[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, 159 insertions, 63 deletions

diff --git a/drivers/video/riva/fbdev.c b/drivers/video/riva/fbdev.c
index 3e9308f0f165..d4384ab1df65 100644
--- a/drivers/video/riva/fbdev.c
+++ b/drivers/video/riva/fbdev.c
@@ -41,6 +41,7 @@
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/pci.h>
+#include <linux/backlight.h>
 #ifdef CONFIG_MTRR
 #include <asm/mtrr.h>
 #endif
@@ -272,34 +273,154 @@ static const struct riva_regs reg_template = {
 /*
  * Backlight control
  */
-#ifdef CONFIG_PMAC_BACKLIGHT
+#ifdef CONFIG_FB_RIVA_BACKLIGHT
+/* 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 int riva_backlight_levels[] = {
-    0x158,
-    0x192,
-    0x1c6,
-    0x200,
-    0x234,
-    0x268,
-    0x2a2,
-    0x2d6,
-    0x310,
-    0x344,
-    0x378,
-    0x3b2,
-    0x3e6,
-    0x41a,
-    0x454,
-    0x534,
-};
+static struct backlight_properties riva_bl_data;
+
+static int riva_bl_get_level_brightness(struct riva_par *par,
+                int level)
+{
+        struct fb_info *info = pci_get_drvdata(par->pdev);
+        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 riva_bl_update_status(struct backlight_device *bd)
+{
+        struct riva_par *par = class_get_devdata(&bd->class_dev);
+        U032 tmp_pcrt, tmp_pmc;
+        int level;
+
+        if (bd->props->power != FB_BLANK_UNBLANK ||
+            bd->props->fb_blank != FB_BLANK_UNBLANK)
+                level = 0;
+        else
+                level = bd->props->brightness;
+
+        tmp_pmc = par->riva.PMC[0x10F0/4] & 0x0000FFFF;
+        tmp_pcrt = par->riva.PCRTC0[0x081C/4] & 0xFFFFFFFC;
+        if(level > 0) {
+                tmp_pcrt |= 0x1;
+                tmp_pmc |= (1 << 31); /* backlight bit */
+                tmp_pmc |= riva_bl_get_level_brightness(par, level) << 16; /* level */
+        }
+        par->riva.PCRTC0[0x081C/4] = tmp_pcrt;
+        par->riva.PMC[0x10F0/4] = tmp_pmc;
+
+        return 0;
+}
+
+static int riva_bl_get_brightness(struct backlight_device *bd)
+{
+        return bd->props->brightness;
+}
 
-static int riva_set_backlight_enable(int on, int level, void *data);
-static int riva_set_backlight_level(int level, void *data);
-static struct backlight_controller riva_backlight_controller = {
-        riva_set_backlight_enable,
-        riva_set_backlight_level
+static struct backlight_properties riva_bl_data = {
+        .owner    = THIS_MODULE,
+        .get_brightness = riva_bl_get_brightness,
+        .update_status  = riva_bl_update_status,
+        .max_brightness = (FB_BACKLIGHT_LEVELS - 1),
 };
-#endif /* CONFIG_PMAC_BACKLIGHT */
+
+static void riva_bl_init(struct riva_par *par)
+{
+        struct fb_info *info = pci_get_drvdata(par->pdev);
+        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), "rivabl%d", info->node);
+
+        bd = backlight_device_register(name, par, &riva_bl_data);
+        if (IS_ERR(bd)) {
+                info->bl_dev = NULL;
+                printk("riva: 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 = riva_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("riva: Backlight initialized (%s)\n", name);
+
+        return;
+
+error:
+        return;
+}
+
+static void riva_bl_exit(struct riva_par *par)
+{
+        struct fb_info *info = pci_get_drvdata(par->pdev);
+
+#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("riva: Backlight unloaded\n");
+        }
+        mutex_unlock(&info->bl_mutex);
+
+#ifdef CONFIG_PMAC_BACKLIGHT
+        mutex_unlock(&pmac_backlight_mutex);
+#endif
+}
+#else
+static inline void riva_bl_init(struct riva_par *par) {}
+static inline void riva_bl_exit(struct riva_par *par) {}
+#endif /* CONFIG_FB_RIVA_BACKLIGHT */
 
 /* ------------------------------------------------------------------------- *
  *
@@ -973,36 +1094,6 @@ static int riva_get_cmap_len(const struct fb_var_screeninfo *var)
 
 /* ------------------------------------------------------------------------- *
  *
- * Backlight operations
- *
- * ------------------------------------------------------------------------- */
-
-#ifdef CONFIG_PMAC_BACKLIGHT
-static int riva_set_backlight_enable(int on, int level, void *data)
-{
-        struct riva_par *par = data;
-        U032 tmp_pcrt, tmp_pmc;
-
-        tmp_pmc = par->riva.PMC[0x10F0/4] & 0x0000FFFF;
-        tmp_pcrt = par->riva.PCRTC0[0x081C/4] & 0xFFFFFFFC;
-        if(on && (level > BACKLIGHT_OFF)) {
-                tmp_pcrt |= 0x1;
-                tmp_pmc |= (1 << 31); // backlight bit
-                tmp_pmc |= riva_backlight_levels[level-1] << 16; // level
-        }
-        par->riva.PCRTC0[0x081C/4] = tmp_pcrt;
-        par->riva.PMC[0x10F0/4] = tmp_pmc;
-        return 0;
-}
-
-static int riva_set_backlight_level(int level, void *data)
-{
-        return riva_set_backlight_enable(1, level, data);
-}
-#endif /* CONFIG_PMAC_BACKLIGHT */
-
-/* ------------------------------------------------------------------------- *
- *
  * framebuffer operations
  *
  * ------------------------------------------------------------------------- */
@@ -1247,10 +1338,15 @@ static int rivafb_blank(int blank, struct fb_info *info)
         SEQout(par, 0x01, tmp);
         CRTCout(par, 0x1a, vesa);
 
-#ifdef CONFIG_PMAC_BACKLIGHT
-        if ( par->FlatPanel && machine_is(powermac)) {
-                set_backlight_enable(!blank);
+#ifdef CONFIG_FB_RIVA_BACKLIGHT
+        mutex_lock(&info->bl_mutex);
+        if (info->bl_dev) {
+                down(&info->bl_dev->sem);
+                info->bl_dev->props->power = blank;
+                info->bl_dev->props->update_status(info->bl_dev);
+                up(&info->bl_dev->sem);
         }
+        mutex_unlock(&info->bl_mutex);
 #endif
 
         NVTRACE_LEAVE();
@@ -2037,11 +2133,9 @@ static int __devinit rivafb_probe(struct pci_dev *pd,
                 RIVAFB_VERSION,
                 info->fix.smem_len / (1024 * 1024),
                 info->fix.smem_start);
-#ifdef CONFIG_PMAC_BACKLIGHT
-        if (default_par->FlatPanel && machine_is(powermac))
-                register_backlight_controller(&riva_backlight_controller,
-                                              default_par, "mnca");
-#endif
+
+        riva_bl_init(info->par);
+
         NVTRACE_LEAVE();
         return 0;
 
@@ -2074,6 +2168,8 @@ static void __exit rivafb_remove(struct pci_dev *pd)
         
         NVTRACE_ENTER();
 
+        riva_bl_exit(par);
+
 #ifdef CONFIG_FB_RIVA_I2C
         riva_delete_i2c_busses(par);
         kfree(par->EDID);