ACER: Add support for accelerometer sensor

This device is present on Iconia Tab W500.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: joeyli <jlee@suse.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>

drivers/platform/x86/acer-wmi.c

@@ -95,6 +95,7 @@ MODULE_ALIAS("wmi:676AA15E-6A47-4D9F-A2CC-1E6D18D14026");
 
 enum acer_wmi_event_ids {
 	WMID_HOTKEY_EVENT = 0x1,
+	WMID_ACCEL_EVENT = 0x5,
 };
 
 static const struct key_entry acer_wmi_keymap[] = {
@@ -130,6 +131,7 @@ static const struct key_entry acer_wmi_keymap[] = {
 };
 
 static struct input_dev *acer_wmi_input_dev;
+static struct input_dev *acer_wmi_accel_dev;
 
 struct event_return_value {
 	u8 function;
@@ -200,6 +202,7 @@ struct hotkey_function_type_aa {
 #define ACER_CAP_BLUETOOTH		(1<<2)
 #define ACER_CAP_BRIGHTNESS		(1<<3)
 #define ACER_CAP_THREEG			(1<<4)
+#define ACER_CAP_ACCEL			(1<<5)
 #define ACER_CAP_ANY			(0xFFFFFFFF)
 
 /*
@@ -1398,6 +1401,60 @@ static void acer_backlight_exit(void)
 	backlight_device_unregister(acer_backlight_device);
 }
 
+/*
+ * Accelerometer device
+ */
+static acpi_handle gsensor_handle;
+
+static int acer_gsensor_init(void)
+{
+	acpi_status status;
+	struct acpi_buffer output;
+	union acpi_object out_obj;
+
+	output.length = sizeof(out_obj);
+	output.pointer = &out_obj;
+	status = acpi_evaluate_object(gsensor_handle, "_INI", NULL, &output);
+	if (ACPI_FAILURE(status))
+		return -1;
+
+	return 0;
+}
+
+static int acer_gsensor_open(struct input_dev *input)
+{
+	return acer_gsensor_init();
+}
+
+static int acer_gsensor_event(void)
+{
+	acpi_status status;
+	struct acpi_buffer output;
+	union acpi_object out_obj[5];
+
+	if (!has_cap(ACER_CAP_ACCEL))
+		return -1;
+
+	output.length = sizeof(out_obj);
+	output.pointer = out_obj;
+
+	status = acpi_evaluate_object(gsensor_handle, "RDVL", NULL, &output);
+	if (ACPI_FAILURE(status))
+		return -1;
+
+	if (out_obj->package.count != 4)
+		return -1;
+
+	input_report_abs(acer_wmi_accel_dev, ABS_X,
+		(s16)out_obj->package.elements[0].integer.value);
+	input_report_abs(acer_wmi_accel_dev, ABS_Y,
+		(s16)out_obj->package.elements[1].integer.value);
+	input_report_abs(acer_wmi_accel_dev, ABS_Z,
+		(s16)out_obj->package.elements[2].integer.value);
+	input_sync(acer_wmi_accel_dev);
+	return 0;
+}
+
 /*
  * Rfkill devices
  */
@@ -1673,6 +1730,9 @@ static void acer_wmi_notify(u32 value, void *context)
 						   1, true);
 		}
 		break;
+	case WMID_ACCEL_EVENT:
+		acer_gsensor_event();
+		break;
 	default:
 		pr_warn("Unknown function number - %d - %d\n",
 			return_value.function, return_value.key_num);
@@ -1758,6 +1818,74 @@ static int acer_wmi_enable_lm(void)
 	return status;
 }
 
+static acpi_status __init acer_wmi_get_handle_cb(acpi_handle ah, u32 level,
+						void *ctx, void **retval)
+{
+	*(acpi_handle *)retval = ah;
+	return AE_OK;
+}
+
+static int __init acer_wmi_get_handle(const char *name, const char *prop,
+					acpi_handle *ah)
+{
+	acpi_status status;
+	acpi_handle handle;
+
+	BUG_ON(!name || !ah);
+
+	handle = 0;
+	status = acpi_get_devices(prop, acer_wmi_get_handle_cb,
+					(void *)name, &handle);
+
+	if (ACPI_SUCCESS(status)) {
+		*ah = handle;
+		return 0;
+	} else {
+		return -ENODEV;
+	}
+}
+
+static int __init acer_wmi_accel_setup(void)
+{
+	int err;
+
+	err = acer_wmi_get_handle("SENR", "BST0001", &gsensor_handle);
+	if (err)
+		return err;
+
+	interface->capability |= ACER_CAP_ACCEL;
+
+	acer_wmi_accel_dev = input_allocate_device();
+	if (!acer_wmi_accel_dev)
+		return -ENOMEM;
+
+	acer_wmi_accel_dev->open = acer_gsensor_open;
+
+	acer_wmi_accel_dev->name = "Acer BMA150 accelerometer";
+	acer_wmi_accel_dev->phys = "wmi/input1";
+	acer_wmi_accel_dev->id.bustype = BUS_HOST;
+	acer_wmi_accel_dev->evbit[0] = BIT_MASK(EV_ABS);
+	input_set_abs_params(acer_wmi_accel_dev, ABS_X, -16384, 16384, 0, 0);
+	input_set_abs_params(acer_wmi_accel_dev, ABS_Y, -16384, 16384, 0, 0);
+	input_set_abs_params(acer_wmi_accel_dev, ABS_Z, -16384, 16384, 0, 0);
+
+	err = input_register_device(acer_wmi_accel_dev);
+	if (err)
+		goto err_free_dev;
+
+	return 0;
+
+err_free_dev:
+	input_free_device(acer_wmi_accel_dev);
+	return err;
+}
+
+static void acer_wmi_accel_destroy(void)
+{
+	input_unregister_device(acer_wmi_accel_dev);
+	input_free_device(acer_wmi_accel_dev);
+}
+
 static int __init acer_wmi_input_setup(void)
 {
 	acpi_status status;
@@ -1912,6 +2040,9 @@ static int acer_resume(struct device *dev)
 	if (has_cap(ACER_CAP_BRIGHTNESS))
 		set_u32(data->brightness, ACER_CAP_BRIGHTNESS);
 
+	if (has_cap(ACER_CAP_ACCEL))
+		acer_gsensor_init();
+
 	return 0;
 }
 
@@ -2090,6 +2221,8 @@ static int __init acer_wmi_init(void)
 			return err;
 	}
 
+	acer_wmi_accel_setup();
+
 	err = platform_driver_register(&acer_platform_driver);
 	if (err) {
 		pr_err("Unable to register platform driver\n");
@@ -2133,6 +2266,8 @@ static int __init acer_wmi_init(void)
 error_platform_register:
 	if (wmi_has_guid(ACERWMID_EVENT_GUID))
 		acer_wmi_input_destroy();
+	if (has_cap(ACER_CAP_ACCEL))
+		acer_wmi_accel_destroy();
 
 	return err;
 }
@@ -2142,6 +2277,9 @@ static void __exit acer_wmi_exit(void)
 	if (wmi_has_guid(ACERWMID_EVENT_GUID))
 		acer_wmi_input_destroy();
 
+	if (has_cap(ACER_CAP_ACCEL))
+		acer_wmi_accel_destroy();
+
 	remove_sysfs(acer_platform_device);
 	remove_debugfs();
 	platform_device_unregister(acer_platform_device);