From 352da9820e5506e3b8496e6052a2ad9c488efae8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 19 Jun 2009 16:58:17 +0200 Subject: i2c: Kill client_register and client_unregister methods These methods were useful in the legacy binding model but no longer in the new (standard) binding model. There are no users left so we can drop them. Signed-off-by: Jean Delvare Cc: David Brownell --- Documentation/feature-removal-schedule.txt | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 8d07ed31207e..9163dade0706 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -368,8 +368,7 @@ Who: Krzysztof Piotr Oledzki --------------------------- -What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client(), - i2c_adapter->client_register(), i2c_adapter->client_unregister +What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client() When: 2.6.30 Check: i2c_attach_client i2c_detach_client Why: Deprecated by the new (standard) device driver binding model. Use -- cgit v1.2.3 From 729d6dd571464954f625e6b80950d9e4e3bd94f7 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 19 Jun 2009 16:58:18 +0200 Subject: i2c: Get rid of the legacy binding model We converted all the legacy i2c drivers so we can finally get rid of the legacy binding model. Hooray! Signed-off-by: Jean Delvare Cc: David Brownell --- Documentation/feature-removal-schedule.txt | 9 ---- Documentation/i2c/writing-clients | 16 ++---- drivers/i2c/i2c-core.c | 83 +++--------------------------- include/linux/i2c.h | 39 ++++---------- 4 files changed, 20 insertions(+), 127 deletions(-) (limited to 'Documentation') diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 9163dade0706..f8cd450be9aa 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -368,15 +368,6 @@ Who: Krzysztof Piotr Oledzki --------------------------- -What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client() -When: 2.6.30 -Check: i2c_attach_client i2c_detach_client -Why: Deprecated by the new (standard) device driver binding model. Use - i2c_driver->probe() and ->remove() instead. -Who: Jean Delvare - ---------------------------- - What: fscher and fscpos drivers When: June 2009 Why: Deprecated by the new fschmd driver. diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index c1a06f989cf7..7860aafb483d 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -126,19 +126,9 @@ different) configuration information, as do drivers handling chip variants that can't be distinguished by protocol probing, or which need some board specific information to operate correctly. -Accordingly, the I2C stack now has two models for associating I2C devices -with their drivers: the original "legacy" model, and a newer one that's -fully compatible with the Linux 2.6 driver model. These models do not mix, -since the "legacy" model requires drivers to create "i2c_client" device -objects after SMBus style probing, while the Linux driver model expects -drivers to be given such device objects in their probe() routines. -The legacy model is deprecated now and will soon be removed, so we no -longer document it here. - - -Standard Driver Model Binding ("New Style") -------------------------------------------- +Device/Driver Binding +--------------------- System infrastructure, typically board-specific initialization code or boot firmware, reports what I2C devices exist. For example, there may be @@ -201,7 +191,7 @@ a given I2C bus. This is for example the case of hardware monitoring devices on a PC's SMBus. In that case, you may want to let your driver detect supported devices automatically. This is how the legacy model was working, and is now available as an extension to the standard -driver model (so that we can finally get rid of the legacy model.) +driver model. You simply have to define a detect callback which will attempt to identify supported devices (returning 0 for supported ones and -ENODEV diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index fc18fdbffd3f..dc8bc9131447 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -43,6 +43,7 @@ static DEFINE_IDR(i2c_adapter_idr); #define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect) +static int i2c_attach_client(struct i2c_client *client); static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); /* ------------------------------------------------------------------------- */ @@ -83,10 +84,6 @@ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) { struct i2c_client *client = to_i2c_client(dev); - /* by definition, legacy drivers can't hotplug */ - if (dev->driver) - return 0; - if (add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name)) return -ENOMEM; @@ -455,7 +452,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); - /* create pre-declared device nodes for new-style drivers */ + /* create pre-declared device nodes */ if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); @@ -617,26 +614,9 @@ int i2c_del_adapter(struct i2c_adapter *adap) if (res) goto out_unlock; - /* detach any active clients. This must be done first, because - * it can fail; in which case we give up. */ + /* Detach any active clients */ list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) { - struct i2c_driver *driver; - - driver = client->driver; - - /* new style, follow standard driver model */ - if (!driver || is_newstyle_driver(driver)) { - i2c_unregister_device(client); - continue; - } - - /* legacy drivers create and remove clients themselves */ - if ((res = driver->detach_client(client))) { - dev_err(&adap->dev, "detach_client failed for client " - "[%s] at address 0x%02x\n", client->name, - client->addr); - goto out_unlock; - } + i2c_unregister_device(client); } /* clean up the sysfs representation */ @@ -680,11 +660,7 @@ static int __attach_adapter(struct device *dev, void *data) /* * An i2c_driver is used with one or more i2c_client (device) nodes to access - * i2c slave chips, on a bus instance associated with some i2c_adapter. There - * are two models for binding the driver to its device: "new style" drivers - * follow the standard Linux driver model and just respond to probe() calls - * issued if the driver core sees they match(); "legacy" drivers create device - * nodes themselves. + * i2c slave chips, on a bus instance associated with some i2c_adapter. */ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) @@ -695,21 +671,11 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) if (unlikely(WARN_ON(!i2c_bus_type.p))) return -EAGAIN; - /* new style driver methods can't mix with legacy ones */ - if (is_newstyle_driver(driver)) { - if (driver->detach_adapter || driver->detach_client) { - printk(KERN_WARNING - "i2c-core: driver [%s] is confused\n", - driver->driver.name); - return -EINVAL; - } - } - /* add the driver to the list of i2c drivers in the driver core */ driver->driver.owner = owner; driver->driver.bus = &i2c_bus_type; - /* for new style drivers, when registration returns the driver core + /* When registration returns, the driver core * will have called probe() for all matching-but-unbound devices. */ res = driver_register(&driver->driver); @@ -748,29 +714,11 @@ static int __detach_adapter(struct device *dev, void *data) if (is_newstyle_driver(driver)) return 0; - /* Have a look at each adapter, if clients of this driver are still - * attached. If so, detach them to be able to kill the driver - * afterwards. - */ if (driver->detach_adapter) { if (driver->detach_adapter(adapter)) dev_err(&adapter->dev, "detach_adapter failed for driver [%s]\n", driver->driver.name); - } else { - struct i2c_client *client, *_n; - - list_for_each_entry_safe(client, _n, &adapter->clients, list) { - if (client->driver != driver) - continue; - dev_dbg(&adapter->dev, - "detaching client [%s] at 0x%02x\n", - client->name, client->addr); - if (driver->detach_client(client)) - dev_err(&adapter->dev, "detach_client " - "failed for client [%s] at 0x%02x\n", - client->name, client->addr); - } } return 0; @@ -812,7 +760,7 @@ static int i2c_check_addr(struct i2c_adapter *adapter, int addr) return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); } -int i2c_attach_client(struct i2c_client *client) +static int i2c_attach_client(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; int res; @@ -854,23 +802,6 @@ out_err: "(%d)\n", client->name, client->addr, res); return res; } -EXPORT_SYMBOL(i2c_attach_client); - -int i2c_detach_client(struct i2c_client *client) -{ - struct i2c_adapter *adapter = client->adapter; - - mutex_lock(&adapter->clist_lock); - list_del(&client->list); - mutex_unlock(&adapter->clist_lock); - - init_completion(&client->released); - device_unregister(&client->dev); - wait_for_completion(&client->released); - - return 0; -} -EXPORT_SYMBOL(i2c_detach_client); /** * i2c_use_client - increments the reference count of the i2c client structure diff --git a/include/linux/i2c.h b/include/linux/i2c.h index b3f4606afa0e..43a3545670b8 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -100,9 +100,8 @@ extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, * @class: What kind of i2c device we instantiate (for detect) * @attach_adapter: Callback for bus addition (for legacy drivers) * @detach_adapter: Callback for bus removal (for legacy drivers) - * @detach_client: Callback for device removal (for legacy drivers) - * @probe: Callback for device binding (new-style drivers) - * @remove: Callback for device unbinding (new-style drivers) + * @probe: Callback for device binding + * @remove: Callback for device unbinding * @shutdown: Callback for device shutdown * @suspend: Callback for device suspend * @resume: Callback for device resume @@ -137,26 +136,14 @@ struct i2c_driver { int id; unsigned int class; - /* Notifies the driver that a new bus has appeared. This routine - * can be used by the driver to test if the bus meets its conditions - * & seek for the presence of the chip(s) it supports. If found, it - * registers the client(s) that are on the bus to the i2c admin. via - * i2c_attach_client. (LEGACY I2C DRIVERS ONLY) + /* Notifies the driver that a new bus has appeared or is about to be + * removed. You should avoid using this if you can, it will probably + * be removed in a near future. */ int (*attach_adapter)(struct i2c_adapter *); int (*detach_adapter)(struct i2c_adapter *); - /* tells the driver that a client is about to be deleted & gives it - * the chance to remove its private data. Also, if the client struct - * has been dynamically allocated by the driver in the function above, - * it must be freed here. (LEGACY I2C DRIVERS ONLY) - */ - int (*detach_client)(struct i2c_client *) __deprecated; - - /* Standard driver model interfaces, for "new style" i2c drivers. - * With the driver model, device enumeration is NEVER done by drivers; - * it's done by infrastructure. (NEW STYLE DRIVERS ONLY) - */ + /* Standard driver model interfaces */ int (*probe)(struct i2c_client *, const struct i2c_device_id *); int (*remove)(struct i2c_client *); @@ -248,11 +235,10 @@ static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) * that, such as chip type, configuration, associated IRQ, and so on. * * i2c_board_info is used to build tables of information listing I2C devices - * that are present. This information is used to grow the driver model tree - * for "new style" I2C drivers. For mainboards this is done statically using - * i2c_register_board_info(); bus numbers identify adapters that aren't - * yet available. For add-on boards, i2c_new_device() does this dynamically - * with the adapter already known. + * that are present. This information is used to grow the driver model tree. + * For mainboards this is done statically using i2c_register_board_info(); + * bus numbers identify adapters that aren't yet available. For add-on boards, + * i2c_new_device() does this dynamically with the adapter already known. */ struct i2c_board_info { char type[I2C_NAME_SIZE]; @@ -425,11 +411,6 @@ static inline int i2c_add_driver(struct i2c_driver *driver) return i2c_register_driver(THIS_MODULE, driver); } -/* These are deprecated, your driver should use the standard .probe() - * and .remove() methods instead. */ -extern int __deprecated i2c_attach_client(struct i2c_client *); -extern int __deprecated i2c_detach_client(struct i2c_client *); - extern struct i2c_client *i2c_use_client(struct i2c_client *client); extern void i2c_release_client(struct i2c_client *client); -- cgit v1.2.3 From 99cd8e25875a109455b709b5a41d4891b8d8e58e Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Fri, 19 Jun 2009 16:58:20 +0200 Subject: i2c: Add a sysfs interface to instantiate devices Add a sysfs interface to instantiate and delete I2C devices. This is primarily a replacement of the force_* module parameters implemented by some i2c drivers. These module parameters were implemented internally by the I2C_CLIENT_INSMOD* macros, which don't scale well. This can also be used when developing a driver on a self-soldered board which doesn't yet have proper I2C device declaration at the platform level, and presumably for various debugging situations. Signed-off-by: Jean Delvare Cc: David Brownell --- Documentation/i2c/instantiating-devices | 44 ++++++++++++ drivers/i2c/i2c-core.c | 123 +++++++++++++++++++++++++++++++- include/linux/i2c.h | 3 +- 3 files changed, 168 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices index b55ce57a84db..c740b7b41088 100644 --- a/Documentation/i2c/instantiating-devices +++ b/Documentation/i2c/instantiating-devices @@ -165,3 +165,47 @@ was done there. Two significant differences are: Once again, method 3 should be avoided wherever possible. Explicit device instantiation (methods 1 and 2) is much preferred for it is safer and faster. + + +Method 4: Instantiate from user-space +------------------------------------- + +In general, the kernel should know which I2C devices are connected and +what addresses they live at. However, in certain cases, it does not, so a +sysfs interface was added to let the user provide the information. This +interface is made of 2 attribute files which are created in every I2C bus +directory: new_device and delete_device. Both files are write only and you +must write the right parameters to them in order to properly instantiate, +respectively delete, an I2C device. + +File new_device takes 2 parameters: the name of the I2C device (a string) +and the address of the I2C device (a number, typically expressed in +hexadecimal starting with 0x, but can also be expressed in decimal.) + +File delete_device takes a single parameter: the address of the I2C +device. As no two devices can live at the same address on a given I2C +segment, the address is sufficient to uniquely identify the device to be +deleted. + +Example: +# echo eeprom 0x50 > /sys/class/i2c-adapter/i2c-3/new_device + +While this interface should only be used when in-kernel device declaration +can't be done, there is a variety of cases where it can be helpful: +* The I2C driver usually detects devices (method 3 above) but the bus + segment your device lives on doesn't have the proper class bit set and + thus detection doesn't trigger. +* The I2C driver usually detects devices, but your device lives at an + unexpected address. +* The I2C driver usually detects devices, but your device is not detected, + either because the detection routine is too strict, or because your + device is not officially supported yet but you know it is compatible. +* You are developing a driver on a test board, where you soldered the I2C + device yourself. + +This interface is a replacement for the force_* module parameters some I2C +drivers implement. Being implemented in i2c-core rather than in each +device driver individually, it is much more efficient, and also has the +advantage that you do not have to reload the driver to change a setting. +You can also instantiate the device before the driver is loaded or even +available, and you don't need to know what driver the device needs. diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index a2f1cd3766f3..eb084fa0df83 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -38,11 +38,12 @@ #include "i2c-core.h" -/* core_lock protects i2c_adapter_idr, and guarantees +/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees that device detection, deletion of detected devices, and attach_adapter and detach_adapter calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); +static LIST_HEAD(userspace_devices); static int i2c_check_addr(struct i2c_adapter *adapter, int addr); static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); @@ -373,8 +374,128 @@ show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) return sprintf(buf, "%s\n", adap->name); } +/* + * Let users instantiate I2C devices through sysfs. This can be used when + * platform initialization code doesn't contain the proper data for + * whatever reason. Also useful for drivers that do device detection and + * detection fails, either because the device uses an unexpected address, + * or this is a compatible device with different ID register values. + * + * Parameter checking may look overzealous, but we really don't want + * the user to provide incorrect parameters. + */ +static ssize_t +i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_adapter *adap = to_i2c_adapter(dev); + struct i2c_board_info info; + struct i2c_client *client; + char *blank, end; + int res; + + dev_warn(dev, "The new_device interface is still experimental " + "and may change in a near future\n"); + memset(&info, 0, sizeof(struct i2c_board_info)); + + blank = strchr(buf, ' '); + if (!blank) { + dev_err(dev, "%s: Missing parameters\n", "new_device"); + return -EINVAL; + } + if (blank - buf > I2C_NAME_SIZE - 1) { + dev_err(dev, "%s: Invalid device name\n", "new_device"); + return -EINVAL; + } + memcpy(info.type, buf, blank - buf); + + /* Parse remaining parameters, reject extra parameters */ + res = sscanf(++blank, "%hi%c", &info.addr, &end); + if (res < 1) { + dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); + return -EINVAL; + } + if (res > 1 && end != '\n') { + dev_err(dev, "%s: Extra parameters\n", "new_device"); + return -EINVAL; + } + + if (info.addr < 0x03 || info.addr > 0x77) { + dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device", + info.addr); + return -EINVAL; + } + + client = i2c_new_device(adap, &info); + if (!client) + return -EEXIST; + + /* Keep track of the added device */ + mutex_lock(&core_lock); + list_add_tail(&client->detected, &userspace_devices); + mutex_unlock(&core_lock); + dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", + info.type, info.addr); + + return count; +} + +/* + * And of course let the users delete the devices they instantiated, if + * they got it wrong. This interface can only be used to delete devices + * instantiated by i2c_sysfs_new_device above. This guarantees that we + * don't delete devices to which some kernel code still has references. + * + * Parameter checking may look overzealous, but we really don't want + * the user to delete the wrong device. + */ +static ssize_t +i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct i2c_adapter *adap = to_i2c_adapter(dev); + struct i2c_client *client, *next; + unsigned short addr; + char end; + int res; + + /* Parse parameters, reject extra parameters */ + res = sscanf(buf, "%hi%c", &addr, &end); + if (res < 1) { + dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); + return -EINVAL; + } + if (res > 1 && end != '\n') { + dev_err(dev, "%s: Extra parameters\n", "delete_device"); + return -EINVAL; + } + + /* Make sure the device was added through sysfs */ + res = -ENOENT; + mutex_lock(&core_lock); + list_for_each_entry_safe(client, next, &userspace_devices, detected) { + if (client->addr == addr && client->adapter == adap) { + dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", + "delete_device", client->name, client->addr); + + list_del(&client->detected); + i2c_unregister_device(client); + res = count; + break; + } + } + mutex_unlock(&core_lock); + + if (res < 0) + dev_err(dev, "%s: Can't find device in list\n", + "delete_device"); + return res; +} + static struct device_attribute i2c_adapter_attrs[] = { __ATTR(name, S_IRUGO, show_adapter_name, NULL), + __ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device), + __ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device), { }, }; diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 5f8157610c64..844d2662a875 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -178,7 +178,8 @@ struct i2c_driver { * @driver: device's driver, hence pointer to access routines * @dev: Driver model device node for the slave. * @irq: indicates the IRQ generated by this device (if any) - * @detected: member of an i2c_driver.clients list + * @detected: member of an i2c_driver.clients list or i2c-core's + * userspace_devices list * * An i2c_client identifies a single device (i.e. chip) connected to an * i2c bus. The behaviour exposed to Linux is defined by the driver -- cgit v1.2.3