/*
   *  controlfb.c -- frame buffer device for the PowerMac 'control' display
   *
   *  Created 12 July 1998 by Dan Jacobowitz <dan@debian.org>
   *  Copyright (C) 1998 Dan Jacobowitz
   *  Copyright (C) 2001 Takashi Oe
   *
   *  Mmap code by Michel Lanners <mlan@cpu.lu>
   *
   *  Frame buffer structure from:
   *    drivers/video/chipsfb.c -- frame buffer device for
   *    Chips & Technologies 65550 chip.
   *
   *    Copyright (C) 1998 Paul Mackerras
   *
   *    This file is derived from the Powermac "chips" driver:
   *    Copyright (C) 1997 Fabio Riccardi.
   *    And from the frame buffer device for Open Firmware-initialized devices:
   *    Copyright (C) 1997 Geert Uytterhoeven.
   *
   *  Hardware information from:
   *    control.c: Console support for PowerMac "control" display adaptor.
   *    Copyright (C) 1996 Paul Mackerras
   *
   *  Updated to 2.5 framebuffer API by Ben Herrenschmidt
   *  <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>,
   *  and James Simmons <jsimmons@infradead.org>.
   *
   *  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/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/delay.h>
  #include <linux/interrupt.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/pci.h>
  #include <linux/nvram.h>
  #include <linux/adb.h>
  #include <linux/cuda.h>
  #include <asm/io.h>
  #include <asm/prom.h>
  #include <asm/pgtable.h>
  #include <asm/btext.h>
  
  #include "macmodes.h"
  #include "controlfb.h"
  
  struct fb_par_control {
  	int	vmode, cmode;
  	int	xres, yres;
  	int	vxres, vyres;
  	int	xoffset, yoffset;
  	int	pitch;
  	struct control_regvals	regvals;
  	unsigned long sync;
  	unsigned char ctrl;
  };
  
  #define DIRTY(z) ((x)->z != (y)->z)
  #define DIRTY_CMAP(z) (memcmp(&((x)->z), &((y)->z), sizeof((y)->z)))
  static inline int PAR_EQUAL(struct fb_par_control *x, struct fb_par_control *y)
  {
  	int i, results;
  
  	results = 1;
  	for (i = 0; i < 3; i++)
  		results &= !DIRTY(regvals.clock_params[i]);
  	if (!results)
  		return 0;
  	for (i = 0; i < 16; i++)
  		results &= !DIRTY(regvals.regs[i]);
  	if (!results)
  		return 0;
  	return (!DIRTY(cmode) && !DIRTY(xres) && !DIRTY(yres)
  		&& !DIRTY(vxres) && !DIRTY(vyres));
  }
  static inline int VAR_MATCH(struct fb_var_screeninfo *x, struct fb_var_screeninfo *y)
  {
  	return (!DIRTY(bits_per_pixel) && !DIRTY(xres)
  		&& !DIRTY(yres) && !DIRTY(xres_virtual)
  		&& !DIRTY(yres_virtual)
  		&& !DIRTY_CMAP(red) && !DIRTY_CMAP(green) && !DIRTY_CMAP(blue));
  }
  
  struct fb_info_control {
  	struct fb_info		info;
  	struct fb_par_control	par;
  	u32			pseudo_palette[16];
  		
  	struct cmap_regs	__iomem *cmap_regs;
  	unsigned long		cmap_regs_phys;
  	
  	struct control_regs	__iomem *control_regs;
  	unsigned long		control_regs_phys;
  	unsigned long		control_regs_size;
  	
  	__u8			__iomem *frame_buffer;
  	unsigned long		frame_buffer_phys;
  	unsigned long		fb_orig_base;
  	unsigned long		fb_orig_size;
  
  	int			control_use_bank2;
  	unsigned long		total_vram;
  	unsigned char		vram_attr;
  };
  
  /* control register access macro */
  #define CNTRL_REG(INFO,REG) (&(((INFO)->control_regs->REG).r))
  
  
  /******************** Prototypes for exported functions ********************/
  /*
   * struct fb_ops
   */
  static int controlfb_pan_display(struct fb_var_screeninfo *var,
  	struct fb_info *info);
  static int controlfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
  	u_int transp, struct fb_info *info);
  static int controlfb_blank(int blank_mode, struct fb_info *info);
  static int controlfb_mmap(struct fb_info *info,
  	struct vm_area_struct *vma);
  static int controlfb_set_par (struct fb_info *info);
  static int controlfb_check_var (struct fb_var_screeninfo *var, struct fb_info *info);
  
  /******************** Prototypes for internal functions **********************/
  
  static void set_control_clock(unsigned char *params);
  static int init_control(struct fb_info_control *p);
  static void control_set_hardware(struct fb_info_control *p,
  	struct fb_par_control *par);
  static int control_of_init(struct device_node *dp);
  static void find_vram_size(struct fb_info_control *p);
  static int read_control_sense(struct fb_info_control *p);
  static int calc_clock_params(unsigned long clk, unsigned char *param);
  static int control_var_to_par(struct fb_var_screeninfo *var,
  	struct fb_par_control *par, const struct fb_info *fb_info);
  static inline void control_par_to_var(struct fb_par_control *par,
  	struct fb_var_screeninfo *var);
  static void control_init_info(struct fb_info *info, struct fb_info_control *p);
  static void control_cleanup(void);
  
  
  /************************** Internal variables *******************************/
  
  static struct fb_info_control *control_fb;
  
  static int default_vmode __initdata = VMODE_NVRAM;
  static int default_cmode __initdata = CMODE_NVRAM;
  
  
  static struct fb_ops controlfb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_check_var	= controlfb_check_var,
  	.fb_set_par	= controlfb_set_par,
  	.fb_setcolreg	= controlfb_setcolreg,
  	.fb_pan_display = controlfb_pan_display,
  	.fb_blank	= controlfb_blank,
  	.fb_mmap	= controlfb_mmap,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };
  
  
  /********************  The functions for controlfb_ops ********************/
  
  #ifdef MODULE
  MODULE_LICENSE("GPL");
  
  int init_module(void)
  {
  	struct device_node *dp;
  	int ret = -ENXIO;
  
  	dp = of_find_node_by_name(NULL, "control");
  	if (dp != 0 && !control_of_init(dp))
  		ret = 0;
  	of_node_put(dp);
  
  	return ret;
  }
  
  void cleanup_module(void)
  {
  	control_cleanup();
  }
  #endif
  
  /*
   * Checks a var structure
   */
  static int controlfb_check_var (struct fb_var_screeninfo *var, struct fb_info *info)
  {
  	struct fb_par_control par;
  	int err;
  
  	err = control_var_to_par(var, &par, info);
  	if (err)
  		return err;	
  	control_par_to_var(&par, var);
  
  	return 0;
  }
  
  /*
   * Applies current var to display
   */
  static int controlfb_set_par (struct fb_info *info)
  {
  	struct fb_info_control *p = (struct fb_info_control *) info;
  	struct fb_par_control par;
  	int err;
  
  	if((err = control_var_to_par(&info->var, &par, info))) {
  		printk (KERN_ERR "controlfb_set_par: error calling"
  				 " control_var_to_par: %d.
  ", err);
  		return err;
  	}
  	
  	control_set_hardware(p, &par);
  
  	info->fix.visual = (p->par.cmode == CMODE_8) ?
  		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_DIRECTCOLOR;
  	info->fix.line_length = p->par.pitch;
  	info->fix.xpanstep = 32 >> p->par.cmode;
  	info->fix.ypanstep = 1;
  
  	return 0;
  }
  
  /*
   * Set screen start address according to var offset values
   */
  static inline void set_screen_start(int xoffset, int yoffset,
  	struct fb_info_control *p)
  {
  	struct fb_par_control *par = &p->par;
  
  	par->xoffset = xoffset;
  	par->yoffset = yoffset;
  	out_le32(CNTRL_REG(p,start_addr),
  		 par->yoffset * par->pitch + (par->xoffset << par->cmode));
  }
  
  
  static int controlfb_pan_display(struct fb_var_screeninfo *var,
  				 struct fb_info *info)
  {
  	unsigned int xoffset, hstep;
  	struct fb_info_control *p = (struct fb_info_control *)info;
  	struct fb_par_control *par = &p->par;
  
  	/*
  	 * make sure start addr will be 32-byte aligned
  	 */
  	hstep = 0x1f >> par->cmode;
  	xoffset = (var->xoffset + hstep) & ~hstep;
  
  	if (xoffset+par->xres > par->vxres ||
  	    var->yoffset+par->yres > par->vyres)
  		return -EINVAL;
  
  	set_screen_start(xoffset, var->yoffset, p);
  
  	return 0;
  }
  
  
  /*
   * Private mmap since we want to have a different caching on the framebuffer
   * for controlfb.
   * Note there's no locking in here; it's done in fb_mmap() in fbmem.c.
   */
  static int controlfb_mmap(struct fb_info *info,
                         struct vm_area_struct *vma)
  {
  	unsigned long mmio_pgoff;
  	unsigned long start;
  	u32 len;
  
  	start = info->fix.smem_start;
  	len = info->fix.smem_len;
  	mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
  	if (vma->vm_pgoff >= mmio_pgoff) {
  		if (info->var.accel_flags)
  			return -EINVAL;
  		vma->vm_pgoff -= mmio_pgoff;
  		start = info->fix.mmio_start;
  		len = info->fix.mmio_len;
  		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  	} else {
  		/* framebuffer */
  		vma->vm_page_prot = pgprot_cached_wthru(vma->vm_page_prot);
  	}
  
  	return vm_iomap_memory(vma, start, len);
  }
  
  static int controlfb_blank(int blank_mode, struct fb_info *info)
  {
  	struct fb_info_control *p = (struct fb_info_control *) info;
  	unsigned ctrl;
  
  	ctrl = ld_le32(CNTRL_REG(p,ctrl));
  	if (blank_mode > 0)
  		switch (blank_mode) {
  		case FB_BLANK_VSYNC_SUSPEND:
  			ctrl &= ~3;
  			break;
  		case FB_BLANK_HSYNC_SUSPEND:
  			ctrl &= ~0x30;
  			break;
  		case FB_BLANK_POWERDOWN:
  			ctrl &= ~0x33;
  			/* fall through */
  		case FB_BLANK_NORMAL:
  			ctrl |= 0x400;
  			break;
  		default:
  			break;
  		}
  	else {
  		ctrl &= ~0x400;
  		ctrl |= 0x33;
  	}
  	out_le32(CNTRL_REG(p,ctrl), ctrl);
  
  	return 0;
  }
  
  static int controlfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
  			     u_int transp, struct fb_info *info)
  {
  	struct fb_info_control *p = (struct fb_info_control *) info;
  	__u8 r, g, b;
  
  	if (regno > 255)
  		return 1;
  
  	r = red >> 8;
  	g = green >> 8;
  	b = blue >> 8;
  
  	out_8(&p->cmap_regs->addr, regno);	/* tell clut what addr to fill	*/
  	out_8(&p->cmap_regs->lut, r);		/* send one color channel at	*/
  	out_8(&p->cmap_regs->lut, g);		/* a time...			*/
  	out_8(&p->cmap_regs->lut, b);
  
  	if (regno < 16) {
  		int i;
  		switch (p->par.cmode) {
  		case CMODE_16:
  			p->pseudo_palette[regno] =
  			    (regno << 10) | (regno << 5) | regno;
  			break;
  		case CMODE_32:
  			i = (regno << 8) | regno;
  			p->pseudo_palette[regno] = (i << 16) | i;
  			break;
  		}
  	}
  
  	return 0;
  }
  
  
  /********************  End of controlfb_ops implementation  ******************/
  
  
  
  static void set_control_clock(unsigned char *params)
  {
  #ifdef CONFIG_ADB_CUDA
  	struct adb_request req;
  	int i;
  
  	for (i = 0; i < 3; ++i) {
  		cuda_request(&req, NULL, 5, CUDA_PACKET, CUDA_GET_SET_IIC,
  			     0x50, i + 1, params[i]);
  		while (!req.complete)
  			cuda_poll();
  	}
  #endif	
  }
  
  
  /*
   * finish off the driver initialization and register
   */
  static int __init init_control(struct fb_info_control *p)
  {
  	int full, sense, vmode, cmode, vyres;
  	struct fb_var_screeninfo var;
  	int rc;
  	
  	printk(KERN_INFO "controlfb: ");
  
  	full = p->total_vram == 0x400000;
  
  	/* Try to pick a video mode out of NVRAM if we have one. */
  #ifdef CONFIG_NVRAM
  	if (default_cmode == CMODE_NVRAM) {
  		cmode = nvram_read_byte(NV_CMODE);
  		if(cmode < CMODE_8 || cmode > CMODE_32)
  			cmode = CMODE_8;
  	} else
  #endif
  		cmode=default_cmode;
  #ifdef CONFIG_NVRAM
  	if (default_vmode == VMODE_NVRAM) {
  		vmode = nvram_read_byte(NV_VMODE);
  		if (vmode < 1 || vmode > VMODE_MAX ||
  		    control_mac_modes[vmode - 1].m[full] < cmode) {
  			sense = read_control_sense(p);
  			printk("Monitor sense value = 0x%x, ", sense);
  			vmode = mac_map_monitor_sense(sense);
  			if (control_mac_modes[vmode - 1].m[full] < cmode)
  				vmode = VMODE_640_480_60;
  		}
  	} else
  #endif
  	{
  		vmode=default_vmode;
  		if (control_mac_modes[vmode - 1].m[full] < cmode) {
  			if (cmode > CMODE_8)
  				cmode--;
  			else
  				vmode = VMODE_640_480_60;
  		}
  	}
  
  	/* Initialize info structure */
  	control_init_info(&p->info, p);
  
  	/* Setup default var */
  	if (mac_vmode_to_var(vmode, cmode, &var) < 0) {
  		/* This shouldn't happen! */
  		printk("mac_vmode_to_var(%d, %d,) failed
  ", vmode, cmode);
  try_again:
  		vmode = VMODE_640_480_60;
  		cmode = CMODE_8;
  		if (mac_vmode_to_var(vmode, cmode, &var) < 0) {
  			printk(KERN_ERR "controlfb: mac_vmode_to_var() failed
  ");
  			return -ENXIO;
  		}
  		printk(KERN_INFO "controlfb: ");
  	}
  	printk("using video mode %d and color mode %d.
  ", vmode, cmode);
  
  	vyres = (p->total_vram - CTRLFB_OFF) / (var.xres << cmode);
  	if (vyres > var.yres)
  		var.yres_virtual = vyres;
  
  	/* Apply default var */
  	var.activate = FB_ACTIVATE_NOW;
  	rc = fb_set_var(&p->info, &var);
  	if (rc && (vmode != VMODE_640_480_60 || cmode != CMODE_8))
  		goto try_again;
  
  	/* Register with fbdev layer */
  	if (register_framebuffer(&p->info) < 0)
  		return -ENXIO;
  
  	fb_info(&p->info, "control display adapter
  ");
  
  	return 0;
  }
  
  #define RADACAL_WRITE(a,d) \
  	out_8(&p->cmap_regs->addr, (a)); \
  	out_8(&p->cmap_regs->dat,   (d))
  
  /* Now how about actually saying, Make it so! */
  /* Some things in here probably don't need to be done each time. */
  static void control_set_hardware(struct fb_info_control *p, struct fb_par_control *par)
  {
  	struct control_regvals	*r;
  	volatile struct preg	__iomem *rp;
  	int			i, cmode;
  
  	if (PAR_EQUAL(&p->par, par)) {
  		/*
  		 * check if only xoffset or yoffset differs.
  		 * this prevents flickers in typical VT switch case.
  		 */
  		if (p->par.xoffset != par->xoffset ||
  		    p->par.yoffset != par->yoffset)
  			set_screen_start(par->xoffset, par->yoffset, p);
  			
  		return;
  	}
  	
  	p->par = *par;
  	cmode = p->par.cmode;
  	r = &par->regvals;
  	
  	/* Turn off display */
  	out_le32(CNTRL_REG(p,ctrl), 0x400 | par->ctrl);
  	
  	set_control_clock(r->clock_params);
  	
  	RADACAL_WRITE(0x20, r->radacal_ctrl);
  	RADACAL_WRITE(0x21, p->control_use_bank2 ? 0 : 1);
  	RADACAL_WRITE(0x10, 0);
  	RADACAL_WRITE(0x11, 0);
  
  	rp = &p->control_regs->vswin;
  	for (i = 0; i < 16; ++i, ++rp)
  		out_le32(&rp->r, r->regs[i]);
  	
  	out_le32(CNTRL_REG(p,pitch), par->pitch);
  	out_le32(CNTRL_REG(p,mode), r->mode);
  	out_le32(CNTRL_REG(p,vram_attr), p->vram_attr);
  	out_le32(CNTRL_REG(p,start_addr), par->yoffset * par->pitch
  		 + (par->xoffset << cmode));
  	out_le32(CNTRL_REG(p,rfrcnt), 0x1e5);
  	out_le32(CNTRL_REG(p,intr_ena), 0);
  
  	/* Turn on display */
  	out_le32(CNTRL_REG(p,ctrl), par->ctrl);
  
  #ifdef CONFIG_BOOTX_TEXT
  	btext_update_display(p->frame_buffer_phys + CTRLFB_OFF,
  			     p->par.xres, p->par.yres,
  			     (cmode == CMODE_32? 32: cmode == CMODE_16? 16: 8),
  			     p->par.pitch);
  #endif /* CONFIG_BOOTX_TEXT */
  }
  
  
  /*
   * Parse user specified options (`video=controlfb:')
   */
  static void __init control_setup(char *options)
  {
  	char *this_opt;
  
  	if (!options || !*options)
  		return;
  
  	while ((this_opt = strsep(&options, ",")) != NULL) {
  		if (!strncmp(this_opt, "vmode:", 6)) {
  			int vmode = simple_strtoul(this_opt+6, NULL, 0);
  			if (vmode > 0 && vmode <= VMODE_MAX &&
  			    control_mac_modes[vmode - 1].m[1] >= 0)
  				default_vmode = vmode;
  		} else if (!strncmp(this_opt, "cmode:", 6)) {
  			int depth = simple_strtoul(this_opt+6, NULL, 0);
  			switch (depth) {
  			 case CMODE_8:
  			 case CMODE_16:
  			 case CMODE_32:
  			 	default_cmode = depth;
  			 	break;
  			 case 8:
  				default_cmode = CMODE_8;
  				break;
  			 case 15:
  			 case 16:
  				default_cmode = CMODE_16;
  				break;
  			 case 24:
  			 case 32:
  				default_cmode = CMODE_32;
  				break;
  			}
  		}
  	}
  }
  
  static int __init control_init(void)
  {
  	struct device_node *dp;
  	char *option = NULL;
  	int ret = -ENXIO;
  
  	if (fb_get_options("controlfb", &option))
  		return -ENODEV;
  	control_setup(option);
  
  	dp = of_find_node_by_name(NULL, "control");
  	if (dp != 0 && !control_of_init(dp))
  		ret = 0;
  	of_node_put(dp);
  
  	return ret;
  }
  
  module_init(control_init);
  
  /* Work out which banks of VRAM we have installed. */
  /* danj: I guess the card just ignores writes to nonexistant VRAM... */
  
  static void __init find_vram_size(struct fb_info_control *p)
  {
  	int bank1, bank2;
  
  	/*
  	 * Set VRAM in 2MB (bank 1) mode
  	 * VRAM Bank 2 will be accessible through offset 0x600000 if present
  	 * and VRAM Bank 1 will not respond at that offset even if present
  	 */
  	out_le32(CNTRL_REG(p,vram_attr), 0x31);
  
  	out_8(&p->frame_buffer[0x600000], 0xb3);
  	out_8(&p->frame_buffer[0x600001], 0x71);
  	asm volatile("eieio; dcbf 0,%0" : : "r" (&p->frame_buffer[0x600000])
  					: "memory" );
  	mb();
  	asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0x600000])
  					: "memory" );
  	mb();
  
  	bank2 = (in_8(&p->frame_buffer[0x600000]) == 0xb3)
  		&& (in_8(&p->frame_buffer[0x600001]) == 0x71);
  
  	/*
  	 * Set VRAM in 2MB (bank 2) mode
  	 * VRAM Bank 1 will be accessible through offset 0x000000 if present
  	 * and VRAM Bank 2 will not respond at that offset even if present
  	 */
  	out_le32(CNTRL_REG(p,vram_attr), 0x39);
  
  	out_8(&p->frame_buffer[0], 0x5a);
  	out_8(&p->frame_buffer[1], 0xc7);
  	asm volatile("eieio; dcbf 0,%0" : : "r" (&p->frame_buffer[0])
  					: "memory" );
  	mb();
  	asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0])
  					: "memory" );
  	mb();
  
  	bank1 = (in_8(&p->frame_buffer[0]) == 0x5a)
  		&& (in_8(&p->frame_buffer[1]) == 0xc7);
  
  	if (bank2) {
  		if (!bank1) {
  			/*
  			 * vram bank 2 only
  			 */
  			p->control_use_bank2 = 1;
  			p->vram_attr = 0x39;
  			p->frame_buffer += 0x600000;
  			p->frame_buffer_phys += 0x600000;
  		} else {
  			/*
  			 * 4 MB vram
  			 */
  			p->vram_attr = 0x51;
  		}
  	} else {
  		/*
  		 * vram bank 1 only
  		 */
  		p->vram_attr = 0x31;
  	}
  
          p->total_vram = (bank1 + bank2) * 0x200000;
  
  	printk(KERN_INFO "controlfb: VRAM Total = %dMB "
  			"(%dMB @ bank 1, %dMB @ bank 2)
  ",
  			(bank1 + bank2) << 1, bank1 << 1, bank2 << 1);
  }
  
  
  /*
   * find "control" and initialize
   */
  static int __init control_of_init(struct device_node *dp)
  {
  	struct fb_info_control	*p;
  	struct resource		fb_res, reg_res;
  
  	if (control_fb) {
  		printk(KERN_ERR "controlfb: only one control is supported
  ");
  		return -ENXIO;
  	}
  
  	if (of_pci_address_to_resource(dp, 2, &fb_res) ||
  	    of_pci_address_to_resource(dp, 1, &reg_res)) {
  		printk(KERN_ERR "can't get 2 addresses for control
  ");
  		return -ENXIO;
  	}
  	p = kzalloc(sizeof(*p), GFP_KERNEL);
  	if (p == 0)
  		return -ENXIO;
  	control_fb = p;	/* save it for cleanups */
  
  	/* Map in frame buffer and registers */
  	p->fb_orig_base = fb_res.start;
  	p->fb_orig_size = resource_size(&fb_res);
  	/* use the big-endian aperture (??) */
  	p->frame_buffer_phys = fb_res.start + 0x800000;
  	p->control_regs_phys = reg_res.start;
  	p->control_regs_size = resource_size(&reg_res);
  
  	if (!p->fb_orig_base ||
  	    !request_mem_region(p->fb_orig_base,p->fb_orig_size,"controlfb")) {
  		p->fb_orig_base = 0;
  		goto error_out;
  	}
  	/* map at most 8MB for the frame buffer */
  	p->frame_buffer = __ioremap(p->frame_buffer_phys, 0x800000,
  				    _PAGE_WRITETHRU);
  
  	if (!p->control_regs_phys ||
  	    !request_mem_region(p->control_regs_phys, p->control_regs_size,
  	    "controlfb regs")) {
  		p->control_regs_phys = 0;
  		goto error_out;
  	}
  	p->control_regs = ioremap(p->control_regs_phys, p->control_regs_size);
  
  	p->cmap_regs_phys = 0xf301b000;	 /* XXX not in prom? */
  	if (!request_mem_region(p->cmap_regs_phys, 0x1000, "controlfb cmap")) {
  		p->cmap_regs_phys = 0;
  		goto error_out;
  	}
  	p->cmap_regs = ioremap(p->cmap_regs_phys, 0x1000);
  
  	if (!p->cmap_regs || !p->control_regs || !p->frame_buffer)
  		goto error_out;
  
  	find_vram_size(p);
  	if (!p->total_vram)
  		goto error_out;
  
  	if (init_control(p) < 0)
  		goto error_out;
  
  	return 0;
  
  error_out:
  	control_cleanup();
  	return -ENXIO;
  }
  
  /*
   * Get the monitor sense value.
   * Note that this can be called before calibrate_delay,
   * so we can't use udelay.
   */
  static int read_control_sense(struct fb_info_control *p)
  {
  	int sense;
  
  	out_le32(CNTRL_REG(p,mon_sense), 7);	/* drive all lines high */
  	__delay(200);
  	out_le32(CNTRL_REG(p,mon_sense), 077);	/* turn off drivers */
  	__delay(2000);
  	sense = (in_le32(CNTRL_REG(p,mon_sense)) & 0x1c0) << 2;
  
  	/* drive each sense line low in turn and collect the other 2 */
  	out_le32(CNTRL_REG(p,mon_sense), 033);	/* drive A low */
  	__delay(2000);
  	sense |= (in_le32(CNTRL_REG(p,mon_sense)) & 0xc0) >> 2;
  	out_le32(CNTRL_REG(p,mon_sense), 055);	/* drive B low */
  	__delay(2000);
  	sense |= ((in_le32(CNTRL_REG(p,mon_sense)) & 0x100) >> 5)
  		| ((in_le32(CNTRL_REG(p,mon_sense)) & 0x40) >> 4);
  	out_le32(CNTRL_REG(p,mon_sense), 066);	/* drive C low */
  	__delay(2000);
  	sense |= (in_le32(CNTRL_REG(p,mon_sense)) & 0x180) >> 7;
  
  	out_le32(CNTRL_REG(p,mon_sense), 077);	/* turn off drivers */
  	
  	return sense;
  }
  
  /**********************  Various translation functions  **********************/
  
  #define CONTROL_PIXCLOCK_BASE	256016
  #define CONTROL_PIXCLOCK_MIN	5000	/* ~ 200 MHz dot clock */
  
  /*
   * calculate the clock paramaters to be sent to CUDA according to given
   * pixclock in pico second.
   */
  static int calc_clock_params(unsigned long clk, unsigned char *param)
  {
  	unsigned long p0, p1, p2, k, l, m, n, min;
  
  	if (clk > (CONTROL_PIXCLOCK_BASE << 3))
  		return 1;
  
  	p2 = ((clk << 4) < CONTROL_PIXCLOCK_BASE)? 3: 2;
  	l = clk << p2;
  	p0 = 0;
  	p1 = 0;
  	for (k = 1, min = l; k < 32; k++) {
  		unsigned long rem;
  
  		m = CONTROL_PIXCLOCK_BASE * k;
  		n = m / l;
  		rem = m % l;
  		if (n && (n < 128) && rem < min) {
  			p0 = k;
  			p1 = n;
  			min = rem;
  		}
  	}
  	if (!p0 || !p1)
  		return 1;
  
  	param[0] = p0;
  	param[1] = p1;
  	param[2] = p2;
  
  	return 0;
  }
  
  
  /*
   * This routine takes a user-supplied var, and picks the best vmode/cmode
   * from it.
   */
  
  static int control_var_to_par(struct fb_var_screeninfo *var,
  	struct fb_par_control *par, const struct fb_info *fb_info)
  {
  	int cmode, piped_diff, hstep;
  	unsigned hperiod, hssync, hsblank, hesync, heblank, piped, heq, hlfln,
  		 hserr, vperiod, vssync, vesync, veblank, vsblank, vswin, vewin;
  	unsigned long pixclock;
  	struct fb_info_control *p = (struct fb_info_control *) fb_info;
  	struct control_regvals *r = &par->regvals;
  
  	switch (var->bits_per_pixel) {
  	case 8:
  		par->cmode = CMODE_8;
  		if (p->total_vram > 0x200000) {
  			r->mode = 3;
  			r->radacal_ctrl = 0x20;
  			piped_diff = 13;
  		} else {
  			r->mode = 2;
  			r->radacal_ctrl = 0x10;
  			piped_diff = 9;
  		}
  		break;
  	case 15:
  	case 16:
  		par->cmode = CMODE_16;
  		if (p->total_vram > 0x200000) {
  			r->mode = 2;
  			r->radacal_ctrl = 0x24;
  			piped_diff = 5;
  		} else {
  			r->mode = 1;
  			r->radacal_ctrl = 0x14;
  			piped_diff = 3;
  		}
  		break;
  	case 32:
  		par->cmode = CMODE_32;
  		if (p->total_vram > 0x200000) {
  			r->mode = 1;
  			r->radacal_ctrl = 0x28;
  		} else {
  			r->mode = 0;
  			r->radacal_ctrl = 0x18;
  		}
  		piped_diff = 1;
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	/*
  	 * adjust xres and vxres so that the corresponding memory widths are
  	 * 32-byte aligned
  	 */
  	hstep = 31 >> par->cmode;
  	par->xres = (var->xres + hstep) & ~hstep;
  	par->vxres = (var->xres_virtual + hstep) & ~hstep;
  	par->xoffset = (var->xoffset + hstep) & ~hstep;
  	if (par->vxres < par->xres)
  		par->vxres = par->xres;
  	par->pitch = par->vxres << par->cmode;
  
  	par->yres = var->yres;
  	par->vyres = var->yres_virtual;
  	par->yoffset = var->yoffset;
  	if (par->vyres < par->yres)
  		par->vyres = par->yres;
  
  	par->sync = var->sync;
  
  	if (par->pitch * par->vyres + CTRLFB_OFF > p->total_vram)
  		return -EINVAL;
  
  	if (par->xoffset + par->xres > par->vxres)
  		par->xoffset = par->vxres - par->xres;
  	if (par->yoffset + par->yres > par->vyres)
  		par->yoffset = par->vyres - par->yres;
  
  	pixclock = (var->pixclock < CONTROL_PIXCLOCK_MIN)? CONTROL_PIXCLOCK_MIN:
  		   var->pixclock;
  	if (calc_clock_params(pixclock, r->clock_params))
  		return -EINVAL;
  
  	hperiod = ((var->left_margin + par->xres + var->right_margin
  		    + var->hsync_len) >> 1) - 2;
  	hssync = hperiod + 1;
  	hsblank = hssync - (var->right_margin >> 1);
  	hesync = (var->hsync_len >> 1) - 1;
  	heblank = (var->left_margin >> 1) + hesync;
  	piped = heblank - piped_diff;
  	heq = var->hsync_len >> 2;
  	hlfln = (hperiod+2) >> 1;
  	hserr = hssync-hesync;
  	vperiod = (var->vsync_len + var->lower_margin + par->yres
  		   + var->upper_margin) << 1;
  	vssync = vperiod - 2;
  	vesync = (var->vsync_len << 1) - vperiod + vssync;
  	veblank = (var->upper_margin << 1) + vesync;
  	vsblank = vssync - (var->lower_margin << 1);
  	vswin = (vsblank+vssync) >> 1;
  	vewin = (vesync+veblank) >> 1;
  
  	r->regs[0] = vswin;
  	r->regs[1] = vsblank;
  	r->regs[2] = veblank;
  	r->regs[3] = vewin;
  	r->regs[4] = vesync;
  	r->regs[5] = vssync;
  	r->regs[6] = vperiod;
  	r->regs[7] = piped;
  	r->regs[8] = hperiod;
  	r->regs[9] = hsblank;
  	r->regs[10] = heblank;
  	r->regs[11] = hesync;
  	r->regs[12] = hssync;
  	r->regs[13] = heq;
  	r->regs[14] = hlfln;
  	r->regs[15] = hserr;
  
  	if (par->xres >= 1280 && par->cmode >= CMODE_16)
  		par->ctrl = 0x7f;
  	else
  		par->ctrl = 0x3b;
  
  	if (mac_var_to_vmode(var, &par->vmode, &cmode))
  		par->vmode = 0;
  
  	return 0;
  }
  
  
  /*
   * Convert hardware data in par to an fb_var_screeninfo
   */
  
  static void control_par_to_var(struct fb_par_control *par, struct fb_var_screeninfo *var)
  {
  	struct control_regints *rv;
  	
  	rv = (struct control_regints *) par->regvals.regs;
  	
  	memset(var, 0, sizeof(*var));
  	var->xres = par->xres;
  	var->yres = par->yres;
  	var->xres_virtual = par->vxres;
  	var->yres_virtual = par->vyres;
  	var->xoffset = par->xoffset;
  	var->yoffset = par->yoffset;
  	
  	switch(par->cmode) {
  	default:
  	case CMODE_8:
  		var->bits_per_pixel = 8;
  		var->red.length = 8;
  		var->green.length = 8;
  		var->blue.length = 8;
  		break;
  	case CMODE_16:	/* RGB 555 */
  		var->bits_per_pixel = 16;
  		var->red.offset = 10;
  		var->red.length = 5;
  		var->green.offset = 5;
  		var->green.length = 5;
  		var->blue.length = 5;
  		break;
  	case CMODE_32:	/* RGB 888 */
  		var->bits_per_pixel = 32;
  		var->red.offset = 16;
  		var->red.length = 8;
  		var->green.offset = 8;
  		var->green.length = 8;
  		var->blue.length = 8;
  		var->transp.offset = 24;
  		var->transp.length = 8;
  		break;
  	}
  	var->height = -1;
  	var->width = -1;
  	var->vmode = FB_VMODE_NONINTERLACED;
  
  	var->left_margin = (rv->heblank - rv->hesync) << 1;
  	var->right_margin = (rv->hssync - rv->hsblank) << 1;
  	var->hsync_len = (rv->hperiod + 2 - rv->hssync + rv->hesync) << 1;
  
  	var->upper_margin = (rv->veblank - rv->vesync) >> 1;
  	var->lower_margin = (rv->vssync - rv->vsblank) >> 1;
  	var->vsync_len = (rv->vperiod - rv->vssync + rv->vesync) >> 1;
  
  	var->sync = par->sync;
  
  	/*
  	 * 10^12 * clock_params[0] / (3906400 * clock_params[1]
  	 *			      * 2^clock_params[2])
  	 * (10^12 * clock_params[0] / (3906400 * clock_params[1]))
  	 * >> clock_params[2]
  	 */
  	/* (255990.17 * clock_params[0] / clock_params[1]) >> clock_params[2] */
  	var->pixclock = CONTROL_PIXCLOCK_BASE * par->regvals.clock_params[0];
  	var->pixclock /= par->regvals.clock_params[1];
  	var->pixclock >>= par->regvals.clock_params[2];
  }
  
  /*
   * Set misc info vars for this driver
   */
  static void __init control_init_info(struct fb_info *info, struct fb_info_control *p)
  {
  	/* Fill fb_info */
  	info->par = &p->par;
  	info->fbops = &controlfb_ops;
  	info->pseudo_palette = p->pseudo_palette;
          info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
  	info->screen_base = p->frame_buffer + CTRLFB_OFF;
  
  	fb_alloc_cmap(&info->cmap, 256, 0);
  
  	/* Fill fix common fields */
  	strcpy(info->fix.id, "control");
  	info->fix.mmio_start = p->control_regs_phys;
  	info->fix.mmio_len = sizeof(struct control_regs);
  	info->fix.type = FB_TYPE_PACKED_PIXELS;
  	info->fix.smem_start = p->frame_buffer_phys + CTRLFB_OFF;
  	info->fix.smem_len = p->total_vram - CTRLFB_OFF;
          info->fix.ywrapstep = 0;
          info->fix.type_aux = 0;
          info->fix.accel = FB_ACCEL_NONE;
  }
  
  
  static void control_cleanup(void)
  {
  	struct fb_info_control	*p = control_fb;
  
  	if (!p)
  		return;
  
  	if (p->cmap_regs)
  		iounmap(p->cmap_regs);
  	if (p->control_regs)
  		iounmap(p->control_regs);
  	if (p->frame_buffer) {
  		if (p->control_use_bank2)
  			p->frame_buffer -= 0x600000;
  		iounmap(p->frame_buffer);
  	}
  	if (p->cmap_regs_phys)
  		release_mem_region(p->cmap_regs_phys, 0x1000);
  	if (p->control_regs_phys)
  		release_mem_region(p->control_regs_phys, p->control_regs_size);
  	if (p->fb_orig_base)
  		release_mem_region(p->fb_orig_base, p->fb_orig_size);
  	kfree(p);
  }