/*
   *	HP300 Topcat framebuffer support (derived from macfb of all things)
   *	Phil Blundell <philb@gnu.org> 1998
   *	DIO-II, colour map and Catseye support by
   *	Kars de Jong <jongk@linux-m68k.org>, May 2004.
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/mm.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/fb.h>
  #include <linux/dio.h>
  
  #include <asm/io.h>
  #include <asm/uaccess.h>
  
  static struct fb_info fb_info = {
  	.fix = {
  		.id		= "HP300 ",
  		.type		= FB_TYPE_PACKED_PIXELS,
  		.visual		= FB_VISUAL_PSEUDOCOLOR,
  		.accel		= FB_ACCEL_NONE,
  	}
  };
  
  static unsigned long fb_regs;
  static unsigned char fb_bitmask;
  
  #define TC_NBLANK	0x4080
  #define TC_WEN		0x4088
  #define TC_REN		0x408c
  #define TC_FBEN		0x4090
  #define TC_PRR		0x40ea
  
  /* These defines match the X window system */
  #define RR_CLEAR	0x0
  #define RR_COPY		0x3
  #define RR_NOOP		0x5
  #define RR_XOR		0x6
  #define RR_INVERT	0xa
  #define RR_COPYINVERTED 0xc
  #define RR_SET		0xf
  
  /* blitter regs */
  #define BUSY		0x4044
  #define WMRR		0x40ef
  #define SOURCE_X	0x40f2
  #define SOURCE_Y	0x40f6
  #define DEST_X		0x40fa
  #define DEST_Y		0x40fe
  #define WHEIGHT		0x4106
  #define WWIDTH		0x4102
  #define WMOVE		0x409c
  
  static struct fb_var_screeninfo hpfb_defined = {
  	.red		= {
  		.length = 8,
  	},
  	.green		= {
  		.length = 8,
  	},
  	.blue		= {
  		.length = 8,
  	},
  	.activate	= FB_ACTIVATE_NOW,
  	.height		= -1,
  	.width		= -1,
  	.vmode		= FB_VMODE_NONINTERLACED,
  };
  
  static int hpfb_setcolreg(unsigned regno, unsigned red, unsigned green,
  			  unsigned blue, unsigned transp,
  			  struct fb_info *info)
  {
  	/* use MSBs */
  	unsigned char _red  =red>>8;
  	unsigned char _green=green>>8;
  	unsigned char _blue =blue>>8;
  	unsigned char _regno=regno;
  
  	/*
  	 *  Set a single color register. The values supplied are
  	 *  already rounded down to the hardware's capabilities
  	 *  (according to the entries in the `var' structure). Return
  	 *  != 0 for invalid regno.
  	 */
  
  	if (regno >= info->cmap.len)
  		return 1;
  	
  	while (in_be16(fb_regs + 0x6002) & 0x4) udelay(1);
  
  	out_be16(fb_regs + 0x60ba, 0xff);
  
  	out_be16(fb_regs + 0x60b2, _red);
  	out_be16(fb_regs + 0x60b4, _green);
  	out_be16(fb_regs + 0x60b6, _blue);
  	out_be16(fb_regs + 0x60b8, ~_regno);
  	out_be16(fb_regs + 0x60f0, 0xff);
  
  	udelay(100);
  
  	while (in_be16(fb_regs + 0x6002) & 0x4) udelay(1);
  	out_be16(fb_regs + 0x60b2, 0);
  	out_be16(fb_regs + 0x60b4, 0);
  	out_be16(fb_regs + 0x60b6, 0);
  	out_be16(fb_regs + 0x60b8, 0);
  
  	return 0;
  }
  
  /* 0 unblank, 1 blank, 2 no vsync, 3 no hsync, 4 off */
  
  static int hpfb_blank(int blank, struct fb_info *info)
  {
  	out_8(fb_regs + TC_NBLANK, (blank ? 0x00 : fb_bitmask));
  
  	return 0;
  }
  
  static void topcat_blit(int x0, int y0, int x1, int y1, int w, int h, int rr)
  {
  	if (rr >= 0) {
  		while (in_8(fb_regs + BUSY) & fb_bitmask)
  			;
  	}
  	out_8(fb_regs + TC_FBEN, fb_bitmask);
  	if (rr >= 0) {
  		out_8(fb_regs + TC_WEN, fb_bitmask);
  		out_8(fb_regs + WMRR, rr);
  	}
  	out_be16(fb_regs + SOURCE_X, x0);
  	out_be16(fb_regs + SOURCE_Y, y0);
  	out_be16(fb_regs + DEST_X, x1);
  	out_be16(fb_regs + DEST_Y, y1);
  	out_be16(fb_regs + WWIDTH, w);
  	out_be16(fb_regs + WHEIGHT, h);
  	out_8(fb_regs + WMOVE, fb_bitmask);
  }
  
  static void hpfb_copyarea(struct fb_info *info, const struct fb_copyarea *area) 
  {
  	topcat_blit(area->sx, area->sy, area->dx, area->dy, area->width, area->height, RR_COPY);
  }
  
  static void hpfb_fillrect(struct fb_info *p, const struct fb_fillrect *region)
  {
  	u8 clr;
  
  	clr = region->color & 0xff;
  
  	while (in_8(fb_regs + BUSY) & fb_bitmask)
  		;
  
  	/* Foreground */
  	out_8(fb_regs + TC_WEN, fb_bitmask & clr);
  	out_8(fb_regs + WMRR, (region->rop == ROP_COPY ? RR_SET : RR_INVERT));
  
  	/* Background */
  	out_8(fb_regs + TC_WEN, fb_bitmask & ~clr);
  	out_8(fb_regs + WMRR, (region->rop == ROP_COPY ? RR_CLEAR : RR_NOOP));
  
  	topcat_blit(region->dx, region->dy, region->dx, region->dy, region->width, region->height, -1);
  }
  
  static int hpfb_sync(struct fb_info *info)
  {
  	/*
  	 * Since we also access the framebuffer directly, we have to wait
  	 * until the block mover is finished
  	 */
  	while (in_8(fb_regs + BUSY) & fb_bitmask)
  		;
  
  	out_8(fb_regs + TC_WEN, fb_bitmask);
  	out_8(fb_regs + TC_PRR, RR_COPY);
  	out_8(fb_regs + TC_FBEN, fb_bitmask);
  
  	return 0;
  }
  
  static struct fb_ops hpfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_setcolreg	= hpfb_setcolreg,
  	.fb_blank	= hpfb_blank,
  	.fb_fillrect	= hpfb_fillrect,
  	.fb_copyarea	= hpfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  	.fb_sync	= hpfb_sync,
  };
  
  /* Common to all HP framebuffers */
  #define HPFB_FBWMSB	0x05	/* Frame buffer width 		*/
  #define HPFB_FBWLSB	0x07
  #define HPFB_FBHMSB	0x09	/* Frame buffer height		*/
  #define HPFB_FBHLSB	0x0b
  #define HPFB_DWMSB	0x0d	/* Display width		*/
  #define HPFB_DWLSB	0x0f
  #define HPFB_DHMSB	0x11	/* Display height		*/
  #define HPFB_DHLSB	0x13
  #define HPFB_NUMPLANES	0x5b	/* Number of colour planes	*/
  #define HPFB_FBOMSB	0x5d	/* Frame buffer offset		*/
  #define HPFB_FBOLSB	0x5f
  
  static int hpfb_init_one(unsigned long phys_base, unsigned long virt_base)
  {
  	unsigned long fboff, fb_width, fb_height, fb_start;
  	int ret;
  
  	fb_regs = virt_base;
  	fboff = (in_8(fb_regs + HPFB_FBOMSB) << 8) | in_8(fb_regs + HPFB_FBOLSB);
  
  	fb_info.fix.smem_start = (in_8(fb_regs + fboff) << 16);
  
  	if (phys_base >= DIOII_BASE) {
  		fb_info.fix.smem_start += phys_base;
  	}
  
  	if (DIO_SECID(fb_regs) != DIO_ID2_TOPCAT) {
  		/* This is the magic incantation the HP X server uses to make Catseye boards work. */
  		while (in_be16(fb_regs+0x4800) & 1)
  			;
  		out_be16(fb_regs+0x4800, 0);	/* Catseye status */
  		out_be16(fb_regs+0x4510, 0);	/* VB */
  		out_be16(fb_regs+0x4512, 0);	/* TCNTRL */
  		out_be16(fb_regs+0x4514, 0);	/* ACNTRL */
  		out_be16(fb_regs+0x4516, 0);	/* PNCNTRL */
  		out_be16(fb_regs+0x4206, 0x90);	/* RUG Command/Status */
  		out_be16(fb_regs+0x60a2, 0);	/* Overlay Mask */
  		out_be16(fb_regs+0x60bc, 0);	/* Ram Select */
  	}
  
  	/*
  	 *	Fill in the available video resolution
  	 */
  	fb_width = (in_8(fb_regs + HPFB_FBWMSB) << 8) | in_8(fb_regs + HPFB_FBWLSB);
  	fb_info.fix.line_length = fb_width;
  	fb_height = (in_8(fb_regs + HPFB_FBHMSB) << 8) | in_8(fb_regs + HPFB_FBHLSB);
  	fb_info.fix.smem_len = fb_width * fb_height;
  	fb_start = (unsigned long)ioremap_writethrough(fb_info.fix.smem_start,
  						       fb_info.fix.smem_len);
  	hpfb_defined.xres = (in_8(fb_regs + HPFB_DWMSB) << 8) | in_8(fb_regs + HPFB_DWLSB);
  	hpfb_defined.yres = (in_8(fb_regs + HPFB_DHMSB) << 8) | in_8(fb_regs + HPFB_DHLSB);
  	hpfb_defined.xres_virtual = hpfb_defined.xres;
  	hpfb_defined.yres_virtual = hpfb_defined.yres;
  	hpfb_defined.bits_per_pixel = in_8(fb_regs + HPFB_NUMPLANES);
  
  	printk(KERN_INFO "hpfb: framebuffer at 0x%lx, mapped to 0x%lx, size %dk
  ",
  	       fb_info.fix.smem_start, fb_start, fb_info.fix.smem_len/1024);
  	printk(KERN_INFO "hpfb: mode is %dx%dx%d, linelength=%d
  ",
  	       hpfb_defined.xres, hpfb_defined.yres, hpfb_defined.bits_per_pixel, fb_info.fix.line_length);
  
  	/*
  	 *	Give the hardware a bit of a prod and work out how many bits per
  	 *	pixel are supported.
  	 */
  	out_8(fb_regs + TC_WEN, 0xff);
  	out_8(fb_regs + TC_PRR, RR_COPY);
  	out_8(fb_regs + TC_FBEN, 0xff);
  	out_8(fb_start, 0xff);
  	fb_bitmask = in_8(fb_start);
  	out_8(fb_start, 0);
  
  	/*
  	 *	Enable reading/writing of all the planes.
  	 */
  	out_8(fb_regs + TC_WEN, fb_bitmask);
  	out_8(fb_regs + TC_PRR, RR_COPY);
  	out_8(fb_regs + TC_REN, fb_bitmask);
  	out_8(fb_regs + TC_FBEN, fb_bitmask);
  
  	/*
  	 *	Clear the screen.
  	 */
  	topcat_blit(0, 0, 0, 0, fb_width, fb_height, RR_CLEAR);
  
  	/*
  	 *	Let there be consoles..
  	 */
  	if (DIO_SECID(fb_regs) == DIO_ID2_TOPCAT)
  		strcat(fb_info.fix.id, "Topcat");
  	else
  		strcat(fb_info.fix.id, "Catseye");
  	fb_info.fbops = &hpfb_ops;
  	fb_info.flags = FBINFO_DEFAULT;
  	fb_info.var   = hpfb_defined;
  	fb_info.screen_base = (char *)fb_start;
  
  	ret = fb_alloc_cmap(&fb_info.cmap, 1 << hpfb_defined.bits_per_pixel, 0);
  	if (ret < 0)
  		goto unmap_screen_base;
  
  	ret = register_framebuffer(&fb_info);
  	if (ret < 0)
  		goto dealloc_cmap;
  
  	fb_info(&fb_info, "%s frame buffer device
  ", fb_info.fix.id);
  
  	return 0;
  
  dealloc_cmap:
  	fb_dealloc_cmap(&fb_info.cmap);
  
  unmap_screen_base:
  	if (fb_info.screen_base) {
  		iounmap(fb_info.screen_base);
  		fb_info.screen_base = NULL;
  	}
  
  	return ret;
  }
  
  /* 
   * Check that the secondary ID indicates that we have some hope of working with this
   * framebuffer.  The catseye boards are pretty much like topcats and we can muddle through.
   */
  
  #define topcat_sid_ok(x)  (((x) == DIO_ID2_LRCATSEYE) || ((x) == DIO_ID2_HRCCATSEYE)    \
  			   || ((x) == DIO_ID2_HRMCATSEYE) || ((x) == DIO_ID2_TOPCAT))
  
  /* 
   * Initialise the framebuffer
   */
  static int hpfb_dio_probe(struct dio_dev *d, const struct dio_device_id *ent)
  {
  	unsigned long paddr, vaddr;
  
  	paddr = d->resource.start;
  	if (!request_mem_region(d->resource.start, resource_size(&d->resource), d->name))
                  return -EBUSY;
  
  	if (d->scode >= DIOII_SCBASE) {
  		vaddr = (unsigned long)ioremap(paddr, resource_size(&d->resource));
  	} else {
  		vaddr = paddr + DIO_VIRADDRBASE;
  	}
  	printk(KERN_INFO "Topcat found at DIO select code %d "
  	       "(secondary id %02x)
  ", d->scode, (d->id >> 8) & 0xff);
  	if (hpfb_init_one(paddr, vaddr)) {
  		if (d->scode >= DIOII_SCBASE)
  			iounmap((void *)vaddr);
  		return -ENOMEM;
  	}
  	return 0;
  }
  
  static void hpfb_remove_one(struct dio_dev *d)
  {
  	unregister_framebuffer(&fb_info);
  	if (d->scode >= DIOII_SCBASE)
  		iounmap((void *)fb_regs);
  	release_mem_region(d->resource.start, resource_size(&d->resource));
  	fb_dealloc_cmap(&fb_info.cmap);
  	if (fb_info.screen_base)
  		iounmap(fb_info.screen_base);
  }
  
  static struct dio_device_id hpfb_dio_tbl[] = {
      { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_LRCATSEYE) },
      { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_HRCCATSEYE) },
      { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_HRMCATSEYE) },
      { DIO_ENCODE_ID(DIO_ID_FBUFFER, DIO_ID2_TOPCAT) },
      { 0 }
  };
  
  static struct dio_driver hpfb_driver = {
      .name      = "hpfb",
      .id_table  = hpfb_dio_tbl,
      .probe     = hpfb_dio_probe,
      .remove    = hpfb_remove_one,
  };
  
  int __init hpfb_init(void)
  {
  	unsigned int sid;
  	mm_segment_t fs;
  	unsigned char i;
  	int err;
  
  	/* Topcats can be on the internal IO bus or real DIO devices.
  	 * The internal variant sits at 0x560000; it has primary
  	 * and secondary ID registers just like the DIO version.
  	 * So we merge the two detection routines.
  	 *
  	 * Perhaps this #define should be in a global header file:
  	 * I believe it's common to all internal fbs, not just topcat.
  	 */
  #define INTFBVADDR 0xf0560000
  #define INTFBPADDR 0x560000
  
  	if (!MACH_IS_HP300)
  		return -ENODEV;
  
  	if (fb_get_options("hpfb", NULL))
  		return -ENODEV;
  
  	err = dio_register_driver(&hpfb_driver);
  	if (err)
  		return err;
  
  	fs = get_fs();
  	set_fs(KERNEL_DS);
  	err = get_user(i, (unsigned char *)INTFBVADDR + DIO_IDOFF);
  	set_fs(fs);
  
  	if (!err && (i == DIO_ID_FBUFFER) && topcat_sid_ok(sid = DIO_SECID(INTFBVADDR))) {
  		if (!request_mem_region(INTFBPADDR, DIO_DEVSIZE, "Internal Topcat"))
  			return -EBUSY;
  		printk(KERN_INFO "Internal Topcat found (secondary id %02x)
  ", sid);
  		if (hpfb_init_one(INTFBPADDR, INTFBVADDR)) {
  			return -ENOMEM;
  		}
  	}
  	return 0;
  }
  
  void __exit hpfb_cleanup_module(void)
  {
  	dio_unregister_driver(&hpfb_driver);
  }
  
  module_init(hpfb_init);
  module_exit(hpfb_cleanup_module);
  
  MODULE_LICENSE("GPL");