backlight: Allow enable/disable of fb backlights, fixing regressions

Enabling the backlight by default appears to cause problems for many
users. This patch disables backlight controls unless explicitly
enabled by users via a module parameter. Since PMAC users are known
to work, default to enabled in that case.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>

drivers/video/aty/aty128fb.c

@@ -357,6 +357,12 @@ static int default_lcd_on __devinitdata = 1;
 static int mtrr = 1;
 #endif
 
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight __devinitdata = 1;
+#else
+static int backlight __devinitdata = 0;
+#endif
+
 /* PLL constants */
 struct aty128_constants {
 	u32 ref_clk;
@@ -1652,6 +1658,9 @@ static int __devinit aty128fb_setup(char *options)
 		} else if (!strncmp(this_opt, "crt:", 4)) {
 			default_crt_on = simple_strtoul(this_opt+4, NULL, 0);
 			continue;
+		} else if (!strncmp(this_opt, "backlight:", 10)) {
+			backlight = simple_strtoul(this_opt+10, NULL, 0);
+			continue;
 		}
 #ifdef CONFIG_MTRR
 		if(!strncmp(this_opt, "nomtrr", 6)) {
@@ -1985,7 +1994,8 @@ static int __devinit aty128_init(struct pci_dev *pdev, const struct pci_device_i
 	par->lock_blank = 0;
 
 #ifdef CONFIG_FB_ATY128_BACKLIGHT
-	aty128_bl_init(par);
+	if (backlight)
+		aty128_bl_init(par);
 #endif
 
 	if (register_framebuffer(info) < 0)

drivers/video/aty/atyfb_base.c

@@ -308,6 +308,12 @@ static int xclk;
 static int comp_sync __devinitdata = -1;
 static char *mode;
 
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight __devinitdata = 1;
+#else
+static int backlight __devinitdata = 0;
+#endif
+
 #ifdef CONFIG_PPC
 static int default_vmode __devinitdata = VMODE_CHOOSE;
 static int default_cmode __devinitdata = CMODE_CHOOSE;
@@ -2575,7 +2581,7 @@ static int __devinit aty_init(struct fb_info *info)
 			   | (USE_F32KHZ | TRISTATE_MEM_EN), par);
 	} else
 #endif
-	if (M64_HAS(MOBIL_BUS)) {
+	if (M64_HAS(MOBIL_BUS) && backlight) {
 #ifdef CONFIG_FB_ATY_BACKLIGHT
 		aty_bl_init (par);
 #endif
@@ -3757,6 +3763,8 @@ static int __init atyfb_setup(char *options)
 			xclk = simple_strtoul(this_opt+5, NULL, 0);
 		else if (!strncmp(this_opt, "comp_sync:", 10))
 			comp_sync = simple_strtoul(this_opt+10, NULL, 0);
+		else if (!strncmp(this_opt, "backlight:", 10))
+			backlight = simple_strtoul(this_opt+10, NULL, 0);
 #ifdef CONFIG_PPC
 		else if (!strncmp(this_opt, "vmode:", 6)) {
 			unsigned int vmode =

drivers/video/aty/radeon_base.c

@@ -268,6 +268,11 @@ static int nomtrr = 0;
 #endif
 static int force_sleep;
 static int ignore_devlist;
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight = 1;
+#else
+static int backlight = 0;
+#endif
 
 /*
  * prototypes
@@ -2348,7 +2353,8 @@ static int __devinit radeonfb_pci_register (struct pci_dev *pdev,
 						 MTRR_TYPE_WRCOMB, 1);
 #endif
 
-	radeonfb_bl_init(rinfo);
+	if (backlight)
+		radeonfb_bl_init(rinfo);
 
 	printk ("radeonfb (%s): %s\n", pci_name(rinfo->pdev), rinfo->name);
 
@@ -2469,6 +2475,8 @@ static int __init radeonfb_setup (char *options)
 			force_dfp = 1;
 		} else if (!strncmp(this_opt, "panel_yres:", 11)) {
 			panel_yres = simple_strtoul((this_opt+11), NULL, 0);
+		} else if (!strncmp(this_opt, "backlight:", 10)) {
+			backlight = simple_strtoul(this_opt+10, NULL, 0);
 #ifdef CONFIG_MTRR
 		} else if (!strncmp(this_opt, "nomtrr", 6)) {
 			nomtrr = 1;

drivers/video/nvidia/nvidia.c

@@ -83,6 +83,11 @@ static int bpp __devinitdata = 8;
 #ifdef CONFIG_MTRR
 static int nomtrr __devinitdata = 0;
 #endif
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight __devinitdata = 1;
+#else
+static int backlight __devinitdata = 0;
+#endif
 
 static char *mode_option __devinitdata = NULL;
 
@@ -1311,7 +1316,10 @@ static int __devinit nvidiafb_probe(struct pci_dev *pd,
 	nvidia_save_vga(par, &par->SavedReg);
 
 	pci_set_drvdata(pd, info);
-	nvidia_bl_init(par);
+
+	if (backlight)
+		nvidia_bl_init(par);
+
 	if (register_framebuffer(info) < 0) {
 		printk(KERN_ERR PFX "error registering nVidia framebuffer\n");
 		goto err_out_iounmap_fb;
@@ -1408,6 +1416,8 @@ static int __devinit nvidiafb_setup(char *options)
 			paneltweak = simple_strtoul(this_opt+11, NULL, 0);
 		} else if (!strncmp(this_opt, "vram:", 5)) {
 			vram = simple_strtoul(this_opt+5, NULL, 0);
+		} else if (!strncmp(this_opt, "backlight:", 10)) {
+			backlight = simple_strtoul(this_opt+10, NULL, 0);
 #ifdef CONFIG_MTRR
 		} else if (!strncmp(this_opt, "nomtrr", 6)) {
 			nomtrr = 1;

drivers/video/riva/fbdev.c

@@ -215,6 +215,11 @@ static int noaccel   __devinitdata = 0;
 #ifdef CONFIG_MTRR
 static int nomtrr __devinitdata = 0;
 #endif
+#ifdef CONFIG_PMAC_BACKLIGHT
+static int backlight __devinitdata = 1;
+#else
+static int backlight __devinitdata = 0;
+#endif
 
 static char *mode_option __devinitdata = NULL;
 static int  strictmode       = 0;
@@ -2059,7 +2064,10 @@ static int __devinit rivafb_probe(struct pci_dev *pd,
 	info->monspecs.modedb = NULL;
 
 	pci_set_drvdata(pd, info);
-	riva_bl_init(info->par);
+
+	if (backlight)
+		riva_bl_init(info->par);
+
 	ret = register_framebuffer(info);
 	if (ret < 0) {
 		printk(KERN_ERR PFX
@@ -2157,6 +2165,8 @@ static int __init rivafb_setup(char *options)
 				forceCRTC = -1;
 		} else if (!strncmp(this_opt, "flatpanel", 9)) {
 			flatpanel = 1;
+		} else if (!strncmp(this_opt, "backlight:", 10)) {
+			backlight = simple_strtoul(this_opt+10, NULL, 0);
 #ifdef CONFIG_MTRR
 		} else if (!strncmp(this_opt, "nomtrr", 6)) {
 			nomtrr = 1;