This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / macintosh / via-pmu-backlight.c

diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c
new file mode 100644 (file)
index 0000000..6c29fe7
--- /dev/null
+++ b/drivers/macintosh/via-pmu-backlight.c
@@ -0,0 +1,187 @@
+/*
+ * 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 backlight_properties pmu_backlight_data;
+static DEFINE_SPINLOCK(pmu_backlight_lock);
+static int sleeping;
+static u8 bl_curve[FB_BACKLIGHT_LEVELS];
+
+static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
+{
+       unsigned int i, flat, count, range = (max - min);
+
+       bl_curve[0] = off;
+
+       for (flat = 1; flat < (FB_BACKLIGHT_LEVELS / 16); ++flat)
+               bl_curve[flat] = min;
+
+       count = FB_BACKLIGHT_LEVELS * 15 / 16;
+       for (i = 0; i < count; ++i)
+               bl_curve[flat + i] = min + (range * (i + 1) / count);
+}
+
+static int pmu_backlight_curve_lookup(int value)
+{
+       int level = (FB_BACKLIGHT_LEVELS - 1);
+       int i, max = 0;
+
+       /* Look for biggest value */
+       for (i = 0; i < FB_BACKLIGHT_LEVELS; i++)
+               max = max((int)bl_curve[i], max);
+
+       /* Look for nearest value */
+       for (i = 0; i < FB_BACKLIGHT_LEVELS; i++) {
+               int diff = abs(bl_curve[i] - value);
+               if (diff < max) {
+                       max = diff;
+                       level = i;
+               }
+       }
+       return level;
+}
+
+static int pmu_backlight_get_level_brightness(int level)
+{
+       int pmulevel;
+
+       /* Get and convert the value */
+       pmulevel = bl_curve[level] * FB_BACKLIGHT_MAX / MAX_PMU_LEVEL;
+       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 adb_request req;
+       unsigned long flags;
+       int level = bd->props->brightness;
+
+       spin_lock_irqsave(&pmu_backlight_lock, flags);
+
+       /* Don't update brightness when sleeping */
+       if (sleeping)
+               goto out;
+
+       if (bd->props->power != FB_BLANK_UNBLANK ||
+           bd->props->fb_blank != FB_BLANK_UNBLANK)
+               level = 0;
+
+       if (level > 0) {
+               int pmulevel = pmu_backlight_get_level_brightness(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 | PMU_POW_ON);
+               pmu_wait_complete(&req);
+       } else {
+               pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
+                       PMU_POW_BACKLIGHT | PMU_POW_OFF);
+               pmu_wait_complete(&req);
+       }
+
+out:
+       spin_unlock_irqrestore(&pmu_backlight_lock, flags);
+
+       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),
+};
+
+#ifdef CONFIG_PM
+void pmu_backlight_set_sleep(int sleep)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&pmu_backlight_lock, flags);
+       sleeping = sleep;
+       spin_unlock_irqrestore(&pmu_backlight_lock, flags);
+}
+#endif /* CONFIG_PM */
+
+void __init pmu_backlight_init()
+{
+       struct backlight_device *bd;
+       char name[10];
+       int level, autosave;
+
+       /* 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;
+
+       snprintf(name, sizeof(name), "pmubl");
+
+       bd = backlight_device_register(name, NULL, &pmu_backlight_data);
+       if (IS_ERR(bd)) {
+               printk("pmubl: Backlight registration failed\n");
+               goto error;
+       }
+       pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
+
+       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);
+
+               level = pmu_backlight_curve_lookup(
+                               (req.reply[0] >> 4) *
+                               pmu_backlight_data.max_brightness / 15);
+       }
+
+       down(&bd->sem);
+       bd->props->brightness = level;
+       bd->props->power = FB_BLANK_UNBLANK;
+       bd->props->update_status(bd);
+       up(&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;
+}