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 <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Acked-by: Andy Shevchenko <[email protected]>
Signed-off-by: Enric Balletbo i Serra <[email protected]>

Author: gwendalcr

drivers/platform/chrome/Makefile

@@ -20,7 +20,8 @@ obj-$(CONFIG_CROS_EC_CHARDEV)		+= cros_ec_chardev.o
 obj-$(CONFIG_CROS_EC_LIGHTBAR)		+= cros_ec_lightbar.o
 obj-$(CONFIG_CROS_EC_VBC)		+= cros_ec_vbc.o
 obj-$(CONFIG_CROS_EC_DEBUGFS)		+= cros_ec_debugfs.o
-obj-$(CONFIG_CROS_EC_SENSORHUB)		+= cros_ec_sensorhub.o
+cros-ec-sensorhub-objs			:= cros_ec_sensorhub.o cros_ec_sensorhub_ring.o
+obj-$(CONFIG_CROS_EC_SENSORHUB)		+= cros-ec-sensorhub.o
 obj-$(CONFIG_CROS_EC_SYSFS)		+= cros_ec_sysfs.o
 obj-$(CONFIG_CROS_USBPD_LOGGER)		+= cros_usbpd_logger.o
 obj-$(CONFIG_CROS_USBPD_NOTIFY)		+= cros_usbpd_notify.o

drivers/platform/chrome/cros_ec_sensorhub.c

@@ -50,10 +50,8 @@ static int cros_ec_sensorhub_register(struct device *dev,
 				      struct cros_ec_sensorhub *sensorhub)
 {
 	int sensor_type[MOTIONSENSE_TYPE_MAX] = { 0 };
+	struct cros_ec_command *msg = sensorhub->msg;
 	struct cros_ec_dev *ec = sensorhub->ec;
-	struct ec_params_motion_sense *params;
-	struct ec_response_motion_sense *resp;
-	struct cros_ec_command *msg;
 	int ret, i, sensor_num;
 	char *name;
 
@@ -71,22 +69,13 @@ static int cros_ec_sensorhub_register(struct device *dev,
 		return -EINVAL;
 	}
 
-	/* Prepare a message to send INFO command to each sensor. */
-	msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
-		      GFP_KERNEL);
-	if (!msg)
-		return -ENOMEM;
-
 	msg->version = 1;
-	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
-	msg->outsize = sizeof(*params);
-	msg->insize = sizeof(*resp);
-	params = (struct ec_params_motion_sense *)msg->data;
-	resp = (struct ec_response_motion_sense *)msg->data;
+	msg->insize = sizeof(struct ec_response_motion_sense);
+	msg->outsize = sizeof(struct ec_params_motion_sense);
 
 	for (i = 0; i < sensor_num; i++) {
-		params->cmd = MOTIONSENSE_CMD_INFO;
-		params->info.sensor_num = i;
+		sensorhub->params->cmd = MOTIONSENSE_CMD_INFO;
+		sensorhub->params->info.sensor_num = i;
 
 		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 		if (ret < 0) {
@@ -95,7 +84,7 @@ static int cros_ec_sensorhub_register(struct device *dev,
 			continue;
 		}
 
-		switch (resp->info.type) {
+		switch (sensorhub->resp->info.type) {
 		case MOTIONSENSE_TYPE_ACCEL:
 			name = "cros-ec-accel";
 			break;
@@ -118,15 +107,16 @@ static int cros_ec_sensorhub_register(struct device *dev,
 			name = "cros-ec-activity";
 			break;
 		default:
-			dev_warn(dev, "unknown type %d\n", resp->info.type);
+			dev_warn(dev, "unknown type %d\n",
+				 sensorhub->resp->info.type);
 			continue;
 		}
 
 		ret = cros_ec_sensorhub_allocate_sensor(dev, name, i);
 		if (ret)
-			goto error;
+			return ret;
 
-		sensor_type[resp->info.type]++;
+		sensor_type[sensorhub->resp->info.type]++;
 	}
 
 	if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
@@ -138,29 +128,41 @@ static int cros_ec_sensorhub_register(struct device *dev,
 							"cros-ec-lid-angle",
 							0);
 		if (ret)
-			goto error;
+			return ret;
 	}
 
-	kfree(msg);
 	return 0;
-
-error:
-	kfree(msg);
-	return ret;
 }
 
 static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct cros_ec_dev *ec = dev_get_drvdata(dev->parent);
 	struct cros_ec_sensorhub *data;
+	struct cros_ec_command *msg;
 	int ret;
 	int i;
 
+	msg = devm_kzalloc(dev, sizeof(struct cros_ec_command) +
+			   max((u16)sizeof(struct ec_params_motion_sense),
+			       ec->ec_dev->max_response), GFP_KERNEL);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
+
 	data = devm_kzalloc(dev, sizeof(struct cros_ec_sensorhub), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;
 
-	data->ec = dev_get_drvdata(dev->parent);
+	mutex_init(&data->cmd_lock);
+
+	data->dev = dev;
+	data->ec = ec;
+	data->msg = msg;
+	data->params = (struct ec_params_motion_sense *)msg->data;
+	data->resp = (struct ec_response_motion_sense *)msg->data;
+
 	dev_set_drvdata(dev, data);
 
 	/* Check whether this EC is a sensor hub. */
@@ -182,12 +184,63 @@ static int cros_ec_sensorhub_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * If the EC does not have a FIFO, the sensors will query their data
+	 * themselves via sysfs or a software trigger.
+	 */
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
+		ret = cros_ec_sensorhub_ring_add(data);
+		if (ret)
+			return ret;
+		/*
+		 * The msg and its data is not under the control of the ring
+		 * handler.
+		 */
+		return devm_add_action_or_reset(dev,
+						cros_ec_sensorhub_ring_remove,
+						data);
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+/*
+ * When the EC is suspending, we must stop sending interrupt,
+ * we may use the same interrupt line for waking up the device.
+ * Tell the EC to stop sending non-interrupt event on the iio ring.
+ */
+static int cros_ec_sensorhub_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
+	struct cros_ec_dev *ec = sensorhub->ec;
+
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
+		return cros_ec_sensorhub_ring_fifo_enable(sensorhub, false);
 	return 0;
 }
 
+static int cros_ec_sensorhub_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct cros_ec_sensorhub *sensorhub = platform_get_drvdata(pdev);
+	struct cros_ec_dev *ec = sensorhub->ec;
+
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO))
+		return cros_ec_sensorhub_ring_fifo_enable(sensorhub, true);
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(cros_ec_sensorhub_pm_ops,
+		cros_ec_sensorhub_suspend,
+		cros_ec_sensorhub_resume);
+
 static struct platform_driver cros_ec_sensorhub_driver = {
 	.driver = {
 		.name = DRV_NAME,
+		.pm = &cros_ec_sensorhub_pm_ops,
 	},
 	.probe = cros_ec_sensorhub_probe,
 };