#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);
/* ------------------------------------------------------------------------- */
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;
{
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;
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));
/**
- * 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.
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);
*/
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);
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),
{ },
};
{
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,
"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)
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)
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;
}
/**
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
*/
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;
-
- /* 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;
- }
+ return res;
- /* 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);
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);
added again */
memset(&adap->dev, 0, sizeof(adap->dev));
- out_unlock:
- mutex_unlock(&core_lock);
- return res;
+ return 0;
}
EXPORT_SYMBOL(i2c_del_adapter);
/*
* 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)
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);
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;
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);
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
* 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)
{
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