/*

   *	linux/drivers/video/pmagb-b-fb.c

   *

   *	PMAGB-B TURBOchannel Smart Frame Buffer (SFB) card support,
   *	derived from:

   *	"HP300 Topcat framebuffer support (derived from macfb of all things)
   *	Phil Blundell <philb@gnu.org> 1998", the original code can be

   *	found in the file hpfb.c in the same directory.

   *

   *	DECstation related code Copyright (C) 1999, 2000, 2001 by
   *	Michael Engel <engel@unix-ag.org>,
   *	Karsten Merker <merker@linuxtag.org> and

   *	Harald Koerfgen.

   *	Copyright (c) 2005, 2006  Maciej W. Rozycki

   *

   *	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.

   */

  #include <linux/compiler.h>

  #include <linux/delay.h>

  #include <linux/errno.h>

  #include <linux/fb.h>

  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/module.h>

  #include <linux/tc.h>

  #include <linux/types.h>

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

  #include <video/pmagb-b-fb.h>

  
  struct pmagbbfb_par {

  	volatile void __iomem *mmio;
  	volatile void __iomem *smem;
  	volatile u32 __iomem *sfb;
  	volatile u32 __iomem *dac;
  	unsigned int osc0;
  	unsigned int osc1;
  	int slot;

  };

  static struct fb_var_screeninfo pmagbbfb_defined __devinitdata = {

  	.bits_per_pixel	= 8,
  	.red.length	= 8,
  	.green.length	= 8,
  	.blue.length	= 8,
  	.activate	= FB_ACTIVATE_NOW,

  	.height		= -1,
  	.width		= -1,

  	.accel_flags	= FB_ACCEL_NONE,

  	.sync		= FB_SYNC_ON_GREEN,

  	.vmode		= FB_VMODE_NONINTERLACED,
  };

  static struct fb_fix_screeninfo pmagbbfb_fix __devinitdata = {

  	.id		= "PMAGB-BA",

  	.smem_len	= (2048 * 1024),

  	.type		= FB_TYPE_PACKED_PIXELS,
  	.visual		= FB_VISUAL_PSEUDOCOLOR,

  	.mmio_len	= PMAGB_B_FBMEM,
  };
  
  
  static inline void sfb_write(struct pmagbbfb_par *par, unsigned int reg, u32 v)
  {
  	writel(v, par->sfb + reg / 4);

  }

  static inline u32 sfb_read(struct pmagbbfb_par *par, unsigned int reg)
  {
  	return readl(par->sfb + reg / 4);
  }
  
  static inline void dac_write(struct pmagbbfb_par *par, unsigned int reg, u8 v)

  {

  	writeb(v, par->dac + reg / 4);

  }

  static inline u8 dac_read(struct pmagbbfb_par *par, unsigned int reg)
  {
  	return readb(par->dac + reg / 4);
  }
  
  static inline void gp0_write(struct pmagbbfb_par *par, u32 v)
  {
  	writel(v, par->mmio + PMAGB_B_GP0);
  }

  /*

   * Set the palette.

   */

  static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
  			      unsigned int green, unsigned int blue,
  			      unsigned int transp, struct fb_info *info)

  {

  	struct pmagbbfb_par *par = info->par;

  	if (regno >= info->cmap.len)
  		return 1;

  
  	red   >>= 8;	/* The cmap fields are 16 bits    */

  	green >>= 8;	/* wide, but the hardware colormap */

  	blue  >>= 8;	/* registers are only 8 bits wide */

  	mb();
  	dac_write(par, BT459_ADDR_LO, regno);
  	dac_write(par, BT459_ADDR_HI, 0x00);
  	wmb();
  	dac_write(par, BT459_CMAP, red);
  	wmb();
  	dac_write(par, BT459_CMAP, green);
  	wmb();
  	dac_write(par, BT459_CMAP, blue);

  	return 0;
  }
  
  static struct fb_ops pmagbbfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_setcolreg	= pmagbbfb_setcolreg,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,

  };

  
  /*
   * Turn the hardware cursor off.
   */
  static void __init pmagbbfb_erase_cursor(struct fb_info *info)
  {
  	struct pmagbbfb_par *par = info->par;
  
  	mb();
  	dac_write(par, BT459_ADDR_LO, 0x00);
  	dac_write(par, BT459_ADDR_HI, 0x03);
  	wmb();
  	dac_write(par, BT459_DATA, 0x00);
  }
  
  /*
   * Set up screen parameters.
   */

  static void __devinit pmagbbfb_screen_setup(struct fb_info *info)

  {
  	struct pmagbbfb_par *par = info->par;
  
  	info->var.xres = ((sfb_read(par, SFB_REG_VID_HOR) >>
  			   SFB_VID_HOR_PIX_SHIFT) & SFB_VID_HOR_PIX_MASK) * 4;
  	info->var.xres_virtual = info->var.xres;
  	info->var.yres = (sfb_read(par, SFB_REG_VID_VER) >>
  			  SFB_VID_VER_SL_SHIFT) & SFB_VID_VER_SL_MASK;
  	info->var.yres_virtual = info->var.yres;
  	info->var.left_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
  				  SFB_VID_HOR_BP_SHIFT) &
  				 SFB_VID_HOR_BP_MASK) * 4;
  	info->var.right_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
  				   SFB_VID_HOR_FP_SHIFT) &
  				  SFB_VID_HOR_FP_MASK) * 4;
  	info->var.upper_margin = (sfb_read(par, SFB_REG_VID_VER) >>
  				  SFB_VID_VER_BP_SHIFT) & SFB_VID_VER_BP_MASK;
  	info->var.lower_margin = (sfb_read(par, SFB_REG_VID_VER) >>
  				  SFB_VID_VER_FP_SHIFT) & SFB_VID_VER_FP_MASK;
  	info->var.hsync_len = ((sfb_read(par, SFB_REG_VID_HOR) >>
  				SFB_VID_HOR_SYN_SHIFT) &
  			       SFB_VID_HOR_SYN_MASK) * 4;
  	info->var.vsync_len = (sfb_read(par, SFB_REG_VID_VER) >>
  			       SFB_VID_VER_SYN_SHIFT) & SFB_VID_VER_SYN_MASK;
  
  	info->fix.line_length = info->var.xres;
  };
  
  /*
   * Determine oscillator configuration.
   */

  static void __devinit pmagbbfb_osc_setup(struct fb_info *info)

  {

  	static unsigned int pmagbbfb_freqs[] __devinitdata = {

  		130808, 119843, 104000, 92980, 74370, 72800,

  		69197, 66000, 65000, 50350, 36000, 32000, 25175
  	};
  	struct pmagbbfb_par *par = info->par;

  	struct tc_bus *tbus = to_tc_dev(info->device)->bus;

  	u32 count0 = 8, count1 = 8, counttc = 16 * 256 + 8;

  	u32 freq0, freq1, freqtc = tc_get_speed(tbus) / 250;

  	int i, j;
  
  	gp0_write(par, 0);				/* select Osc0 */
  	for (j = 0; j < 16; j++) {
  		mb();
  		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
  		mb();
  		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
  			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
  				break;
  			udelay(1);
  		}
  		count0 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
  	}
  
  	gp0_write(par, 1);				/* select Osc1 */
  	for (j = 0; j < 16; j++) {
  		mb();
  		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
  
  		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
  			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
  				break;
  			udelay(1);
  		}
  		count1 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
  	}
  
  	freq0 = (freqtc * count0 + counttc / 2) / counttc;
  	par->osc0 = freq0;
  	if (freq0 >= pmagbbfb_freqs[0] - (pmagbbfb_freqs[0] + 32) / 64 &&
  	    freq0 <= pmagbbfb_freqs[0] + (pmagbbfb_freqs[0] + 32) / 64)
  		par->osc0 = pmagbbfb_freqs[0];
  
  	freq1 = (par->osc0 * count1 + count0 / 2) / count0;
  	par->osc1 = freq1;

  	for (i = 0; i < ARRAY_SIZE(pmagbbfb_freqs); i++)

  		if (freq1 >= pmagbbfb_freqs[i] -
  			     (pmagbbfb_freqs[i] + 128) / 256 &&
  		    freq1 <= pmagbbfb_freqs[i] +
  			     (pmagbbfb_freqs[i] + 128) / 256) {
  			par->osc1 = pmagbbfb_freqs[i];
  			break;
  		}
  
  	if (par->osc0 - par->osc1 <= (par->osc0 + par->osc1 + 256) / 512 ||
  	    par->osc1 - par->osc0 <= (par->osc0 + par->osc1 + 256) / 512)
  		par->osc1 = 0;
  
  	gp0_write(par, par->osc1 != 0);			/* reselect OscX */
  
  	info->var.pixclock = par->osc1 ?
  			     (1000000000 + par->osc1 / 2) / par->osc1 :
  			     (1000000000 + par->osc0 / 2) / par->osc0;
  };

  static int __devinit pmagbbfb_probe(struct device *dev)

  {

  	struct tc_dev *tdev = to_tc_dev(dev);
  	resource_size_t start, len;

  	struct fb_info *info;
  	struct pmagbbfb_par *par;

  	char freq0[12], freq1[12];

  	u32 vid_base;

  	int err;

  	info = framebuffer_alloc(sizeof(struct pmagbbfb_par), dev);

  	if (!info) {

  		printk(KERN_ERR "%s: Cannot allocate memory
  ", dev_name(dev));

  		return -ENOMEM;

  	}

  
  	par = info->par;

  	dev_set_drvdata(dev, info);

  	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
  		printk(KERN_ERR "%s: Cannot allocate color map
  ",

  		       dev_name(dev));

  		err = -ENOMEM;

  		goto err_alloc;

  	}

  	info->fbops = &pmagbbfb_ops;

  	info->fix = pmagbbfb_fix;

  	info->var = pmagbbfb_defined;

  	info->flags = FBINFO_DEFAULT;

  	/* Request the I/O MEM resource.  */
  	start = tdev->resource.start;
  	len = tdev->resource.end - start + 1;

  	if (!request_mem_region(start, len, dev_name(dev))) {
  		printk(KERN_ERR "%s: Cannot reserve FB region
  ",
  		       dev_name(dev));

  		err = -EBUSY;

  		goto err_cmap;

  	}

  	/* MMIO mapping setup.  */

  	info->fix.mmio_start = start;

  	par->mmio = ioremap_nocache(info->fix.mmio_start, info->fix.mmio_len);

  	if (!par->mmio) {

  		printk(KERN_ERR "%s: Cannot map MMIO
  ", dev_name(dev));

  		err = -ENOMEM;

  		goto err_resource;

  	}

  	par->sfb = par->mmio + PMAGB_B_SFB;
  	par->dac = par->mmio + PMAGB_B_BT459;
  
  	/* Frame buffer mapping setup.  */

  	info->fix.smem_start = start + PMAGB_B_FBMEM;

  	par->smem = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);

  	if (!par->smem) {

  		printk(KERN_ERR "%s: Cannot map FB
  ", dev_name(dev));

  		err = -ENOMEM;

  		goto err_mmio_map;

  	}

  	vid_base = sfb_read(par, SFB_REG_VID_BASE);
  	info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
  	info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;
  
  	pmagbbfb_erase_cursor(info);
  	pmagbbfb_screen_setup(info);
  	pmagbbfb_osc_setup(info);

  	err = register_framebuffer(info);
  	if (err < 0) {
  		printk(KERN_ERR "%s: Cannot register framebuffer
  ",

  		       dev_name(dev));

  		goto err_smem_map;

  	}

  	get_device(dev);

  	snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
  		 par->osc0 / 1000, par->osc0 % 1000);
  	snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
  		 par->osc1 / 1000, par->osc1 % 1000);

  	pr_info("fb%d: %s frame buffer device at %s
  ",

  		info->node, info->fix.id, dev_name(dev));

  	pr_info("fb%d: Osc0: %s, Osc1: %s, Osc%u selected
  ",
  		info->node, freq0, par->osc1 ? freq1 : "disabled",
  		par->osc1 != 0);

  	return 0;

  
  
  err_smem_map:
  	iounmap(par->smem);
  
  err_mmio_map:
  	iounmap(par->mmio);

  err_resource:
  	release_mem_region(start, len);

  err_cmap:
  	fb_dealloc_cmap(&info->cmap);
  
  err_alloc:

  	framebuffer_release(info);

  	return err;

  }

  static int __exit pmagbbfb_remove(struct device *dev)

  {

  	struct tc_dev *tdev = to_tc_dev(dev);
  	struct fb_info *info = dev_get_drvdata(dev);

  	struct pmagbbfb_par *par = info->par;

  	resource_size_t start, len;

  	put_device(dev);

  	unregister_framebuffer(info);
  	iounmap(par->smem);
  	iounmap(par->mmio);

  	start = tdev->resource.start;
  	len = tdev->resource.end - start + 1;
  	release_mem_region(start, len);

  	fb_dealloc_cmap(&info->cmap);

  	framebuffer_release(info);

  	return 0;

  }

  
  /*

   * Initialize the framebuffer.

   */

  static const struct tc_device_id pmagbbfb_tc_table[] = {
  	{ "DEC     ", "PMAGB-BA" },
  	{ }
  };
  MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);
  
  static struct tc_driver pmagbbfb_driver = {
  	.id_table	= pmagbbfb_tc_table,
  	.driver		= {
  		.name	= "pmagbbfb",
  		.bus	= &tc_bus_type,
  		.probe	= pmagbbfb_probe,
  		.remove	= __exit_p(pmagbbfb_remove),
  	},
  };

  static int __init pmagbbfb_init(void)

  {

  #ifndef MODULE

  	if (fb_get_options("pmagbbfb", NULL))

  		return -ENXIO;

  #endif
  	return tc_register_driver(&pmagbbfb_driver);

  }
  
  static void __exit pmagbbfb_exit(void)
  {

  	tc_unregister_driver(&pmagbbfb_driver);

  }

  module_init(pmagbbfb_init);

  module_exit(pmagbbfb_exit);

  MODULE_LICENSE("GPL");