#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);
-
-#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
+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);
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;
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));
client->dev.parent = &client->adapter->dev;
client->dev.bus = &i2c_bus_type;
-
- 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;
+ client->dev.release = i2c_client_dev_release;
dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
client->addr);
if (status)
goto out_err;
- mutex_lock(&adap->clist_lock);
- list_add_tail(&client->list, &adap->clients);
- mutex_unlock(&adap->clist_lock);
-
dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
client->name, dev_name(&client->dev));
*/
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;
- }
-
- 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)
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;
+ return res;
- /* Detach any active clients */
- list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
- i2c_unregister_device(client);
- }
+ /* 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);
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;
-
if (driver->detach_adapter) {
if (driver->detach_adapter(adapter))
dev_err(&adapter->dev,
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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff