HID: hid-sensor-hub: Extend API for async reads

Add additional flag to read in async mode. In this mode the caller will get
reply via registered callback for capture_sample. Callbacks can be registered
using sensor_hub_register_callback function. The usage id parameter of the
capture_sample can be matched with the usage id of the requested attribute.

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

10 files changed, 64 insertions, 44 deletions

diff --git a/drivers/hid/hid-sensor-hub.c b/drivers/hid/hid-sensor-hub.c
index c325f85fa3a6..0a9162363164 100644
--- a/drivers/hid/hid-sensor-hub.c
+++ b/drivers/hid/hid-sensor-hub.c
@@ -250,48 +250,53 @@ EXPORT_SYMBOL_GPL(sensor_hub_get_feature);
 
 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
                                         u32 usage_id,
-                                        u32 attr_usage_id, u32 report_id)
+                                        u32 attr_usage_id, u32 report_id,
+                                        enum sensor_hub_read_flags flag)
 {
         struct sensor_hub_data *data = hid_get_drvdata(hsdev->hdev);
         unsigned long flags;
         struct hid_report *report;
         int ret_val = 0;
 
-        mutex_lock(&hsdev->mutex);
-        memset(&hsdev->pending, 0, sizeof(hsdev->pending));
-        init_completion(&hsdev->pending.ready);
-        hsdev->pending.usage_id = usage_id;
-        hsdev->pending.attr_usage_id = attr_usage_id;
-        hsdev->pending.raw_size = 0;
-
-        spin_lock_irqsave(&data->lock, flags);
-        hsdev->pending.status = true;
-        spin_unlock_irqrestore(&data->lock, flags);
-        report = sensor_hub_report(report_id, hsdev->hdev, HID_INPUT_REPORT);
+        report = sensor_hub_report(report_id, hsdev->hdev,
+                                   HID_INPUT_REPORT);
         if (!report)
-                goto err_free;
+                return -EINVAL;
 
+        mutex_lock(&hsdev->mutex);
+        if (flag == SENSOR_HUB_SYNC) {
+                memset(&hsdev->pending, 0, sizeof(hsdev->pending));
+                init_completion(&hsdev->pending.ready);
+                hsdev->pending.usage_id = usage_id;
+                hsdev->pending.attr_usage_id = attr_usage_id;
+                hsdev->pending.raw_size = 0;
+
+                spin_lock_irqsave(&data->lock, flags);
+                hsdev->pending.status = true;
+                spin_unlock_irqrestore(&data->lock, flags);
+        }
         mutex_lock(&data->mutex);
         hid_hw_request(hsdev->hdev, report, HID_REQ_GET_REPORT);
         mutex_unlock(&data->mutex);
-        wait_for_completion_interruptible_timeout(&hsdev->pending.ready, HZ*5);
-        switch (hsdev->pending.raw_size) {
-        case 1:
-                ret_val = *(u8 *)hsdev->pending.raw_data;
-                break;
-        case 2:
-                ret_val = *(u16 *)hsdev->pending.raw_data;
-                break;
-        case 4:
-                ret_val = *(u32 *)hsdev->pending.raw_data;
-                break;
-        default:
-                ret_val = 0;
+        if (flag == SENSOR_HUB_SYNC) {
+                wait_for_completion_interruptible_timeout(
+                                                &hsdev->pending.ready, HZ*5);
+                switch (hsdev->pending.raw_size) {
+                case 1:
+                        ret_val = *(u8 *)hsdev->pending.raw_data;
+                        break;
+                case 2:
+                        ret_val = *(u16 *)hsdev->pending.raw_data;
+                        break;
+                case 4:
+                        ret_val = *(u32 *)hsdev->pending.raw_data;
+                        break;
+                default:
+                        ret_val = 0;
+                }
+                kfree(hsdev->pending.raw_data);
+                hsdev->pending.status = false;
         }
-        kfree(hsdev->pending.raw_data);
-
-err_free:
-        hsdev->pending.status = false;
         mutex_unlock(&hsdev->mutex);
 
         return ret_val;
diff --git a/drivers/iio/accel/hid-sensor-accel-3d.c b/drivers/iio/accel/hid-sensor-accel-3d.c
index d5d95317003a..0085c2faeaaa 100644
--- a/drivers/iio/accel/hid-sensor-accel-3d.c
+++ b/drivers/iio/accel/hid-sensor-accel-3d.c
@@ -130,7 +130,8 @@ static int accel_3d_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                         accel_state->common_attributes.hsdev,
                                         HID_USAGE_SENSOR_ACCEL_3D, address,
-                                        report_id);
+                                        report_id,
+                                        SENSOR_HUB_SYNC);
                 else {
                         *val = 0;
                         hid_sensor_power_state(&accel_state->common_attributes,
diff --git a/drivers/iio/gyro/hid-sensor-gyro-3d.c b/drivers/iio/gyro/hid-sensor-gyro-3d.c
index a3ea1e8785d7..bdcd105aba26 100644
--- a/drivers/iio/gyro/hid-sensor-gyro-3d.c
+++ b/drivers/iio/gyro/hid-sensor-gyro-3d.c
@@ -130,7 +130,8 @@ static int gyro_3d_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                         gyro_state->common_attributes.hsdev,
                                         HID_USAGE_SENSOR_GYRO_3D, address,
-                                        report_id);
+                                        report_id,
+                                        SENSOR_HUB_SYNC);
                 else {
                         *val = 0;
                         hid_sensor_power_state(&gyro_state->common_attributes,
diff --git a/drivers/iio/light/hid-sensor-als.c b/drivers/iio/light/hid-sensor-als.c
index a5283d75c096..321862da626b 100644
--- a/drivers/iio/light/hid-sensor-als.c
+++ b/drivers/iio/light/hid-sensor-als.c
@@ -109,7 +109,8 @@ static int als_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                         als_state->common_attributes.hsdev,
                                         HID_USAGE_SENSOR_ALS, address,
-                                        report_id);
+                                        report_id,
+                                        SENSOR_HUB_SYNC);
                         hid_sensor_power_state(&als_state->common_attributes,
                                                 false);
                 } else {
diff --git a/drivers/iio/light/hid-sensor-prox.c b/drivers/iio/light/hid-sensor-prox.c
index f5a514698fd8..db9c60e47276 100644
--- a/drivers/iio/light/hid-sensor-prox.c
+++ b/drivers/iio/light/hid-sensor-prox.c
@@ -105,7 +105,8 @@ static int prox_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                 prox_state->common_attributes.hsdev,
                                 HID_USAGE_SENSOR_PROX, address,
-                                report_id);
+                                report_id,
+                                SENSOR_HUB_SYNC);
                         hid_sensor_power_state(&prox_state->common_attributes,
                                                 false);
                 } else {
diff --git a/drivers/iio/magnetometer/hid-sensor-magn-3d.c b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
index 6294575d2777..4d299f39ffd1 100644
--- a/drivers/iio/magnetometer/hid-sensor-magn-3d.c
+++ b/drivers/iio/magnetometer/hid-sensor-magn-3d.c
@@ -178,7 +178,8 @@ static int magn_3d_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                 magn_state->common_attributes.hsdev,
                                 HID_USAGE_SENSOR_COMPASS_3D, address,
-                                report_id);
+                                report_id,
+                                SENSOR_HUB_SYNC);
                 else {
                         *val = 0;
                         hid_sensor_power_state(&magn_state->common_attributes,
diff --git a/drivers/iio/orientation/hid-sensor-incl-3d.c b/drivers/iio/orientation/hid-sensor-incl-3d.c
index 1ff181bbbcef..45bed080b4a6 100644
--- a/drivers/iio/orientation/hid-sensor-incl-3d.c
+++ b/drivers/iio/orientation/hid-sensor-incl-3d.c
@@ -132,7 +132,8 @@ static int incl_3d_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                 incl_state->common_attributes.hsdev,
                                 HID_USAGE_SENSOR_INCLINOMETER_3D, address,
-                                report_id);
+                                report_id,
+                                SENSOR_HUB_SYNC);
                 else {
                         hid_sensor_power_state(&incl_state->common_attributes,
                                                 false);
diff --git a/drivers/iio/pressure/hid-sensor-press.c b/drivers/iio/pressure/hid-sensor-press.c
index 764928682df2..ac150f0c8b02 100644
--- a/drivers/iio/pressure/hid-sensor-press.c
+++ b/drivers/iio/pressure/hid-sensor-press.c
@@ -108,7 +108,8 @@ static int press_read_raw(struct iio_dev *indio_dev,
                         *val = sensor_hub_input_attr_get_raw_value(
                                 press_state->common_attributes.hsdev,
                                 HID_USAGE_SENSOR_PRESSURE, address,
-                                report_id);
+                                report_id,
+                                SENSOR_HUB_SYNC);
                         hid_sensor_power_state(&press_state->common_attributes,
                                                 false);
                 } else {
diff --git a/drivers/rtc/rtc-hid-sensor-time.c b/drivers/rtc/rtc-hid-sensor-time.c
index ae7c2ba440cf..af4f85a66b39 100644
--- a/drivers/rtc/rtc-hid-sensor-time.c
+++ b/drivers/rtc/rtc-hid-sensor-time.c
@@ -213,7 +213,7 @@ static int hid_rtc_read_time(struct device *dev, struct rtc_time *tm)
         /* get a report with all values through requesting one value */
         sensor_hub_input_attr_get_raw_value(time_state->common_attributes.hsdev,
                         HID_USAGE_SENSOR_TIME, hid_time_addresses[0],
-                        time_state->info[0].report_id);
+                        time_state->info[0].report_id, SENSOR_HUB_SYNC);
         /* wait for all values (event) */
         ret = wait_for_completion_killable_timeout(
                         &time_state->comp_last_time, HZ*6);
diff --git a/include/linux/hid-sensor-hub.h b/include/linux/hid-sensor-hub.h
index 60a34277ddf2..4c49b041922d 100644
--- a/include/linux/hid-sensor-hub.h
+++ b/include/linux/hid-sensor-hub.h
@@ -169,19 +169,27 @@ int sensor_hub_input_get_attribute_info(struct hid_sensor_hub_device *hsdev,
                         struct hid_sensor_hub_attribute_info *info);
 
 /**
-* sensor_hub_input_attr_get_raw_value() - Synchronous read request
+* sensor_hub_input_attr_get_raw_value() - Attribute read request
 * @usage_id:    Attribute usage id of parent physical device as per spec
 * @attr_usage_id:       Attribute usage id as per spec
 * @report_id:   Report id to look for
+* @flag:      Synchronous or asynchronous read
 *
-* Issues a synchronous read request for an input attribute. Returns
-* data upto 32 bits. Since client can get events, so this call should
-* not be used for data paths, this will impact performance.
+* Issues a synchronous or asynchronous read request for an input attribute.
+* Returns data upto 32 bits.
 */
 
+enum sensor_hub_read_flags {
+        SENSOR_HUB_SYNC,
+        SENSOR_HUB_ASYNC,
+};
+
 int sensor_hub_input_attr_get_raw_value(struct hid_sensor_hub_device *hsdev,
-                        u32 usage_id,
-                        u32 attr_usage_id, u32 report_id);
+                                        u32 usage_id,
+                                        u32 attr_usage_id, u32 report_id,
+                                        enum sensor_hub_read_flags flag
+);
+
 /**
 * sensor_hub_set_feature() - Feature set request
 * @report_id:   Report id to look for