[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>
diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c
new file mode 100644
index 0000000..b42d05f
--- /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;
+}
