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-rw-r--r--drivers/macintosh/via-pmu-backlight.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/macintosh/via-pmu-backlight.c b/drivers/macintosh/via-pmu-backlight.c
new file mode 100644
index 000000000..219401612
--- /dev/null
+++ b/drivers/macintosh/via-pmu-backlight.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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>
+
+#define MAX_PMU_LEVEL 0xFF
+
+static const struct backlight_ops pmu_backlight_data;
+static DEFINE_SPINLOCK(pmu_backlight_lock);
+static int sleeping, uses_pmu_bl;
+static u8 bl_curve[FB_BACKLIGHT_LEVELS];
+
+static void pmu_backlight_init_curve(u8 off, u8 min, u8 max)
+{
+ 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;
+ int level = bd->props.brightness;
+
+
+ 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);
+ }
+
+ return 0;
+}
+
+static int pmu_backlight_update_status(struct backlight_device *bd)
+{
+ unsigned long flags;
+ int rc = 0;
+
+ spin_lock_irqsave(&pmu_backlight_lock, flags);
+ /* Don't update brightness when sleeping */
+ if (!sleeping)
+ rc = __pmu_backlight_update_status(bd);
+ spin_unlock_irqrestore(&pmu_backlight_lock, flags);
+ return rc;
+}
+
+
+static const struct backlight_ops pmu_backlight_data = {
+ .update_status = pmu_backlight_update_status,
+
+};
+
+#ifdef CONFIG_PM
+void pmu_backlight_set_sleep(int sleep)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&pmu_backlight_lock, flags);
+ sleeping = sleep;
+ if (pmac_backlight && uses_pmu_bl) {
+ if (sleep) {
+ struct adb_request req;
+
+ pmu_request(&req, NULL, 2, PMU_POWER_CTRL,
+ PMU_POW_BACKLIGHT | PMU_POW_OFF);
+ pmu_wait_complete(&req);
+ } else
+ __pmu_backlight_update_status(pmac_backlight);
+ }
+ spin_unlock_irqrestore(&pmu_backlight_lock, flags);
+}
+#endif /* CONFIG_PM */
+
+void __init pmu_backlight_init(void)
+{
+ struct backlight_properties props;
+ struct backlight_device *bd;
+ char name[10];
+ int level, autosave;
+
+ /* Special case for the old PowerBook since I can't test on it */
+ autosave =
+ of_machine_is_compatible("AAPL,3400/2400") ||
+ of_machine_is_compatible("AAPL,3500");
+
+ if (!autosave &&
+ !pmac_has_backlight_type("pmu") &&
+ !of_machine_is_compatible("AAPL,PowerBook1998") &&
+ !of_machine_is_compatible("PowerBook1,1"))
+ return;
+
+ snprintf(name, sizeof(name), "pmubl");
+
+ memset(&props, 0, sizeof(struct backlight_properties));
+ props.type = BACKLIGHT_PLATFORM;
+ props.max_brightness = FB_BACKLIGHT_LEVELS - 1;
+ bd = backlight_device_register(name, NULL, NULL, &pmu_backlight_data,
+ &props);
+ if (IS_ERR(bd)) {
+ printk(KERN_ERR "PMU Backlight registration failed\n");
+ return;
+ }
+ uses_pmu_bl = 1;
+ pmu_backlight_init_curve(0x7F, 0x46, 0x0E);
+
+ level = bd->props.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) *
+ bd->props.max_brightness / 15);
+ }
+
+ bd->props.brightness = level;
+ bd->props.power = FB_BLANK_UNBLANK;
+ backlight_update_status(bd);
+
+ printk(KERN_INFO "PMU Backlight initialized (%s)\n", name);
+}