[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>

5 files changed, 199 insertions, 119 deletions

diff --git a/drivers/macintosh/Kconfig b/drivers/macintosh/Kconfig
index ccf5df44cde4..37cd6ee4586b 100644
--- a/drivers/macintosh/Kconfig
+++ b/drivers/macintosh/Kconfig
@@ -99,17 +99,22 @@ config PMAC_MEDIABAY
 	  devices are not fully supported in the bay as I never had one to
 	  try with
 
-# made a separate option since backlight may end up beeing used
-# on non-powerbook machines (but only on PMU based ones AFAIK)
 config PMAC_BACKLIGHT
 	bool "Backlight control for LCD screens"
 	depends on ADB_PMU && (BROKEN || !PPC64)
 	help
-	  Say Y here to build in code to manage the LCD backlight on a
-	  Macintosh PowerBook.  With this code, the backlight will be turned
-	  on and off appropriately on power-management and lid-open/lid-closed
-	  events; also, the PowerBook button device will be enabled so you can
-	  change the screen brightness.
+	  Say Y here to enable Macintosh specific extensions of the generic
+	  backlight code. With this enabled, the brightness keys on older
+	  PowerBooks will be enabled so you can change the screen brightness.
+	  Newer models should use an userspace daemon like pbbuttonsd.
+
+config PMAC_BACKLIGHT_LEGACY
+	bool "Provide legacy ioctl's on /dev/pmu for the backlight"
+	depends on PMAC_BACKLIGHT && (BROKEN || !PPC64)
+	help
+	  Say Y if you want to enable legacy ioctl's on /dev/pmu. This is for
+	  programs which use this old interface. New and updated programs
+	  should use the backlight classes in sysfs.
 
 config ADB_MACIO
 	bool "Include MacIO (CHRP) ADB driver"
diff --git a/drivers/macintosh/Makefile b/drivers/macintosh/Makefile
index 6081acdea404..8972e53d2dcb 100644
--- a/drivers/macintosh/Makefile
+++ b/drivers/macintosh/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_INPUT_ADBHID)	+= adbhid.o
 obj-$(CONFIG_ANSLCD)		+= ans-lcd.o
 
 obj-$(CONFIG_ADB_PMU)		+= via-pmu.o
+obj-$(CONFIG_PMAC_BACKLIGHT)	+= via-pmu-backlight.o
 obj-$(CONFIG_ADB_CUDA)		+= via-cuda.o
 obj-$(CONFIG_PMAC_APM_EMU)	+= apm_emu.o
 obj-$(CONFIG_PMAC_SMU)		+= smu.o
diff --git a/drivers/macintosh/adbhid.c b/drivers/macintosh/adbhid.c
index 394334ec5765..c26e1236b275 100644
--- a/drivers/macintosh/adbhid.c
+++ b/drivers/macintosh/adbhid.c
@@ -503,9 +503,7 @@ adbhid_buttons_input(unsigned char *data, int nb, struct pt_regs *regs, int auto
 	case 0x1f: /* Powerbook button device */
 	  {
 		int down = (data[1] == (data[1] & 0xf));
-#ifdef CONFIG_PMAC_BACKLIGHT
-		int backlight = get_backlight_level();
-#endif
+
 		/*
 		 * XXX: Where is the contrast control for the passive?
 		 *  -- Cort
@@ -530,29 +528,17 @@ adbhid_buttons_input(unsigned char *data, int nb, struct pt_regs *regs, int auto
 
 		case 0xa:	/* brightness decrease */
 #ifdef CONFIG_PMAC_BACKLIGHT
-			if (!disable_kernel_backlight) {
-				if (down && backlight >= 0) {
-					if (backlight > BACKLIGHT_OFF)
-						set_backlight_level(backlight-1);
-					else
-						set_backlight_level(BACKLIGHT_OFF);
-				}
-			}
-#endif /* CONFIG_PMAC_BACKLIGHT */
+			if (!disable_kernel_backlight && down)
+				pmac_backlight_key_down();
+#endif
 			input_report_key(adbhid[id]->input, KEY_BRIGHTNESSDOWN, down);
 			break;
 
 		case 0x9:	/* brightness increase */
 #ifdef CONFIG_PMAC_BACKLIGHT
-			if (!disable_kernel_backlight) {
-				if (down && backlight >= 0) {
-					if (backlight < BACKLIGHT_MAX)
-						set_backlight_level(backlight+1);
-					else 
-						set_backlight_level(BACKLIGHT_MAX);
-				}
-			}
-#endif /* CONFIG_PMAC_BACKLIGHT */
+			if (!disable_kernel_backlight && down)
+				pmac_backlight_key_up();
+#endif
 			input_report_key(adbhid[id]->input, KEY_BRIGHTNESSUP, down);
 			break;
 
diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c
new file mode 100644
index 000000000000..b42d05f2aaff
--- /dev/null
+++ b/drivers/macintosh/via-pmu-backlight.c
@@ -0,0 +1,150 @@
+/*
+ * Backlight code for via-pmu
+ *
+ * Copyright (C) 1998 Paul Mackerras and Fabio Riccardi.
+ * Copyright (C) 2001-2002 Benjamin Herrenschmidt
+ * Copyright (C) 2006      Michael Hanselmann <linux-kernel@hansmi.ch>
+ *
+ */
+
+#include <asm/ptrace.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+#include <asm/backlight.h>
+#include <asm/prom.h>
+
+#define MAX_PMU_LEVEL 0xFF
+
+static struct device_node *vias;
+static struct backlight_properties pmu_backlight_data;
+
+static int pmu_backlight_get_level_brightness(struct fb_info *info,
+		int level)
+{
+	int pmulevel;
+
+	/* Get and convert the value */
+	mutex_lock(&info->bl_mutex);
+	pmulevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
+	mutex_unlock(&info->bl_mutex);
+
+	if (pmulevel < 0)
+		pmulevel = 0;
+	else if (pmulevel > MAX_PMU_LEVEL)
+		pmulevel = MAX_PMU_LEVEL;
+
+	return pmulevel;
+}
+
+static int pmu_backlight_update_status(struct backlight_device *bd)
+{
+	struct fb_info *info = class_get_devdata(&bd->class_dev);
+	struct adb_request req;
+	int pmulevel, level = bd->props->brightness;
+
+	if (vias == NULL)
+		return -ENODEV;
+
+	if (bd->props->power != FB_BLANK_UNBLANK ||
+	    bd->props->fb_blank != FB_BLANK_UNBLANK)
+		level = 0;
+
+	pmulevel = pmu_backlight_get_level_brightness(info, level);
+
+	pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT, pmulevel);
+	pmu_wait_complete(&req);
+
+	pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
+		PMU_POW_BACKLIGHT | (level > 0 ? PMU_POW_ON : PMU_POW_OFF));
+	pmu_wait_complete(&req);
+
+	return 0;
+}
+
+static int pmu_backlight_get_brightness(struct backlight_device *bd)
+{
+	return bd->props->brightness;
+}
+
+static struct backlight_properties pmu_backlight_data = {
+	.owner		= THIS_MODULE,
+	.get_brightness	= pmu_backlight_get_brightness,
+	.update_status	= pmu_backlight_update_status,
+	.max_brightness	= (FB_BACKLIGHT_LEVELS - 1),
+};
+
+void __init pmu_backlight_init(struct device_node *in_vias)
+{
+	struct backlight_device *bd;
+	struct fb_info *info;
+	char name[10];
+	int level, autosave;
+
+	vias = in_vias;
+
+	/* Special case for the old PowerBook since I can't test on it */
+	autosave =
+		machine_is_compatible("AAPL,3400/2400") ||
+		machine_is_compatible("AAPL,3500");
+
+	if (!autosave &&
+	    !pmac_has_backlight_type("pmu") &&
+	    !machine_is_compatible("AAPL,PowerBook1998") &&
+	    !machine_is_compatible("PowerBook1,1"))
+		return;
+
+	/* Actually, this is a hack, but I don't know of a better way
+	 * to get the first framebuffer device.
+	 */
+	info = registered_fb[0];
+	if (!info) {
+		printk("pmubl: No framebuffer found\n");
+		goto error;
+	}
+
+	snprintf(name, sizeof(name), "pmubl%d", info->node);
+
+	bd = backlight_device_register(name, info, &pmu_backlight_data);
+	if (IS_ERR(bd)) {
+		printk("pmubl: Backlight registration failed\n");
+		goto error;
+	}
+
+	mutex_lock(&info->bl_mutex);
+	info->bl_dev = bd;
+	fb_bl_default_curve(info, 0x7F, 0x46, 0x0E);
+	mutex_unlock(&info->bl_mutex);
+
+	level = pmu_backlight_data.max_brightness;
+
+	if (autosave) {
+		/* read autosaved value if available */
+		struct adb_request req;
+		pmu_request(&req, NULL, 2, 0xd9, 0);
+		pmu_wait_complete(&req);
+
+		mutex_lock(&info->bl_mutex);
+		level = pmac_backlight_curve_lookup(info,
+				(req.reply[0] >> 4) *
+				pmu_backlight_data.max_brightness / 15);
+		mutex_unlock(&info->bl_mutex);
+	}
+
+	up(&bd->sem);
+	bd->props->brightness = level;
+	bd->props->power = FB_BLANK_UNBLANK;
+	bd->props->update_status(bd);
+	down(&bd->sem);
+
+	mutex_lock(&pmac_backlight_mutex);
+	if (!pmac_backlight)
+		pmac_backlight = bd;
+	mutex_unlock(&pmac_backlight_mutex);
+
+	printk("pmubl: Backlight initialized (%s)\n", name);
+
+	return;
+
+error:
+	return;
+}
diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c
index c63d4e7984be..2a355ae59562 100644
--- a/drivers/macintosh/via-pmu.c
+++ b/drivers/macintosh/via-pmu.c
@@ -144,7 +144,6 @@ static int data_index;
 static int data_len;
 static volatile int adb_int_pending;
 static volatile int disable_poll;
-static struct adb_request bright_req_1, bright_req_2;
 static struct device_node *vias;
 static int pmu_kind = PMU_UNKNOWN;
 static int pmu_fully_inited = 0;
@@ -161,7 +160,7 @@ static int drop_interrupts;
 #if defined(CONFIG_PM) && defined(CONFIG_PPC32)
 static int option_lid_wakeup = 1;
 #endif /* CONFIG_PM && CONFIG_PPC32 */
-#if (defined(CONFIG_PM)&&defined(CONFIG_PPC32))||defined(CONFIG_PMAC_BACKLIGHT)
+#if (defined(CONFIG_PM)&&defined(CONFIG_PPC32))||defined(CONFIG_PMAC_BACKLIGHT_LEGACY)
 static int sleep_in_progress;
 #endif
 static unsigned long async_req_locks;
@@ -208,10 +207,6 @@ static int proc_get_info(char *page, char **start, off_t off,
 			  int count, int *eof, void *data);
 static int proc_get_irqstats(char *page, char **start, off_t off,
 			  int count, int *eof, void *data);
-#ifdef CONFIG_PMAC_BACKLIGHT
-static int pmu_set_backlight_level(int level, void* data);
-static int pmu_set_backlight_enable(int on, int level, void* data);
-#endif /* CONFIG_PMAC_BACKLIGHT */
 static void pmu_pass_intr(unsigned char *data, int len);
 static int proc_get_batt(char *page, char **start, off_t off,
 			int count, int *eof, void *data);
@@ -292,13 +287,6 @@ static char *pbook_type[] = {
 	"Core99"
 };
 
-#ifdef CONFIG_PMAC_BACKLIGHT
-static struct backlight_controller pmu_backlight_controller = {
-	pmu_set_backlight_enable,
-	pmu_set_backlight_level
-};
-#endif /* CONFIG_PMAC_BACKLIGHT */
-
 int __init find_via_pmu(void)
 {
 	u64 taddr;
@@ -417,8 +405,6 @@ static int __init via_pmu_start(void)
 	if (vias == NULL)
 		return -ENODEV;
 
-	bright_req_1.complete = 1;
-	bright_req_2.complete = 1;
 	batt_req.complete = 1;
 
 #ifndef CONFIG_PPC_MERGE
@@ -483,9 +469,9 @@ static int __init via_pmu_dev_init(void)
 		return -ENODEV;
 
 #ifdef CONFIG_PMAC_BACKLIGHT
-	/* Enable backlight */
-	register_backlight_controller(&pmu_backlight_controller, NULL, "pmu");
-#endif /* CONFIG_PMAC_BACKLIGHT */
+	/* Initialize backlight */
+	pmu_backlight_init(vias);
+#endif
 
 #ifdef CONFIG_PPC32
   	if (machine_is_compatible("AAPL,3400/2400") ||
@@ -1424,7 +1410,7 @@ next:
 #ifdef CONFIG_INPUT_ADBHID
 			if (!disable_kernel_backlight)
 #endif /* CONFIG_INPUT_ADBHID */
-				set_backlight_level(data[1] >> 4);
+				pmac_backlight_set_legacy_brightness(data[1] >> 4);
 #endif /* CONFIG_PMAC_BACKLIGHT */
 	}
 	/* Tick interrupt */
@@ -1674,61 +1660,6 @@ gpio1_interrupt(int irq, void *arg, struct pt_regs *regs)
 	return IRQ_NONE;
 }
 
-#ifdef CONFIG_PMAC_BACKLIGHT
-static int backlight_to_bright[] = {
-	0x7f, 0x46, 0x42, 0x3e, 0x3a, 0x36, 0x32, 0x2e,
-	0x2a, 0x26, 0x22, 0x1e, 0x1a, 0x16, 0x12, 0x0e
-};
- 
-static int
-pmu_set_backlight_enable(int on, int level, void* data)
-{
-	struct adb_request req;
-	
-	if (vias == NULL)
-		return -ENODEV;
-
-	if (on) {
-		pmu_request(&req, NULL, 2, PMU_BACKLIGHT_BRIGHT,
-			    backlight_to_bright[level]);
-		pmu_wait_complete(&req);
-	}
-	pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
-		    PMU_POW_BACKLIGHT | (on ? PMU_POW_ON : PMU_POW_OFF));
-       	pmu_wait_complete(&req);
-
-	return 0;
-}
-
-static void
-pmu_bright_complete(struct adb_request *req)
-{
-	if (req == &bright_req_1)
-		clear_bit(1, &async_req_locks);
-	if (req == &bright_req_2)
-		clear_bit(2, &async_req_locks);
-}
-
-static int
-pmu_set_backlight_level(int level, void* data)
-{
-	if (vias == NULL)
-		return -ENODEV;
-
-	if (test_and_set_bit(1, &async_req_locks))
-		return -EAGAIN;
-	pmu_request(&bright_req_1, pmu_bright_complete, 2, PMU_BACKLIGHT_BRIGHT,
-		backlight_to_bright[level]);
-	if (test_and_set_bit(2, &async_req_locks))
-		return -EAGAIN;
-	pmu_request(&bright_req_2, pmu_bright_complete, 2, PMU_POWER_CTRL,
-		    PMU_POW_BACKLIGHT | (level > BACKLIGHT_OFF ?
-					 PMU_POW_ON : PMU_POW_OFF));
-
-	return 0;
-}
-#endif /* CONFIG_PMAC_BACKLIGHT */
-
 void
 pmu_enable_irled(int on)
 {
@@ -2145,9 +2076,8 @@ pmac_suspend_devices(void)
 		return -EBUSY;
 	}
 
-	/* Wait for completion of async backlight requests */
-	while (!bright_req_1.complete || !bright_req_2.complete ||
-			!batt_req.complete)
+	/* Wait for completion of async requests */
+	while (!batt_req.complete)
 		pmu_poll();
 
 	/* Giveup the lazy FPU & vec so we don't have to back them
@@ -2678,26 +2608,34 @@ pmu_ioctl(struct inode * inode, struct file *filp,
 			return put_user(1, argp);
 #endif /* CONFIG_PM && CONFIG_PPC32 */
 
-#ifdef CONFIG_PMAC_BACKLIGHT
-	/* Backlight should have its own device or go via
-	 * the fbdev
-	 */
+#ifdef CONFIG_PMAC_BACKLIGHT_LEGACY
+	/* Compatibility ioctl's for backlight */
 	case PMU_IOC_GET_BACKLIGHT:
+	{
+		int brightness;
+
 		if (sleep_in_progress)
 			return -EBUSY;
-		error = get_backlight_level();
-		if (error < 0)
-			return error;
-		return put_user(error, argp);
+
+		brightness = pmac_backlight_get_legacy_brightness();
+		if (brightness < 0)
+			return brightness;
+		else
+			return put_user(brightness, argp);
+
+	}
 	case PMU_IOC_SET_BACKLIGHT:
 	{
-		__u32 value;
+		int brightness;
+
 		if (sleep_in_progress)
 			return -EBUSY;
-		error = get_user(value, argp);
-		if (!error)
-			error = set_backlight_level(value);
-		break;
+
+		error = get_user(brightness, argp);
+		if (error)
+			return error;
+
+		return pmac_backlight_set_legacy_brightness(brightness);
 	}
 #ifdef CONFIG_INPUT_ADBHID
 	case PMU_IOC_GRAB_BACKLIGHT: {
@@ -2713,7 +2651,7 @@ pmu_ioctl(struct inode * inode, struct file *filp,
 		return 0;
 	}
 #endif /* CONFIG_INPUT_ADBHID */
-#endif /* CONFIG_PMAC_BACKLIGHT */
+#endif /* CONFIG_PMAC_BACKLIGHT_LEGACY */
 	case PMU_IOC_GET_MODEL:
 	    	return put_user(pmu_kind, argp);
 	case PMU_IOC_HAS_ADB: