[PATCH v2 2/5] mfd: cros_ec: Get rid of cros_ec_check_features from cros_ec_dev.

[Enric Balletbo i Serra]

The cros_ec_dev driver should be used only to expose the Chrome OS Embedded
Controller to user-space and should not be used to add MFD devices by
calling mfd_add_devices. This patch moves this logic to the MFD cros_ec
driver and removes the MFD bits from the character device driver. Also
makes independent the IIO driver from the character device as also has no
sense.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
---

  As pointed by Lee Jones in this thread [1] we should not use the MFD API
outside of MFD. For this reason the cros-ec-rtc did not get accepted yet.
The reality is that we are calling mfd_add_devices from cros-ec-dev driver
already, so this patch get rid off the MFD calls inside the chardev driver
and moves to cros-ec MFD. Also I think the chardev device should simply
implement the ioctl calls to access to it from userspace.

Changes since v1:
 - Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>

[1]  https://www.spinics.net/lists/kernel/msg2465099.html

 .../iio/common/cros_ec_sensors/cros_ec_sensors.c   |   8 -
 .../common/cros_ec_sensors/cros_ec_sensors_core.c  |   8 +-
 drivers/iio/light/cros_ec_light_prox.c             |   8 -
 drivers/iio/pressure/cros_ec_baro.c                |   8 -
 drivers/mfd/cros_ec.c                              | 160 ++++++++++++++++++++
 drivers/platform/chrome/cros_ec_dev.c              | 161 ---------------------
 include/linux/mfd/cros_ec.h                        |   6 +-
 7 files changed, 170 insertions(+), 189 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 38e8783..9b53a01 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -191,19 +191,11 @@ static const struct iio_info ec_sensors_info = {
 static int cros_ec_sensors_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
-	struct cros_ec_device *ec_device;
 	struct iio_dev *indio_dev;
 	struct cros_ec_sensors_state *state;
 	struct iio_chan_spec *channel;
 	int ret, i;
 
-	if (!ec_dev || !ec_dev->ec_dev) {
-		dev_warn(&pdev->dev, "No CROS EC device found.\n");
-		return -EINVAL;
-	}
-	ec_device = ec_dev->ec_dev;
-
 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
 	if (!indio_dev)
 		return -ENOMEM;
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 416cae5..0cdb64a 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -41,12 +41,13 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
-	struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
+	struct cros_ec_device *ec_dev = dev_get_drvdata(pdev->dev.parent);
 	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
 
 	platform_set_drvdata(pdev, indio_dev);
 
-	state->ec = ec->ec_dev;
+	state->ec = ec_dev;
+
 	state->msg = devm_kzalloc(&pdev->dev,
 				max((u16)sizeof(struct ec_params_motion_sense),
 				state->ec->max_response), GFP_KERNEL);
@@ -59,7 +60,8 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
 
 	/* Set up the host command structure. */
 	state->msg->version = 2;
-	state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
+	state->msg->command = EC_CMD_MOTION_SENSE_CMD +
+				sensor_platform->cmd_offset;
 	state->msg->outsize = sizeof(struct ec_params_motion_sense);
 
 	indio_dev->dev.parent = &pdev->dev;
diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
index 7217223..2133ddc 100644
--- a/drivers/iio/light/cros_ec_light_prox.c
+++ b/drivers/iio/light/cros_ec_light_prox.c
@@ -181,19 +181,11 @@ static const struct iio_info cros_ec_light_prox_info = {
 static int cros_ec_light_prox_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
-	struct cros_ec_device *ec_device;
 	struct iio_dev *indio_dev;
 	struct cros_ec_light_prox_state *state;
 	struct iio_chan_spec *channel;
 	int ret;
 
-	if (!ec_dev || !ec_dev->ec_dev) {
-		dev_warn(dev, "No CROS EC device found.\n");
-		return -EINVAL;
-	}
-	ec_device = ec_dev->ec_dev;
-
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
 	if (!indio_dev)
 		return -ENOMEM;
diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
index 48b2a30..dbea18b 100644
--- a/drivers/iio/pressure/cros_ec_baro.c
+++ b/drivers/iio/pressure/cros_ec_baro.c
@@ -126,19 +126,11 @@ static const struct iio_info cros_ec_baro_info = {
 static int cros_ec_baro_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
-	struct cros_ec_device *ec_device;
 	struct iio_dev *indio_dev;
 	struct cros_ec_baro_state *state;
 	struct iio_chan_spec *channel;
 	int ret;
 
-	if (!ec_dev || !ec_dev->ec_dev) {
-		dev_warn(dev, "No CROS EC device found.\n");
-		return -EINVAL;
-	}
-	ec_device = ec_dev->ec_dev;
-
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
 	if (!indio_dev)
 		return -ENOMEM;
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index d4a407e..bbc17ab 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -84,6 +84,160 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
 	return cros_ec_cmd_xfer(ec_dev, &buf.msg);
 }
 
+static int cros_ec_check_features(struct cros_ec_device *ec_dev, int feature)
+{
+	struct cros_ec_command *msg;
+	int ret;
+
+	if (ec_dev->features[0] == -1U && ec_dev->features[1] == -1U) {
+		/* features bitmap not read yet */
+
+		msg = kmalloc(sizeof(*msg) + sizeof(ec_dev->features),
+			      GFP_KERNEL);
+		if (!msg)
+			return -ENOMEM;
+
+		msg->version = 0;
+		msg->command = EC_CMD_GET_FEATURES + ec_p.cmd_offset;
+		msg->insize = sizeof(ec_dev->features);
+		msg->outsize = 0;
+
+		ret = cros_ec_cmd_xfer(ec_dev, msg);
+		if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+			dev_warn(ec_dev->dev, "cannot get EC features: %d/%d\n",
+				 ret, msg->result);
+			memset(ec_dev->features, 0, sizeof(ec_dev->features));
+		}
+
+		memcpy(ec_dev->features, msg->data, sizeof(ec_dev->features));
+
+		dev_dbg(ec_dev->dev, "EC features %08x %08x\n",
+			ec_dev->features[0], ec_dev->features[1]);
+
+		kfree(msg);
+	}
+
+	return ec_dev->features[feature / 32] & EC_FEATURE_MASK_0(feature);
+}
+
+static void cros_ec_sensors_register(struct cros_ec_device *ec_dev)
+{
+	/*
+	 * 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_p.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_dev, msg);
+	if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+		dev_warn(ec_dev->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_dev, msg);
+		if (ret < 0 || msg->result != EC_RES_SUCCESS) {
+			dev_warn(ec_dev->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_BARO:
+			sensor_cells[id].name = "cros-ec-baro";
+			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->dev, "unknown type %d\n",
+				 resp->info.type);
+			continue;
+		}
+		sensor_platforms[id].sensor_num = i;
+		sensor_platforms[id].cmd_offset = ec_p.cmd_offset;
+		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++;
+	}
+
+	ret = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, sensor_cells,
+			      id, NULL, 0, NULL);
+	if (ret)
+		dev_err(ec_dev->dev, "failed to add EC sensors\n");
+
+	kfree(sensor_platforms);
+error_platforms:
+	kfree(sensor_cells);
+error:
+	kfree(msg);
+}
+
 int cros_ec_register(struct cros_ec_device *ec_dev)
 {
 	struct device *dev = ec_dev->dev;
@@ -94,6 +248,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 	ec_dev->max_request = sizeof(struct ec_params_hello);
 	ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
 	ec_dev->max_passthru = 0;
+	ec_dev->features[0] = -1U; /* Not cached yet */
+	ec_dev->features[1] = -1U; /* Not cached yet */
 
 	ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
 	if (!ec_dev->din)
@@ -127,6 +283,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
 		goto fail_mfd;
 	}
 
+	/* Check whether this EC is a sensor hub. */
+	if (cros_ec_check_features(ec_dev, EC_FEATURE_MOTION_SENSE))
+		cros_ec_sensors_register(ec_dev);
+
 	if (ec_dev->max_passthru) {
 		/*
 		 * Register a PD device as well on top of this device.
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index b9bf086..4947650 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -90,41 +90,6 @@ static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
 	return ret;
 }
 
-static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
-{
-	struct cros_ec_command *msg;
-	int ret;
-
-	if (ec->features[0] == -1U && ec->features[1] == -1U) {
-		/* features bitmap not read yet */
-
-		msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
-		if (!msg)
-			return -ENOMEM;
-
-		msg->version = 0;
-		msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
-		msg->insize = sizeof(ec->features);
-		msg->outsize = 0;
-
-		ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
-		if (ret < 0 || msg->result != EC_RES_SUCCESS) {
-			dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
-				 ret, msg->result);
-			memset(ec->features, 0, sizeof(ec->features));
-		}
-
-		memcpy(ec->features, msg->data, sizeof(ec->features));
-
-		dev_dbg(ec->dev, "EC features %08x %08x\n",
-			ec->features[0], ec->features[1]);
-
-		kfree(msg);
-	}
-
-	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
-}
-
 /* Device file ops */
 static int ec_device_open(struct inode *inode, struct file *filp)
 {
@@ -268,126 +233,6 @@ 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_BARO:
-			sensor_cells[id].name = "cros-ec-baro";
-			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;
@@ -402,8 +247,6 @@ static int ec_device_probe(struct platform_device *pdev)
 	ec->ec_dev = dev_get_drvdata(dev->parent);
 	ec->dev = dev;
 	ec->cmd_offset = ec_platform->cmd_offset;
-	ec->features[0] = -1U; /* Not cached yet */
-	ec->features[1] = -1U; /* Not cached yet */
 	device_initialize(&ec->class_dev);
 	cdev_init(&ec->cdev, &fops);
 
@@ -432,10 +275,6 @@ static int ec_device_probe(struct platform_device *pdev)
 	if (cros_ec_debugfs_init(ec))
 		dev_warn(dev, "failed to create debugfs directory\n");
 
-	/* check whether this EC is a sensor hub. */
-	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
-		cros_ec_sensors_register(ec);
-
 	/* Take control of the lightbar from the EC. */
 	lb_manual_suspend_ctrl(ec, 1);
 
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 3b16c90..8f87999 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -115,6 +115,7 @@ struct cros_ec_command {
  * @event_notifier: interrupt event notifier for transport devices.
  * @event_data: raw payload transferred with the MKBP event.
  * @event_size: size in bytes of the event data.
+ * @features: stores the EC features.
  */
 struct cros_ec_device {
 
@@ -149,15 +150,19 @@ struct cros_ec_device {
 
 	struct ec_response_get_next_event event_data;
 	int event_size;
+	u32 features[2];
 };
 
 /**
  * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information
  *
  * @sensor_num: Id of the sensor, as reported by the EC.
+ * @cmd_offset: offset to apply for each command. Set when
+ * registering a devicde behind another one.
  */
 struct cros_ec_sensor_platform {
 	u8 sensor_num;
+	u16 cmd_offset;
 };
 
 /* struct cros_ec_platform - ChromeOS EC platform information
@@ -191,7 +196,6 @@ struct cros_ec_dev {
 	struct device *dev;
 	struct cros_ec_debugfs *debug_info;
 	u16 cmd_offset;
-	u32 features[2];
 };
 
 /**
-- 
2.9.3