diff options
Diffstat (limited to 'drivers/i2c/i2c-core-of.c')
| -rw-r--r-- | drivers/i2c/i2c-core-of.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c new file mode 100644 index 000000000000..ccf82fdbcd8e --- /dev/null +++ b/drivers/i2c/i2c-core-of.c @@ -0,0 +1,276 @@ +/* + * 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 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" + +static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, + struct device_node *node) +{ + struct i2c_client *result; + struct i2c_board_info info = {}; + struct dev_archdata dev_ad = {}; + const __be32 *addr_be; + u32 addr; + int len; + + dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); + + if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { + dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", + node->full_name); + return ERR_PTR(-EINVAL); + } + + addr_be = of_get_property(node, "reg", &len); + if (!addr_be || (len < sizeof(*addr_be))) { + dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", + node->full_name); + return ERR_PTR(-EINVAL); + } + + addr = be32_to_cpup(addr_be); + 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; + } + + if (i2c_check_addr_validity(addr, info.flags)) { + dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", + addr, node->full_name); + return ERR_PTR(-EINVAL); + } + + info.addr = addr; + info.of_node = of_node_get(node); + info.archdata = &dev_ad; + + 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; + + result = i2c_new_device(adap, &info); + if (result == NULL) { + dev_err(&adap->dev, "of_i2c: Failure registering %s\n", + node->full_name); + of_node_put(node); + return ERR_PTR(-EINVAL); + } + return result; +} + +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_warn(&adap->dev, + "Failed to create I2C device for %s\n", + node->full_name); + 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)) { + dev_err(&adap->dev, "failed to create client for '%s'\n", + rd->dn->full_name); + 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 */ |