+
+ return buffer.pointer;
+}
+
+/**
+ * radeon_atpx_parse_functions - parse supported functions
+ *
+ * @f: supported functions struct
+ * @mask: supported functions mask from ATPX
+ *
+ * Use the supported functions mask from ATPX function
+ * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
+ * are supported (all asics).
+ */
+static void radeon_atpx_parse_functions(struct radeon_atpx_functions *f, u32 mask)
+{
+ f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
+ f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
+ f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
+ f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
+ f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
+ f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
+ f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
+ f->disp_detetion_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
+}
+
+/**
+ * radeon_atpx_verify_interface - verify ATPX
+ *
+ * @handle: acpi handle
+ * @atpx: radeon atpx struct
+ *
+ * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
+ * to initialize ATPX and determine what features are supported
+ * (all asics).
+ * returns 0 on success, error on failure.
+ */
+static int radeon_atpx_verify_interface(acpi_handle handle,
+ struct radeon_atpx *atpx)
+{
+ union acpi_object *info;
+ struct atpx_verify_interface output;
+ size_t size;
+ int err = 0;
+
+ info = radeon_atpx_call(handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
+ if (!info)
+ return -EIO;
+
+ memset(&output, 0, sizeof(output));
+
+ size = *(u16 *) info->buffer.pointer;
+ if (size < 8) {
+ printk("ATPX buffer is too small: %lu\n", size);
+ err = -EINVAL;
+ goto out;
+ }
+ size = min(sizeof(output), size);
+
+ memcpy(&output, info->buffer.pointer, size);
+
+ /* TODO: check version? */
+ printk("ATPX version %u\n", output.version);
+
+ radeon_atpx_parse_functions(&atpx->functions, output.function_bits);
+
+out:
+ kfree(info);
+ return err;