[PATCH v4 4/4] platform/chrome: cros_ec_dev - Register cros-ec sensors

[Enric Balletbo i Serra <enric.balletbo@collabora.com>]

Check whether the ChromeOS Embedded Controller is a sensor hub and in
such case issue a command to get the number of sensors and register them
all.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
---

Changes since v3:
 - Remove Unnecessary ( ) around 'ret < 0'.
 - Add Reviewed-by tag

 .../iio/common/cros_ec_sensors/cros_ec_sensors.c   |   4 +-
 drivers/platform/chrome/cros_ec_dev.c              | 122 +++++++++++++++++++++
 2 files changed, 124 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 48edeba..d6c372b 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -51,7 +51,7 @@ static int cros_ec_sensors_read(struct iio_dev *indio_dev,
 	s16 data = 0;
 	s64 val64;
 	int i;
-	int ret = IIO_VAL_INT;
+	int ret;
 	int idx = chan->scan_index;
 
 	mutex_lock(&st->core.cmd_lock);
@@ -137,7 +137,7 @@ static int cros_ec_sensors_write(struct iio_dev *indio_dev,
 {
 	struct cros_ec_sensors_state *st = iio_priv(indio_dev);
 	int i;
-	int ret = 0;
+	int ret;
 	int idx = chan->scan_index;
 
 	mutex_lock(&st->core.cmd_lock);
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 7eb5307..47268ec 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -18,6 +18,7 @@
  */
 
 #include <linux/fs.h>
+#include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -265,6 +266,123 @@ static void __remove(struct device *dev)
 	kfree(ec);
 }
 
+static void cros_ec_sensors_register(struct cros_ec_dev *ec)
+{
+	/*
+	 * Issue a command to get the number of sensor reported.
+	 * Build an array of sensors driver and register them all.
+	 */
+	int ret, i, id, sensor_num;
+	struct mfd_cell *sensor_cells;
+	struct cros_ec_sensor_platform *sensor_platforms;
+	int sensor_type[MOTIONSENSE_TYPE_MAX];
+	struct ec_params_motion_sense *params;
+	struct ec_response_motion_sense *resp;
+	struct cros_ec_command *msg;
+
+	msg = kzalloc(sizeof(struct cros_ec_command) +
+		      max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
+	if (msg == NULL)
+		return;
+
+	msg->version = 2;
+	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;
+	params->cmd = MOTIONSENSE_CMD_DUMP;
+
+	ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+	if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+		dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
+			 ret, msg->result);
+		goto error;
+	}
+
+	resp = (struct ec_response_motion_sense *)msg->data;
+	sensor_num = resp->dump.sensor_count;
+	/* Allocate 2 extra sensors in case lid angle or FIFO are needed */
+	sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 2),
+			       GFP_KERNEL);
+	if (sensor_cells == NULL)
+		goto error;
+
+	sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) *
+		  (sensor_num + 1), GFP_KERNEL);
+	if (sensor_platforms == NULL)
+		goto error_platforms;
+
+	memset(sensor_type, 0, sizeof(sensor_type));
+	id = 0;
+	for (i = 0; i < sensor_num; i++) {
+		params->cmd = MOTIONSENSE_CMD_INFO;
+		params->info.sensor_num = i;
+		ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
+		if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+			dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
+				 i, ret, msg->result);
+			continue;
+		}
+		switch (resp->info.type) {
+		case MOTIONSENSE_TYPE_ACCEL:
+			sensor_cells[id].name = "cros-ec-accel";
+			break;
+		case MOTIONSENSE_TYPE_GYRO:
+			sensor_cells[id].name = "cros-ec-gyro";
+			break;
+		case MOTIONSENSE_TYPE_MAG:
+			sensor_cells[id].name = "cros-ec-mag";
+			break;
+		case MOTIONSENSE_TYPE_PROX:
+			sensor_cells[id].name = "cros-ec-prox";
+			break;
+		case MOTIONSENSE_TYPE_LIGHT:
+			sensor_cells[id].name = "cros-ec-light";
+			break;
+		case MOTIONSENSE_TYPE_ACTIVITY:
+			sensor_cells[id].name = "cros-ec-activity";
+			break;
+		default:
+			dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
+			continue;
+		}
+		sensor_platforms[id].sensor_num = i;
+		sensor_cells[id].id = sensor_type[resp->info.type];
+		sensor_cells[id].platform_data = &sensor_platforms[id];
+		sensor_cells[id].pdata_size =
+			sizeof(struct cros_ec_sensor_platform);
+
+		sensor_type[resp->info.type]++;
+		id++;
+	}
+	if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) {
+		sensor_platforms[id].sensor_num = sensor_num;
+
+		sensor_cells[id].name = "cros-ec-angle";
+		sensor_cells[id].id = 0;
+		sensor_cells[id].platform_data = &sensor_platforms[id];
+		sensor_cells[id].pdata_size =
+			sizeof(struct cros_ec_sensor_platform);
+		id++;
+	}
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
+		sensor_cells[id].name = "cros-ec-ring";
+		id++;
+	}
+
+	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
+			      NULL, 0, NULL);
+	if (ret)
+		dev_err(ec->dev, "failed to add EC sensors\n");
+
+	kfree(sensor_platforms);
+error_platforms:
+	kfree(sensor_cells);
+error:
+	kfree(msg);
+}
+
 static int ec_device_probe(struct platform_device *pdev)
 {
 	int retval = -ENOMEM;
@@ -319,6 +437,10 @@ static int ec_device_probe(struct platform_device *pdev)
 		goto dev_reg_failed;
 	}
 
+	/* check whether this EC is a sensor hub. */
+	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
+		cros_ec_sensors_register(ec);
+
 	return 0;
 
 dev_reg_failed:
-- 
2.1.0