diff options
| -rw-r--r-- | drivers/i2c/i2c-core.c | 78 | ||||
| -rw-r--r-- | drivers/i2c/i2c-dev.c | 29 | ||||
| -rw-r--r-- | include/linux/i2c.h | 8 |
3 files changed, 63 insertions, 52 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index ddd1b83f44d..c8bbd672226 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -199,6 +199,25 @@ static struct bus_type i2c_bus_type = { .resume = i2c_device_resume, }; + +/** + * i2c_verify_client - return parameter as i2c_client, or NULL + * @dev: device, probably from some driver model iterator + * + * When traversing the driver model tree, perhaps using driver model + * iterators like @device_for_each_child(), you can't assume very much + * about the nodes you find. Use this function to avoid oopses caused + * by wrongly treating some non-I2C device as an i2c_client. + */ +struct i2c_client *i2c_verify_client(struct device *dev) +{ + return (dev->bus == &i2c_bus_type) + ? to_i2c_client(dev) + : NULL; +} +EXPORT_SYMBOL(i2c_verify_client); + + /** * i2c_new_device - instantiate an i2c device for use with a new style driver * @adap: the adapter managing the device @@ -670,28 +689,19 @@ EXPORT_SYMBOL(i2c_del_driver); /* ------------------------------------------------------------------------- */ -static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr) +static int __i2c_check_addr(struct device *dev, void *addrp) { - struct list_head *item; - struct i2c_client *client; + struct i2c_client *client = i2c_verify_client(dev); + int addr = *(int *)addrp; - list_for_each(item,&adapter->clients) { - client = list_entry(item, struct i2c_client, list); - if (client->addr == addr) - return -EBUSY; - } + if (client && client->addr == addr) + return -EBUSY; return 0; } static int i2c_check_addr(struct i2c_adapter *adapter, int addr) { - int rval; - - mutex_lock(&adapter->clist_lock); - rval = __i2c_check_addr(adapter, addr); - mutex_unlock(&adapter->clist_lock); - - return rval; + return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); } int i2c_attach_client(struct i2c_client *client) @@ -700,7 +710,7 @@ int i2c_attach_client(struct i2c_client *client) int res = 0; mutex_lock(&adapter->clist_lock); - if (__i2c_check_addr(client->adapter, client->addr)) { + if (i2c_check_addr(client->adapter, client->addr)) { res = -EBUSY; goto out_unlock; } @@ -804,24 +814,28 @@ void i2c_release_client(struct i2c_client *client) } EXPORT_SYMBOL(i2c_release_client); +struct i2c_cmd_arg { + unsigned cmd; + void *arg; +}; + +static int i2c_cmd(struct device *dev, void *_arg) +{ + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_cmd_arg *arg = _arg; + + if (client && client->driver && client->driver->command) + client->driver->command(client, arg->cmd, arg->arg); + return 0; +} + void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) { - struct list_head *item; - struct i2c_client *client; + struct i2c_cmd_arg cmd_arg; - mutex_lock(&adap->clist_lock); - list_for_each(item,&adap->clients) { - client = list_entry(item, struct i2c_client, list); - if (!try_module_get(client->driver->driver.owner)) - continue; - if (NULL != client->driver->command) { - mutex_unlock(&adap->clist_lock); - client->driver->command(client,cmd,arg); - mutex_lock(&adap->clist_lock); - } - module_put(client->driver->driver.owner); - } - mutex_unlock(&adap->clist_lock); + cmd_arg.cmd = cmd; + cmd_arg.arg = arg; + device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); } EXPORT_SYMBOL(i2c_clients_command); @@ -1087,7 +1101,7 @@ i2c_new_probed_device(struct i2c_adapter *adap, } /* Check address availability */ - if (__i2c_check_addr(adap, addr_list[i])) { + if (i2c_check_addr(adap, addr_list[i])) { dev_dbg(&adap->dev, "Address 0x%02x already in " "use, not probing\n", addr_list[i]); continue; diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index df540d5dfaf..393e679d9fa 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -182,27 +182,22 @@ static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t c return ret; } +static int i2cdev_check(struct device *dev, void *addrp) +{ + struct i2c_client *client = i2c_verify_client(dev); + + if (!client || client->addr != *(unsigned int *)addrp) + return 0; + + return dev->driver ? -EBUSY : 0; +} + /* This address checking function differs from the one in i2c-core in that it considers an address with a registered device, but no - bound driver, as NOT busy. */ + driver bound to it, as NOT busy. */ static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) { - struct list_head *item; - struct i2c_client *client; - int res = 0; - - mutex_lock(&adapter->clist_lock); - list_for_each(item, &adapter->clients) { - client = list_entry(item, struct i2c_client, list); - if (client->addr == addr) { - if (client->driver) - res = -EBUSY; - break; - } - } - mutex_unlock(&adapter->clist_lock); - - return res; + return device_for_each_child(&adapter->dev, &addr, i2cdev_check); } static int i2cdev_ioctl(struct inode *inode, struct file *file, diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 0fc59efd80e..731928ae972 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -158,7 +158,7 @@ struct i2c_driver { * @irq: indicates the IRQ generated by this device (if any) * @driver_name: Identifies new-style driver used with this device; also * used as the module name for hotplug/coldplug modprobe support. - * @list: list of active/busy clients + * @list: list of active/busy clients (DEPRECATED) * @released: used to synchronize client releases & detaches and references * * An i2c_client identifies a single device (i.e. chip) connected to an @@ -176,11 +176,13 @@ struct i2c_client { struct device dev; /* the device structure */ int irq; /* irq issued by device (or -1) */ char driver_name[KOBJ_NAME_LEN]; - struct list_head list; + struct list_head list; /* DEPRECATED */ struct completion released; }; #define to_i2c_client(d) container_of(d, struct i2c_client, dev) +extern struct i2c_client *i2c_verify_client(struct device *dev); + static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) { struct device * const dev = container_of(kobj, struct device, kobj); @@ -315,7 +317,7 @@ struct i2c_adapter { struct device dev; /* the adapter device */ int nr; - struct list_head clients; + struct list_head clients; /* DEPRECATED */ char name[48]; struct completion dev_released; }; |