1 files changed, 202 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/backlight.c b/arch/powerpc/platforms/powermac/backlight.c
new file mode 100644
index 000000000000..8be2f7d071f0
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/backlight.c
@@ -0,0 +1,202 @@
+/*
+ * Miscellaneous procedures for dealing with the PowerMac hardware.
+ * Contains support for the backlight.
+ *
+ *   Copyright (C) 2000 Benjamin Herrenschmidt
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stddef.h>
+#include <linux/reboot.h>
+#include <linux/nvram.h>
+#include <linux/console.h>
+#include <asm/sections.h>
+#include <asm/ptrace.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/nvram.h>
+#include <asm/backlight.h>
+
+#include <linux/adb.h>
+#include <linux/pmu.h>
+
+static struct backlight_controller *backlighter;
+static void* backlighter_data;
+static int backlight_autosave;
+static int backlight_level = BACKLIGHT_MAX;
+static int backlight_enabled = 1;
+static int backlight_req_level = -1;
+static int backlight_req_enable = -1;
+
+static void backlight_callback(void *);
+static DECLARE_WORK(backlight_work, backlight_callback, NULL);
+
+void register_backlight_controller(struct backlight_controller *ctrler,
+                                          void *data, char *type)
+{
+        struct device_node* bk_node;
+        char *prop;
+        int valid = 0;
+
+        /* There's already a matching controller, bail out */
+        if (backlighter != NULL)
+                return;
+
+        bk_node = find_devices("backlight");
+
+#ifdef CONFIG_ADB_PMU
+        /* Special case for the old PowerBook since I can't test on it */
+        backlight_autosave = machine_is_compatible("AAPL,3400/2400")
+                || machine_is_compatible("AAPL,3500");
+        if ((backlight_autosave
+             || machine_is_compatible("AAPL,PowerBook1998")
+             || machine_is_compatible("PowerBook1,1"))
+            && !strcmp(type, "pmu"))
+                valid = 1;
+#endif
+        if (bk_node) {
+                prop = get_property(bk_node, "backlight-control", NULL);
+                if (prop && !strncmp(prop, type, strlen(type)))
+                        valid = 1;
+        }
+        if (!valid)
+                return;
+        backlighter = ctrler;
+        backlighter_data = data;
+
+        if (bk_node && !backlight_autosave)
+                prop = get_property(bk_node, "bklt", NULL);
+        else
+                prop = NULL;
+        if (prop) {
+                backlight_level = ((*prop)+1) >> 1;
+                if (backlight_level > BACKLIGHT_MAX)
+                        backlight_level = BACKLIGHT_MAX;
+        }
+
+#ifdef CONFIG_ADB_PMU
+        if (backlight_autosave) {
+                struct adb_request req;
+                pmu_request(&req, NULL, 2, 0xd9, 0);
+                while (!req.complete)
+                        pmu_poll();
+                backlight_level = req.reply[0] >> 4;
+        }
+#endif
+        acquire_console_sem();
+        if (!backlighter->set_enable(1, backlight_level, data))
+                backlight_enabled = 1;
+        release_console_sem();
+
+        printk(KERN_INFO "Registered \"%s\" backlight controller,"
+               "level: %d/15\n", type, backlight_level);
+}
+EXPORT_SYMBOL(register_backlight_controller);
+
+void unregister_backlight_controller(struct backlight_controller
+                                            *ctrler, void *data)
+{
+        /* We keep the current backlight level (for now) */
+        if (ctrler == backlighter && data == backlighter_data)
+                backlighter = NULL;
+}
+EXPORT_SYMBOL(unregister_backlight_controller);
+
+static int __set_backlight_enable(int enable)
+{
+        int rc;
+
+        if (!backlighter)
+                return -ENODEV;
+        acquire_console_sem();
+        rc = backlighter->set_enable(enable, backlight_level,
+                                     backlighter_data);
+        if (!rc)
+                backlight_enabled = enable;
+        release_console_sem();
+        return rc;
+}
+int set_backlight_enable(int enable)
+{
+        if (!backlighter)
+                return -ENODEV;
+        backlight_req_enable = enable;
+        schedule_work(&backlight_work);
+        return 0;
+}
+
+EXPORT_SYMBOL(set_backlight_enable);
+
+int get_backlight_enable(void)
+{
+        if (!backlighter)
+                return -ENODEV;
+        return backlight_enabled;
+}
+EXPORT_SYMBOL(get_backlight_enable);
+
+static int __set_backlight_level(int level)
+{
+        int rc = 0;
+
+        if (!backlighter)
+                return -ENODEV;
+        if (level < BACKLIGHT_MIN)
+                level = BACKLIGHT_OFF;
+        if (level > BACKLIGHT_MAX)
+                level = BACKLIGHT_MAX;
+        acquire_console_sem();
+        if (backlight_enabled)
+                rc = backlighter->set_level(level, backlighter_data);
+        if (!rc)
+                backlight_level = level;
+        release_console_sem();
+        if (!rc && !backlight_autosave) {
+                level <<=1;
+                if (level & 0x10)
+                        level |= 0x01;
+                // -- todo: save to property "bklt"
+        }
+        return rc;
+}
+int set_backlight_level(int level)
+{
+        if (!backlighter)
+                return -ENODEV;
+        backlight_req_level = level;
+        schedule_work(&backlight_work);
+        return 0;
+}
+
+EXPORT_SYMBOL(set_backlight_level);
+
+int get_backlight_level(void)
+{
+        if (!backlighter)
+                return -ENODEV;
+        return backlight_level;
+}
+EXPORT_SYMBOL(get_backlight_level);
+
+static void backlight_callback(void *dummy)
+{
+        int level, enable;
+
+        do {
+                level = backlight_req_level;
+                enable = backlight_req_enable;
+                mb();
+
+                if (level >= 0)
+                        __set_backlight_level(level);
+                if (enable >= 0)
+                        __set_backlight_enable(enable);
+        } while(cmpxchg(&backlight_req_level, level, -1) != level ||
+                cmpxchg(&backlight_req_enable, enable, -1) != enable);
+}