drivers/greybus/core.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Greybus "Core"
  *
  * Copyright 2014-2015 Google Inc.
  * Copyright 2014-2015 Linaro Ltd.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #define CREATE_TRACE_POINTS
 #include <linux/greybus.h>
 #include "greybus_trace.h"

 #define GB_BUNDLE_AUTOSUSPEND_MS	3000

 /* Allow greybus to be disabled at boot if needed */
 static bool nogreybus;
 #ifdef MODULE
 module_param(nogreybus, bool, 0444);
 #else
 core_param(nogreybus, nogreybus, bool, 0444);
 #endif
 int greybus_disabled(void)
 {
 	return nogreybus;
 }
 EXPORT_SYMBOL_GPL(greybus_disabled);

 static int is_gb_host_device(const struct device *dev)
 {
 	return dev->type == &greybus_hd_type;
 }

 static int is_gb_module(const struct device *dev)
 {
 	return dev->type == &greybus_module_type;
 }

 static int is_gb_interface(const struct device *dev)
 {
 	return dev->type == &greybus_interface_type;
 }

 static int is_gb_control(const struct device *dev)
 {
 	return dev->type == &greybus_control_type;
 }

 static int is_gb_bundle(const struct device *dev)
 {
 	return dev->type == &greybus_bundle_type;
 }

 static int is_gb_svc(const struct device *dev)
 {
 	return dev->type == &greybus_svc_type;
 }

 static bool greybus_match_one_id(struct gb_bundle *bundle,
 				 const struct greybus_bundle_id *id)
 {
 	if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
 	    (id->vendor != bundle->intf->vendor_id))
 		return false;

 	if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
 	    (id->product != bundle->intf->product_id))
 		return false;

 	if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
 	    (id->class != bundle->class))
 		return false;

 	return true;
 }

 static const struct greybus_bundle_id *
 greybus_match_id(struct gb_bundle *bundle, const struct greybus_bundle_id *id)
 {
 	if (!id)
 		return NULL;

 	for (; id->vendor || id->product || id->class || id->driver_info;
 									id++) {
 		if (greybus_match_one_id(bundle, id))
 			return id;
 	}

 	return NULL;
 }

 static int greybus_match_device(struct device *dev, const struct device_driver *drv)
 {
 	const struct greybus_driver *driver = to_greybus_driver(drv);
 	struct gb_bundle *bundle;
 	const struct greybus_bundle_id *id;

 	if (!is_gb_bundle(dev))
 		return 0;

 	bundle = to_gb_bundle(dev);

 	id = greybus_match_id(bundle, driver->id_table);
 	if (id)
 		return 1;
 	/* FIXME - Dynamic ids? */
 	return 0;
 }

 static int greybus_uevent(const struct device *dev, struct kobj_uevent_env *env)
 {
 	const struct gb_host_device *hd;
 	const struct gb_module *module = NULL;
 	const struct gb_interface *intf = NULL;
 	const struct gb_control *control = NULL;
 	const struct gb_bundle *bundle = NULL;
 	const struct gb_svc *svc = NULL;

 	if (is_gb_host_device(dev)) {
 		hd = to_gb_host_device(dev);
 	} else if (is_gb_module(dev)) {
 		module = to_gb_module(dev);
 		hd = module->hd;
 	} else if (is_gb_interface(dev)) {
 		intf = to_gb_interface(dev);
 		module = intf->module;
 		hd = intf->hd;
 	} else if (is_gb_control(dev)) {
 		control = to_gb_control(dev);
 		intf = control->intf;
 		module = intf->module;
 		hd = intf->hd;
 	} else if (is_gb_bundle(dev)) {
 		bundle = to_gb_bundle(dev);
 		intf = bundle->intf;
 		module = intf->module;
 		hd = intf->hd;
 	} else if (is_gb_svc(dev)) {
 		svc = to_gb_svc(dev);
 		hd = svc->hd;
 	} else {
 		dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
 		return -EINVAL;
 	}

 	if (add_uevent_var(env, "BUS=%u", hd->bus_id))
 		return -ENOMEM;

 	if (module) {
 		if (add_uevent_var(env, "MODULE=%u", module->module_id))
 			return -ENOMEM;
 	}

 	if (intf) {
 		if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
 			return -ENOMEM;
 		if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
 				   intf->vendor_id, intf->product_id))
 			return -ENOMEM;
 	}

 	if (bundle) {
 		// FIXME
 		// add a uevent that can "load" a bundle type
 		// This is what we need to bind a driver to so use the info
 		// in gmod here as well

 		if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
 			return -ENOMEM;
 		if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
 			return -ENOMEM;
 	}

 	return 0;
 }

 static void greybus_shutdown(struct device *dev)
 {
 	if (is_gb_host_device(dev)) {
 		struct gb_host_device *hd;

 		hd = to_gb_host_device(dev);
 		gb_hd_shutdown(hd);
 	}
 }

 const struct bus_type greybus_bus_type = {
 	.name =		"greybus",
 	.match =	greybus_match_device,
 	.uevent =	greybus_uevent,
 	.shutdown =	greybus_shutdown,
 };

 static int greybus_probe(struct device *dev)
 {
 	struct greybus_driver *driver = to_greybus_driver(dev->driver);
 	struct gb_bundle *bundle = to_gb_bundle(dev);
 	const struct greybus_bundle_id *id;
 	int retval;

 	/* match id */
 	id = greybus_match_id(bundle, driver->id_table);
 	if (!id)
 		return -ENODEV;

 	retval = pm_runtime_get_sync(&bundle->intf->dev);
 	if (retval < 0) {
 		pm_runtime_put_noidle(&bundle->intf->dev);
 		return retval;
 	}

 	retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
 	if (retval) {
 		pm_runtime_put(&bundle->intf->dev);
 		return retval;
 	}

 	/*
 	 * Unbound bundle devices are always deactivated. During probe, the
 	 * Runtime PM is set to enabled and active and the usage count is
 	 * incremented. If the driver supports runtime PM, it should call
 	 * pm_runtime_put() in its probe routine and pm_runtime_get_sync()
 	 * in remove routine.
 	 */
 	pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_get_noresume(dev);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);

 	retval = driver->probe(bundle, id);
 	if (retval) {
 		/*
 		 * Catch buggy drivers that fail to destroy their connections.
 		 */
 		WARN_ON(!list_empty(&bundle->connections));

 		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

 		pm_runtime_disable(dev);
 		pm_runtime_set_suspended(dev);
 		pm_runtime_put_noidle(dev);
 		pm_runtime_dont_use_autosuspend(dev);
 		pm_runtime_put(&bundle->intf->dev);

 		return retval;
 	}

 	pm_runtime_put(&bundle->intf->dev);

 	return 0;
 }

 static int greybus_remove(struct device *dev)
 {
 	struct greybus_driver *driver = to_greybus_driver(dev->driver);
 	struct gb_bundle *bundle = to_gb_bundle(dev);
 	struct gb_connection *connection;
 	int retval;

 	retval = pm_runtime_get_sync(dev);
 	if (retval < 0)
 		dev_err(dev, "failed to resume bundle: %d\n", retval);

 	/*
 	 * Disable (non-offloaded) connections early in case the interface is
 	 * already gone to avoid unceccessary operation timeouts during
 	 * driver disconnect. Otherwise, only disable incoming requests.
 	 */
 	list_for_each_entry(connection, &bundle->connections, bundle_links) {
 		if (gb_connection_is_offloaded(connection))
 			continue;

 		if (bundle->intf->disconnected)
 			gb_connection_disable_forced(connection);
 		else
 			gb_connection_disable_rx(connection);
 	}

 	driver->disconnect(bundle);

 	/* Catch buggy drivers that fail to destroy their connections. */
 	WARN_ON(!list_empty(&bundle->connections));

 	if (!bundle->intf->disconnected)
 		gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

 	pm_runtime_put_noidle(dev);
 	pm_runtime_disable(dev);
 	pm_runtime_set_suspended(dev);
 	pm_runtime_dont_use_autosuspend(dev);
 	pm_runtime_put_noidle(dev);

 	return 0;
 }

 int greybus_register_driver(struct greybus_driver *driver, struct module *owner,
 			    const char *mod_name)
 {
 	int retval;

 	if (greybus_disabled())
 		return -ENODEV;

 	driver->driver.bus = &greybus_bus_type;
 	driver->driver.name = driver->name;
 	driver->driver.probe = greybus_probe;
 	driver->driver.remove = greybus_remove;
 	driver->driver.owner = owner;
 	driver->driver.mod_name = mod_name;

 	retval = driver_register(&driver->driver);
 	if (retval)
 		return retval;

 	pr_info("registered new driver %s\n", driver->name);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(greybus_register_driver);

 void greybus_deregister_driver(struct greybus_driver *driver)
 {
 	driver_unregister(&driver->driver);
 }
 EXPORT_SYMBOL_GPL(greybus_deregister_driver);

 static int __init gb_init(void)
 {
 	int retval;

 	if (greybus_disabled())
 		return -ENODEV;

 	BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);

 	gb_debugfs_init();

 	retval = bus_register(&greybus_bus_type);
 	if (retval) {
 		pr_err("bus_register failed (%d)\n", retval);
 		goto error_bus;
 	}

 	retval = gb_hd_init();
 	if (retval) {
 		pr_err("gb_hd_init failed (%d)\n", retval);
 		goto error_hd;
 	}

 	retval = gb_operation_init();
 	if (retval) {
 		pr_err("gb_operation_init failed (%d)\n", retval);
 		goto error_operation;
 	}
 	return 0;	/* Success */

 error_operation:
 	gb_hd_exit();
 error_hd:
 	bus_unregister(&greybus_bus_type);
 error_bus:
 	gb_debugfs_cleanup();

 	return retval;
 }
 module_init(gb_init);

 static void __exit gb_exit(void)
 {
 	gb_operation_exit();
 	gb_hd_exit();
 	bus_unregister(&greybus_bus_type);
 	gb_debugfs_cleanup();
 	tracepoint_synchronize_unregister();
 }
 module_exit(gb_exit);
 MODULE_DESCRIPTION("Greybus core driver");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Greybus "Core"
	*
	* Copyright 2014-2015 Google Inc.
	* Copyright 2014-2015 Linaro Ltd.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#define CREATE_TRACE_POINTS
	#include <linux/greybus.h>
	#include "greybus_trace.h"

	#define GB_BUNDLE_AUTOSUSPEND_MS 3000

	/* Allow greybus to be disabled at boot if needed */
	static bool nogreybus;
	#ifdef MODULE
	module_param(nogreybus, bool, 0444);
	#else
	core_param(nogreybus, nogreybus, bool, 0444);
	#endif
	int greybus_disabled(void)
	{
	return nogreybus;
	}
	EXPORT_SYMBOL_GPL(greybus_disabled);

	static int is_gb_host_device(const struct device *dev)
	{
	return dev->type == &greybus_hd_type;
	}

	static int is_gb_module(const struct device *dev)
	{
	return dev->type == &greybus_module_type;
	}

	static int is_gb_interface(const struct device *dev)
	{
	return dev->type == &greybus_interface_type;
	}

	static int is_gb_control(const struct device *dev)
	{
	return dev->type == &greybus_control_type;
	}

	static int is_gb_bundle(const struct device *dev)
	{
	return dev->type == &greybus_bundle_type;
	}

	static int is_gb_svc(const struct device *dev)
	{
	return dev->type == &greybus_svc_type;
	}

	static bool greybus_match_one_id(struct gb_bundle *bundle,
	const struct greybus_bundle_id *id)
	{
	if ((id->match_flags & GREYBUS_ID_MATCH_VENDOR) &&
	(id->vendor != bundle->intf->vendor_id))
	return false;

	if ((id->match_flags & GREYBUS_ID_MATCH_PRODUCT) &&
	(id->product != bundle->intf->product_id))
	return false;

	if ((id->match_flags & GREYBUS_ID_MATCH_CLASS) &&
	(id->class != bundle->class))
	return false;

	return true;
	}

	static const struct greybus_bundle_id *
	greybus_match_id(struct gb_bundle bundle, const struct greybus_bundle_id id)
	{
	if (!id)
	return NULL;

	for (; id->vendor \|\| id->product \|\| id->class \|\| id->driver_info;
	id++) {
	if (greybus_match_one_id(bundle, id))
	return id;
	}

	return NULL;
	}

	static int greybus_match_device(struct device dev, const struct device_driver drv)
	{
	const struct greybus_driver *driver = to_greybus_driver(drv);
	struct gb_bundle *bundle;
	const struct greybus_bundle_id *id;

	if (!is_gb_bundle(dev))
	return 0;

	bundle = to_gb_bundle(dev);

	id = greybus_match_id(bundle, driver->id_table);
	if (id)
	return 1;
	/* FIXME - Dynamic ids? */
	return 0;
	}

	static int greybus_uevent(const struct device dev, struct kobj_uevent_env env)
	{
	const struct gb_host_device *hd;
	const struct gb_module *module = NULL;
	const struct gb_interface *intf = NULL;
	const struct gb_control *control = NULL;
	const struct gb_bundle *bundle = NULL;
	const struct gb_svc *svc = NULL;

	if (is_gb_host_device(dev)) {
	hd = to_gb_host_device(dev);
	} else if (is_gb_module(dev)) {
	module = to_gb_module(dev);
	hd = module->hd;
	} else if (is_gb_interface(dev)) {
	intf = to_gb_interface(dev);
	module = intf->module;
	hd = intf->hd;
	} else if (is_gb_control(dev)) {
	control = to_gb_control(dev);
	intf = control->intf;
	module = intf->module;
	hd = intf->hd;
	} else if (is_gb_bundle(dev)) {
	bundle = to_gb_bundle(dev);
	intf = bundle->intf;
	module = intf->module;
	hd = intf->hd;
	} else if (is_gb_svc(dev)) {
	svc = to_gb_svc(dev);
	hd = svc->hd;
	} else {
	dev_WARN(dev, "uevent for unknown greybus device \"type\"!\n");
	return -EINVAL;
	}

	if (add_uevent_var(env, "BUS=%u", hd->bus_id))
	return -ENOMEM;

	if (module) {
	if (add_uevent_var(env, "MODULE=%u", module->module_id))
	return -ENOMEM;
	}

	if (intf) {
	if (add_uevent_var(env, "INTERFACE=%u", intf->interface_id))
	return -ENOMEM;
	if (add_uevent_var(env, "GREYBUS_ID=%08x/%08x",
	intf->vendor_id, intf->product_id))
	return -ENOMEM;
	}

	if (bundle) {
	// FIXME
	// add a uevent that can "load" a bundle type
	// This is what we need to bind a driver to so use the info
	// in gmod here as well

	if (add_uevent_var(env, "BUNDLE=%u", bundle->id))
	return -ENOMEM;
	if (add_uevent_var(env, "BUNDLE_CLASS=%02x", bundle->class))
	return -ENOMEM;
	}

	return 0;
	}

	static void greybus_shutdown(struct device *dev)
	{
	if (is_gb_host_device(dev)) {
	struct gb_host_device *hd;

	hd = to_gb_host_device(dev);
	gb_hd_shutdown(hd);
	}
	}

	const struct bus_type greybus_bus_type = {
	.name = "greybus",
	.match = greybus_match_device,
	.uevent = greybus_uevent,
	.shutdown = greybus_shutdown,
	};

	static int greybus_probe(struct device *dev)
	{
	struct greybus_driver *driver = to_greybus_driver(dev->driver);
	struct gb_bundle *bundle = to_gb_bundle(dev);
	const struct greybus_bundle_id *id;
	int retval;

	/* match id */
	id = greybus_match_id(bundle, driver->id_table);
	if (!id)
	return -ENODEV;

	retval = pm_runtime_get_sync(&bundle->intf->dev);
	if (retval < 0) {
	pm_runtime_put_noidle(&bundle->intf->dev);
	return retval;
	}

	retval = gb_control_bundle_activate(bundle->intf->control, bundle->id);
	if (retval) {
	pm_runtime_put(&bundle->intf->dev);
	return retval;
	}

	/*
	* Unbound bundle devices are always deactivated. During probe, the
	* Runtime PM is set to enabled and active and the usage count is
	* incremented. If the driver supports runtime PM, it should call
	* pm_runtime_put() in its probe routine and pm_runtime_get_sync()
	* in remove routine.
	*/
	pm_runtime_set_autosuspend_delay(dev, GB_BUNDLE_AUTOSUSPEND_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	retval = driver->probe(bundle, id);
	if (retval) {
	/*
	* Catch buggy drivers that fail to destroy their connections.
	*/
	WARN_ON(!list_empty(&bundle->connections));

	gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

	pm_runtime_disable(dev);
	pm_runtime_set_suspended(dev);
	pm_runtime_put_noidle(dev);
	pm_runtime_dont_use_autosuspend(dev);
	pm_runtime_put(&bundle->intf->dev);

	return retval;
	}

	pm_runtime_put(&bundle->intf->dev);

	return 0;
	}

	static int greybus_remove(struct device *dev)
	{
	struct greybus_driver *driver = to_greybus_driver(dev->driver);
	struct gb_bundle *bundle = to_gb_bundle(dev);
	struct gb_connection *connection;
	int retval;

	retval = pm_runtime_get_sync(dev);
	if (retval < 0)
	dev_err(dev, "failed to resume bundle: %d\n", retval);

	/*
	* Disable (non-offloaded) connections early in case the interface is
	* already gone to avoid unceccessary operation timeouts during
	* driver disconnect. Otherwise, only disable incoming requests.
	*/
	list_for_each_entry(connection, &bundle->connections, bundle_links) {
	if (gb_connection_is_offloaded(connection))
	continue;

	if (bundle->intf->disconnected)
	gb_connection_disable_forced(connection);
	else
	gb_connection_disable_rx(connection);
	}

	driver->disconnect(bundle);

	/* Catch buggy drivers that fail to destroy their connections. */
	WARN_ON(!list_empty(&bundle->connections));

	if (!bundle->intf->disconnected)
	gb_control_bundle_deactivate(bundle->intf->control, bundle->id);

	pm_runtime_put_noidle(dev);
	pm_runtime_disable(dev);
	pm_runtime_set_suspended(dev);
	pm_runtime_dont_use_autosuspend(dev);
	pm_runtime_put_noidle(dev);

	return 0;
	}

	int greybus_register_driver(struct greybus_driver driver, struct module owner,
	const char *mod_name)
	{
	int retval;

	if (greybus_disabled())
	return -ENODEV;

	driver->driver.bus = &greybus_bus_type;
	driver->driver.name = driver->name;
	driver->driver.probe = greybus_probe;
	driver->driver.remove = greybus_remove;
	driver->driver.owner = owner;
	driver->driver.mod_name = mod_name;

	retval = driver_register(&driver->driver);
	if (retval)
	return retval;

	pr_info("registered new driver %s\n", driver->name);
	return 0;
	}
	EXPORT_SYMBOL_GPL(greybus_register_driver);

	void greybus_deregister_driver(struct greybus_driver *driver)
	{
	driver_unregister(&driver->driver);
	}
	EXPORT_SYMBOL_GPL(greybus_deregister_driver);

	static int __init gb_init(void)
	{
	int retval;

	if (greybus_disabled())
	return -ENODEV;

	BUILD_BUG_ON(CPORT_ID_MAX >= (long)CPORT_ID_BAD);

	gb_debugfs_init();

	retval = bus_register(&greybus_bus_type);
	if (retval) {
	pr_err("bus_register failed (%d)\n", retval);
	goto error_bus;
	}

	retval = gb_hd_init();
	if (retval) {
	pr_err("gb_hd_init failed (%d)\n", retval);
	goto error_hd;
	}

	retval = gb_operation_init();
	if (retval) {
	pr_err("gb_operation_init failed (%d)\n", retval);
	goto error_operation;
	}
	return 0; /* Success */

	error_operation:
	gb_hd_exit();
	error_hd:
	bus_unregister(&greybus_bus_type);
	error_bus:
	gb_debugfs_cleanup();

	return retval;
	}
	module_init(gb_init);

	static void __exit gb_exit(void)
	{
	gb_operation_exit();
	gb_hd_exit();
	bus_unregister(&greybus_bus_type);
	gb_debugfs_cleanup();
	tracepoint_synchronize_unregister();
	}
	module_exit(gb_exit);
	MODULE_DESCRIPTION("Greybus core driver");
	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");