[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>

1 files changed, 175 insertions, 0 deletions

diff --git a/drivers/video/nvidia/nv_backlight.c b/drivers/video/nvidia/nv_backlight.c
new file mode 100644
index 000000000000..1c1c10c699c5
--- /dev/null
+++ b/drivers/video/nvidia/nv_backlight.c
@@ -0,0 +1,175 @@
+/*
+ * Backlight code for nVidia based graphic cards
+ *
+ * Copyright 2004 Antonino Daplas <adaplas@pol.net>
+ * Copyright (c) 2006 Michael Hanselmann <linux-kernel@hansmi.ch>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/backlight.h>
+#include <linux/fb.h>
+#include <linux/pci.h>
+#include "nv_local.h"
+#include "nv_type.h"
+#include "nv_proto.h"
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+#include <asm/backlight.h>
+#include <asm/machdep.h>
+#endif
+
+/* We do not have any information about which values are allowed, thus
+ * we used safe values.
+ */
+#define MIN_LEVEL 0x158
+#define MAX_LEVEL 0x534
+
+static struct backlight_properties nvidia_bl_data;
+
+static int nvidia_bl_get_level_brightness(struct nvidia_par *par,
+                int level)
+{
+        struct fb_info *info = pci_get_drvdata(par->pci_dev);
+        int nlevel;
+
+        /* Get and convert the value */
+        mutex_lock(&info->bl_mutex);
+        nlevel = info->bl_curve[level] * FB_BACKLIGHT_MAX / MAX_LEVEL;
+        mutex_unlock(&info->bl_mutex);
+
+        if (nlevel < 0)
+                nlevel = 0;
+        else if (nlevel < MIN_LEVEL)
+                nlevel = MIN_LEVEL;
+        else if (nlevel > MAX_LEVEL)
+                nlevel = MAX_LEVEL;
+
+        return nlevel;
+}
+
+static int nvidia_bl_update_status(struct backlight_device *bd)
+{
+        struct nvidia_par *par = class_get_devdata(&bd->class_dev);
+        u32 tmp_pcrt, tmp_pmc, fpcontrol;
+        int level;
+
+        if (!par->FlatPanel)
+                return 0;
+
+        if (bd->props->power != FB_BLANK_UNBLANK ||
+            bd->props->fb_blank != FB_BLANK_UNBLANK)
+                level = 0;
+        else
+                level = bd->props->brightness;
+
+        tmp_pmc = NV_RD32(par->PMC, 0x10F0) & 0x0000FFFF;
+        tmp_pcrt = NV_RD32(par->PCRTC0, 0x081C) & 0xFFFFFFFC;
+        fpcontrol = NV_RD32(par->PRAMDAC, 0x0848) & 0xCFFFFFCC;
+
+        if (level > 0) {
+                tmp_pcrt |= 0x1;
+                tmp_pmc |= (1 << 31); /* backlight bit */
+                tmp_pmc |= nvidia_bl_get_level_brightness(par, level) << 16;
+                fpcontrol |= par->fpSyncs;
+        } else
+                fpcontrol |= 0x20000022;
+
+        NV_WR32(par->PCRTC0, 0x081C, tmp_pcrt);
+        NV_WR32(par->PMC, 0x10F0, tmp_pmc);
+        NV_WR32(par->PRAMDAC, 0x848, fpcontrol);
+
+        return 0;
+}
+
+static int nvidia_bl_get_brightness(struct backlight_device *bd)
+{
+        return bd->props->brightness;
+}
+
+static struct backlight_properties nvidia_bl_data = {
+        .owner          = THIS_MODULE,
+        .get_brightness = nvidia_bl_get_brightness,
+        .update_status  = nvidia_bl_update_status,
+        .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
+};
+
+void nvidia_bl_init(struct nvidia_par *par)
+{
+        struct fb_info *info = pci_get_drvdata(par->pci_dev);
+        struct backlight_device *bd;
+        char name[12];
+
+        if (!par->FlatPanel)
+                return;
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+        if (!machine_is(powermac) ||
+            !pmac_has_backlight_type("mnca"))
+                return;
+#endif
+
+        snprintf(name, sizeof(name), "nvidiabl%d", info->node);
+
+        bd = backlight_device_register(name, par, &nvidia_bl_data);
+        if (IS_ERR(bd)) {
+                info->bl_dev = NULL;
+                printk("nvidia: Backlight registration failed\n");
+                goto error;
+        }
+
+        mutex_lock(&info->bl_mutex);
+        info->bl_dev = bd;
+        fb_bl_default_curve(info, 0,
+                0x158 * FB_BACKLIGHT_MAX / MAX_LEVEL,
+                0x534 * FB_BACKLIGHT_MAX / MAX_LEVEL);
+        mutex_unlock(&info->bl_mutex);
+
+        up(&bd->sem);
+        bd->props->brightness = nvidia_bl_data.max_brightness;
+        bd->props->power = FB_BLANK_UNBLANK;
+        bd->props->update_status(bd);
+        down(&bd->sem);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+        mutex_lock(&pmac_backlight_mutex);
+        if (!pmac_backlight)
+                pmac_backlight = bd;
+        mutex_unlock(&pmac_backlight_mutex);
+#endif
+
+        printk("nvidia: Backlight initialized (%s)\n", name);
+
+        return;
+
+error:
+        return;
+}
+
+void nvidia_bl_exit(struct nvidia_par *par)
+{
+        struct fb_info *info = pci_get_drvdata(par->pci_dev);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+        mutex_lock(&pmac_backlight_mutex);
+#endif
+
+        mutex_lock(&info->bl_mutex);
+        if (info->bl_dev) {
+#ifdef CONFIG_PMAC_BACKLIGHT
+                if (pmac_backlight == info->bl_dev)
+                        pmac_backlight = NULL;
+#endif
+
+                backlight_device_unregister(info->bl_dev);
+
+                printk("nvidia: Backlight unloaded\n");
+        }
+        mutex_unlock(&info->bl_mutex);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+        mutex_unlock(&pmac_backlight_mutex);
+#endif
+}