drivers/mfd/cros_ec_dev.c - linux - 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/dmi.h>
 #include <linux/kconfig.h>
 #include <linux/mfd/core.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
 #include <linux/of.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 = {
 	.name           = "chromeos",
 };

 /**
  * struct 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;
 };

 /**
  * struct 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_ec_sensorhub_cells[] = {
 	{ .name = "cros-ec-sensorhub", },
 };

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

 static const struct mfd_cell cros_usbpd_notify_cells[] = {
 	{ .name = "cros-usbpd-notify", },
 };

 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-sysfs", },
 };

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

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

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

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

 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);
 	struct ec_response_pchg_count pchg_count;
 	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.flags[0] = -1U; /* Not cached yet */
 	ec->features.flags[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_get_sensor_count(ec) > 0) {
 		retval = mfd_add_hotplug_devices(ec->dev,
 				cros_ec_sensorhub_cells,
 				ARRAY_SIZE(cros_ec_sensorhub_cells));
 		if (retval)
 			dev_err(ec->dev, "failed to add %s subdevice: %d\n",
 				cros_ec_sensorhub_cells->name, retval);
 	}

 	/*
 	 * 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);
 		}
 	}

 	/*
 	 * Lightbar is a special case. Newer devices support autodetection,
 	 * but older ones do not.
 	 */
 	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) ||
 	    dmi_match(DMI_PRODUCT_NAME, "Link")) {
 		retval = mfd_add_hotplug_devices(ec->dev,
 					cros_ec_lightbar_cells,
 					ARRAY_SIZE(cros_ec_lightbar_cells));
 		if (retval)
 			dev_warn(ec->dev, "failed to add lightbar: %d\n",
 				 retval);
 	}

 	/*
 	 * The PD notifier driver cell is separate since it only needs to be
 	 * explicitly added on platforms that don't have the PD notifier ACPI
 	 * device entry defined.
 	 */
 	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
 		if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
 			retval = mfd_add_hotplug_devices(ec->dev,
 					cros_usbpd_notify_cells,
 					ARRAY_SIZE(cros_usbpd_notify_cells));
 			if (retval)
 				dev_err(ec->dev,
 					"failed to add PD notify devices: %d\n",
 					retval);
 		}
 	}

 	/*
 	 * The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
 	 * it can be detected by querying the number of peripheral chargers.
 	 */
 	retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
 			     &pchg_count, sizeof(pchg_count));
 	if (retval >= 0 && pchg_count.port_count) {
 		retval = mfd_add_hotplug_devices(ec->dev,
 					cros_ec_pchg_cells,
 					ARRAY_SIZE(cros_ec_pchg_cells));
 		if (retval)
 			dev_warn(ec->dev, "failed to add pchg: %d\n",
 				 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_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/dmi.h>
	#include <linux/kconfig.h>
	#include <linux/mfd/core.h>
	#include <linux/module.h>
	#include <linux/mod_devicetable.h>
	#include <linux/of.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 = {
	.name = "chromeos",
	};

	/**
	* struct 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;
	};

	/**
	* struct 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_ec_sensorhub_cells[] = {
	{ .name = "cros-ec-sensorhub", },
	};

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

	static const struct mfd_cell cros_usbpd_notify_cells[] = {
	{ .name = "cros-usbpd-notify", },
	};

	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-sysfs", },
	};

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

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

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

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

	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);
	struct ec_response_pchg_count pchg_count;
	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.flags[0] = -1U; /* Not cached yet */
	ec->features.flags[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_get_sensor_count(ec) > 0) {
	retval = mfd_add_hotplug_devices(ec->dev,
	cros_ec_sensorhub_cells,
	ARRAY_SIZE(cros_ec_sensorhub_cells));
	if (retval)
	dev_err(ec->dev, "failed to add %s subdevice: %d\n",
	cros_ec_sensorhub_cells->name, retval);
	}

	/*
	* 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);
	}
	}

	/*
	* Lightbar is a special case. Newer devices support autodetection,
	* but older ones do not.
	*/
	if (cros_ec_check_features(ec, EC_FEATURE_LIGHTBAR) \|\|
	dmi_match(DMI_PRODUCT_NAME, "Link")) {
	retval = mfd_add_hotplug_devices(ec->dev,
	cros_ec_lightbar_cells,
	ARRAY_SIZE(cros_ec_lightbar_cells));
	if (retval)
	dev_warn(ec->dev, "failed to add lightbar: %d\n",
	retval);
	}

	/*
	* The PD notifier driver cell is separate since it only needs to be
	* explicitly added on platforms that don't have the PD notifier ACPI
	* device entry defined.
	*/
	if (IS_ENABLED(CONFIG_OF) && ec->ec_dev->dev->of_node) {
	if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
	retval = mfd_add_hotplug_devices(ec->dev,
	cros_usbpd_notify_cells,
	ARRAY_SIZE(cros_usbpd_notify_cells));
	if (retval)
	dev_err(ec->dev,
	"failed to add PD notify devices: %d\n",
	retval);
	}
	}

	/*
	* The PCHG device cannot be detected by sending EC_FEATURE_GET_CMD, but
	* it can be detected by querying the number of peripheral chargers.
	*/
	retval = cros_ec_cmd(ec->ec_dev, 0, EC_CMD_PCHG_COUNT, NULL, 0,
	&pchg_count, sizeof(pchg_count));
	if (retval >= 0 && pchg_count.port_count) {
	retval = mfd_add_hotplug_devices(ec->dev,
	cros_ec_pchg_cells,
	ARRAY_SIZE(cros_ec_pchg_cells));
	if (retval)
	dev_warn(ec->dev, "failed to add pchg: %d\n",
	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_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
	MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
	MODULE_VERSION("1.0");
	MODULE_LICENSE("GPL");