/* cg3.c: CGTHREE 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) 1997 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 cg3_setcolreg(unsigned, unsigned, unsigned, unsigned,
  			 unsigned, struct fb_info *);
  static int cg3_blank(int, struct fb_info *);
  
  static int cg3_mmap(struct fb_info *, struct vm_area_struct *);
  static int cg3_ioctl(struct fb_info *, unsigned int, unsigned long);
  
  /*
   *  Frame buffer operations
   */
  
  static struct fb_ops cg3_ops = {
  	.owner			= THIS_MODULE,
  	.fb_setcolreg		= cg3_setcolreg,
  	.fb_blank		= cg3_blank,
  	.fb_fillrect		= cfb_fillrect,
  	.fb_copyarea		= cfb_copyarea,
  	.fb_imageblit		= cfb_imageblit,
  	.fb_mmap		= cg3_mmap,
  	.fb_ioctl		= cg3_ioctl,
  #ifdef CONFIG_COMPAT
  	.fb_compat_ioctl	= sbusfb_compat_ioctl,
  #endif
  };
  
  
  /* Control Register Constants */
  #define CG3_CR_ENABLE_INTS      0x80
  #define CG3_CR_ENABLE_VIDEO     0x40
  #define CG3_CR_ENABLE_TIMING    0x20
  #define CG3_CR_ENABLE_CURCMP    0x10
  #define CG3_CR_XTAL_MASK        0x0c
  #define CG3_CR_DIVISOR_MASK     0x03
  
  /* Status Register Constants */
  #define CG3_SR_PENDING_INT      0x80
  #define CG3_SR_RES_MASK         0x70
  #define CG3_SR_1152_900_76_A    0x40
  #define CG3_SR_1152_900_76_B    0x60
  #define CG3_SR_ID_MASK          0x0f
  #define CG3_SR_ID_COLOR         0x01
  #define CG3_SR_ID_MONO          0x02
  #define CG3_SR_ID_MONO_ECL      0x03
  
  enum cg3_type {
  	CG3_AT_66HZ = 0,
  	CG3_AT_76HZ,
  	CG3_RDI
  };
  
  struct bt_regs {
  	u32 addr;
  	u32 color_map;
  	u32 control;
  	u32 cursor;
  };
  
  struct cg3_regs {
  	struct bt_regs	cmap;
  	u8	control;
  	u8	status;
  	u8	cursor_start;
  	u8	cursor_end;
  	u8	h_blank_start;
  	u8	h_blank_end;
  	u8	h_sync_start;
  	u8	h_sync_end;
  	u8	comp_sync_end;
  	u8	v_blank_start_high;
  	u8	v_blank_start_low;
  	u8	v_blank_end;
  	u8	v_sync_start;
  	u8	v_sync_end;
  	u8	xfer_holdoff_start;
  	u8	xfer_holdoff_end;
  };
  
  /* Offset of interesting structures in the OBIO space */
  #define CG3_REGS_OFFSET	     0x400000UL
  #define CG3_RAM_OFFSET	     0x800000UL
  
  struct cg3_par {
  	spinlock_t		lock;
  	struct cg3_regs		__iomem *regs;
  	u32			sw_cmap[((256 * 3) + 3) / 4];
  
  	u32			flags;
  #define CG3_FLAG_BLANKED	0x00000001
  #define CG3_FLAG_RDI		0x00000002
  
  	unsigned long		which_io;
  };
  
  /**
   *      cg3_setcolreg - Optional function. Sets a color register.
   *      @regno: boolean, 0 copy local, 1 get_user() function
   *      @red: frame buffer colormap structure
   *      @green: The green value which can be up to 16 bits wide
   *      @blue:  The blue value which can be up to 16 bits wide.
   *      @transp: If supported the alpha value which can be up to 16 bits wide.
   *      @info: frame buffer info structure
   *
   * The cg3 palette is loaded with 4 color values at each time
   * so you end up with: (rgb)(r), (gb)(rg), (b)(rgb), and so on.
   * We keep a sw copy of the hw cmap to assist us in this esoteric
   * loading procedure.
   */
  static int cg3_setcolreg(unsigned regno,
  			 unsigned red, unsigned green, unsigned blue,
  			 unsigned transp, struct fb_info *info)
  {
  	struct cg3_par *par = (struct cg3_par *) info->par;
  	struct bt_regs __iomem *bt = &par->regs->cmap;
  	unsigned long flags;
  	u32 *p32;
  	u8 *p8;
  	int count;
  
  	if (regno >= 256)
  		return 1;
  
  	red >>= 8;
  	green >>= 8;
  	blue >>= 8;
  
  	spin_lock_irqsave(&par->lock, flags);
  
  	p8 = (u8 *)par->sw_cmap + (regno * 3);
  	p8[0] = red;
  	p8[1] = green;
  	p8[2] = blue;
  
  #define D4M3(x) ((((x)>>2)<<1) + ((x)>>2))      /* (x/4)*3 */
  #define D4M4(x) ((x)&~0x3)                      /* (x/4)*4 */
  
  	count = 3;
  	p32 = &par->sw_cmap[D4M3(regno)];
  	sbus_writel(D4M4(regno), &bt->addr);
  	while (count--)
  		sbus_writel(*p32++, &bt->color_map);
  
  #undef D4M3
  #undef D4M4
  
  	spin_unlock_irqrestore(&par->lock, flags);
  
  	return 0;
  }
  
  /**
   *      cg3_blank - Optional function.  Blanks the display.
   *      @blank_mode: the blank mode we want.
   *      @info: frame buffer structure that represents a single frame buffer
   */
  static int cg3_blank(int blank, struct fb_info *info)
  {
  	struct cg3_par *par = (struct cg3_par *) info->par;
  	struct cg3_regs __iomem *regs = par->regs;
  	unsigned long flags;
  	u8 val;
  
  	spin_lock_irqsave(&par->lock, flags);
  
  	switch (blank) {
  	case FB_BLANK_UNBLANK: /* Unblanking */
  		val = sbus_readb(&regs->control);
  		val |= CG3_CR_ENABLE_VIDEO;
  		sbus_writeb(val, &regs->control);
  		par->flags &= ~CG3_FLAG_BLANKED;
  		break;
  
  	case FB_BLANK_NORMAL: /* Normal blanking */
  	case FB_BLANK_VSYNC_SUSPEND: /* VESA blank (vsync off) */
  	case FB_BLANK_HSYNC_SUSPEND: /* VESA blank (hsync off) */
  	case FB_BLANK_POWERDOWN: /* Poweroff */
  		val = sbus_readb(&regs->control);
  		val &= ~CG3_CR_ENABLE_VIDEO;
  		sbus_writeb(val, &regs->control);
  		par->flags |= CG3_FLAG_BLANKED;
  		break;
  	}
  
  	spin_unlock_irqrestore(&par->lock, flags);
  
  	return 0;
  }
  
  static struct sbus_mmap_map cg3_mmap_map[] = {
  	{
  		.voff	= CG3_MMAP_OFFSET,
  		.poff	= CG3_RAM_OFFSET,
  		.size	= SBUS_MMAP_FBSIZE(1)
  	},
  	{ .size = 0 }
  };
  
  static int cg3_mmap(struct fb_info *info, struct vm_area_struct *vma)
  {
  	struct cg3_par *par = (struct cg3_par *)info->par;
  
  	return sbusfb_mmap_helper(cg3_mmap_map,
  				  info->fix.smem_start, info->fix.smem_len,
  				  par->which_io,
  				  vma);
  }
  
  static int cg3_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
  {
  	return sbusfb_ioctl_helper(cmd, arg, info,
  				   FBTYPE_SUN3COLOR, 8, info->fix.smem_len);
  }
  
  /*
   *  Initialisation
   */
  
  static void cg3_init_fix(struct fb_info *info, int linebytes,
  			 struct device_node *dp)
  {
  	strlcpy(info->fix.id, dp->name, sizeof(info->fix.id));
  
  	info->fix.type = FB_TYPE_PACKED_PIXELS;
  	info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
  
  	info->fix.line_length = linebytes;
  
  	info->fix.accel = FB_ACCEL_SUN_CGTHREE;
  }
  
  static void cg3_rdi_maybe_fixup_var(struct fb_var_screeninfo *var,
  				    struct device_node *dp)
  {
  	const char *params;
  	char *p;
  	int ww, hh;
  
  	params = of_get_property(dp, "params", NULL);
  	if (params) {
  		ww = simple_strtoul(params, &p, 10);
  		if (ww && *p == 'x') {
  			hh = simple_strtoul(p + 1, &p, 10);
  			if (hh && *p == '-') {
  				if (var->xres != ww ||
  				    var->yres != hh) {
  					var->xres = var->xres_virtual = ww;
  					var->yres = var->yres_virtual = hh;
  				}
  			}
  		}
  	}
  }
  
  static u8 cg3regvals_66hz[] = {	/* 1152 x 900, 66 Hz */
  	0x14, 0xbb,	0x15, 0x2b,	0x16, 0x04,	0x17, 0x14,
  	0x18, 0xae,	0x19, 0x03,	0x1a, 0xa8,	0x1b, 0x24,
  	0x1c, 0x01,	0x1d, 0x05,	0x1e, 0xff,	0x1f, 0x01,
  	0x10, 0x20,	0
  };
  
  static u8 cg3regvals_76hz[] = {	/* 1152 x 900, 76 Hz */
  	0x14, 0xb7,	0x15, 0x27,	0x16, 0x03,	0x17, 0x0f,
  	0x18, 0xae,	0x19, 0x03,	0x1a, 0xae,	0x1b, 0x2a,
  	0x1c, 0x01,	0x1d, 0x09,	0x1e, 0xff,	0x1f, 0x01,
  	0x10, 0x24,	0
  };
  
  static u8 cg3regvals_rdi[] = {	/* 640 x 480, cgRDI */
  	0x14, 0x70,	0x15, 0x20,	0x16, 0x08,	0x17, 0x10,
  	0x18, 0x06,	0x19, 0x02,	0x1a, 0x31,	0x1b, 0x51,
  	0x1c, 0x06,	0x1d, 0x0c,	0x1e, 0xff,	0x1f, 0x01,
  	0x10, 0x22,	0
  };
  
  static u8 *cg3_regvals[] = {
  	cg3regvals_66hz, cg3regvals_76hz, cg3regvals_rdi
  };
  
  static u_char cg3_dacvals[] = {
  	4, 0xff,	5, 0x00,	6, 0x70,	7, 0x00,	0
  };
  
  static int cg3_do_default_mode(struct cg3_par *par)
  {
  	enum cg3_type type;
  	u8 *p;
  
  	if (par->flags & CG3_FLAG_RDI)
  		type = CG3_RDI;
  	else {
  		u8 status = sbus_readb(&par->regs->status), mon;
  		if ((status & CG3_SR_ID_MASK) == CG3_SR_ID_COLOR) {
  			mon = status & CG3_SR_RES_MASK;
  			if (mon == CG3_SR_1152_900_76_A ||
  			    mon == CG3_SR_1152_900_76_B)
  				type = CG3_AT_76HZ;
  			else
  				type = CG3_AT_66HZ;
  		} else {
  			printk(KERN_ERR "cgthree: can't handle SR %02x
  ",
  			       status);
  			return -EINVAL;
  		}
  	}
  
  	for (p = cg3_regvals[type]; *p; p += 2) {
  		u8 __iomem *regp = &((u8 __iomem *)par->regs)[p[0]];
  		sbus_writeb(p[1], regp);
  	}
  	for (p = cg3_dacvals; *p; p += 2) {
  		u8 __iomem *regp;
  
  		regp = (u8 __iomem *)&par->regs->cmap.addr;
  		sbus_writeb(p[0], regp);
  		regp = (u8 __iomem *)&par->regs->cmap.control;
  		sbus_writeb(p[1], regp);
  	}
  	return 0;
  }
  
  static int cg3_probe(struct platform_device *op)
  {
  	struct device_node *dp = op->dev.of_node;
  	struct fb_info *info;
  	struct cg3_par *par;
  	int linebytes, err;
  
  	info = framebuffer_alloc(sizeof(struct cg3_par), &op->dev);
  
  	err = -ENOMEM;
  	if (!info)
  		goto out_err;
  	par = info->par;
  
  	spin_lock_init(&par->lock);
  
  	info->fix.smem_start = op->resource[0].start;
  	par->which_io = op->resource[0].flags & IORESOURCE_BITS;
  
  	sbusfb_fill_var(&info->var, dp, 8);
  	info->var.red.length = 8;
  	info->var.green.length = 8;
  	info->var.blue.length = 8;
  	if (!strcmp(dp->name, "cgRDI"))
  		par->flags |= CG3_FLAG_RDI;
  	if (par->flags & CG3_FLAG_RDI)
  		cg3_rdi_maybe_fixup_var(&info->var, dp);
  
  	linebytes = of_getintprop_default(dp, "linebytes",
  					  info->var.xres);
  	info->fix.smem_len = PAGE_ALIGN(linebytes * info->var.yres);
  
  	par->regs = of_ioremap(&op->resource[0], CG3_REGS_OFFSET,
  			       sizeof(struct cg3_regs), "cg3 regs");
  	if (!par->regs)
  		goto out_release_fb;
  
  	info->flags = FBINFO_DEFAULT;
  	info->fbops = &cg3_ops;
  	info->screen_base = of_ioremap(&op->resource[0], CG3_RAM_OFFSET,
  				       info->fix.smem_len, "cg3 ram");
  	if (!info->screen_base)
  		goto out_unmap_regs;
  
  	cg3_blank(FB_BLANK_UNBLANK, info);
  
  	if (!of_find_property(dp, "width", NULL)) {
  		err = cg3_do_default_mode(par);
  		if (err)
  			goto out_unmap_screen;
  	}
  
  	err = fb_alloc_cmap(&info->cmap, 256, 0);
  	if (err)
  		goto out_unmap_screen;
  
  	fb_set_cmap(&info->cmap, info);
  
  	cg3_init_fix(info, linebytes, dp);
  
  	err = register_framebuffer(info);
  	if (err < 0)
  		goto out_dealloc_cmap;
  
  	dev_set_drvdata(&op->dev, info);
  
  	printk(KERN_INFO "%s: cg3 at %lx:%lx
  ",
  	       dp->full_name, par->which_io, info->fix.smem_start);
  
  	return 0;
  
  out_dealloc_cmap:
  	fb_dealloc_cmap(&info->cmap);
  
  out_unmap_screen:
  	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
  
  out_unmap_regs:
  	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
  
  out_release_fb:
  	framebuffer_release(info);
  
  out_err:
  	return err;
  }
  
  static int cg3_remove(struct platform_device *op)
  {
  	struct fb_info *info = dev_get_drvdata(&op->dev);
  	struct cg3_par *par = info->par;
  
  	unregister_framebuffer(info);
  	fb_dealloc_cmap(&info->cmap);
  
  	of_iounmap(&op->resource[0], par->regs, sizeof(struct cg3_regs));
  	of_iounmap(&op->resource[0], info->screen_base, info->fix.smem_len);
  
  	framebuffer_release(info);
  
  	return 0;
  }
  
  static const struct of_device_id cg3_match[] = {
  	{
  		.name = "cgthree",
  	},
  	{
  		.name = "cgRDI",
  	},
  	{},
  };
  MODULE_DEVICE_TABLE(of, cg3_match);
  
  static struct platform_driver cg3_driver = {
  	.driver = {
  		.name = "cg3",
  		.owner = THIS_MODULE,
  		.of_match_table = cg3_match,
  	},
  	.probe		= cg3_probe,
  	.remove		= cg3_remove,
  };
  
  static int __init cg3_init(void)
  {
  	if (fb_get_options("cg3fb", NULL))
  		return -ENODEV;
  
  	return platform_driver_register(&cg3_driver);
  }
  
  static void __exit cg3_exit(void)
  {
  	platform_driver_unregister(&cg3_driver);
  }
  
  module_init(cg3_init);
  module_exit(cg3_exit);
  
  MODULE_DESCRIPTION("framebuffer driver for CGthree chipsets");
  MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
  MODULE_VERSION("2.0");
  MODULE_LICENSE("GPL");