diff options
| -rw-r--r-- | drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c | 66 |
1 files 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 3e8ec3ed5d24..39e585faf0c5 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; @@ -557,7 +612,14 @@ 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"); |