[PATCH] sony-laptop: limit brightness range to DSDT provided ones
The new style brightness control provides an operating range of 9 values
(seems consistent over a large number of models sharing the same
brightness control methods).
Read and use the minimum and maximum values to limit the backlight
interface between those boundaries.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/sony-laptop.c b/drivers/platform/x86/sony-laptop.c
index 9d80ae4..6fe8cd6 100644
--- a/drivers/platform/x86/sony-laptop.c
+++ b/drivers/platform/x86/sony-laptop.c
@@ -934,6 +934,14 @@
/*
* Backlight device
*/
+struct sony_backlight_props {
+ struct backlight_device *dev;
+ int handle;
+ u8 offset;
+ u8 maxlvl;
+};
+struct sony_backlight_props sony_bl_props;
+
static int sony_backlight_update_status(struct backlight_device *bd)
{
return acpi_callsetfunc(sony_nc_acpi_handle, "SBRT",
@@ -954,19 +962,23 @@
{
int result;
int *handle = (int *)bl_get_data(bd);
+ struct sony_backlight_props *sdev =
+ (struct sony_backlight_props *)bl_get_data(bd);
- sony_call_snc_handle(*handle, 0x0200, &result);
+ sony_call_snc_handle(sdev->handle, 0x0200, &result);
- return result & 0xff;
+ return (result & 0xff) - sdev->offset;
}
static int sony_nc_update_status_ng(struct backlight_device *bd)
{
int value, result;
int *handle = (int *)bl_get_data(bd);
+ struct sony_backlight_props *sdev =
+ (struct sony_backlight_props *)bl_get_data(bd);
- value = bd->props.brightness;
- if (sony_call_snc_handle(*handle, 0x0100 | (value << 16), &result))
+ value = bd->props.brightness + sdev->offset;
+ if (sony_call_snc_handle(sdev->handle, 0x0100 | (value << 16), &result))
return -EIO;
return value;
@@ -982,8 +994,6 @@
.update_status = sony_nc_update_status_ng,
.get_brightness = sony_nc_get_brightness_ng,
};
-static int backlight_ng_handle;
-static struct backlight_device *sony_backlight_device;
/*
* New SNC-only Vaios event mapping to driver known keys
@@ -1550,6 +1560,75 @@
&ignore);
}
+static void sony_nc_backlight_ng_read_limits(int handle,
+ struct sony_backlight_props *props)
+{
+ int offset;
+ acpi_status status;
+ u8 brlvl, i;
+ u8 min = 0xff, max = 0x00;
+ struct acpi_object_list params;
+ union acpi_object in_obj;
+ union acpi_object *lvl_enum;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+ props->handle = handle;
+ props->offset = 0;
+ props->maxlvl = 0xff;
+
+ offset = sony_find_snc_handle(handle);
+ if (offset < 0)
+ return;
+
+ /* try to read the boundaries from ACPI tables, if we fail the above
+ * defaults should be reasonable
+ */
+ params.count = 1;
+ params.pointer = &in_obj;
+ in_obj.type = ACPI_TYPE_INTEGER;
+ in_obj.integer.value = offset;
+ status = acpi_evaluate_object(sony_nc_acpi_handle, "SN06", ¶ms,
+ &buffer);
+ if (ACPI_FAILURE(status))
+ return;
+
+ lvl_enum = (union acpi_object *) buffer.pointer;
+ if (!lvl_enum) {
+ pr_err("No SN06 return object.");
+ return;
+ }
+ if (lvl_enum->type != ACPI_TYPE_BUFFER) {
+ pr_err("Invalid SN06 return object 0x%.2x\n",
+ lvl_enum->type);
+ goto out_invalid;
+ }
+
+ /* the buffer lists brightness levels available, brightness levels are
+ * from 0 to 8 in the array, other values are used by ALS control.
+ */
+ for (i = 0; i < 9 && i < lvl_enum->buffer.length; i++) {
+
+ brlvl = *(lvl_enum->buffer.pointer + i);
+ dprintk("Brightness level: %d\n", brlvl);
+
+ if (!brlvl)
+ break;
+
+ if (brlvl > max)
+ max = brlvl;
+ if (brlvl < min)
+ min = brlvl;
+ }
+ props->offset = min;
+ props->maxlvl = max;
+ dprintk("Brightness levels: min=%d max=%d\n", props->offset,
+ props->maxlvl);
+
+out_invalid:
+ kfree(buffer.pointer);
+ return;
+}
+
static void sony_nc_backlight_setup(void)
{
acpi_handle unused;
@@ -1558,14 +1637,14 @@
struct backlight_properties props;
if (sony_find_snc_handle(0x12f) != -1) {
- backlight_ng_handle = 0x12f;
ops = &sony_backlight_ng_ops;
- max_brightness = 0xff;
+ sony_nc_backlight_ng_read_limits(0x12f, &sony_bl_props);
+ max_brightness = sony_bl_props.maxlvl - sony_bl_props.offset;
} else if (sony_find_snc_handle(0x137) != -1) {
- backlight_ng_handle = 0x137;
ops = &sony_backlight_ng_ops;
- max_brightness = 0xff;
+ sony_nc_backlight_ng_read_limits(0x137, &sony_bl_props);
+ max_brightness = sony_bl_props.maxlvl - sony_bl_props.offset;
} else if (ACPI_SUCCESS(acpi_get_handle(sony_nc_acpi_handle, "GBRT",
&unused))) {
@@ -1578,22 +1657,22 @@
memset(&props, 0, sizeof(struct backlight_properties));
props.type = BACKLIGHT_PLATFORM;
props.max_brightness = max_brightness;
- sony_backlight_device = backlight_device_register("sony", NULL,
- &backlight_ng_handle,
- ops, &props);
+ sony_bl_props.dev = backlight_device_register("sony", NULL,
+ &sony_bl_props,
+ ops, &props);
- if (IS_ERR(sony_backlight_device)) {
- pr_warning(DRV_PFX "unable to register backlight device\n");
- sony_backlight_device = NULL;
+ if (IS_ERR(sony_bl_props.dev)) {
+ pr_warn(DRV_PFX "unable to register backlight device\n");
+ sony_bl_props.dev = NULL;
} else
- sony_backlight_device->props.brightness =
- ops->get_brightness(sony_backlight_device);
+ sony_bl_props.dev->props.brightness =
+ ops->get_brightness(sony_bl_props.dev);
}
static void sony_nc_backlight_cleanup(void)
{
- if (sony_backlight_device)
- backlight_device_unregister(sony_backlight_device);
+ if (sony_bl_props.dev)
+ backlight_device_unregister(sony_bl_props.dev);
}
static int sony_nc_add(struct acpi_device *device)
@@ -2591,7 +2670,7 @@
mutex_lock(&spic_dev.lock);
switch (cmd) {
case SONYPI_IOCGBRT:
- if (sony_backlight_device == NULL) {
+ if (sony_bl_props.dev == NULL) {
ret = -EIO;
break;
}
@@ -2604,7 +2683,7 @@
ret = -EFAULT;
break;
case SONYPI_IOCSBRT:
- if (sony_backlight_device == NULL) {
+ if (sony_bl_props.dev == NULL) {
ret = -EIO;
break;
}
@@ -2618,8 +2697,8 @@
break;
}
/* sync the backlight device status */
- sony_backlight_device->props.brightness =
- sony_backlight_get_brightness(sony_backlight_device);
+ sony_bl_props.dev->props.brightness =
+ sony_backlight_get_brightness(sony_bl_props.dev);
break;
case SONYPI_IOCGBAT1CAP:
if (ec_read16(SONYPI_BAT1_FULL, &val16)) {