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Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging 

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c: New macro to initialize i2c address lists on the fly
  i2c: Don't advertise i2c functions when not available
  i2c: Use rwsem instead of mutex for board info
  i2c: Add a sysfs interface to instantiate devices
  i2c: Limit core locking to the necessary sections
  i2c: Kill the redundant client list
  i2c: Kill is_newstyle_driver
  i2c: Merge i2c_attach_client into i2c_new_device
  i2c: Drop i2c_probe function
  i2c: Get rid of the legacy binding model
  i2c: Kill client_register and client_unregister methods
This commit is contained in:
Linus Torvalds 2009-06-19 17:45:51 -07:00
parent 31583d6acf c70366732f
commit 5c6fb0059c
7 changed files with 275 additions and 435 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
Documentation/feature-removal-schedule.txt
View File

@ -368,16 +368,6 @@ Who: Krzysztof Piotr Oledzki <ole@ans.pl>
---------------------------
What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client(),
i2c_adapter->client_register(), i2c_adapter->client_unregister
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 <khali@linux-fr.org>
---------------------------
What: fscher and fscpos drivers
When: June 2009
Why: Deprecated by the new fschmd driver.

44
Documentation/i2c/instantiating-devices
View File

@ -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.

16
Documentation/i2c/writing-clients
View File

@ -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

7
drivers/i2c/i2c-boardinfo.c
View File

@ -18,6 +18,7 @@
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/rwsem.h>
#include "i2c-core.h"
@ -25,7 +26,7 @@
/* These symbols are exported ONLY FOR the i2c core.
* No other users will be supported.
*/
DEFINE_MUTEX(__i2c_board_lock);
DECLARE_RWSEM(__i2c_board_lock);
EXPORT_SYMBOL_GPL(__i2c_board_lock);
LIST_HEAD(__i2c_board_list);
@ -63,7 +64,7 @@ i2c_register_board_info(int busnum,
{
int status;
mutex_lock(&__i2c_board_lock);
down_write(&__i2c_board_lock);
/* dynamic bus numbers will be assigned after the last static one */
if (busnum >= __i2c_first_dynamic_bus_num)
@ -84,7 +85,7 @@ i2c_register_board_info(int busnum,
list_add_tail(&devinfo->list, &__i2c_board_list);
}
mutex_unlock(&__i2c_board_lock);
up_write(&__i2c_board_lock);
return status;
}

557
drivers/i2c/i2c-core.c
View File

@ -33,16 +33,20 @@
#include <linux/completion.h>
#include <linux/hardirq.h>
#include <linux/irqflags.h>
#include <linux/rwsem.h>
#include <asm/uaccess.h>
#include "i2c-core.h"
/* 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);
#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
/* ------------------------------------------------------------------------- */
@ -63,12 +67,6 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv)
struct i2c_client *client = to_i2c_client(dev);
struct i2c_driver *driver = to_i2c_driver(drv);
/* make legacy i2c drivers bypass driver model probing entirely;
* such drivers scan each i2c adapter/bus themselves.
*/
if (!is_newstyle_driver(driver))
return 0;
/* match on an id table if there is one */
if (driver->id_table)
return i2c_match_id(driver->id_table, client) != NULL;
@ -83,10 +81,6 @@ 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;
@ -175,12 +169,6 @@ static int i2c_device_resume(struct device *dev)
return driver->resume(to_i2c_client(dev));
}
static void i2c_client_release(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
complete(&client->released);
}
static void i2c_client_dev_release(struct device *dev)
{
kfree(to_i2c_client(dev));
@ -240,15 +228,17 @@ EXPORT_SYMBOL(i2c_verify_client);
/**
* i2c_new_device - instantiate an i2c device for use with a new style driver
* i2c_new_device - instantiate an i2c device
* @adap: the adapter managing the device
* @info: describes one I2C device; bus_num is ignored
* Context: can sleep
*
* Create a device to work with a new style i2c driver, where binding is
* handled through driver model probe()/remove() methods. This call is not
* appropriate for use by mainboad initialization logic, which usually runs
* during an arch_initcall() long before any i2c_adapter could exist.
* Create an i2c device. Binding is handled through driver model
* probe()/remove() methods. A driver may be bound to this device when we
* return from this function, or any later moment (e.g. maybe hotplugging will
* load the driver module). This call is not appropriate for use by mainboard
* initialization logic, which usually runs during an arch_initcall() long
* before any i2c_adapter could exist.
*
* This returns the new i2c client, which may be saved for later use with
* i2c_unregister_device(); or NULL to indicate an error.
@ -276,17 +266,31 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
strlcpy(client->name, info->type, sizeof(client->name));
/* a new style driver may be bound to this device when we
* return from this function, or any later moment (e.g. maybe
* hotplugging will load the driver module). and the device
* refcount model is the standard driver model one.
*/
status = i2c_attach_client(client);
if (status < 0) {
kfree(client);
client = NULL;
}
/* Check for address business */
status = i2c_check_addr(adap, client->addr);
if (status)
goto out_err;
client->dev.parent = &client->adapter->dev;
client->dev.bus = &i2c_bus_type;
client->dev.release = i2c_client_dev_release;
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
client->addr);
status = device_register(&client->dev);
if (status)
goto out_err;
dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
client->name, dev_name(&client->dev));
return client;
out_err:
dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
"(%d)\n", client->name, client->addr, status);
kfree(client);
return NULL;
}
EXPORT_SYMBOL_GPL(i2c_new_device);
@ -298,28 +302,6 @@ EXPORT_SYMBOL_GPL(i2c_new_device);
*/
void i2c_unregister_device(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
struct i2c_driver *driver = client->driver;
if (driver && !is_newstyle_driver(driver)) {
dev_err(&client->dev, "can't unregister devices "
"with legacy drivers\n");
WARN_ON(1);
return;
}
if (adapter->client_unregister) {
if (adapter->client_unregister(client)) {
dev_warn(&client->dev,
"client_unregister [%s] failed\n",
client->name);
}
}
mutex_lock(&adapter->clist_lock);
list_del(&client->list);
mutex_unlock(&adapter->clist_lock);
device_unregister(&client->dev);
}
EXPORT_SYMBOL_GPL(i2c_unregister_device);
@ -393,8 +375,128 @@ 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),
{ },
};
@ -408,7 +510,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
{
struct i2c_devinfo *devinfo;
mutex_lock(&__i2c_board_lock);
down_read(&__i2c_board_lock);
list_for_each_entry(devinfo, &__i2c_board_list, list) {
if (devinfo->busnum == adapter->nr
&& !i2c_new_device(adapter,
@ -417,7 +519,7 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
"Can't create device at 0x%02x\n",
devinfo->board_info.addr);
}
mutex_unlock(&__i2c_board_lock);
up_read(&__i2c_board_lock);
}
static int i2c_do_add_adapter(struct device_driver *d, void *data)
@ -441,14 +543,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
int res = 0, dummy;
/* Can't register until after driver model init */
if (unlikely(WARN_ON(!i2c_bus_type.p)))
return -EAGAIN;
if (unlikely(WARN_ON(!i2c_bus_type.p))) {
res = -EAGAIN;
goto out_list;
}
mutex_init(&adap->bus_lock);
mutex_init(&adap->clist_lock);
INIT_LIST_HEAD(&adap->clients);
mutex_lock(&core_lock);
/* Set default timeout to 1 second if not already set */
if (adap->timeout == 0)
@ -463,21 +563,23 @@ 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);
/* Notify drivers */
mutex_lock(&core_lock);
dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
i2c_do_add_adapter);
out_unlock:
mutex_unlock(&core_lock);
return res;
return 0;
out_list:
mutex_lock(&core_lock);
idr_remove(&i2c_adapter_idr, adap->nr);
goto out_unlock;
mutex_unlock(&core_lock);
return res;
}
/**
@ -596,6 +698,14 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
return res;
}
static int __unregister_client(struct device *dev, void *dummy)
{
struct i2c_client *client = i2c_verify_client(dev);
if (client)
i2c_unregister_device(client);
return 0;
}
/**
* i2c_del_adapter - unregister I2C adapter
* @adap: the adapter being unregistered
@ -606,46 +716,30 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data)
*/
int i2c_del_adapter(struct i2c_adapter *adap)
{
struct i2c_client *client, *_n;
int res = 0;
mutex_lock(&core_lock);
struct i2c_adapter *found;
/* First make sure that this adapter was ever added */
if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
mutex_lock(&core_lock);
found = idr_find(&i2c_adapter_idr, adap->nr);
mutex_unlock(&core_lock);
if (found != adap) {
pr_debug("i2c-core: attempting to delete unregistered "
"adapter [%s]\n", adap->name);
res = -EINVAL;
goto out_unlock;
return -EINVAL;
}
/* Tell drivers about this removal */
mutex_lock(&core_lock);
res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
i2c_do_del_adapter);
mutex_unlock(&core_lock);
if (res)
goto out_unlock;
return res;
/* detach any active clients. This must be done first, because
* it can fail; in which case we give up. */
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;
}
}
/* Detach any active clients. This can't fail, thus we do not
checking the returned value. */
res = device_for_each_child(&adap->dev, NULL, __unregister_client);
/* clean up the sysfs representation */
init_completion(&adap->dev_released);
@ -655,7 +749,9 @@ int i2c_del_adapter(struct i2c_adapter *adap)
wait_for_completion(&adap->dev_released);
/* free bus id */
mutex_lock(&core_lock);
idr_remove(&i2c_adapter_idr, adap->nr);
mutex_unlock(&core_lock);
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
@ -663,9 +759,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
added again */
memset(&adap->dev, 0, sizeof(adap->dev));
out_unlock:
mutex_unlock(&core_lock);
return res;
return 0;
}
EXPORT_SYMBOL(i2c_del_adapter);
@ -688,11 +782,7 @@ 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)
@ -703,37 +793,26 @@ 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);
if (res)
return res;
mutex_lock(&core_lock);
pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
INIT_LIST_HEAD(&driver->clients);
/* Walk the adapters that are already present */
mutex_lock(&core_lock);
class_for_each_device(&i2c_adapter_class, NULL, driver,
__attach_adapter);
mutex_unlock(&core_lock);
return 0;
}
EXPORT_SYMBOL(i2c_register_driver);
@ -753,32 +832,11 @@ static int __detach_adapter(struct device *dev, void *data)
i2c_unregister_device(client);
}
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;
@ -792,14 +850,12 @@ static int __detach_adapter(struct device *dev, void *data)
void i2c_del_driver(struct i2c_driver *driver)
{
mutex_lock(&core_lock);
class_for_each_device(&i2c_adapter_class, NULL, driver,
__detach_adapter);
mutex_unlock(&core_lock);
driver_unregister(&driver->driver);
pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
mutex_unlock(&core_lock);
}
EXPORT_SYMBOL(i2c_del_driver);
@ -820,86 +876,6 @@ 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)
{
struct i2c_adapter *adapter = client->adapter;
int res;
/* Check for address business */
res = i2c_check_addr(adapter, client->addr);
if (res)
return res;
client->dev.parent = &client->adapter->dev;
client->dev.bus = &i2c_bus_type;
if (client->driver)
client->dev.driver = &client->driver->driver;
if (client->driver && !is_newstyle_driver(client->driver)) {
client->dev.release = i2c_client_release;
dev_set_uevent_suppress(&client->dev, 1);
} else
client->dev.release = i2c_client_dev_release;
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adapter),
client->addr);
res = device_register(&client->dev);
if (res)
goto out_err;
mutex_lock(&adapter->clist_lock);
list_add_tail(&client->list, &adapter->clients);
mutex_unlock(&adapter->clist_lock);
dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
client->name, dev_name(&client->dev));
if (adapter->client_register) {
if (adapter->client_register(client)) {
dev_dbg(&adapter->dev, "client_register "
"failed for client [%s] at 0x%02x\n",
client->name, client->addr);
}
}
return 0;
out_err:
dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
"(%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;
int res = 0;
if (adapter->client_unregister) {
res = adapter->client_unregister(client);
if (res) {
dev_err(&client->dev,
"client_unregister [%s] failed, "
"client not detached\n", client->name);
goto out;
}
}
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);
out:
return res;
}
EXPORT_SYMBOL(i2c_detach_client);
/**
* i2c_use_client - increments the reference count of the i2c client structure
* @client: the client being referenced
@ -1129,144 +1105,7 @@ EXPORT_SYMBOL(i2c_master_recv);
* Will not work for 10-bit addresses!
* ----------------------------------------------------
*/
static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind,
int (*found_proc) (struct i2c_adapter *, int, int))
{
int err;
/* Make sure the address is valid */
if (addr < 0x03 || addr > 0x77) {
dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
addr);
return -EINVAL;
}
/* Skip if already in use */
if (i2c_check_addr(adapter, addr))
return 0;
/* Make sure there is something at this address, unless forced */
if (kind < 0) {
if (i2c_smbus_xfer(adapter, addr, 0, 0, 0,
I2C_SMBUS_QUICK, NULL) < 0)
return 0;
/* prevent 24RF08 corruption */
if ((addr & ~0x0f) == 0x50)
i2c_smbus_xfer(adapter, addr, 0, 0, 0,
I2C_SMBUS_QUICK, NULL);
}
/* Finally call the custom detection function */
err = found_proc(adapter, addr, kind);
/* -ENODEV can be returned if there is a chip at the given address
but it isn't supported by this chip driver. We catch it here as
this isn't an error. */
if (err == -ENODEV)
err = 0;
if (err)
dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n",
addr, err);
return err;
}
int i2c_probe(struct i2c_adapter *adapter,
const struct i2c_client_address_data *address_data,
int (*found_proc) (struct i2c_adapter *, int, int))
{
int i, err;
int adap_id = i2c_adapter_id(adapter);
/* Force entries are done first, and are not affected by ignore
entries */
if (address_data->forces) {
const unsigned short * const *forces = address_data->forces;
int kind;
for (kind = 0; forces[kind]; kind++) {
for (i = 0; forces[kind][i] != I2C_CLIENT_END;
i += 2) {
if (forces[kind][i] == adap_id
|| forces[kind][i] == ANY_I2C_BUS) {
dev_dbg(&adapter->dev, "found force "
"parameter for adapter %d, "
"addr 0x%02x, kind %d\n",
adap_id, forces[kind][i + 1],
kind);
err = i2c_probe_address(adapter,
forces[kind][i + 1],
kind, found_proc);
if (err)
return err;
}
}
}
}
/* Stop here if we can't use SMBUS_QUICK */
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
if (address_data->probe[0] == I2C_CLIENT_END
&& address_data->normal_i2c[0] == I2C_CLIENT_END)
return 0;
dev_dbg(&adapter->dev, "SMBus Quick command not supported, "
"can't probe for chips\n");
return -EOPNOTSUPP;
}
/* Probe entries are done second, and are not affected by ignore
entries either */
for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) {
if (address_data->probe[i] == adap_id
|| address_data->probe[i] == ANY_I2C_BUS) {
dev_dbg(&adapter->dev, "found probe parameter for "
"adapter %d, addr 0x%02x\n", adap_id,
address_data->probe[i + 1]);
err = i2c_probe_address(adapter,
address_data->probe[i + 1],
-1, found_proc);
if (err)
return err;
}
}
/* Normal entries are done last, unless shadowed by an ignore entry */
for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) {
int j, ignore;
ignore = 0;
for (j = 0; address_data->ignore[j] != I2C_CLIENT_END;
j += 2) {
if ((address_data->ignore[j] == adap_id ||
address_data->ignore[j] == ANY_I2C_BUS)
&& address_data->ignore[j + 1]
== address_data->normal_i2c[i]) {
dev_dbg(&adapter->dev, "found ignore "
"parameter for adapter %d, "
"addr 0x%02x\n", adap_id,
address_data->ignore[j + 1]);
ignore = 1;
break;
}
}
if (ignore)
continue;
dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
"addr 0x%02x\n", adap_id,
address_data->normal_i2c[i]);
err = i2c_probe_address(adapter, address_data->normal_i2c[i],
-1, found_proc);
if (err)
return err;
}
return 0;
}
EXPORT_SYMBOL(i2c_probe);
/* Separate detection function for new-style drivers */
static int i2c_detect_address(struct i2c_client *temp_client, int kind,
struct i2c_driver *driver)
{

4
drivers/i2c/i2c-core.h
View File

@ -16,6 +16,8 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/rwsem.h>
struct i2c_devinfo {
struct list_head list;
int busnum;
@ -25,7 +27,7 @@ struct i2c_devinfo {
/* board_lock protects board_list and first_dynamic_bus_num.
* only i2c core components are allowed to use these symbols.
*/
extern struct mutex __i2c_board_lock;
extern struct rw_semaphore __i2c_board_lock;
extern struct list_head __i2c_board_list;
extern int __i2c_first_dynamic_bus_num;

72
include/linux/i2c.h
View File

@ -47,6 +47,7 @@ struct i2c_driver;
union i2c_smbus_data;
struct i2c_board_info;
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
/*
* The master routines are the ones normally used to transmit data to devices
* on a bus (or read from them). Apart from two basic transfer functions to
@ -93,6 +94,7 @@ extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client,
extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client,
u8 command, u8 length,
const u8 *values);
#endif /* I2C */
/**
* struct i2c_driver - represent an I2C device driver
@ -100,9 +102,8 @@ 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 +138,14 @@ 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 *);
@ -191,9 +180,8 @@ 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)
* @list: list of active/busy clients (DEPRECATED)
* @detected: member of an i2c_driver.clients list
* @released: used to synchronize client releases & detaches and references
* @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
@ -209,9 +197,7 @@ struct i2c_client {
struct i2c_driver *driver; /* and our access routines */
struct device dev; /* the device structure */
int irq; /* irq issued by device */
struct list_head list; /* DEPRECATED */
struct list_head detected;
struct completion released;
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)
@ -248,11 +234,10 @@ 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];
@ -277,6 +262,7 @@ struct i2c_board_info {
.type = dev_type, .addr = (dev_addr)
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
/* Add-on boards should register/unregister their devices; e.g. a board
* with integrated I2C, a config eeprom, sensors, and a codec that's
* used in conjunction with the primary hardware.
@ -300,6 +286,7 @@ extern struct i2c_client *
i2c_new_dummy(struct i2c_adapter *adap, u16 address);
extern void i2c_unregister_device(struct i2c_client *);
#endif /* I2C */
/* Mainboard arch_initcall() code should register all its I2C devices.
* This is done at arch_initcall time, before declaring any i2c adapters.
@ -316,7 +303,7 @@ i2c_register_board_info(int busnum, struct i2c_board_info const *info,
{
return 0;
}
#endif
#endif /* I2C_BOARDINFO */
/*
* The following structs are for those who like to implement new bus drivers:
@ -352,21 +339,15 @@ struct i2c_adapter {
const struct i2c_algorithm *algo; /* the algorithm to access the bus */
void *algo_data;
/* --- administration stuff. */
int (*client_register)(struct i2c_client *) __deprecated;
int (*client_unregister)(struct i2c_client *) __deprecated;
/* data fields that are valid for all devices */
u8 level; /* nesting level for lockdep */
struct mutex bus_lock;
struct mutex clist_lock;
int timeout; /* in jiffies */
int retries;
struct device dev; /* the adapter device */
int nr;
struct list_head clients; /* DEPRECATED */
char name[48];
struct completion dev_released;
};
@ -412,11 +393,16 @@ struct i2c_client_address_data {
/* The numbers to use to set I2C bus address */
#define ANY_I2C_BUS 0xffff
/* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
#define I2C_ADDRS(addr, addrs...) \
((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
/* ----- functions exported by i2c.o */
/* administration...
*/
#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);
extern int i2c_add_numbered_adapter(struct i2c_adapter *);
@ -429,11 +415,6 @@ 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);
@ -442,14 +423,6 @@ extern void i2c_release_client(struct i2c_client *client);
extern void i2c_clients_command(struct i2c_adapter *adap,
unsigned int cmd, void *arg);
/* Detect function. It iterates over all possible addresses itself.
* It will only call found_proc if some client is connected at the
* specific address (unless a 'force' matched);
*/
extern int i2c_probe(struct i2c_adapter *adapter,
const struct i2c_client_address_data *address_data,
int (*found_proc) (struct i2c_adapter *, int, int));
extern struct i2c_adapter *i2c_get_adapter(int id);
extern void i2c_put_adapter(struct i2c_adapter *adap);
@ -471,6 +444,7 @@ static inline int i2c_adapter_id(struct i2c_adapter *adap)
{
return adap->nr;
}
#endif /* I2C */
#endif /* __KERNEL__ */
/**