Subject: [PATCH] [acpi video] Improve LCD detection
- Get rid of is_lcd() helper
- Set ->v_lcd when we have an LCD device
- Set ->v_br when we can control brightness correctly
- Add is_method() helper for determinig presence of certain methods
Signed-off-by: Patrick Mochel <mochel@linux.intel.com>
---
drivers/acpi/drivers/video/dev-device.c | 55 +++++++++++++++++++++++--------
1 files changed, 41 insertions(+), 14 deletions(-)
applies-to: d172c78655649439c130777b2dfb360d65b68ea4
3dd229894e32e4a151bf045c7f564acf18c9e4bd
diff --git a/drivers/acpi/drivers/video/dev-device.c b/drivers/acpi/drivers/video/dev-device.c
index 2b297c7..fd46229 100644
--- a/drivers/acpi/drivers/video/dev-device.c
+++ b/drivers/acpi/drivers/video/dev-device.c
@@ -14,6 +14,15 @@
#include "video.h"
+static int is_method(struct acpi_dev * ad, char * obj)
+{
+ acpi_handle h;
+ acpi_status status;
+
+ status = acpi_get_handle(ad->acpi_device->handle, obj, &h);
+ return ACPI_SUCCESS(status) ? 1 : 0;
+}
+
static int get_int(struct acpi_dev * ad, char * method, unsigned long * val)
{
acpi_status status;
@@ -165,10 +174,21 @@ int video_dev_test(struct acpi_dev * ad)
}
-static int is_lcd(struct acpi_video_dev * vd)
-{
- return (vd->v_id.v_type == VIDEO_DEV_LCD);
-}
+/**
+ * lcd_init - Initialize LCD capabilities of device
+ * @vd: The ACPI video device
+ *
+ * First, check if this device is advertised as an LCD.
+ * If so, then make sure that it has a good set of methods.
+ * - No methods are required, but if _BCL is there, then
+ * so must _BCM and _BQC.
+ * - EDID is also optional, so we don't check for that.
+ *
+ * If that doesn't work, then return an error, because that's
+ * going to cause problems.
+ * If it does have everything that it needs, cache the brightness
+ * levels in the device.
+ */
static int lcd_init(struct acpi_video_dev * vd)
{
@@ -177,17 +197,24 @@ static int lcd_init(struct acpi_video_de
int ret = 0;
int i;
- if (is_lcd(vd)) {
- ret = get_int_array(vd->v_ad, "_BCL", values, &num);
- if (ret)
- return ret;
-
- vd->v_br_ac = values[0];
- vd->v_br_batt = values[1];
-
- for (i = 0; (i + 2) < num; i++)
- vd->v_br_levels[i] = values[i + 2];
+ if (vd->v_id.v_type == VIDEO_DEV_LCD) {
+ if (is_method(vd->v_ad, "_BCL")) {
+ if (!(is_method(vd->v_ad, "_BCM") &&
+ is_method(vd->v_ad, "_BQC")))
+ return -EIO;
+
+ ret = get_int_array(vd->v_ad, "_BCL", values, &num);
+ if (ret)
+ return ret;
+
+ vd->v_br = 1;
+ vd->v_br_ac = values[0];
+ vd->v_br_batt = values[1];
+ for (i = 0; (i + 2) < num; i++)
+ vd->v_br_levels[i] = values[i + 2];
+ }
+ vd->v_lcd = 1;
}
return ret;
}
---
0.99.9.GIT