HID: Delay opening HID device

Don't call hid_open_device till there is actually an user. This saves
power by not opening underlying transport for HID. Also close device
if there are no active mfd client using HID sensor hub.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 35 insertions, 10 deletions

diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index 10e1581022cf..88fc5aefcd96 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -465,6 +465,39 @@ static int sensor_hub_raw_event(struct hid_device *hdev,
 	return 1;
 }
 
+int sensor_hub_device_open(struct hid_sensor_hub_device *hsdev)
+{
+	int ret = 0;
+	struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);
+
+	mutex_lock(&data->mutex);
+	if (!hsdev->ref_cnt) {
+		ret = hid_hw_open(hsdev->hdev);
+		if (ret) {
+			hid_err(hsdev->hdev, "failed to open hid device\n");
+			mutex_unlock(&data->mutex);
+			return ret;
+		}
+	}
+	hsdev->ref_cnt++;
+	mutex_unlock(&data->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(sensor_hub_device_open);
+
+void sensor_hub_device_close(struct hid_sensor_hub_device *hsdev)
+{
+	struct sensor_hub_data *data =  hid_get_drvdata(hsdev->hdev);
+
+	mutex_lock(&data->mutex);
+	hsdev->ref_cnt--;
+	if (!hsdev->ref_cnt)
+		hid_hw_close(hsdev->hdev);
+	mutex_unlock(&data->mutex);
+}
+EXPORT_SYMBOL_GPL(sensor_hub_device_close);
+
 static int sensor_hub_probe(struct hid_device *hdev,
 				const struct hid_device_id *id)
 {
@@ -506,12 +539,6 @@ static int sensor_hub_probe(struct hid_device *hdev,
 		hid_err(hdev, "hw start failed\n");
 		return ret;
 	}
-	ret = hid_hw_open(hdev);
-	if (ret) {
-		hid_err(hdev, "failed to open input interrupt pipe\n");
-		goto err_stop_hw;
-	}
-
 	INIT_LIST_HEAD(&sd->dyn_callback_list);
 	sd->hid_sensor_client_cnt = 0;
 	report_enum = &hdev->report_enum[HID_INPUT_REPORT];
@@ -520,7 +547,7 @@ static int sensor_hub_probe(struct hid_device *hdev,
 	if (dev_cnt > HID_MAX_PHY_DEVICES) {
 		hid_err(hdev, "Invalid Physical device count\n");
 		ret = -EINVAL;
-		goto err_close;
+		goto err_stop_hw;
 	}
 	sd->hid_sensor_hub_client_devs = kzalloc(dev_cnt *
 						sizeof(struct mfd_cell),
@@ -528,7 +555,7 @@ static int sensor_hub_probe(struct hid_device *hdev,
 	if (sd->hid_sensor_hub_client_devs == NULL) {
 		hid_err(hdev, "Failed to allocate memory for mfd cells\n");
 			ret = -ENOMEM;
-			goto err_close;
+			goto err_stop_hw;
 	}
 	list_for_each_entry(report, &report_enum->report_list, list) {
 		hid_dbg(hdev, "Report id:%x\n", report->id);
@@ -565,8 +592,6 @@ err_free_names:
 	for (i = 0; i < sd->hid_sensor_client_cnt ; ++i)
 		kfree(sd->hid_sensor_hub_client_devs[i].name);
 	kfree(sd->hid_sensor_hub_client_devs);
-err_close:
-	hid_hw_close(hdev);
 err_stop_hw:
 	hid_hw_stop(hdev);