text: /*
   *  linux/drivers/video/clps711xfb.c
   *
   *  Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   *
   *  Framebuffer driver for the CLPS7111 and EP7212 processors.
   */
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/slab.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/proc_fs.h>
  #include <linux/delay.h>
  
  #include <mach/hardware.h>
  #include <asm/mach-types.h>
  #include <linux/uaccess.h>
  
  #include <asm/hardware/clps7111.h>
  #include <mach/syspld.h>
  
  struct fb_info	*cfb;
  
  #define CMAP_MAX_SIZE	16
  
  /* The /proc entry for the backlight. */
  static struct proc_dir_entry *clps7111fb_backlight_proc_entry = NULL;
  
  static int clps7111fb_proc_backlight_read(char *page, char **start, off_t off,
  		int count, int *eof, void *data);
  static int clps7111fb_proc_backlight_write(struct file *file, 
  		const char *buffer, unsigned long count, void *data);
  
  /*
   * LCD AC Prescale.  This comes from the LCD panel manufacturers specifications.
   * This determines how many clocks + 1 of CL1 before the M signal toggles.
   * The number of lines on the display must not be divisible by this number.
   */
  static unsigned int lcd_ac_prescale = 13;
  
  /*
   *    Set a single color register. Return != 0 for invalid regno.
   */
  static int
  clps7111fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
  		     u_int transp, struct fb_info *info)
  {
  	unsigned int level, mask, shift, pal;
  
  	if (regno >= (1 << info->var.bits_per_pixel))
  		return 1;
  
  	/* gray = 0.30*R + 0.58*G + 0.11*B */
  	level = (red * 77 + green * 151 + blue * 28) >> 20;
  
  	/*
  	 * On an LCD, a high value is dark, while a low value is light. 
  	 * So we invert the level.
  	 *
  	 * This isn't true on all machines, so we only do it on EDB7211.
  	 *  --rmk
  	 */
  	if (machine_is_edb7211()) {
  		level = 15 - level;
  	}
  
  	shift = 4 * (regno & 7);
  	level <<= shift;
  	mask  = 15 << shift;
  	level &= mask;
  
  	regno = regno < 8 ? PALLSW : PALMSW;
  
  	pal = clps_readl(regno);
  	pal = (pal & ~mask) | level;
  	clps_writel(pal, regno);
  
  	return 0;
  }
  
  /*
   * Validate the purposed mode.
   */	
  static int
  clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
  {
  	var->transp.msb_right	= 0;
  	var->transp.offset	= 0;
  	var->transp.length	= 0;
  	var->red.msb_right	= 0;
  	var->red.offset		= 0;
  	var->red.length		= var->bits_per_pixel;
  	var->green		= var->red;
  	var->blue		= var->red;
  
  	if (var->bits_per_pixel > 4) 
  		return -EINVAL;
  
  	return 0;
  }
  
  /*
   * Set the hardware state.
   */ 
  static int 
  clps7111fb_set_par(struct fb_info *info)
  {
  	unsigned int lcdcon, syscon, pixclock;
  
  	switch (info->var.bits_per_pixel) {
  	case 1:
  		info->fix.visual = FB_VISUAL_MONO01;
  		break;
  	case 2:
  		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
  		break;
  	case 4:
  		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
  		break;
  	}
  
  	info->fix.line_length = info->var.xres_virtual * info->var.bits_per_pixel / 8;
  
  	lcdcon = (info->var.xres_virtual * info->var.yres_virtual * info->var.bits_per_pixel) / 128 - 1;
  	lcdcon |= ((info->var.xres_virtual / 16) - 1) << 13;
  	lcdcon |= lcd_ac_prescale << 25;
  
  	/*
  	 * Calculate pixel prescale value from the pixclock.  This is:
  	 *  36.864MHz / pixclock_mhz - 1.
  	 * However, pixclock is in picoseconds, so this ends up being:
  	 *  36864000 * pixclock_ps / 10^12 - 1
  	 * and this will overflow the 32-bit math.  We perform this as
  	 * (9 * 4096000 == 36864000):
  	 *  pixclock_ps * 9 * (4096000 / 10^12) - 1
  	 */
  	pixclock = 9 * info->var.pixclock / 244140 - 1;
  	lcdcon |= pixclock << 19;
  
  	if (info->var.bits_per_pixel == 4)
  		lcdcon |= LCDCON_GSMD;
  	if (info->var.bits_per_pixel >= 2)
  		lcdcon |= LCDCON_GSEN;
  
  	/*
  	 * LCDCON must only be changed while the LCD is disabled
  	 */
  	syscon = clps_readl(SYSCON1);
  	clps_writel(syscon & ~SYSCON1_LCDEN, SYSCON1);
  	clps_writel(lcdcon, LCDCON);
  	clps_writel(syscon | SYSCON1_LCDEN, SYSCON1);
  	return 0;
  }
  
  static int clps7111fb_blank(int blank, struct fb_info *info)
  {
      	if (blank) {
  		if (machine_is_edb7211()) {
  			/* Turn off the LCD backlight. */
  			clps_writeb(clps_readb(PDDR) & ~EDB_PD3_LCDBL, PDDR);
  
  			/* Power off the LCD DC-DC converter. */
  			clps_writeb(clps_readb(PDDR) & ~EDB_PD1_LCD_DC_DC_EN, PDDR);
  
  			/* Delay for a little while (half a second). */
  			udelay(100);
  
  			/* Power off the LCD panel. */
  			clps_writeb(clps_readb(PDDR) & ~EDB_PD2_LCDEN, PDDR);
  
  			/* Power off the LCD controller. */
  			clps_writel(clps_readl(SYSCON1) & ~SYSCON1_LCDEN, 
  					SYSCON1);
  		}
  	} else {
  		if (machine_is_edb7211()) {
  			/* Power up the LCD controller. */
  			clps_writel(clps_readl(SYSCON1) | SYSCON1_LCDEN,
  					SYSCON1);
  
  			/* Power up the LCD panel. */
  			clps_writeb(clps_readb(PDDR) | EDB_PD2_LCDEN, PDDR);
  
  			/* Delay for a little while. */
  			udelay(100);
  
  			/* Power up the LCD DC-DC converter. */
  			clps_writeb(clps_readb(PDDR) | EDB_PD1_LCD_DC_DC_EN,
  					PDDR);
  
  			/* Turn on the LCD backlight. */
  			clps_writeb(clps_readb(PDDR) | EDB_PD3_LCDBL, PDDR);
  		}
  	}
  	return 0;
  }
  
  static struct fb_ops clps7111fb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_check_var	= clps7111fb_check_var,
  	.fb_set_par	= clps7111fb_set_par,
  	.fb_setcolreg	= clps7111fb_setcolreg,
  	.fb_blank	= clps7111fb_blank,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };
  
  static int 
  clps7111fb_proc_backlight_read(char *page, char **start, off_t off,
  		int count, int *eof, void *data)
  {
  	/* We need at least two characters, one for the digit, and one for
  	 * the terminating NULL. */
  	if (count < 2) 
  		return -EINVAL;
  
  	if (machine_is_edb7211()) {
  		return sprintf(page, "%d\n", 
  				(clps_readb(PDDR) & EDB_PD3_LCDBL) ? 1 : 0);
  	}
  
  	return 0;
  }
  
  static int 
  clps7111fb_proc_backlight_write(struct file *file, const char *buffer, 
  		unsigned long count, void *data)
  {
  	unsigned char char_value;
  	int value;
  
  	if (count < 1) {
  		return -EINVAL;
  	}
  
  	if (copy_from_user(&char_value, buffer, 1)) 
  		return -EFAULT;
  
  	value = char_value - '0';
  
  	if (machine_is_edb7211()) {
  		unsigned char port_d;
  
  		port_d = clps_readb(PDDR);
  
  		if (value) {
  			port_d |= EDB_PD3_LCDBL;
  		} else {
  			port_d &= ~EDB_PD3_LCDBL;
  		}
  
  		clps_writeb(port_d, PDDR);
  	}
  
  	return count;
  }
  
  static void __init clps711x_guess_lcd_params(struct fb_info *info)
  {
  	unsigned int lcdcon, syscon, size;
  	unsigned long phys_base = PAGE_OFFSET;
  	void *virt_base = (void *)PAGE_OFFSET;
  
  	info->var.xres_virtual	 = 640;
  	info->var.yres_virtual	 = 240;
  	info->var.bits_per_pixel = 4;
  	info->var.activate	 = FB_ACTIVATE_NOW;
  	info->var.height	 = -1;
  	info->var.width		 = -1;
  	info->var.pixclock	 = 93006; /* 10.752MHz pixel clock */
  
  	/*
  	 * If the LCD controller is already running, decode the values
  	 * in LCDCON to xres/yres/bpp/pixclock/acprescale
  	 */
  	syscon = clps_readl(SYSCON1);
  	if (syscon & SYSCON1_LCDEN) {
  		lcdcon = clps_readl(LCDCON);
  
  		/*
  		 * Decode GSMD and GSEN bits to bits per pixel
  		 */
  		switch (lcdcon & (LCDCON_GSMD | LCDCON_GSEN)) {
  		case LCDCON_GSMD | LCDCON_GSEN:
  			info->var.bits_per_pixel = 4;
  			break;
  
  		case LCDCON_GSEN:
  			info->var.bits_per_pixel = 2;
  			break;
  
  		default:
  			info->var.bits_per_pixel = 1;
  			break;
  		}
  
  		/*
  		 * Decode xres/yres
  		 */
  		info->var.xres_virtual = (((lcdcon >> 13) & 0x3f) + 1) * 16;
  		info->var.yres_virtual = (((lcdcon & 0x1fff) + 1) * 128) /
  					  (info->var.xres_virtual *
  					   info->var.bits_per_pixel);
  
  		/*
  		 * Calculate pixclock
  		 */
  		info->var.pixclock = (((lcdcon >> 19) & 0x3f) + 1) * 244140 / 9;
  
  		/*
  		 * Grab AC prescale
  		 */
  		lcd_ac_prescale = (lcdcon >> 25) & 0x1f;
  	}
  
  	info->var.xres = info->var.xres_virtual;
  	info->var.yres = info->var.yres_virtual;
  	info->var.grayscale = info->var.bits_per_pixel > 1;
  
  	size = info->var.xres * info->var.yres * info->var.bits_per_pixel / 8;
  
  	/*
  	 * Might be worth checking to see if we can use the on-board
  	 * RAM if size here...
  	 * CLPS7110 - no on-board SRAM
  	 * EP7212   - 38400 bytes
  	 */
  	if (size <= 38400) {
  		printk(KERN_INFO "CLPS711xFB: could use on-board SRAM?\n");
  	}
  
  	if ((syscon & SYSCON1_LCDEN) == 0) {
  		/*
  		 * The display isn't running.  Ensure that
  		 * the display memory is empty.
  		 */
  		memset(virt_base, 0, size);
  	}
  
  	info->screen_base    = virt_base;
  	info->fix.smem_start = phys_base;
  	info->fix.smem_len   = PAGE_ALIGN(size);
  	info->fix.type       = FB_TYPE_PACKED_PIXELS;
  }
  
  int __init clps711xfb_init(void)
  {
  	int err = -ENOMEM;
  
  	if (fb_get_options("clps711xfb", NULL))
  		return -ENODEV;
  
  	cfb = kzalloc(sizeof(*cfb), GFP_KERNEL);
  	if (!cfb)
  		goto out;
  
  	strcpy(cfb->fix.id, "clps711x");
  
  	cfb->fbops		= &clps7111fb_ops;
  	cfb->flags		= FBINFO_DEFAULT;
  
  	clps711x_guess_lcd_params(cfb);
  
  	fb_alloc_cmap(&cfb->cmap, CMAP_MAX_SIZE, 0);
  
  	/* Register the /proc entries. */
  	clps7111fb_backlight_proc_entry = create_proc_entry("backlight", 0444,
  		NULL);
  	if (clps7111fb_backlight_proc_entry == NULL) {
  		printk("Couldn't create the /proc entry for the backlight.\n");
  		return -EINVAL;
  	}
  
  	clps7111fb_backlight_proc_entry->read_proc = 
  		&clps7111fb_proc_backlight_read;
  	clps7111fb_backlight_proc_entry->write_proc = 
  		&clps7111fb_proc_backlight_write;
  
  	/*
  	 * Power up the LCD
  	 */
  	if (machine_is_p720t()) {
  		PLD_LCDEN = PLD_LCDEN_EN;
  		PLD_PWR |= (PLD_S4_ON|PLD_S3_ON|PLD_S2_ON|PLD_S1_ON);
  	}
  
  	if (machine_is_edb7211()) {
  		/* Power up the LCD panel. */
  		clps_writeb(clps_readb(PDDR) | EDB_PD2_LCDEN, PDDR);
  
  		/* Delay for a little while. */
  		udelay(100);
  
  		/* Power up the LCD DC-DC converter. */
  		clps_writeb(clps_readb(PDDR) | EDB_PD1_LCD_DC_DC_EN, PDDR);
  
  		/* Turn on the LCD backlight. */
  		clps_writeb(clps_readb(PDDR) | EDB_PD3_LCDBL, PDDR);
  	}
  
  	err = register_framebuffer(cfb);
  
  out:	return err;
  }
  
  static void __exit clps711xfb_exit(void)
  {
  	unregister_framebuffer(cfb);
  	kfree(cfb);
  
  	/*
  	 * Power down the LCD
  	 */
  	if (machine_is_p720t()) {
  		PLD_LCDEN = 0;
  		PLD_PWR &= ~(PLD_S4_ON|PLD_S3_ON|PLD_S2_ON|PLD_S1_ON);
  	}
  }
  
  module_init(clps711xfb_init);
  module_exit(clps711xfb_exit);
  
  MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
  MODULE_DESCRIPTION("CLPS711x framebuffer driver");
  MODULE_LICENSE("GPL");
  