Newer devices don't place the PMIC CLK line inside an EFI
var. Instead, those are found at the _PR0 table.
Add a parser for it, using info stored via the DSDT table.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
---
.../media/atomisp/pci/atomisp_gmin_platform.c | 66 ++++++++++++++++++-
1 file changed, 64 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index 2903aa52115b..e476cf1f3294 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -444,6 +444,61 @@ static int gmin_i2c_write(struct device *dev, u16 i2c_addr, u8 reg,
return ret;
}
+static int atomisp_get_acpi_power(struct device *dev, acpi_handle handle)
+{
+ char name[5];
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ struct acpi_buffer b_name = { sizeof(name), name };
+ union acpi_object *package, *element;
+ acpi_handle rhandle;
+ acpi_status status;
+ int clock_num = -1;
+ int i;
+
+ status = acpi_evaluate_object(handle, "_PR0", NULL, &buffer);
+ if (!ACPI_SUCCESS(status))
+ return -1;
+
+ package = buffer.pointer;
+
+ if (!buffer.length || !package
+ || package->type != ACPI_TYPE_PACKAGE
+ || !package->package.count)
+ goto fail;
+
+ for (i = 0; i < package->package.count; i++) {
+ element = &package->package.elements[i];
+
+ if (element->type != ACPI_TYPE_LOCAL_REFERENCE)
+ continue;
+
+ rhandle = element->reference.handle;
+ if (!rhandle)
+ goto fail;
+
+ acpi_get_name(rhandle, ACPI_SINGLE_NAME, &b_name);
+
+ dev_dbg(dev, "Found PM resource '%s'\n", name);
+ if (strlen(name) == 4 && !strncmp(name, "CLK", 3)) {
+ if (name[3] >= '0' && name[3] <= '4')
+ clock_num = name[3] - '0';
+#if 0
+ /*
+ * We could abort here, but let's parse all resources,
+ * as this is helpful for debugging purposes
+ */
+ if (clock_num >= 0)
+ break;
+#endif
+ }
+ }
+
+fail:
+ ACPI_FREE(buffer.pointer);
+
+ return clock_num;
+}
+
static struct gmin_subdev *gmin_subdev_add(struct v4l2_subdev *subdev)
{
struct i2c_client *power = NULL, *client = v4l2_get_subdevdata(subdev);
@@ -451,7 +506,7 @@ static struct gmin_subdev *gmin_subdev_add(struct v4l2_subdev *subdev)
struct gmin_subdev *gs;
acpi_handle handle;
struct device *dev;
- int i, ret, clock_num;
+ int i, ret, clock_num = -1;
if (!client)
return NULL;
@@ -570,7 +625,14 @@ static struct gmin_subdev *gmin_subdev_add(struct v4l2_subdev *subdev)
* is a power resource already, falling back to the EFI vars detection
* otherwise.
*/
- clock_num = gmin_get_var_int(dev, false, "CamClk", -1);
+
+ /* Try first to use ACPI to get the clock resource */
+ if (acpi_device_power_manageable(adev))
+ clock_num = atomisp_get_acpi_power(dev, handle);
+
+ /* Fall-back use EFI and/or DMI match */
+ if (clock_num < 0)
+ clock_num = gmin_get_var_int(dev, false, "CamClk", 0);
if (clock_num < 0 || clock_num > MAX_CLK_COUNT) {
dev_err(dev, "Invalid clock number\n");
--
2.26.2
