drivers/i2c/i2c-core-of.c - linux - Git at Google

 /*
  * Linux I2C core OF support code
  *
  * Copyright (C) 2008 Jochen Friedrich <jochen@scram.de>
  * based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
  *
  * Copyright (C) 2013, 2018 Wolfram Sang <wsa@the-dreams.de>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option)
  * any later version.
  */

 #include <dt-bindings/i2c/i2c.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 #include "i2c-core.h"

 int of_i2c_get_board_info(struct device *dev, struct device_node *node,
 			  struct i2c_board_info *info)
 {
 	u32 addr;
 	int ret;

 	memset(info, 0, sizeof(*info));

 	if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) {
 		dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
 		return -EINVAL;
 	}

 	ret = of_property_read_u32(node, "reg", &addr);
 	if (ret) {
 		dev_err(dev, "of_i2c: invalid reg on %pOF\n", node);
 		return ret;
 	}

 	if (addr & I2C_TEN_BIT_ADDRESS) {
 		addr &= ~I2C_TEN_BIT_ADDRESS;
 		info->flags |= I2C_CLIENT_TEN;
 	}

 	if (addr & I2C_OWN_SLAVE_ADDRESS) {
 		addr &= ~I2C_OWN_SLAVE_ADDRESS;
 		info->flags |= I2C_CLIENT_SLAVE;
 	}

 	info->addr = addr;
 	info->of_node = node;

 	if (of_property_read_bool(node, "host-notify"))
 		info->flags |= I2C_CLIENT_HOST_NOTIFY;

 	if (of_get_property(node, "wakeup-source", NULL))
 		info->flags |= I2C_CLIENT_WAKE;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_i2c_get_board_info);

 static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap,
 						 struct device_node *node)
 {
 	struct i2c_client *client;
 	struct i2c_board_info info;
 	int ret;

 	dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node);

 	ret = of_i2c_get_board_info(&adap->dev, node, &info);
 	if (ret)
 		return ERR_PTR(ret);

 	client = i2c_new_device(adap, &info);
 	if (!client) {
 		dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node);
 		return ERR_PTR(-EINVAL);
 	}
 	return client;
 }

 void of_i2c_register_devices(struct i2c_adapter *adap)
 {
 	struct device_node *bus, *node;
 	struct i2c_client *client;

 	/* Only register child devices if the adapter has a node pointer set */
 	if (!adap->dev.of_node)
 		return;

 	dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");

 	bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
 	if (!bus)
 		bus = of_node_get(adap->dev.of_node);

 	for_each_available_child_of_node(bus, node) {
 		if (of_node_test_and_set_flag(node, OF_POPULATED))
 			continue;

 		client = of_i2c_register_device(adap, node);
 		if (IS_ERR(client)) {
 			dev_err(&adap->dev,
 				 "Failed to create I2C device for %pOF\n",
 				 node);
 			of_node_clear_flag(node, OF_POPULATED);
 		}
 	}

 	of_node_put(bus);
 }

 static int of_dev_node_match(struct device *dev, void *data)
 {
 	return dev->of_node == data;
 }

 static int of_dev_or_parent_node_match(struct device *dev, void *data)
 {
 	if (dev->of_node == data)
 		return 1;

 	if (dev->parent)
 		return dev->parent->of_node == data;

 	return 0;
 }

 /* must call put_device() when done with returned i2c_client device */
 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
 {
 	struct device *dev;
 	struct i2c_client *client;

 	dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
 	if (!dev)
 		return NULL;

 	client = i2c_verify_client(dev);
 	if (!client)
 		put_device(dev);

 	return client;
 }
 EXPORT_SYMBOL(of_find_i2c_device_by_node);

 /* must call put_device() when done with returned i2c_adapter device */
 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
 {
 	struct device *dev;
 	struct i2c_adapter *adapter;

 	dev = bus_find_device(&i2c_bus_type, NULL, node,
 			      of_dev_or_parent_node_match);
 	if (!dev)
 		return NULL;

 	adapter = i2c_verify_adapter(dev);
 	if (!adapter)
 		put_device(dev);

 	return adapter;
 }
 EXPORT_SYMBOL(of_find_i2c_adapter_by_node);

 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
 {
 	struct i2c_adapter *adapter;

 	adapter = of_find_i2c_adapter_by_node(node);
 	if (!adapter)
 		return NULL;

 	if (!try_module_get(adapter->owner)) {
 		put_device(&adapter->dev);
 		adapter = NULL;
 	}

 	return adapter;
 }
 EXPORT_SYMBOL(of_get_i2c_adapter_by_node);

 static const struct of_device_id*
 i2c_of_match_device_sysfs(const struct of_device_id *matches,
 				  struct i2c_client *client)
 {
 	const char *name;

 	for (; matches->compatible[0]; matches++) {
 		/*
 		 * Adding devices through the i2c sysfs interface provides us
 		 * a string to match which may be compatible with the device
 		 * tree compatible strings, however with no actual of_node the
 		 * of_match_device() will not match
 		 */
 		if (sysfs_streq(client->name, matches->compatible))
 			return matches;

 		name = strchr(matches->compatible, ',');
 		if (!name)
 			name = matches->compatible;
 		else
 			name++;

 		if (sysfs_streq(client->name, name))
 			return matches;
 	}

 	return NULL;
 }

 const struct of_device_id
 *i2c_of_match_device(const struct of_device_id *matches,
 		     struct i2c_client *client)
 {
 	const struct of_device_id *match;

 	if (!(client && matches))
 		return NULL;

 	match = of_match_device(matches, &client->dev);
 	if (match)
 		return match;

 	return i2c_of_match_device_sysfs(matches, client);
 }
 EXPORT_SYMBOL_GPL(i2c_of_match_device);

 #if IS_ENABLED(CONFIG_OF_DYNAMIC)
 static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
 			 void *arg)
 {
 	struct of_reconfig_data *rd = arg;
 	struct i2c_adapter *adap;
 	struct i2c_client *client;

 	switch (of_reconfig_get_state_change(action, rd)) {
 	case OF_RECONFIG_CHANGE_ADD:
 		adap = of_find_i2c_adapter_by_node(rd->dn->parent);
 		if (adap == NULL)
 			return NOTIFY_OK;	/* not for us */

 		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
 			put_device(&adap->dev);
 			return NOTIFY_OK;
 		}

 		client = of_i2c_register_device(adap, rd->dn);
 		put_device(&adap->dev);

 		if (IS_ERR(client)) {
 			dev_err(&adap->dev, "failed to create client for '%pOF'\n",
 				 rd->dn);
 			of_node_clear_flag(rd->dn, OF_POPULATED);
 			return notifier_from_errno(PTR_ERR(client));
 		}
 		break;
 	case OF_RECONFIG_CHANGE_REMOVE:
 		/* already depopulated? */
 		if (!of_node_check_flag(rd->dn, OF_POPULATED))
 			return NOTIFY_OK;

 		/* find our device by node */
 		client = of_find_i2c_device_by_node(rd->dn);
 		if (client == NULL)
 			return NOTIFY_OK;	/* no? not meant for us */

 		/* unregister takes one ref away */
 		i2c_unregister_device(client);

 		/* and put the reference of the find */
 		put_device(&client->dev);
 		break;
 	}

 	return NOTIFY_OK;
 }

 struct notifier_block i2c_of_notifier = {
 	.notifier_call = of_i2c_notify,
 };
 #endif /* CONFIG_OF_DYNAMIC */
	/*
	* Linux I2C core OF support code
	*
	* Copyright (C) 2008 Jochen Friedrich <jochen@scram.de>
	* based on a previous patch from Jon Smirl <jonsmirl@gmail.com>
	*
	* Copyright (C) 2013, 2018 Wolfram Sang <wsa@the-dreams.de>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the Free
	* Software Foundation; either version 2 of the License, or (at your option)
	* any later version.
	*/

	#include <dt-bindings/i2c/i2c.h>
	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	#include "i2c-core.h"

	int of_i2c_get_board_info(struct device dev, struct device_node node,
	struct i2c_board_info *info)
	{
	u32 addr;
	int ret;

	memset(info, 0, sizeof(*info));

	if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) {
	dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
	return -EINVAL;
	}

	ret = of_property_read_u32(node, "reg", &addr);
	if (ret) {
	dev_err(dev, "of_i2c: invalid reg on %pOF\n", node);
	return ret;
	}

	if (addr & I2C_TEN_BIT_ADDRESS) {
	addr &= ~I2C_TEN_BIT_ADDRESS;
	info->flags \|= I2C_CLIENT_TEN;
	}

	if (addr & I2C_OWN_SLAVE_ADDRESS) {
	addr &= ~I2C_OWN_SLAVE_ADDRESS;
	info->flags \|= I2C_CLIENT_SLAVE;
	}

	info->addr = addr;
	info->of_node = node;

	if (of_property_read_bool(node, "host-notify"))
	info->flags \|= I2C_CLIENT_HOST_NOTIFY;

	if (of_get_property(node, "wakeup-source", NULL))
	info->flags \|= I2C_CLIENT_WAKE;

	return 0;
	}
	EXPORT_SYMBOL_GPL(of_i2c_get_board_info);

	static struct i2c_client of_i2c_register_device(struct i2c_adapter adap,
	struct device_node *node)
	{
	struct i2c_client *client;
	struct i2c_board_info info;
	int ret;

	dev_dbg(&adap->dev, "of_i2c: register %pOF\n", node);

	ret = of_i2c_get_board_info(&adap->dev, node, &info);
	if (ret)
	return ERR_PTR(ret);

	client = i2c_new_device(adap, &info);
	if (!client) {
	dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node);
	return ERR_PTR(-EINVAL);
	}
	return client;
	}

	void of_i2c_register_devices(struct i2c_adapter *adap)
	{
	struct device_node bus, node;
	struct i2c_client *client;

	/* Only register child devices if the adapter has a node pointer set */
	if (!adap->dev.of_node)
	return;

	dev_dbg(&adap->dev, "of_i2c: walking child nodes\n");

	bus = of_get_child_by_name(adap->dev.of_node, "i2c-bus");
	if (!bus)
	bus = of_node_get(adap->dev.of_node);

	for_each_available_child_of_node(bus, node) {
	if (of_node_test_and_set_flag(node, OF_POPULATED))
	continue;

	client = of_i2c_register_device(adap, node);
	if (IS_ERR(client)) {
	dev_err(&adap->dev,
	"Failed to create I2C device for %pOF\n",
	node);
	of_node_clear_flag(node, OF_POPULATED);
	}
	}

	of_node_put(bus);
	}

	static int of_dev_node_match(struct device dev, void data)
	{
	return dev->of_node == data;
	}

	static int of_dev_or_parent_node_match(struct device dev, void data)
	{
	if (dev->of_node == data)
	return 1;

	if (dev->parent)
	return dev->parent->of_node == data;

	return 0;
	}

	/* must call put_device() when done with returned i2c_client device */
	struct i2c_client of_find_i2c_device_by_node(struct device_node node)
	{
	struct device *dev;
	struct i2c_client *client;

	dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match);
	if (!dev)
	return NULL;

	client = i2c_verify_client(dev);
	if (!client)
	put_device(dev);

	return client;
	}
	EXPORT_SYMBOL(of_find_i2c_device_by_node);

	/* must call put_device() when done with returned i2c_adapter device */
	struct i2c_adapter of_find_i2c_adapter_by_node(struct device_node node)
	{
	struct device *dev;
	struct i2c_adapter *adapter;

	dev = bus_find_device(&i2c_bus_type, NULL, node,
	of_dev_or_parent_node_match);
	if (!dev)
	return NULL;

	adapter = i2c_verify_adapter(dev);
	if (!adapter)
	put_device(dev);

	return adapter;
	}
	EXPORT_SYMBOL(of_find_i2c_adapter_by_node);

	/* must call i2c_put_adapter() when done with returned i2c_adapter device */
	struct i2c_adapter of_get_i2c_adapter_by_node(struct device_node node)
	{
	struct i2c_adapter *adapter;

	adapter = of_find_i2c_adapter_by_node(node);
	if (!adapter)
	return NULL;

	if (!try_module_get(adapter->owner)) {
	put_device(&adapter->dev);
	adapter = NULL;
	}

	return adapter;
	}
	EXPORT_SYMBOL(of_get_i2c_adapter_by_node);

	static const struct of_device_id*
	i2c_of_match_device_sysfs(const struct of_device_id *matches,
	struct i2c_client *client)
	{
	const char *name;

	for (; matches->compatible[0]; matches++) {
	/*
	* Adding devices through the i2c sysfs interface provides us
	* a string to match which may be compatible with the device
	* tree compatible strings, however with no actual of_node the
	* of_match_device() will not match
	*/
	if (sysfs_streq(client->name, matches->compatible))
	return matches;

	name = strchr(matches->compatible, ',');
	if (!name)
	name = matches->compatible;
	else
	name++;

	if (sysfs_streq(client->name, name))
	return matches;
	}

	return NULL;
	}

	const struct of_device_id
	i2c_of_match_device(const struct of_device_id matches,
	struct i2c_client *client)
	{
	const struct of_device_id *match;

	if (!(client && matches))
	return NULL;

	match = of_match_device(matches, &client->dev);
	if (match)
	return match;

	return i2c_of_match_device_sysfs(matches, client);
	}
	EXPORT_SYMBOL_GPL(i2c_of_match_device);

	#if IS_ENABLED(CONFIG_OF_DYNAMIC)
	static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
	void *arg)
	{
	struct of_reconfig_data *rd = arg;
	struct i2c_adapter *adap;
	struct i2c_client *client;

	switch (of_reconfig_get_state_change(action, rd)) {
	case OF_RECONFIG_CHANGE_ADD:
	adap = of_find_i2c_adapter_by_node(rd->dn->parent);
	if (adap == NULL)
	return NOTIFY_OK; /* not for us */

	if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
	put_device(&adap->dev);
	return NOTIFY_OK;
	}

	client = of_i2c_register_device(adap, rd->dn);
	put_device(&adap->dev);

	if (IS_ERR(client)) {
	dev_err(&adap->dev, "failed to create client for '%pOF'\n",
	rd->dn);
	of_node_clear_flag(rd->dn, OF_POPULATED);
	return notifier_from_errno(PTR_ERR(client));
	}
	break;
	case OF_RECONFIG_CHANGE_REMOVE:
	/* already depopulated? */
	if (!of_node_check_flag(rd->dn, OF_POPULATED))
	return NOTIFY_OK;

	/* find our device by node */
	client = of_find_i2c_device_by_node(rd->dn);
	if (client == NULL)
	return NOTIFY_OK; /* no? not meant for us */

	/* unregister takes one ref away */
	i2c_unregister_device(client);

	/* and put the reference of the find */
	put_device(&client->dev);
	break;
	}

	return NOTIFY_OK;
	}

	struct notifier_block i2c_of_notifier = {
	.notifier_call = of_i2c_notify,
	};
	#endif /* CONFIG_OF_DYNAMIC */