG6_FBC_VBLANK			0x00080000

#define CG6_FBC_MODE_IGNORE		0x00000000
#define CG6_FBC_MODE_COLOR8		0x00020000
#define CG6_FBC_MODE_COLOR1		0x00040000
#define CG6_FBC_MODE_HRMONO		0x00060000
#define CG6_FBC_MODE_MASK		0x00060000

#define CG6_FBC_DRAW_IGNORE		0x00000000
#define CG6_FBC_DRAW_RENDER		0x00008000
#define CG6_FBC_DRAW_PICK		0x00010000
#define CG6_FBC_DRAW_ILLEGAL		0x00018000
#define CG6_FBC_DRAW_MASK		0x00018000

#define CG6_FBC_BWRITE0_IGNORE		0x00000000
#define CG6_FBC_BWRITE0_ENABLE		0x00002000
#define CG6_FBC_BWRITE0_DISABLE		0x00004000
#define CG6_FBC_BWRITE0_ILLEGAL		0x00006000
#define CG6_FBC_BWRITE0_MASK		0x00006000

#define CG6_FBC_BWRITE1_IGNORE		0x00000000
#define CG6_FBC_BWRITE1_ENABLE		0x00000800
#define CG6_FBC_BWRITE1_DISABLE		0x00001000
#define CG6_FBC_BWRITE1_ILLEGAL		0x00001800
#define CG6_FBC_BWRITE1_MASK		0x00001800

#define CG6_FBC_BREAD_IGNORE		0x00000000
#define CG6_FBC_BREAD_0			0x00000200
#define CG6_FBC_BREAD_1			0x00000400
#define CG6_FBC_BREAD_ILLEGAL		0x00000600
#define CG6_FBC_BREAD_MASK		0x00000600

#define CG6_FBC_BDISP_IGNORE		0x00000000
#define CG6_FBC_BDISP_0			0x00000080
#define CG6_FBC_BDISP_1			0x00000100
#define CG6_FBC_BDISP_ILLEGAL		0x00000180
#define CG6_FBC_BDISP_MASK		0x00000180

#define CG6_FBC_INDEX_MOD		0x00000040
#define CG6_FBC_INDEX_MASK		0x00000030

/* THC definitions */
#define CG6_THC_MISC_REV_SHIFT		16
#define CG6_THC_MISC_REV_MASK		15
#define CG6_THC_MISC_RESET		(1 << 12)
#define CG6_THC_MISC_VIDEO		(1 << 10)
#define CG6_THC_MISC_SYNC		(1 << 9)
#define CG6_THC_MISC_VSYNC		(1 << 8)
#define CG6_THC_MISC_SYNC_ENAB		(1 << 7)
#define CG6_THC_MISC_CURS_RES		(1 << 6)
#define CG6_THC_MISC_INT_ENAB		(1 << 5)
#define CG6_THC_MISC_INT		(1 << 4)
#define CG6_THC_MISC_INIT		0x9f
#define CG6_THC_CURSOFF			((65536-32) | ((65536-32) << 16))

/* The contents are unknown */
struct cg6_tec {
	int tec_matrix;
	int tec_clip;
	int tec_vdc;
};

struct cg6_thc {
	u32	thc_pad0[512];
	u32	thc_hs;		/* hsync timing */
	u32	thc_hsdvs;
	u32	thc_hd;
	u32	thc_vs;		/* vsync timing */
	u32	thc_vd;
	u32	thc_refresh;
	u32	thc_misc;
	u32	thc_pad1[56];
	u32	thc_cursxy;	/* cursor x,y position (16 bits each) */
	u32	thc_cursmask[32];	/* cursor mask bits */
	u32	thc_cursbits[32];	/* what to show where mask enabled */
};

struct cg6_fbc {
	u32	xxx0[1];
	u32	mode;
	u32	clip;
	u32	xxx1[1];
	u32	s;
	u32	draw;
	u32	blit;
	u32	font;
	u32	xxx2[24];
	u32	x0, y0, z0, color0;
	u32	x1, y1, z1, color1;
	u32	x2, y2, z2, color2;
	u32	x3, y3, z3, color3;
	u32	offx, offy;
	u32	xxx3[2];
	u32	incx, incy;
	u32	xxx4[2];
	u32	clipminx, clipminy;
	u32	xxx5[2];
	u32	clipmaxx, clipmaxy;
	u32	xxx6[2];
	u32	fg;
	u32	bg;
	u32	alu;
	u32	pm;
	u32	pixelm;
	u32	xxx7[2];
	u32	patalign;
	u32	pattern[8];
	u32	xxx8[432];
	u32	apointx, apointy, apointz;
	u32	xxx9[1];
	u32	rpointx, rpointy, rpointz;
	u32	xxx10[5];
	u32	pointr, pointg, pointb, pointa;
	u32	alinex, aliney, alinez;
	u32	xxx11[1];
	u32	rlinex, rliney, rlinez;
	u32	xxx12[5];
	u32	liner, lineg, lineb, linea;
	u32	atrix, atriy, atriz;
	u32	xxx13[1];
	u32	rtrix, rtriy, rtriz;
	u32	xxx14[5];
	u32	trir, trig, trib, tria;
	u32	aquadx, aquady, aquadz;
	u32	xxx15[1];
	u32	rquadx, rquady, rquadz;
	u32	xxx16[5];
	u32	quadr, quadg, quadb, quada;
	u32	arectx, arecty, arectz;
	u32	xxx17[1];
	u32	rrectx, rrecty, rrectz;
	u32	xxx18[5];
	u32	rectr, rectg, rectb, recta;
};

struct bt_regs {
	u32	addr;
	u32	color_map;
	u32	control;
	u32	cursor;
};

struct cg6_par {
	spinlock_t		lock;
	struct bt_regs		__iomem *bt;
	struct cg6_fbc		__iomem *fbc;
	struct cg6_thc		__iomem *thc;
	struct cg6_tec		__iomem *tec;
	u32			__iomem *fhc;

	u32			flags;
#define CG6_FLAG_BLANKED	0x00000001

	unsigned long		which_io;
};

static int cg6_sync(struct fb_info *info)
{
	struct cg6_par *par = (struct cg6_par *)info->par;
	struct cg6_fbc __iomem *fbc = par->fbc;
	int limit = 10000;

	do {
		if (!(sbus_readl(&fbc->s) & 0x10000000))
			break;
		udelay(10);
	} while (--limit > 0);

	return 0;
}

static void cg6_switch_from_graph(struct cg6_par *par)
{
	struct cg6_thc __iomem *thc = par->thc;
	unsigned long flags;

	spin_lock_irqsave(&par->lock, flags);

	/* Hide the cursor. */
	sbus_writel(CG6_THC_CURSOFF, &thc->thc_cursxy);

	spin_unlock_irqrestore(&par->lock, flags);
}

static int cg6_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct cg6_par *par = (struct cg6_par *)info->par;

	/* We just use this to catch switches out of
	 * graphics mode.
	 */
	cg6_switch_from_graph(par);

	if (var->xoffset || var->yoffset || var->vmode)
		return -EINVAL;
	return 0;
}

/**
 *	cg6_fillrect -	Draws a rectangle on the screen.
 *
 *	@info: frame buffer structure that represents a single frame buffer
 *	@rect: structure defining the rectagle and operation.
 */
static void cg6_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
	struct cg6_par *par = (struct cg6_par *)info->par;
	struct cg6_fbc __iomem *fbc = par->fbc;
	unsigned long flags;
	s32 val;

	/* CG6 doesn't handle ROP_XOR */

	spin_lock_irqsave(&par->lock, flags);

	cg6_sync(info);

	sbus_writel(rect->color, &fbc->fg);
	sbus_writel(~(u32)0, &fbc->pixelm);
	sbus_writel(0xea80ff00, &fbc->alu);
	sbus_writel(0, &fbc->s);
	sbus_writel(0, &fbc->clip);
	sbus_writel(~(u32)0, &fbc->pm);
	sbus_writel(rect->dy, &fbc->arecty);
	sbus_writel(rect->dx, &fbc->arectx);
	sbus_writel(rect->dy + rect->height, &fbc->arecty);
	sbus_writel(rect->dx + rect->width, &fbc->arectx);
	do {
		val = sbus_readl(&fbc->draw);
	} while (val < 0 && (val & 0x20000000));
	spin_unlock_irqrestore(&par->lock, flags);
}

/**
 *	cg6_copyarea - Copies one area of the screen to another area.
 *
 *	@info: frame buffer structure that represents a single frame buffer
 *	@area: Structure providing the data to copy the framebuffer contents
 *		from one region to another.
 *
 *	This drawing operation copies a rectangular area from one area of the
 *	screen to another area.
 */
static void cg6_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
	struct cg6_par *par = (struct cg6_par *)info->par;
	struct cg6_fbc __iomem *fbc = par->fbc;
	unsigned long flags;
	int i;

	spin_lock_irqsave(&par->lock, flags);

	cg6_sync(info);

	sbus_writel(0xff, &fbc->fg);
	sbus_writel(0x00, &fbc->bg);
	sbus_writel(~0, &fbc->pixelm);
	sbus_writel(0xe880cccc, &fbc->alu);
	sbus_writel(0, &fbc->s);
	sbus_writel(0, &fbc->clip);

	sbus_writel(area->sy, &fbc->y0);
	sbus_writel(area->sx, &fbc->x0);
	sbus_writel(area->sy + area->height - 1, &fbc->y1);
	sbus_writel(area->sx + area->width - 1, &fbc->x1);
	sbus_writel(area->dy, &fbc->y2);
	sbus_writel(area->dx, &fbc->x2);
	sbus_writel(area->dy + area->height - 1, &fbc->y3);
	sbus_writel(area->dx + area->width - 1, &fbc->x3);
	do {
		i = sbus_readl(&fbc->blit);
	} while (i < 0 && (i & 0x20000000));
	spin_unlock_irqrestore(&par->lock, flags);
}

/**
 *	cg6_imageblit -	Copies a image from system memory to the screen.
 *
 *	@info: frame buffer structure that represents a single frame buffer
 *	@image: structure defining the image.
 */
static void cg6_imageblit(struct fb_info *info, const struct fb_image *image)
{
	struct cg6_par *par = (struct cg6_par *)info->par;
	struct cg6_fbc __iomem *fbc = par->fbc;
	const u8 *data = image->data;
	unsigned long flags;
	u32 x, y;