drivers/platform/chrome/cros_usbpd_notify.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2020 Google LLC
  *
  * This driver serves as the receiver of cros_ec PD host events.
  */

 #include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/platform_data/cros_usbpd_notify.h>
 #include <linux/platform_device.h>

 #define DRV_NAME "cros-usbpd-notify"
 #define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
 #define ACPI_DRV_NAME "GOOG0003"

 static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);

 struct cros_usbpd_notify_data {
 	struct device *dev;
 	struct cros_ec_device *ec;
 	struct notifier_block nb;
 };

 /**
  * cros_usbpd_register_notify - Register a notifier callback for PD events.
  * @nb: Notifier block pointer to register
  *
  * On ACPI platforms this corresponds to host events on the ECPD
  * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events
  * for USB PD events.
  *
  * Return: 0 on success or negative error code.
  */
 int cros_usbpd_register_notify(struct notifier_block *nb)
 {
 	return blocking_notifier_chain_register(&cros_usbpd_notifier_list,
 						nb);
 }
 EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);

 /**
  * cros_usbpd_unregister_notify - Unregister notifier callback for PD events.
  * @nb: Notifier block pointer to unregister
  *
  * Unregister a notifier callback that was previously registered with
  * cros_usbpd_register_notify().
  */
 void cros_usbpd_unregister_notify(struct notifier_block *nb)
 {
 	blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);
 }
 EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);

 static void cros_usbpd_get_event_and_notify(struct device  *dev,
 					    struct cros_ec_device *ec_dev)
 {
 	struct ec_response_host_event_status host_event_status;
 	u32 event = 0;
 	int ret;

 	/*
 	 * We still send a 0 event out to older devices which don't
 	 * have the updated device heirarchy.
 	 */
 	if (!ec_dev) {
 		dev_dbg(dev,
 			"EC device inaccessible; sending 0 event status.\n");
 		goto send_notify;
 	}

 	/* Check for PD host events on EC. */
 	ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS,
 			  NULL, 0, &host_event_status, sizeof(host_event_status));
 	if (ret < 0) {
 		dev_warn(dev, "Can't get host event status (err: %d)\n", ret);
 		goto send_notify;
 	}

 	event = host_event_status.status;

 send_notify:
 	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
 }

 #ifdef CONFIG_ACPI

 static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
 {
 	struct cros_usbpd_notify_data *pdnotify = data;

 	cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec);
 }

 static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
 {
 	struct cros_usbpd_notify_data *pdnotify;
 	struct device *dev = &pdev->dev;
 	struct acpi_device *adev;
 	struct cros_ec_device *ec_dev;
 	acpi_status status;

 	adev = ACPI_COMPANION(dev);

 	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
 	if (!pdnotify)
 		return -ENOMEM;

 	/* Get the EC device pointer needed to talk to the EC. */
 	ec_dev = dev_get_drvdata(dev->parent);
 	if (!ec_dev) {
 		/*
 		 * We continue even for older devices which don't have the
 		 * correct device heirarchy, namely, GOOG0003 is a child
 		 * of GOOG0004.
 		 */
 		dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
 	}

 	pdnotify->dev = dev;
 	pdnotify->ec = ec_dev;

 	status = acpi_install_notify_handler(adev->handle,
 					     ACPI_ALL_NOTIFY,
 					     cros_usbpd_notify_acpi,
 					     pdnotify);
 	if (ACPI_FAILURE(status)) {
 		dev_warn(dev, "Failed to register notify handler %08x\n",
 			 status);
 		return -EINVAL;
 	}

 	return 0;
 }

 static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct acpi_device *adev = ACPI_COMPANION(dev);

 	acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
 				   cros_usbpd_notify_acpi);

 	return 0;
 }

 static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
 	{ ACPI_DRV_NAME, 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);

 static struct platform_driver cros_usbpd_notify_acpi_driver = {
 	.driver = {
 		.name = DRV_NAME_PLAT_ACPI,
 		.acpi_match_table = cros_usbpd_notify_acpi_device_ids,
 	},
 	.probe = cros_usbpd_notify_probe_acpi,
 	.remove = cros_usbpd_notify_remove_acpi,
 };

 #endif /* CONFIG_ACPI */

 static int cros_usbpd_notify_plat(struct notifier_block *nb,
 				  unsigned long queued_during_suspend,
 				  void *data)
 {
 	struct cros_usbpd_notify_data *pdnotify = container_of(nb,
 			struct cros_usbpd_notify_data, nb);
 	struct cros_ec_device *ec_dev = (struct cros_ec_device *)data;
 	u32 host_event = cros_ec_get_host_event(ec_dev);

 	if (!host_event)
 		return NOTIFY_DONE;

 	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
 			  EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
 		cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev);
 		return NOTIFY_OK;
 	}
 	return NOTIFY_DONE;
 }

 static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
 	struct cros_usbpd_notify_data *pdnotify;
 	int ret;

 	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
 	if (!pdnotify)
 		return -ENOMEM;

 	pdnotify->dev = dev;
 	pdnotify->ec = ecdev->ec_dev;
 	pdnotify->nb.notifier_call = cros_usbpd_notify_plat;

 	dev_set_drvdata(dev, pdnotify);

 	ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
 					       &pdnotify->nb);
 	if (ret < 0) {
 		dev_err(dev, "Failed to register notifier\n");
 		return ret;
 	}

 	return 0;
 }

 static int cros_usbpd_notify_remove_plat(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
 	struct cros_usbpd_notify_data *pdnotify =
 		(struct cros_usbpd_notify_data *)dev_get_drvdata(dev);

 	blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
 					   &pdnotify->nb);

 	return 0;
 }

 static struct platform_driver cros_usbpd_notify_plat_driver = {
 	.driver = {
 		.name = DRV_NAME,
 	},
 	.probe = cros_usbpd_notify_probe_plat,
 	.remove = cros_usbpd_notify_remove_plat,
 };

 static int __init cros_usbpd_notify_init(void)
 {
 	int ret;

 	ret = platform_driver_register(&cros_usbpd_notify_plat_driver);
 	if (ret < 0)
 		return ret;

 #ifdef CONFIG_ACPI
 	ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);
 	if (ret) {
 		platform_driver_unregister(&cros_usbpd_notify_plat_driver);
 		return ret;
 	}
 #endif
 	return 0;
 }

 static void __exit cros_usbpd_notify_exit(void)
 {
 #ifdef CONFIG_ACPI
 	platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
 #endif
 	platform_driver_unregister(&cros_usbpd_notify_plat_driver);
 }

 module_init(cros_usbpd_notify_init);
 module_exit(cros_usbpd_notify_exit);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
 MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>");
 MODULE_ALIAS("platform:" DRV_NAME);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright 2020 Google LLC
	*
	* This driver serves as the receiver of cros_ec PD host events.
	*/

	#include <linux/acpi.h>
	#include <linux/module.h>
	#include <linux/platform_data/cros_ec_proto.h>
	#include <linux/platform_data/cros_usbpd_notify.h>
	#include <linux/platform_device.h>

	#define DRV_NAME "cros-usbpd-notify"
	#define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi"
	#define ACPI_DRV_NAME "GOOG0003"

	static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list);

	struct cros_usbpd_notify_data {
	struct device *dev;
	struct cros_ec_device *ec;
	struct notifier_block nb;
	};

	/**
	* cros_usbpd_register_notify - Register a notifier callback for PD events.
	* @nb: Notifier block pointer to register
	*
	* On ACPI platforms this corresponds to host events on the ECPD
	* "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events
	* for USB PD events.
	*
	* Return: 0 on success or negative error code.
	*/
	int cros_usbpd_register_notify(struct notifier_block *nb)
	{
	return blocking_notifier_chain_register(&cros_usbpd_notifier_list,
	nb);
	}
	EXPORT_SYMBOL_GPL(cros_usbpd_register_notify);

	/**
	* cros_usbpd_unregister_notify - Unregister notifier callback for PD events.
	* @nb: Notifier block pointer to unregister
	*
	* Unregister a notifier callback that was previously registered with
	* cros_usbpd_register_notify().
	*/
	void cros_usbpd_unregister_notify(struct notifier_block *nb)
	{
	blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb);
	}
	EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify);

	static void cros_usbpd_get_event_and_notify(struct device *dev,
	struct cros_ec_device *ec_dev)
	{
	struct ec_response_host_event_status host_event_status;
	u32 event = 0;
	int ret;

	/*
	* We still send a 0 event out to older devices which don't
	* have the updated device heirarchy.
	*/
	if (!ec_dev) {
	dev_dbg(dev,
	"EC device inaccessible; sending 0 event status.\n");
	goto send_notify;
	}

	/* Check for PD host events on EC. */
	ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS,
	NULL, 0, &host_event_status, sizeof(host_event_status));
	if (ret < 0) {
	dev_warn(dev, "Can't get host event status (err: %d)\n", ret);
	goto send_notify;
	}

	event = host_event_status.status;

	send_notify:
	blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL);
	}

	#ifdef CONFIG_ACPI

	static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data)
	{
	struct cros_usbpd_notify_data *pdnotify = data;

	cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec);
	}

	static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev)
	{
	struct cros_usbpd_notify_data *pdnotify;
	struct device *dev = &pdev->dev;
	struct acpi_device *adev;
	struct cros_ec_device *ec_dev;
	acpi_status status;

	adev = ACPI_COMPANION(dev);

	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
	if (!pdnotify)
	return -ENOMEM;

	/* Get the EC device pointer needed to talk to the EC. */
	ec_dev = dev_get_drvdata(dev->parent);
	if (!ec_dev) {
	/*
	* We continue even for older devices which don't have the
	* correct device heirarchy, namely, GOOG0003 is a child
	* of GOOG0004.
	*/
	dev_warn(dev, "Couldn't get Chrome EC device pointer.\n");
	}

	pdnotify->dev = dev;
	pdnotify->ec = ec_dev;

	status = acpi_install_notify_handler(adev->handle,
	ACPI_ALL_NOTIFY,
	cros_usbpd_notify_acpi,
	pdnotify);
	if (ACPI_FAILURE(status)) {
	dev_warn(dev, "Failed to register notify handler %08x\n",
	status);
	return -EINVAL;
	}

	return 0;
	}

	static int cros_usbpd_notify_remove_acpi(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct acpi_device *adev = ACPI_COMPANION(dev);

	acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY,
	cros_usbpd_notify_acpi);

	return 0;
	}

	static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = {
	{ ACPI_DRV_NAME, 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids);

	static struct platform_driver cros_usbpd_notify_acpi_driver = {
	.driver = {
	.name = DRV_NAME_PLAT_ACPI,
	.acpi_match_table = cros_usbpd_notify_acpi_device_ids,
	},
	.probe = cros_usbpd_notify_probe_acpi,
	.remove = cros_usbpd_notify_remove_acpi,
	};

	#endif /* CONFIG_ACPI */

	static int cros_usbpd_notify_plat(struct notifier_block *nb,
	unsigned long queued_during_suspend,
	void *data)
	{
	struct cros_usbpd_notify_data *pdnotify = container_of(nb,
	struct cros_usbpd_notify_data, nb);
	struct cros_ec_device ec_dev = (struct cros_ec_device )data;
	u32 host_event = cros_ec_get_host_event(ec_dev);

	if (!host_event)
	return NOTIFY_DONE;

	if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) \|
	EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) {
	cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev);
	return NOTIFY_OK;
	}
	return NOTIFY_DONE;
	}

	static int cros_usbpd_notify_probe_plat(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
	struct cros_usbpd_notify_data *pdnotify;
	int ret;

	pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL);
	if (!pdnotify)
	return -ENOMEM;

	pdnotify->dev = dev;
	pdnotify->ec = ecdev->ec_dev;
	pdnotify->nb.notifier_call = cros_usbpd_notify_plat;

	dev_set_drvdata(dev, pdnotify);

	ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier,
	&pdnotify->nb);
	if (ret < 0) {
	dev_err(dev, "Failed to register notifier\n");
	return ret;
	}

	return 0;
	}

	static int cros_usbpd_notify_remove_plat(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent);
	struct cros_usbpd_notify_data *pdnotify =
	(struct cros_usbpd_notify_data *)dev_get_drvdata(dev);

	blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier,
	&pdnotify->nb);

	return 0;
	}

	static struct platform_driver cros_usbpd_notify_plat_driver = {
	.driver = {
	.name = DRV_NAME,
	},
	.probe = cros_usbpd_notify_probe_plat,
	.remove = cros_usbpd_notify_remove_plat,
	};

	static int __init cros_usbpd_notify_init(void)
	{
	int ret;

	ret = platform_driver_register(&cros_usbpd_notify_plat_driver);
	if (ret < 0)
	return ret;

	#ifdef CONFIG_ACPI
	ret = platform_driver_register(&cros_usbpd_notify_acpi_driver);
	if (ret) {
	platform_driver_unregister(&cros_usbpd_notify_plat_driver);
	return ret;
	}
	#endif
	return 0;
	}

	static void __exit cros_usbpd_notify_exit(void)
	{
	#ifdef CONFIG_ACPI
	platform_driver_unregister(&cros_usbpd_notify_acpi_driver);
	#endif
	platform_driver_unregister(&cros_usbpd_notify_plat_driver);
	}

	module_init(cros_usbpd_notify_init);
	module_exit(cros_usbpd_notify_exit);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("ChromeOS power delivery notifier device");
	MODULE_AUTHOR("Jon Flatley <jflat@chromium.org>");
	MODULE_ALIAS("platform:" DRV_NAME);