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authorMario Schwalbe <schwalbe@inf.tu-dresden.de>2009-01-11 00:19:31 +0000
committerRichard Purdie <rpurdie@linux.intel.com>2009-04-06 16:06:55 +0100
commit1a468ba10c3bdbc25ef7aa7fecda20ee27007bdf (patch)
treee7836bd9643e4cc32bc76e2f4286ece19ea05f1e /drivers
parentc78a628849675580c7c5e1f07193c632e4b6827f (diff)
downloadlinux-stericsson-1a468ba10c3bdbc25ef7aa7fecda20ee27007bdf.tar.gz
backlight: mbp_nvidia_bl - Add a debug switch
This patch adds a debug switch to enable (little) diagnostic output, to help to trace down the remaining problems. Signed-off-by: Mario Schwalbe <schwalbe@inf.tu-dresden.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/video/backlight/mbp_nvidia_bl.c33
1 files changed, 31 insertions, 2 deletions
diff --git a/drivers/video/backlight/mbp_nvidia_bl.c b/drivers/video/backlight/mbp_nvidia_bl.c
index ce09b83244ac..3bb4c0a50c62 100644
--- a/drivers/video/backlight/mbp_nvidia_bl.c
+++ b/drivers/video/backlight/mbp_nvidia_bl.c
@@ -36,6 +36,11 @@ struct dmi_match_data {
struct backlight_ops backlight_ops;
};
+/* Module parameters. */
+static int debug;
+module_param_named(debug, debug, int, 0644);
+MODULE_PARM_DESC(debug, "Set to one to enable debugging messages.");
+
/*
* Implementation for MacBooks with Intel chipset.
*/
@@ -43,6 +48,10 @@ static int intel_chipset_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
+ if (debug)
+ printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n",
+ intensity);
+
outb(0x04 | (intensity << 4), 0xb3);
outb(0xbf, 0xb2);
return 0;
@@ -50,9 +59,17 @@ static int intel_chipset_send_intensity(struct backlight_device *bd)
static int intel_chipset_get_intensity(struct backlight_device *bd)
{
+ int intensity;
+
outb(0x03, 0xb3);
outb(0xbf, 0xb2);
- return inb(0xb3) >> 4;
+ intensity = inb(0xb3) >> 4;
+
+ if (debug)
+ printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n",
+ intensity);
+
+ return intensity;
}
static const struct dmi_match_data intel_chipset_data = {
@@ -72,6 +89,10 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd)
{
int intensity = bd->props.brightness;
+ if (debug)
+ printk(KERN_DEBUG "mbp_nvidia_bl: setting brightness to %d\n",
+ intensity);
+
outb(0x04 | (intensity << 4), 0x52f);
outb(0xbf, 0x52e);
return 0;
@@ -79,9 +100,17 @@ static int nvidia_chipset_send_intensity(struct backlight_device *bd)
static int nvidia_chipset_get_intensity(struct backlight_device *bd)
{
+ int intensity;
+
outb(0x03, 0x52f);
outb(0xbf, 0x52e);
- return inb(0x52f) >> 4;
+ intensity = inb(0x52f) >> 4;
+
+ if (debug)
+ printk(KERN_DEBUG "mbp_nvidia_bl: read brightness of %d\n",
+ intensity);
+
+ return intensity;
}
static const struct dmi_match_data nvidia_chipset_data = {