diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 184 |
1 files changed, 182 insertions, 2 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 48e31ed69dbf..780599ce4657 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -23,7 +23,11 @@ SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and Jean Delvare <khali@linux-fr.org> Mux support by Rodolfo Giometti <giometti@enneenne.com> and - Michael Lawnick <michael.lawnick.ext@nsn.com> */ + Michael Lawnick <michael.lawnick.ext@nsn.com> + OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> + (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and + (c) 2013 Wolfram Sang <wsa@the-dreams.de> + */ #include <linux/module.h> #include <linux/kernel.h> @@ -35,7 +39,9 @@ #include <linux/init.h> #include <linux/idr.h> #include <linux/mutex.h> +#include <linux/of.h> #include <linux/of_device.h> +#include <linux/of_irq.h> #include <linux/completion.h> #include <linux/hardirq.h> #include <linux/irqflags.h> @@ -43,6 +49,7 @@ #include <linux/pm_runtime.h> #include <linux/acpi.h> #include <asm/uaccess.h> +#include <linux/err.h> #include "i2c-core.h" @@ -697,6 +704,10 @@ EXPORT_SYMBOL_GPL(i2c_new_device); */ void i2c_unregister_device(struct i2c_client *client) { +#if IS_ENABLED(CONFIG_OF_DYNAMIC) + if (client->dev.of_node) + of_node_clear_flag(client->dev.of_node, OF_POPULATED); +#endif device_unregister(&client->dev); } EXPORT_SYMBOL_GPL(i2c_unregister_device); @@ -954,6 +965,113 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter) up_read(&__i2c_board_lock); } +/* OF support code */ + +#if IS_ENABLED(CONFIG_OF) +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; + 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 = of_get_property(node, "reg", &len); + if (!addr || (len < sizeof(int))) { + dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", + node->full_name); + return ERR_PTR(-EINVAL); + } + + info.addr = be32_to_cpup(addr); + if (info.addr > (1 << 10) - 1) { + dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", + info.addr, node->full_name); + return ERR_PTR(-EINVAL); + } + + info.irq = irq_of_parse_and_map(node, 0); + info.of_node = of_node_get(node); + info.archdata = &dev_ad; + + if (of_get_property(node, "wakeup-source", NULL)) + info.flags |= I2C_CLIENT_WAKE; + + request_module("%s%s", I2C_MODULE_PREFIX, info.type); + + 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); + irq_dispose_mapping(info.irq); + return ERR_PTR(-EINVAL); + } + return result; +} + +static void internal_of_i2c_register_devices(struct i2c_adapter *adap) +{ + struct device_node *node; + + /* 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"); + + for_each_available_child_of_node(adap->dev.of_node, node) { + if (of_node_test_and_set_flag(node, OF_POPULATED)) + continue; + of_i2c_register_device(adap, node); + } +} + +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; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_client(dev); +} +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; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_adapter(dev); +} +EXPORT_SYMBOL(of_find_i2c_adapter_by_node); +#else +static void internal_of_i2c_register_devices(struct i2c_adapter *adap) { } +#endif /* CONFIG_OF */ + static int i2c_do_add_adapter(struct i2c_driver *driver, struct i2c_adapter *adap) { @@ -1058,6 +1176,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap) exit_recovery: /* create pre-declared device nodes */ + internal_of_i2c_register_devices(adap); + if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); @@ -1282,7 +1402,6 @@ void i2c_del_adapter(struct i2c_adapter *adap) } EXPORT_SYMBOL(i2c_del_adapter); - /* ------------------------------------------------------------------------- */ int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) @@ -1426,6 +1545,61 @@ void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) } EXPORT_SYMBOL(i2c_clients_command); +#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)) { + pr_err("%s: failed to create for '%s'\n", + __func__, rd->dn->full_name); + 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; +} +static struct notifier_block i2c_of_notifier = { + .notifier_call = of_i2c_notify, +}; +#else +extern struct notifier_block i2c_of_notifier; +#endif /* CONFIG_OF_DYNAMIC */ + static int __init i2c_init(void) { int retval; @@ -1443,6 +1617,10 @@ static int __init i2c_init(void) retval = i2c_add_driver(&dummy_driver); if (retval) goto class_err; + + if (IS_ENABLED(CONFIG_OF_DYNAMIC)) + WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); + return 0; class_err: @@ -1456,6 +1634,8 @@ bus_err: static void __exit i2c_exit(void) { + if (IS_ENABLED(CONFIG_OF_DYNAMIC)) + WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); i2c_del_driver(&dummy_driver); #ifdef CONFIG_I2C_COMPAT class_compat_unregister(i2c_adapter_compat_class); |