i2c-core-of.c 6.51 KB
Newer Older
1 2 3 4 5 6
/*
 * 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>
 *
7
 * Copyright (C) 2013, 2018 Wolfram Sang <wsa@the-dreams.de>
8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
 *
 * 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"

25 26
int of_i2c_get_board_info(struct device *dev, struct device_node *node,
			  struct i2c_board_info *info)
27 28
{
	u32 addr;
29
	int ret;
30

31
	memset(info, 0, sizeof(*info));
32

33 34 35
	if (of_modalias_node(node, info->type, sizeof(info->type)) < 0) {
		dev_err(dev, "of_i2c: modalias failure on %pOF\n", node);
		return -EINVAL;
36 37
	}

38 39
	ret = of_property_read_u32(node, "reg", &addr);
	if (ret) {
40 41
		dev_err(dev, "of_i2c: invalid reg on %pOF\n", node);
		return ret;
42 43 44 45
	}

	if (addr & I2C_TEN_BIT_ADDRESS) {
		addr &= ~I2C_TEN_BIT_ADDRESS;
46
		info->flags |= I2C_CLIENT_TEN;
47 48 49 50
	}

	if (addr & I2C_OWN_SLAVE_ADDRESS) {
		addr &= ~I2C_OWN_SLAVE_ADDRESS;
51
		info->flags |= I2C_CLIENT_SLAVE;
52 53
	}

54 55
	info->addr = addr;
	info->of_node = node;
56 57

	if (of_property_read_bool(node, "host-notify"))
58
		info->flags |= I2C_CLIENT_HOST_NOTIFY;
59 60

	if (of_get_property(node, "wakeup-source", NULL))
61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78
		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);
79

80 81
	client = i2c_new_device(adap, &info);
	if (!client) {
82
		dev_err(&adap->dev, "of_i2c: Failure registering %pOF\n", node);
83 84
		return ERR_PTR(-EINVAL);
	}
85
	return client;
86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108
}

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)) {
109
			dev_err(&adap->dev,
110 111
				 "Failed to create I2C device for %pOF\n",
				 node);
112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
			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;
}

/* 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_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)) {
247 248
			dev_err(&adap->dev, "failed to create client for '%pOF'\n",
				 rd->dn);
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
			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 */