[PATCH] Rewritten backlight infrastructure for portable Apple computers

This patch contains a total rewrite of the backlight infrastructure for
portable Apple computers.  Backward compatibility is retained.  A sysfs
interface allows userland to control the brightness with more steps than
before.  Userland is allowed to upload a brightness curve for different
monitors, similar to Mac OS X.

[akpm@osdl.org: add needed exports]
Signed-off-by: Michael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 201 insertions, 82 deletions

diff --git a/drivers/video/nvidia/Makefile b/drivers/video/nvidia/Makefile
index 690d37e8de5..ca47432113e 100644
--- a/drivers/video/nvidia/Makefile
+++ b/drivers/video/nvidia/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_FB_NVIDIA)          += nvidiafb.o
 nvidiafb-y                       := nvidia.o nv_hw.o nv_setup.o \
 			            nv_accel.o
 nvidiafb-$(CONFIG_FB_NVIDIA_I2C) += nv_i2c.o
+nvidiafb-$(CONFIG_FB_NVIDIA_BACKLIGHT)  += nv_backlight.o
 nvidiafb-$(CONFIG_PPC_OF)	 += nv_of.o
 
-nvidiafb-objs                    := $(nvidiafb-y)
\ No newline at end of file
+nvidiafb-objs                    := $(nvidiafb-y)
diff --git a/drivers/video/nvidia/nv_backlight.c b/drivers/video/nvidia/nv_backlight.c
new file mode 100644
index 00000000000..1c1c10c699c
--- /dev/null
+++ b/drivers/video/nvidia/nv_backlight.c
@@ -0,0 +1,175 @@
+/*
+ * Backlight code for nVidia based graphic cards
+ *
+ * Copyright 2004 Antonino Daplas <adaplas@pol.net>
+ * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/backlight.h>
+#include <linux/fb.h>
+#include <linux/pci.h>
+#include "nv_local.h"
+#include "nv_type.h"
+#include "nv_proto.h"
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+#include <asm/backlight.h>
+#include <asm/machdep.h>
+#endif
+
+/* We do not have any information about which values are allowed, thus
+ * we used safe values.
+ */
+#define MIN_LEVEL 0x158
+#define MAX_LEVEL 0x534
+
+static struct backlight_properties nvidia_bl_data;
+
+static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
+		int level)
+{
+	struct fb_info *info = pci_get_drvdata(par->pci_dev);
+	int nlevel;
+
+	/* Get and convert the value */
+	mutex_lock(&info->bl_mutex);
+	nlevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
+	mutex_unlock(&info->bl_mutex);
+
+	if (nlevel < 0)
+		nlevel = 0;
+	else if (nlevel < MIN_LEVEL)
+		nlevel = MIN_LEVEL;
+	else if (nlevel > MAX_LEVEL)
+		nlevel = MAX_LEVEL;
+
+	return nlevel;
+}
+
+static int nvidia_bl_update_status(struct backlight_device *bd)
+{
+	struct nvidia_par *par = class_get_devdata(&bd->class_dev);
+	u32 tmp_pcrt, tmp_pmc, fpcontrol;
+	int level;
+
+	if (!par->FlatPanel)
+		return 0;
+
+	if (bd->props->power != FB_BLANK_UNBLANK ||
+	    bd->props->fb_blank != FB_BLANK_UNBLANK)
+		level = 0;
+	else
+		level = bd->props->brightness;
+
+	tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
+	tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
+	fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
+
+	if (level > 0) {
+		tmp_pcrt |= 0x1;
+		tmp_pmc |= (1 << 31); /* backlight bit */
+		tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
+		fpcontrol |= par->fpSyncs;
+	} else
+		fpcontrol |= 0x20000022;
+
+	NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
+	NV_WR32(par->PMC, 0x10F0, tmp_pmc);
+	NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
+
+	return 0;
+}
+
+static int nvidia_bl_get_brightness(struct backlight_device *bd)
+{
+	return bd->props->brightness;
+}
+
+static struct backlight_properties nvidia_bl_data = {
+	.owner		= THIS_MODULE,
+	.get_brightness = nvidia_bl_get_brightness,
+	.update_status	= nvidia_bl_update_status,
+	.max_brightness = (FB_BACKLIGHT_LEVELS - 1),
+};
+
+void nvidia_bl_init(struct nvidia_par *par)
+{
+	struct fb_info *info = pci_get_drvdata(par->pci_dev);
+	struct backlight_device *bd;
+	char name[12];
+
+	if (!par->FlatPanel)
+		return;
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	if (!machine_is(powermac) ||
+	    !pmac_has_backlight_type("mnca"))
+		return;
+#endif
+
+	snprintf(name, sizeof(name), "nvidiabl%d", info->node);
+
+	bd = backlight_device_register(name, par, &nvidia_bl_data);
+	if (IS_ERR(bd)) {
+		info->bl_dev = NULL;
+		printk("nvidia: Backlight registration failed\n");
+		goto error;
+	}
+
+	mutex_lock(&info->bl_mutex);
+	info->bl_dev = bd;
+	fb_bl_default_curve(info, 0,
+		0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
+		0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
+	mutex_unlock(&info->bl_mutex);
+
+	up(&bd->sem);
+	bd->props->brightness = nvidia_bl_data.max_brightness;
+	bd->props->power = FB_BLANK_UNBLANK;
+	bd->props->update_status(bd);
+	down(&bd->sem);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_lock(&pmac_backlight_mutex);
+	if (!pmac_backlight)
+		pmac_backlight = bd;
+	mutex_unlock(&pmac_backlight_mutex);
+#endif
+
+	printk("nvidia: Backlight initialized (%s)\n", name);
+
+	return;
+
+error:
+	return;
+}
+
+void nvidia_bl_exit(struct nvidia_par *par)
+{
+	struct fb_info *info = pci_get_drvdata(par->pci_dev);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_lock(&pmac_backlight_mutex);
+#endif
+
+	mutex_lock(&info->bl_mutex);
+	if (info->bl_dev) {
+#ifdef CONFIG_PMAC_BACKLIGHT
+		if (pmac_backlight == info->bl_dev)
+			pmac_backlight = NULL;
+#endif
+
+		backlight_device_unregister(info->bl_dev);
+
+		printk("nvidia: Backlight unloaded\n");
+	}
+	mutex_unlock(&info->bl_mutex);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+	mutex_unlock(&pmac_backlight_mutex);
+#endif
+}
diff --git a/drivers/video/nvidia/nv_proto.h b/drivers/video/nvidia/nv_proto.h
index b149a690ee0..6fba656cd56 100644
--- a/drivers/video/nvidia/nv_proto.h
+++ b/drivers/video/nvidia/nv_proto.h
@@ -63,4 +63,14 @@ extern void nvidiafb_imageblit(struct fb_info *info,
 			       const struct fb_image *image);
 extern int nvidiafb_sync(struct fb_info *info);
 extern u8 byte_rev[256];
+
+/* in nv_backlight.h */
+#ifdef CONFIG_FB_NVIDIA_BACKLIGHT
+extern void nvidia_bl_init(struct nvidia_par *par);
+extern void nvidia_bl_exit(struct nvidia_par *par);
+#else
+static inline void nvidia_bl_init(struct nvidia_par *par) {}
+static inline void nvidia_bl_exit(struct nvidia_par *par) {}
+#endif
+
 #endif				/* __NV_PROTO_H__ */
diff --git a/drivers/video/nvidia/nvidia.c b/drivers/video/nvidia/nvidia.c
index 093ab9977c7..03a7c1e9ce3 100644
--- a/drivers/video/nvidia/nvidia.c
+++ b/drivers/video/nvidia/nvidia.c
@@ -22,6 +22,7 @@
 #include <linux/init.h>
 #include <linux/pci.h>
 #include <linux/console.h>
+#include <linux/backlight.h>
 #ifdef CONFIG_MTRR
 #include <asm/mtrr.h>
 #endif
@@ -29,10 +30,6 @@
 #include <asm/prom.h>
 #include <asm/pci-bridge.h>
 #endif
-#ifdef CONFIG_PMAC_BACKLIGHT
-#include <asm/machdep.h>
-#include <asm/backlight.h>
-#endif
 
 #include "nv_local.h"
 #include "nv_type.h"
@@ -470,75 +467,6 @@ static struct fb_var_screeninfo __devinitdata nvidiafb_default_var = {
 	.vmode = FB_VMODE_NONINTERLACED
 };
 
-/*
- * Backlight control
- */
-#ifdef CONFIG_PMAC_BACKLIGHT
-
-static int nvidia_backlight_levels[] = {
-	0x158,
-	0x192,
-	0x1c6,
-	0x200,
-	0x234,
-	0x268,
-	0x2a2,
-	0x2d6,
-	0x310,
-	0x344,
-	0x378,
-	0x3b2,
-	0x3e6,
-	0x41a,
-	0x454,
-	0x534,
-};
-
-/* ------------------------------------------------------------------------- *
- *
- * Backlight operations
- *
- * ------------------------------------------------------------------------- */
-
-static int nvidia_set_backlight_enable(int on, int level, void *data)
-{
-	struct nvidia_par *par = data;
-	u32 tmp_pcrt, tmp_pmc, fpcontrol;
-
-	tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
-	tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
-	fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
-
-	if (on && (level > BACKLIGHT_OFF)) {
-		tmp_pcrt |= 0x1;
-		tmp_pmc |= (1 << 31);	// backlight bit
-		tmp_pmc |= nvidia_backlight_levels[level - 1] << 16;
-	}
-
-	if (on)
-		fpcontrol |= par->fpSyncs;
-	else
-		fpcontrol |= 0x20000022;
-
-	NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
-	NV_WR32(par->PMC, 0x10F0, tmp_pmc);
-	NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
-
-	return 0;
-}
-
-static int nvidia_set_backlight_level(int level, void *data)
-{
-	return nvidia_set_backlight_enable(1, level, data);
-}
-
-static struct backlight_controller nvidia_backlight_controller = {
-	nvidia_set_backlight_enable,
-	nvidia_set_backlight_level
-};
-
-#endif				/* CONFIG_PMAC_BACKLIGHT */
-
 static void nvidiafb_load_cursor_image(struct nvidia_par *par, u8 * data8,
 				       u16 bg, u16 fg, u32 w, u32 h)
 {
@@ -1355,10 +1283,15 @@ static int nvidiafb_blank(int blank, struct fb_info *info)
 	NVWriteSeq(par, 0x01, tmp);
 	NVWriteCrtc(par, 0x1a, vesa);
 
-#ifdef CONFIG_PMAC_BACKLIGHT
-	if (par->FlatPanel && machine_is(powermac)) {
-		set_backlight_enable(!blank);
+#ifdef CONFIG_FB_NVIDIA_BACKLIGHT
+	mutex_lock(&info->bl_mutex);
+	if (info->bl_dev) {
+		down(&info->bl_dev->sem);
+		info->bl_dev->props->power = blank;
+		info->bl_dev->props->update_status(info->bl_dev);
+		up(&info->bl_dev->sem);
 	}
+	mutex_unlock(&info->bl_mutex);
 #endif
 
 	NVTRACE_LEAVE();
@@ -1741,11 +1674,9 @@ static int __devinit nvidiafb_probe(struct pci_dev *pd,
 	       "PCI nVidia %s framebuffer (%dMB @ 0x%lX)\n",
 	       info->fix.id,
 	       par->FbMapSize / (1024 * 1024), info->fix.smem_start);
-#ifdef CONFIG_PMAC_BACKLIGHT
-	if (par->FlatPanel && machine_is(powermac))
-		register_backlight_controller(&nvidia_backlight_controller,
-					      par, "mnca");
-#endif
+
+	nvidia_bl_init(par);
+
 	NVTRACE_LEAVE();
 	return 0;
 
@@ -1775,6 +1706,8 @@ static void __exit nvidiafb_remove(struct pci_dev *pd)
 
 	NVTRACE_ENTER();
 
+	nvidia_bl_exit(par);
+
 	unregister_framebuffer(info);
 #ifdef CONFIG_MTRR
 	if (par->mtrr.vram_valid)