platform/chrome: cros_ec_sensorhub: Add FIFO support

cros_ec_sensorhub registers a listener and query motion sense FIFO,
spread to iio sensors registers.

To test, we can use libiio:
  iiod&
  iio_readdev -u ip:localhost -T 10000 -s 25 -b 16 cros-ec-gyro | od -x

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/include/linux/platform_data/cros_ec_sensorhub.h b/include/linux/platform_data/cros_ec_sensorhub.h
index 7e46a47fd642..b0950814f820 100644
--- a/include/linux/platform_data/cros_ec_sensorhub.h
+++ b/include/linux/platform_data/cros_ec_sensorhub.h
@@ -8,8 +8,13 @@
 #ifndef __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
 #define __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H
 
+#include <linux/ktime.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
 #include <linux/platform_data/cros_ec_commands.h>
 
+struct iio_dev;
+
 /**
  * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information.
  * @sensor_num: Id of the sensor, as reported by the EC.
@@ -19,14 +24,85 @@ struct cros_ec_sensor_platform {
 };
 
 /**
+ * typedef cros_ec_sensorhub_push_data_cb_t - Callback function to send datum
+ *					      to specific sensors.
+ *
+ * @indio_dev: The IIO device that will process the sample.
+ * @data: Vector array of the ring sample.
+ * @timestamp: Timestamp in host timespace when the sample was acquired by
+ *             the EC.
+ */
+typedef int (*cros_ec_sensorhub_push_data_cb_t)(struct iio_dev *indio_dev,
+						s16 *data,
+						s64 timestamp);
+
+struct cros_ec_sensorhub_sensor_push_data {
+	struct iio_dev *indio_dev;
+	cros_ec_sensorhub_push_data_cb_t push_data_cb;
+};
+
+enum {
+	CROS_EC_SENSOR_LAST_TS,
+	CROS_EC_SENSOR_NEW_TS,
+	CROS_EC_SENSOR_ALL_TS
+};
+
+struct cros_ec_sensors_ring_sample {
+	u8  sensor_id;
+	u8  flag;
+	s16 vector[3];
+	s64 timestamp;
+} __packed;
+
+/**
  * struct cros_ec_sensorhub - Sensor Hub device data.
  *
+ * @dev: Device object, mostly used for logging.
  * @ec: Embedded Controller where the hub is located.
  * @sensor_num: Number of MEMS sensors present in the EC.
+ * @msg: Structure to send FIFO requests.
+ * @params: Pointer to parameters in msg.
+ * @resp: Pointer to responses in msg.
+ * @cmd_lock : Lock for sending msg.
+ * @notifier: Notifier to kick the FIFO interrupt.
+ * @ring: Preprocessed ring to store events.
+ * @fifo_timestamp: array for event timestamp and spreading.
+ * @fifo_info: copy of FIFO information coming from the EC.
+ * @fifo_size: size of the ring.
+ * @push_data: array of callback to send datums to iio sensor object.
  */
 struct cros_ec_sensorhub {
+	struct device *dev;
 	struct cros_ec_dev *ec;
 	int sensor_num;
+
+	struct cros_ec_command *msg;
+	struct ec_params_motion_sense *params;
+	struct ec_response_motion_sense *resp;
+	struct mutex cmd_lock;  /* Lock for protecting msg structure. */
+
+	struct notifier_block notifier;
+
+	struct cros_ec_sensors_ring_sample *ring;
+
+	ktime_t fifo_timestamp[CROS_EC_SENSOR_ALL_TS];
+	struct ec_response_motion_sense_fifo_info *fifo_info;
+	int fifo_size;
+
+	struct cros_ec_sensorhub_sensor_push_data *push_data;
 };
 
+int cros_ec_sensorhub_register_push_data(struct cros_ec_sensorhub *sensorhub,
+					 u8 sensor_num,
+					 struct iio_dev *indio_dev,
+					 cros_ec_sensorhub_push_data_cb_t cb);
+
+void cros_ec_sensorhub_unregister_push_data(struct cros_ec_sensorhub *sensorhub,
+					    u8 sensor_num);
+
+int cros_ec_sensorhub_ring_add(struct cros_ec_sensorhub *sensorhub);
+void cros_ec_sensorhub_ring_remove(void *arg);
+int cros_ec_sensorhub_ring_fifo_enable(struct cros_ec_sensorhub *sensorhub,
+				       bool on);
+
 #endif   /* __LINUX_PLATFORM_DATA_CROS_EC_SENSORHUB_H */