[ARM] Update clps711x fbcon driver.

drivers/video/clps711xfb.c

@@ -25,6 +25,7 @@
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/proc_fs.h>
+#include <linux/delay.h>
 
 #include <video/fbcon.h>
 
@@ -37,7 +38,7 @@
 
 struct fb_info	*cfb;
 
-#define CMAP_SIZE	16
+#define CMAP_MAX_SIZE	16
 
 /* The /proc entry for the backlight. */
 static struct proc_dir_entry *clps7111fb_backlight_proc_entry = NULL;
@@ -47,6 +48,13 @@ static int clps7111fb_proc_backlight_read(char *page, char **start, off_t off,
 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.
  */
@@ -56,7 +64,7 @@ clps7111fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
 {
 	unsigned int level, mask, shift, pal;
 
-	if (regno >= CMAP_SIZE)
+	if (regno >= (1 << info->var.bits_per_pixel))
 		return 1;
 
 	/* gray = 0.30*R + 0.58*G + 0.11*B */
@@ -104,6 +112,8 @@ clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 
 	if (var->bits_per_pixel > 4) 
 		return -EINVAL;
+
+	return 0;
 }
 
 /*
@@ -112,32 +122,46 @@ clps7111fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 static int 
 clps7111fb_set_par(struct fb_info *info)
 {
-	unsigned int lcdcon, syscon;
+	unsigned int lcdcon, syscon, pixclock;
 
-	switch (var->bits_per_pixel) {
+	switch (info->var.bits_per_pixel) {
 	case 1:
-		info->fix.visual	= FB_VISUAL_MONO01;
+		info->fix.visual = FB_VISUAL_MONO01;
 		break;
 	case 2:
-		info->fix.visual	= FB_VISUAL_PSEUDOCOLOR;
+		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 		break;
 	case 4:
-		info->fix.visual	= FB_VISUAL_PSEUDOCOLOR;
+		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
 		break;
 	}
 
 	info->fix.line_length = info->var.xres_virtual * info->var.bits_per_pixel / 8;
 
-	/*
-	 * LCDCON must only be changed while the LCD is disabled
-	 */
 	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 |= 2 << 19;
-	lcdcon |= 13 << 25;
-	lcdcon |= LCDCON_GSEN;
-	lcdcon |= LCDCON_GSMD;
+	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);
@@ -149,8 +173,6 @@ static int clps7111fb_blank(int blank, struct fb_info *info)
 {
     	if (blank) {
 		if (machine_is_edb7211()) {
-			int i;
-
 			/* Turn off the LCD backlight. */
 			clps_writeb(clps_readb(PDDR) & ~EDB_PD3_LCDBL, PDDR);
 
@@ -169,8 +191,6 @@ static int clps7111fb_blank(int blank, struct fb_info *info)
 		}
 	} else {
 		if (machine_is_edb7211()) {
-			int i;
-
 			/* Power up the LCD controller. */
 			clps_writel(clps_readl(SYSCON1) | SYSCON1_LCDEN,
 					SYSCON1);
@@ -256,6 +276,93 @@ clps7111fb_proc_backlight_write(struct file *file, const char *buffer,
 	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)
 {
@@ -266,34 +373,19 @@ int __init clps711xfb_init(void)
 		goto out;
 
 	memset(cfb, 0, sizeof(*cfb) + sizeof(struct display));
-	memset((void *)PAGE_OFFSET, 0, 0x14000);
+	strcpy(cfb->fix.id, "clps711x");
 
 	cfb->currcon		= -1;
-
-	strcpy(cfb->fix.id, "clps7111");
-	cfb->screen_base	= (void *)PAGE_OFFSET;
-	cfb->fix.smem_start	= PAGE_OFFSET;
-	cfb->fix.smem_len	= 0x14000;
-	cfb->fix.type	= FB_TYPE_PACKED_PIXELS;
-
-	cfb->var.xres	 = 640;
-	cfb->var.xres_virtual = 640;
-	cfb->var.yres	 = 240;
-	cfb->var.yres_virtual = 240;
-	cfb->var.bits_per_pixel = 4;
-	cfb->var.grayscale   = 1;
-	cfb->var.activate	= FB_ACTIVATE_NOW;
-	cfb->var.height	= -1;
-	cfb->var.width	= -1;
-
 	cfb->fbops		= &clps7111fb_ops;
-	cfb->changevar	= NULL;
-	cfb->switch_con	= gen_switch;
-	cfb->updatevar	= gen_update_var;
+	cfb->changevar		= NULL;
+	cfb->switch_con		= gen_switch;
+	cfb->updatevar		= gen_update_var;
 	cfb->flags		= FBINFO_FLAG_DEFAULT;
 	cfb->disp		= (struct display *)(cfb + 1);
 
-	fb_alloc_cmap(&cfb->cmap, CMAP_SIZE, 0);
+	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,
@@ -317,8 +409,6 @@ int __init clps711xfb_init(void)
 	}
 
 	if (machine_is_edb7211()) {
-		int i;
-
 		/* Power up the LCD panel. */
 		clps_writeb(clps_readb(PDDR) | EDB_PD2_LCDEN, PDDR);