drivers/mfd/cros_ec_dev.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
  *
  * Copyright (C) 2014 Google, Inc.
  */

 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/cros_ec_chardev.h>
 #include <linux/platform_data/cros_ec_commands.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/slab.h>

 #define DRV_NAME "cros-ec-dev"

 static struct class cros_class = {
 	.owner          = THIS_MODULE,
 	.name           = "chromeos",
 };

 /**
  * cros_feature_to_name - CrOS feature id to name/short description.
  * @id: The feature identifier.
  * @name: Device name associated with the feature id.
  * @desc: Short name that will be displayed.
  */
 struct cros_feature_to_name {
 	unsigned int id;
 	const char *name;
 	const char *desc;
 };

 /**
  * cros_feature_to_cells - CrOS feature id to mfd cells association.
  * @id: The feature identifier.
  * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
  * @num_cells: Number of mfd cells into the array.
  */
 struct cros_feature_to_cells {
 	unsigned int id;
 	const struct mfd_cell *mfd_cells;
 	unsigned int num_cells;
 };

 static const struct cros_feature_to_name cros_mcu_devices[] = {
 	{
 		.id	= EC_FEATURE_FINGERPRINT,
 		.name	= CROS_EC_DEV_FP_NAME,
 		.desc	= "Fingerprint",
 	},
 	{
 		.id	= EC_FEATURE_ISH,
 		.name	= CROS_EC_DEV_ISH_NAME,
 		.desc	= "Integrated Sensor Hub",
 	},
 	{
 		.id	= EC_FEATURE_SCP,
 		.name	= CROS_EC_DEV_SCP_NAME,
 		.desc	= "System Control Processor",
 	},
 	{
 		.id	= EC_FEATURE_TOUCHPAD,
 		.name	= CROS_EC_DEV_TP_NAME,
 		.desc	= "Touchpad",
 	},
 };

 static const struct mfd_cell cros_ec_cec_cells[] = {
 	{ .name = "cros-ec-cec", },
 };

 static const struct mfd_cell cros_ec_rtc_cells[] = {
 	{ .name = "cros-ec-rtc", },
 };

 static const struct mfd_cell cros_usbpd_charger_cells[] = {
 	{ .name = "cros-usbpd-charger", },
 	{ .name = "cros-usbpd-logger", },
 };

 static const struct cros_feature_to_cells cros_subdevices[] = {
 	{
 		.id		= EC_FEATURE_CEC,
 		.mfd_cells	= cros_ec_cec_cells,
 		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
 	},
 	{
 		.id		= EC_FEATURE_RTC,
 		.mfd_cells	= cros_ec_rtc_cells,
 		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
 	},
 	{
 		.id		= EC_FEATURE_USB_PD,
 		.mfd_cells	= cros_usbpd_charger_cells,
 		.num_cells	= ARRAY_SIZE(cros_usbpd_charger_cells),
 	},
 };

 static const struct mfd_cell cros_ec_platform_cells[] = {
 	{ .name = "cros-ec-chardev", },
 	{ .name = "cros-ec-debugfs", },
 	{ .name = "cros-ec-lightbar", },
 	{ .name = "cros-ec-sysfs", },
 };

 static const struct mfd_cell cros_ec_vbc_cells[] = {
 	{ .name = "cros-ec-vbc", }
 };

 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 = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
 		if (!msg)
 			return -ENOMEM;

 		msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
 		msg->insize = sizeof(ec->features);

 		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
 		if (ret < 0) {
 			dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
 				 ret, msg->result);
 			memset(ec->features, 0, sizeof(ec->features));
 		} else {
 			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);
 }

 static void cros_ec_class_release(struct device *dev)
 {
 	kfree(to_cros_ec_dev(dev));
 }

 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_status(ec->ec_dev, msg);
 	if (ret < 0) {
 		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 if lid angle sensor and/or FIFO are needed.
 	 */
 	sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
 			       GFP_KERNEL);
 	if (sensor_cells == NULL)
 		goto error;

 	sensor_platforms = kcalloc(sensor_num,
 				   sizeof(struct cros_ec_sensor_platform),
 				   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_status(ec->ec_dev, msg);
 		if (ret < 0) {
 			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)
 		ec->has_kb_wake_angle = true;

 	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
 		sensor_cells[id].name = "cros-ec-ring";
 		id++;
 	}
 	if (cros_ec_check_features(ec,
 				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
 		sensor_cells[id].name = "cros-ec-lid-angle";
 		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 struct cros_ec_sensor_platform sensor_platforms[] = {
 	{ .sensor_num = 0 },
 	{ .sensor_num = 1 }
 };

 static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
 	{
 		.name = "cros-ec-accel-legacy",
 		.platform_data = &sensor_platforms[0],
 		.pdata_size = sizeof(struct cros_ec_sensor_platform),
 	},
 	{
 		.name = "cros-ec-accel-legacy",
 		.platform_data = &sensor_platforms[1],
 		.pdata_size = sizeof(struct cros_ec_sensor_platform),
 	}
 };

 static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
 {
 	struct cros_ec_device *ec_dev = ec->ec_dev;
 	u8 status;
 	int ret;

 	/*
 	 * ECs that need legacy support are the main EC, directly connected to
 	 * the AP.
 	 */
 	if (ec->cmd_offset != 0)
 		return;

 	/*
 	 * Check if EC supports direct memory reads and if EC has
 	 * accelerometers.
 	 */
 	if (ec_dev->cmd_readmem) {
 		ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
 					  &status);
 		if (ret < 0) {
 			dev_warn(ec->dev, "EC direct read error.\n");
 			return;
 		}

 		/* Check if EC has accelerometers. */
 		if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
 			dev_info(ec->dev, "EC does not have accelerometers.\n");
 			return;
 		}
 	}

 	/*
 	 * The device may still support accelerometers:
 	 * it would be an older ARM based device that do not suppor the
 	 * EC_CMD_GET_FEATURES command.
 	 *
 	 * Register 2 accelerometers, we will fail in the IIO driver if there
 	 * are no sensors.
 	 */
 	ret = mfd_add_hotplug_devices(ec->dev, cros_ec_accel_legacy_cells,
 				      ARRAY_SIZE(cros_ec_accel_legacy_cells));
 	if (ret)
 		dev_err(ec_dev->dev, "failed to add EC sensors\n");
 }

 static int ec_device_probe(struct platform_device *pdev)
 {
 	int retval = -ENOMEM;
 	struct device_node *node;
 	struct device *dev = &pdev->dev;
 	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
 	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
 	int i;

 	if (!ec)
 		return retval;

 	dev_set_drvdata(dev, ec);
 	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);

 	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
 		/*
 		 * Check whether this is actually a dedicated MCU rather
 		 * than an standard EC.
 		 */
 		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
 			dev_info(dev, "CrOS %s MCU detected\n",
 				 cros_mcu_devices[i].desc);
 			/*
 			 * Help userspace differentiating ECs from other MCU,
 			 * regardless of the probing order.
 			 */
 			ec_platform->ec_name = cros_mcu_devices[i].name;
 			break;
 		}
 	}

 	/*
 	 * Add the class device
 	 */
 	ec->class_dev.class = &cros_class;
 	ec->class_dev.parent = dev;
 	ec->class_dev.release = cros_ec_class_release;

 	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
 	if (retval) {
 		dev_err(dev, "dev_set_name failed => %d\n", retval);
 		goto failed;
 	}

 	retval = device_add(&ec->class_dev);
 	if (retval)
 		goto failed;

 	/* check whether this EC is a sensor hub. */
 	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
 		cros_ec_sensors_register(ec);
 	else
 		/* Workaroud for older EC firmware */
 		cros_ec_accel_legacy_register(ec);

 	/*
 	 * The following subdevices can be detected by sending the
 	 * EC_FEATURE_GET_CMD Embedded Controller device.
 	 */
 	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
 		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
 			retval = mfd_add_hotplug_devices(ec->dev,
 						cros_subdevices[i].mfd_cells,
 						cros_subdevices[i].num_cells);
 			if (retval)
 				dev_err(ec->dev,
 					"failed to add %s subdevice: %d\n",
 					cros_subdevices[i].mfd_cells->name,
 					retval);
 		}
 	}

 	/*
 	 * The following subdevices cannot be detected by sending the
 	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
 	 */
 	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
 					 ARRAY_SIZE(cros_ec_platform_cells));
 	if (retval)
 		dev_warn(ec->dev,
 			 "failed to add cros-ec platform devices: %d\n",
 			 retval);

 	/* Check whether this EC instance has a VBC NVRAM */
 	node = ec->ec_dev->dev->of_node;
 	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
 		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
 						ARRAY_SIZE(cros_ec_vbc_cells));
 		if (retval)
 			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
 				 retval);
 	}

 	return 0;

 failed:
 	put_device(&ec->class_dev);
 	return retval;
 }

 static int ec_device_remove(struct platform_device *pdev)
 {
 	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);

 	mfd_remove_devices(ec->dev);
 	device_unregister(&ec->class_dev);
 	return 0;
 }

 static const struct platform_device_id cros_ec_id[] = {
 	{ DRV_NAME, 0 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_id);

 static struct platform_driver cros_ec_dev_driver = {
 	.driver = {
 		.name = DRV_NAME,
 	},
 	.id_table = cros_ec_id,
 	.probe = ec_device_probe,
 	.remove = ec_device_remove,
 };

 static int __init cros_ec_dev_init(void)
 {
 	int ret;

 	ret  = class_register(&cros_class);
 	if (ret) {
 		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
 		return ret;
 	}

 	/* Register the driver */
 	ret = platform_driver_register(&cros_ec_dev_driver);
 	if (ret < 0) {
 		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
 		goto failed_devreg;
 	}
 	return 0;

 failed_devreg:
 	class_unregister(&cros_class);
 	return ret;
 }

 static void __exit cros_ec_dev_exit(void)
 {
 	platform_driver_unregister(&cros_ec_dev_driver);
 	class_unregister(&cros_class);
 }

 module_init(cros_ec_dev_init);
 module_exit(cros_ec_dev_exit);

 MODULE_ALIAS("platform:" DRV_NAME);
 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
 MODULE_VERSION("1.0");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
	*
	* Copyright (C) 2014 Google, Inc.
	*/

	#include <linux/mfd/core.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/module.h>
	#include <linux/mod_devicetable.h>
	#include <linux/of_platform.h>
	#include <linux/platform_device.h>
	#include <linux/platform_data/cros_ec_chardev.h>
	#include <linux/platform_data/cros_ec_commands.h>
	#include <linux/platform_data/cros_ec_proto.h>
	#include <linux/slab.h>

	#define DRV_NAME "cros-ec-dev"

	static struct class cros_class = {
	.owner = THIS_MODULE,
	.name = "chromeos",
	};

	/**
	* cros_feature_to_name - CrOS feature id to name/short description.
	* @id: The feature identifier.
	* @name: Device name associated with the feature id.
	* @desc: Short name that will be displayed.
	*/
	struct cros_feature_to_name {
	unsigned int id;
	const char *name;
	const char *desc;
	};

	/**
	* cros_feature_to_cells - CrOS feature id to mfd cells association.
	* @id: The feature identifier.
	* @mfd_cells: Pointer to the array of mfd cells that needs to be added.
	* @num_cells: Number of mfd cells into the array.
	*/
	struct cros_feature_to_cells {
	unsigned int id;
	const struct mfd_cell *mfd_cells;
	unsigned int num_cells;
	};

	static const struct cros_feature_to_name cros_mcu_devices[] = {
	{
	.id = EC_FEATURE_FINGERPRINT,
	.name = CROS_EC_DEV_FP_NAME,
	.desc = "Fingerprint",
	},
	{
	.id = EC_FEATURE_ISH,
	.name = CROS_EC_DEV_ISH_NAME,
	.desc = "Integrated Sensor Hub",
	},
	{
	.id = EC_FEATURE_SCP,
	.name = CROS_EC_DEV_SCP_NAME,
	.desc = "System Control Processor",
	},
	{
	.id = EC_FEATURE_TOUCHPAD,
	.name = CROS_EC_DEV_TP_NAME,
	.desc = "Touchpad",
	},
	};

	static const struct mfd_cell cros_ec_cec_cells[] = {
	{ .name = "cros-ec-cec", },
	};

	static const struct mfd_cell cros_ec_rtc_cells[] = {
	{ .name = "cros-ec-rtc", },
	};

	static const struct mfd_cell cros_usbpd_charger_cells[] = {
	{ .name = "cros-usbpd-charger", },
	{ .name = "cros-usbpd-logger", },
	};

	static const struct cros_feature_to_cells cros_subdevices[] = {
	{
	.id = EC_FEATURE_CEC,
	.mfd_cells = cros_ec_cec_cells,
	.num_cells = ARRAY_SIZE(cros_ec_cec_cells),
	},
	{
	.id = EC_FEATURE_RTC,
	.mfd_cells = cros_ec_rtc_cells,
	.num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
	},
	{
	.id = EC_FEATURE_USB_PD,
	.mfd_cells = cros_usbpd_charger_cells,
	.num_cells = ARRAY_SIZE(cros_usbpd_charger_cells),
	},
	};

	static const struct mfd_cell cros_ec_platform_cells[] = {
	{ .name = "cros-ec-chardev", },
	{ .name = "cros-ec-debugfs", },
	{ .name = "cros-ec-lightbar", },
	{ .name = "cros-ec-sysfs", },
	};

	static const struct mfd_cell cros_ec_vbc_cells[] = {
	{ .name = "cros-ec-vbc", }
	};

	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 = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
	if (!msg)
	return -ENOMEM;

	msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
	msg->insize = sizeof(ec->features);

	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0) {
	dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
	ret, msg->result);
	memset(ec->features, 0, sizeof(ec->features));
	} else {
	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);
	}

	static void cros_ec_class_release(struct device *dev)
	{
	kfree(to_cros_ec_dev(dev));
	}

	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_status(ec->ec_dev, msg);
	if (ret < 0) {
	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 if lid angle sensor and/or FIFO are needed.
	*/
	sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
	GFP_KERNEL);
	if (sensor_cells == NULL)
	goto error;

	sensor_platforms = kcalloc(sensor_num,
	sizeof(struct cros_ec_sensor_platform),
	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_status(ec->ec_dev, msg);
	if (ret < 0) {
	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)
	ec->has_kb_wake_angle = true;

	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
	sensor_cells[id].name = "cros-ec-ring";
	id++;
	}
	if (cros_ec_check_features(ec,
	EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
	sensor_cells[id].name = "cros-ec-lid-angle";
	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 struct cros_ec_sensor_platform sensor_platforms[] = {
	{ .sensor_num = 0 },
	{ .sensor_num = 1 }
	};

	static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
	{
	.name = "cros-ec-accel-legacy",
	.platform_data = &sensor_platforms[0],
	.pdata_size = sizeof(struct cros_ec_sensor_platform),
	},
	{
	.name = "cros-ec-accel-legacy",
	.platform_data = &sensor_platforms[1],
	.pdata_size = sizeof(struct cros_ec_sensor_platform),
	}
	};

	static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
	{
	struct cros_ec_device *ec_dev = ec->ec_dev;
	u8 status;
	int ret;

	/*
	* ECs that need legacy support are the main EC, directly connected to
	* the AP.
	*/
	if (ec->cmd_offset != 0)
	return;

	/*
	* Check if EC supports direct memory reads and if EC has
	* accelerometers.
	*/
	if (ec_dev->cmd_readmem) {
	ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
	&status);
	if (ret < 0) {
	dev_warn(ec->dev, "EC direct read error.\n");
	return;
	}

	/* Check if EC has accelerometers. */
	if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
	dev_info(ec->dev, "EC does not have accelerometers.\n");
	return;
	}
	}

	/*
	* The device may still support accelerometers:
	* it would be an older ARM based device that do not suppor the
	* EC_CMD_GET_FEATURES command.
	*
	* Register 2 accelerometers, we will fail in the IIO driver if there
	* are no sensors.
	*/
	ret = mfd_add_hotplug_devices(ec->dev, cros_ec_accel_legacy_cells,
	ARRAY_SIZE(cros_ec_accel_legacy_cells));
	if (ret)
	dev_err(ec_dev->dev, "failed to add EC sensors\n");
	}

	static int ec_device_probe(struct platform_device *pdev)
	{
	int retval = -ENOMEM;
	struct device_node *node;
	struct device *dev = &pdev->dev;
	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
	struct cros_ec_dev ec = kzalloc(sizeof(ec), GFP_KERNEL);
	int i;

	if (!ec)
	return retval;

	dev_set_drvdata(dev, ec);
	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);

	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
	/*
	* Check whether this is actually a dedicated MCU rather
	* than an standard EC.
	*/
	if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
	dev_info(dev, "CrOS %s MCU detected\n",
	cros_mcu_devices[i].desc);
	/*
	* Help userspace differentiating ECs from other MCU,
	* regardless of the probing order.
	*/
	ec_platform->ec_name = cros_mcu_devices[i].name;
	break;
	}
	}

	/*
	* Add the class device
	*/
	ec->class_dev.class = &cros_class;
	ec->class_dev.parent = dev;
	ec->class_dev.release = cros_ec_class_release;

	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
	if (retval) {
	dev_err(dev, "dev_set_name failed => %d\n", retval);
	goto failed;
	}

	retval = device_add(&ec->class_dev);
	if (retval)
	goto failed;

	/* check whether this EC is a sensor hub. */
	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
	cros_ec_sensors_register(ec);
	else
	/* Workaroud for older EC firmware */
	cros_ec_accel_legacy_register(ec);

	/*
	* The following subdevices can be detected by sending the
	* EC_FEATURE_GET_CMD Embedded Controller device.
	*/
	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
	if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
	retval = mfd_add_hotplug_devices(ec->dev,
	cros_subdevices[i].mfd_cells,
	cros_subdevices[i].num_cells);
	if (retval)
	dev_err(ec->dev,
	"failed to add %s subdevice: %d\n",
	cros_subdevices[i].mfd_cells->name,
	retval);
	}
	}

	/*
	* The following subdevices cannot be detected by sending the
	* EC_FEATURE_GET_CMD to the Embedded Controller device.
	*/
	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
	ARRAY_SIZE(cros_ec_platform_cells));
	if (retval)
	dev_warn(ec->dev,
	"failed to add cros-ec platform devices: %d\n",
	retval);

	/* Check whether this EC instance has a VBC NVRAM */
	node = ec->ec_dev->dev->of_node;
	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
	ARRAY_SIZE(cros_ec_vbc_cells));
	if (retval)
	dev_warn(ec->dev, "failed to add VBC devices: %d\n",
	retval);
	}

	return 0;

	failed:
	put_device(&ec->class_dev);
	return retval;
	}

	static int ec_device_remove(struct platform_device *pdev)
	{
	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);

	mfd_remove_devices(ec->dev);
	device_unregister(&ec->class_dev);
	return 0;
	}

	static const struct platform_device_id cros_ec_id[] = {
	{ DRV_NAME, 0 },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(platform, cros_ec_id);

	static struct platform_driver cros_ec_dev_driver = {
	.driver = {
	.name = DRV_NAME,
	},
	.id_table = cros_ec_id,
	.probe = ec_device_probe,
	.remove = ec_device_remove,
	};

	static int __init cros_ec_dev_init(void)
	{
	int ret;

	ret = class_register(&cros_class);
	if (ret) {
	pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
	return ret;
	}

	/* Register the driver */
	ret = platform_driver_register(&cros_ec_dev_driver);
	if (ret < 0) {
	pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
	goto failed_devreg;
	}
	return 0;

	failed_devreg:
	class_unregister(&cros_class);
	return ret;
	}

	static void __exit cros_ec_dev_exit(void)
	{
	platform_driver_unregister(&cros_ec_dev_driver);
	class_unregister(&cros_class);
	}

	module_init(cros_ec_dev_init);
	module_exit(cros_ec_dev_exit);

	MODULE_ALIAS("platform:" DRV_NAME);
	MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
	MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
	MODULE_VERSION("1.0");
	MODULE_LICENSE("GPL");