Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
-/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
+/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
Jean Delvare <khali@linux-fr.org> */
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/idr.h>
-#include <linux/seq_file.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
+#include <linux/completion.h>
+#include <linux/hardirq.h>
+#include <linux/irqflags.h>
#include <asm/uaccess.h>
+#include "i2c-core.h"
-static LIST_HEAD(adapters);
-static LIST_HEAD(drivers);
-static DEFINE_MUTEX(core_lists);
+
+static DEFINE_MUTEX(core_lock);
static DEFINE_IDR(i2c_adapter_idr);
-/* match always succeeds, as we want the probe() to tell if we really accept this match */
-static int i2c_device_match(struct device *dev, struct device_driver *drv)
+#define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect)
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
+
+/* ------------------------------------------------------------------------- */
+
+static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
+ const struct i2c_client *client)
{
- return 1;
+ while (id->name[0]) {
+ if (strcmp(client->name, id->name) == 0)
+ return id;
+ id++;
+ }
+ return NULL;
}
-static int i2c_bus_suspend(struct device * dev, pm_message_t state)
+static int i2c_device_match(struct device *dev, struct device_driver *drv)
{
- int rc = 0;
+ 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;
- if (dev->driver && dev->driver->suspend)
- rc = dev->driver->suspend(dev, state);
- return rc;
+ return 0;
}
-static int i2c_bus_resume(struct device * dev)
+#ifdef CONFIG_HOTPLUG
+
+/* uevent helps with hotplug: modprobe -q $(MODALIAS) */
+static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
- int rc = 0;
-
- if (dev->driver && dev->driver->resume)
- rc = dev->driver->resume(dev);
- return rc;
+ 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;
+ dev_dbg(dev, "uevent\n");
+ return 0;
}
+#else
+#define i2c_device_uevent NULL
+#endif /* CONFIG_HOTPLUG */
+
static int i2c_device_probe(struct device *dev)
{
- return -ENODEV;
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_driver *driver = to_i2c_driver(dev->driver);
+ int status;
+
+ if (!driver->probe || !driver->id_table)
+ return -ENODEV;
+ client->driver = driver;
+ if (!device_can_wakeup(&client->dev))
+ device_init_wakeup(&client->dev,
+ client->flags & I2C_CLIENT_WAKE);
+ dev_dbg(dev, "probe\n");
+
+ status = driver->probe(client, i2c_match_id(driver->id_table, client));
+ if (status)
+ client->driver = NULL;
+ return status;
}
static int i2c_device_remove(struct device *dev)
{
- return 0;
-}
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_driver *driver;
+ int status;
-struct bus_type i2c_bus_type = {
- .name = "i2c",
- .match = i2c_device_match,
- .probe = i2c_device_probe,
- .remove = i2c_device_remove,
- .suspend = i2c_bus_suspend,
- .resume = i2c_bus_resume,
-};
+ if (!dev->driver)
+ return 0;
-void i2c_adapter_dev_release(struct device *dev)
-{
- struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
- complete(&adap->dev_released);
+ driver = to_i2c_driver(dev->driver);
+ if (driver->remove) {
+ dev_dbg(dev, "remove\n");
+ status = driver->remove(client);
+ } else {
+ dev->driver = NULL;
+ status = 0;
+ }
+ if (status == 0)
+ client->driver = NULL;
+ return status;
}
-struct device_driver i2c_adapter_driver = {
- .owner = THIS_MODULE,
- .name = "i2c_adapter",
- .bus = &i2c_bus_type,
-};
-
-static void i2c_adapter_class_dev_release(struct class_device *dev)
+static void i2c_device_shutdown(struct device *dev)
{
- struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev);
- complete(&adap->class_dev_released);
-}
+ struct i2c_driver *driver;
-struct class i2c_adapter_class = {
- .owner = THIS_MODULE,
- .name = "i2c-adapter",
- .release = &i2c_adapter_class_dev_release,
-};
+ if (!dev->driver)
+ return;
+ driver = to_i2c_driver(dev->driver);
+ if (driver->shutdown)
+ driver->shutdown(to_i2c_client(dev));
+}
-static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
+static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
{
- struct i2c_adapter *adap = dev_to_i2c_adapter(dev);
- return sprintf(buf, "%s\n", adap->name);
+ struct i2c_driver *driver;
+
+ if (!dev->driver)
+ return 0;
+ driver = to_i2c_driver(dev->driver);
+ if (!driver->suspend)
+ return 0;
+ return driver->suspend(to_i2c_client(dev), mesg);
}
-static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL);
+static int i2c_device_resume(struct device *dev)
+{
+ struct i2c_driver *driver;
+
+ if (!dev->driver)
+ return 0;
+ driver = to_i2c_driver(dev->driver);
+ if (!driver->resume)
+ return 0;
+ return driver->resume(to_i2c_client(dev));
+}
static void i2c_client_release(struct device *dev)
{
complete(&client->released);
}
-static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
+static void i2c_client_dev_release(struct device *dev)
+{
+ kfree(to_i2c_client(dev));
+}
+
+static ssize_t
+show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
return sprintf(buf, "%s\n", client->name);
}
-/*
- * We can't use the DEVICE_ATTR() macro here as we want the same filename for a
- * different type of a device. So beware if the DEVICE_ATTR() macro ever
- * changes, this definition will also have to change.
- */
-static struct device_attribute dev_attr_client_name = {
- .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE },
- .show = &show_client_name,
+static ssize_t
+show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
+}
+
+static struct device_attribute i2c_dev_attrs[] = {
+ __ATTR(name, S_IRUGO, show_client_name, NULL),
+ /* modalias helps coldplug: modprobe $(cat .../modalias) */
+ __ATTR(modalias, S_IRUGO, show_modalias, NULL),
+ { },
};
+struct bus_type i2c_bus_type = {
+ .name = "i2c",
+ .dev_attrs = i2c_dev_attrs,
+ .match = i2c_device_match,
+ .uevent = i2c_device_uevent,
+ .probe = i2c_device_probe,
+ .remove = i2c_device_remove,
+ .shutdown = i2c_device_shutdown,
+ .suspend = i2c_device_suspend,
+ .resume = i2c_device_resume,
+};
+EXPORT_SYMBOL_GPL(i2c_bus_type);
+
+
+/**
+ * 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
+ * @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.
+ *
+ * This returns the new i2c client, which may be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
+ */
+struct i2c_client *
+i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
+{
+ struct i2c_client *client;
+ int status;
+
+ client = kzalloc(sizeof *client, GFP_KERNEL);
+ if (!client)
+ return NULL;
+
+ client->adapter = adap;
+
+ client->dev.platform_data = info->platform_data;
+
+ if (info->archdata)
+ client->dev.archdata = *info->archdata;
+
+ client->flags = info->flags;
+ client->addr = info->addr;
+ client->irq = info->irq;
+
+ strlcpy(client->name, info->type, sizeof(client->name));
-/* ---------------------------------------------------
- * registering functions
- * ---------------------------------------------------
+ /* 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;
+ }
+ return client;
+}
+EXPORT_SYMBOL_GPL(i2c_new_device);
+
+
+/**
+ * i2c_unregister_device - reverse effect of i2c_new_device()
+ * @client: value returned from i2c_new_device()
+ * Context: can sleep
*/
+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);
+
+
+static const struct i2c_device_id dummy_id[] = {
+ { "dummy", 0 },
+ { },
+};
-/* -----
- * i2c_add_adapter is called from within the algorithm layer,
- * when a new hw adapter registers. A new device is register to be
- * available for clients.
+static int dummy_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ return 0;
+}
+
+static int dummy_remove(struct i2c_client *client)
+{
+ return 0;
+}
+
+static struct i2c_driver dummy_driver = {
+ .driver.name = "dummy",
+ .probe = dummy_probe,
+ .remove = dummy_remove,
+ .id_table = dummy_id,
+};
+
+/**
+ * i2c_new_dummy - return a new i2c device bound to a dummy driver
+ * @adapter: the adapter managing the device
+ * @address: seven bit address to be used
+ * Context: can sleep
+ *
+ * This returns an I2C client bound to the "dummy" driver, intended for use
+ * with devices that consume multiple addresses. Examples of such chips
+ * include various EEPROMS (like 24c04 and 24c08 models).
+ *
+ * These dummy devices have two main uses. First, most I2C and SMBus calls
+ * except i2c_transfer() need a client handle; the dummy will be that handle.
+ * And second, this prevents the specified address from being bound to a
+ * different driver.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
*/
-int i2c_add_adapter(struct i2c_adapter *adap)
+struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
{
- int id, res = 0;
- struct list_head *item;
- struct i2c_driver *driver;
+ struct i2c_board_info info = {
+ I2C_BOARD_INFO("dummy", address),
+ };
- mutex_lock(&core_lists);
+ return i2c_new_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_dummy);
- if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
- res = -ENOMEM;
- goto out_unlock;
+/* ------------------------------------------------------------------------- */
+
+/* I2C bus adapters -- one roots each I2C or SMBUS segment */
+
+static void i2c_adapter_dev_release(struct device *dev)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ complete(&adap->dev_released);
+}
+
+static ssize_t
+show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(dev);
+ return sprintf(buf, "%s\n", adap->name);
+}
+
+static struct device_attribute i2c_adapter_attrs[] = {
+ __ATTR(name, S_IRUGO, show_adapter_name, NULL),
+ { },
+};
+
+static struct class i2c_adapter_class = {
+ .owner = THIS_MODULE,
+ .name = "i2c-adapter",
+ .dev_attrs = i2c_adapter_attrs,
+};
+
+static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
+{
+ struct i2c_devinfo *devinfo;
+
+ mutex_lock(&__i2c_board_lock);
+ list_for_each_entry(devinfo, &__i2c_board_list, list) {
+ if (devinfo->busnum == adapter->nr
+ && !i2c_new_device(adapter,
+ &devinfo->board_info))
+ dev_err(&adapter->dev,
+ "Can't create device at 0x%02x\n",
+ devinfo->board_info.addr);
}
+ mutex_unlock(&__i2c_board_lock);
+}
- res = idr_get_new(&i2c_adapter_idr, adap, &id);
- if (res < 0) {
- if (res == -EAGAIN)
- res = -ENOMEM;
- goto out_unlock;
+static int i2c_do_add_adapter(struct device_driver *d, void *data)
+{
+ struct i2c_driver *driver = to_i2c_driver(d);
+ struct i2c_adapter *adap = data;
+
+ /* Detect supported devices on that bus, and instantiate them */
+ i2c_detect(adap, driver);
+
+ /* Let legacy drivers scan this bus for matching devices */
+ if (driver->attach_adapter) {
+ /* We ignore the return code; if it fails, too bad */
+ driver->attach_adapter(adap);
}
+ return 0;
+}
+
+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;
- adap->nr = id & MAX_ID_MASK;
- init_MUTEX(&adap->bus_lock);
- init_MUTEX(&adap->clist_lock);
- list_add_tail(&adap->list,&adapters);
+ mutex_init(&adap->bus_lock);
+ mutex_init(&adap->clist_lock);
INIT_LIST_HEAD(&adap->clients);
+ mutex_lock(&core_lock);
+
/* Add the adapter to the driver core.
* If the parent pointer is not set up,
* we add this adapter to the host bus.
*/
- if (adap->dev.parent == NULL)
+ if (adap->dev.parent == NULL) {
adap->dev.parent = &platform_bus;
- sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
- adap->dev.driver = &i2c_adapter_driver;
- adap->dev.release = &i2c_adapter_dev_release;
- device_register(&adap->dev);
- device_create_file(&adap->dev, &dev_attr_name);
+ pr_debug("I2C adapter driver [%s] forgot to specify "
+ "physical device\n", adap->name);
+ }
- /* Add this adapter to the i2c_adapter class */
- memset(&adap->class_dev, 0x00, sizeof(struct class_device));
- adap->class_dev.dev = &adap->dev;
- adap->class_dev.class = &i2c_adapter_class;
- strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE);
- class_device_register(&adap->class_dev);
+ /* Set default timeout to 1 second if not already set */
+ if (adap->timeout == 0)
+ adap->timeout = HZ;
+
+ dev_set_name(&adap->dev, "i2c-%d", adap->nr);
+ adap->dev.release = &i2c_adapter_dev_release;
+ adap->dev.class = &i2c_adapter_class;
+ res = device_register(&adap->dev);
+ if (res)
+ goto out_list;
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
- /* inform drivers of new adapters */
- list_for_each(item,&drivers) {
- driver = list_entry(item, struct i2c_driver, list);
- if (driver->attach_adapter)
- /* We ignore the return code; if it fails, too bad */
- driver->attach_adapter(adap);
- }
+ /* create pre-declared device nodes for new-style drivers */
+ if (adap->nr < __i2c_first_dynamic_bus_num)
+ i2c_scan_static_board_info(adap);
+
+ /* Notify drivers */
+ dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
+ i2c_do_add_adapter);
out_unlock:
- mutex_unlock(&core_lists);
+ mutex_unlock(&core_lock);
return res;
+
+out_list:
+ idr_remove(&i2c_adapter_idr, adap->nr);
+ goto out_unlock;
+}
+
+/**
+ * i2c_add_adapter - declare i2c adapter, use dynamic bus number
+ * @adapter: the adapter to add
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * doesn't matter. Examples: for I2C adapters dynamically added by
+ * USB links or PCI plugin cards.
+ *
+ * When this returns zero, a new bus number was allocated and stored
+ * in adap->nr, and the specified adapter became available for clients.
+ * Otherwise, a negative errno value is returned.
+ */
+int i2c_add_adapter(struct i2c_adapter *adapter)
+{
+ int id, res = 0;
+
+retry:
+ if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
+ return -ENOMEM;
+
+ mutex_lock(&core_lock);
+ /* "above" here means "above or equal to", sigh */
+ res = idr_get_new_above(&i2c_adapter_idr, adapter,
+ __i2c_first_dynamic_bus_num, &id);
+ mutex_unlock(&core_lock);
+
+ if (res < 0) {
+ if (res == -EAGAIN)
+ goto retry;
+ return res;
+ }
+
+ adapter->nr = id;
+ return i2c_register_adapter(adapter);
+}
+EXPORT_SYMBOL(i2c_add_adapter);
+
+/**
+ * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
+ * @adap: the adapter to register (with adap->nr initialized)
+ * Context: can sleep
+ *
+ * This routine is used to declare an I2C adapter when its bus number
+ * matters. For example, use it for I2C adapters from system-on-chip CPUs,
+ * or otherwise built in to the system's mainboard, and where i2c_board_info
+ * is used to properly configure I2C devices.
+ *
+ * If no devices have pre-been declared for this bus, then be sure to
+ * register the adapter before any dynamically allocated ones. Otherwise
+ * the required bus ID may not be available.
+ *
+ * When this returns zero, the specified adapter became available for
+ * clients using the bus number provided in adap->nr. Also, the table
+ * of I2C devices pre-declared using i2c_register_board_info() is scanned,
+ * and the appropriate driver model device nodes are created. Otherwise, a
+ * negative errno value is returned.
+ */
+int i2c_add_numbered_adapter(struct i2c_adapter *adap)
+{
+ int id;
+ int status;
+
+ if (adap->nr & ~MAX_ID_MASK)
+ return -EINVAL;
+
+retry:
+ if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
+ return -ENOMEM;
+
+ mutex_lock(&core_lock);
+ /* "above" here means "above or equal to", sigh;
+ * we need the "equal to" result to force the result
+ */
+ status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
+ if (status == 0 && id != adap->nr) {
+ status = -EBUSY;
+ idr_remove(&i2c_adapter_idr, id);
+ }
+ mutex_unlock(&core_lock);
+ if (status == -EAGAIN)
+ goto retry;
+
+ if (status == 0)
+ status = i2c_register_adapter(adap);
+ return status;
}
+EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
+static int i2c_do_del_adapter(struct device_driver *d, void *data)
+{
+ struct i2c_driver *driver = to_i2c_driver(d);
+ struct i2c_adapter *adapter = data;
+ struct i2c_client *client, *_n;
+ int res;
+
+ /* Remove the devices we created ourselves as the result of hardware
+ * probing (using a driver's detect method) */
+ list_for_each_entry_safe(client, _n, &driver->clients, detected) {
+ if (client->adapter == adapter) {
+ dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
+ client->name, client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
+ }
+
+ if (!driver->detach_adapter)
+ return 0;
+ res = driver->detach_adapter(adapter);
+ if (res)
+ dev_err(&adapter->dev, "detach_adapter failed (%d) "
+ "for driver [%s]\n", res, driver->driver.name);
+ return res;
+}
+/**
+ * i2c_del_adapter - unregister I2C adapter
+ * @adap: the adapter being unregistered
+ * Context: can sleep
+ *
+ * This unregisters an I2C adapter which was previously registered
+ * by @i2c_add_adapter or @i2c_add_numbered_adapter.
+ */
int i2c_del_adapter(struct i2c_adapter *adap)
{
- struct list_head *item, *_n;
- struct i2c_adapter *adap_from_list;
- struct i2c_driver *driver;
- struct i2c_client *client;
+ struct i2c_client *client, *_n;
int res = 0;
- mutex_lock(&core_lists);
+ mutex_lock(&core_lock);
/* First make sure that this adapter was ever added */
- list_for_each_entry(adap_from_list, &adapters, list) {
- if (adap_from_list == adap)
- break;
- }
- if (adap_from_list != adap) {
+ if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
pr_debug("i2c-core: attempting to delete unregistered "
"adapter [%s]\n", adap->name);
res = -EINVAL;
goto out_unlock;
}
- list_for_each(item,&drivers) {
- driver = list_entry(item, struct i2c_driver, list);
- if (driver->detach_adapter)
- if ((res = driver->detach_adapter(adap))) {
- dev_err(&adap->dev, "detach_adapter failed "
- "for driver [%s]\n",
- driver->driver.name);
- goto out_unlock;
- }
- }
+ /* Tell drivers about this removal */
+ res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
+ i2c_do_del_adapter);
+ 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_safe(item, _n, &adap->clients) {
- client = list_entry(item, struct i2c_client, list);
+ list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
+ struct i2c_driver *driver;
+
+ driver = client->driver;
- if ((res=client->driver->detach_client(client))) {
+ /* 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);
/* clean up the sysfs representation */
init_completion(&adap->dev_released);
- init_completion(&adap->class_dev_released);
- class_device_unregister(&adap->class_dev);
- device_remove_file(&adap->dev, &dev_attr_name);
device_unregister(&adap->dev);
- list_del(&adap->list);
/* wait for sysfs to drop all references */
wait_for_completion(&adap->dev_released);
- wait_for_completion(&adap->class_dev_released);
- /* free dynamically allocated bus id */
+ /* free bus id */
idr_remove(&i2c_adapter_idr, adap->nr);
dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
+ /* Clear the device structure in case this adapter is ever going to be
+ added again */
+ memset(&adap->dev, 0, sizeof(adap->dev));
+
out_unlock:
- mutex_unlock(&core_lists);
+ mutex_unlock(&core_lock);
return res;
}
+EXPORT_SYMBOL(i2c_del_adapter);
+
+/* ------------------------------------------------------------------------- */
+
+static int __attach_adapter(struct device *dev, void *data)
+{
+ struct i2c_adapter *adapter = to_i2c_adapter(dev);
+ struct i2c_driver *driver = data;
+
+ i2c_detect(adapter, driver);
+
+ /* Legacy drivers scan i2c busses directly */
+ if (driver->attach_adapter)
+ driver->attach_adapter(adapter);
-/* -----
- * What follows is the "upwards" interface: commands for talking to clients,
- * which implement the functions to access the physical information of the
- * chips.
+ return 0;
+}
+
+/*
+ * 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.
*/
int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
{
- struct list_head *item;
- struct i2c_adapter *adapter;
- int res = 0;
+ int res;
+
+ /* Can't register until after driver model init */
+ if (unlikely(WARN_ON(!i2c_bus_type.p)))
+ return -EAGAIN;
- mutex_lock(&core_lists);
+ /* 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
+ * will have called probe() for all matching-but-unbound devices.
+ */
res = driver_register(&driver->driver);
if (res)
- goto out_unlock;
-
- list_add_tail(&driver->list,&drivers);
+ return res;
+
+ mutex_lock(&core_lock);
+
pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
- /* now look for instances of driver on our adapters */
- if (driver->attach_adapter) {
- list_for_each(item,&adapters) {
- adapter = list_entry(item, struct i2c_adapter, list);
- driver->attach_adapter(adapter);
- }
- }
+ INIT_LIST_HEAD(&driver->clients);
+ /* Walk the adapters that are already present */
+ class_for_each_device(&i2c_adapter_class, NULL, driver,
+ __attach_adapter);
- out_unlock:
- mutex_unlock(&core_lists);
- return res;
+ mutex_unlock(&core_lock);
+ return 0;
}
EXPORT_SYMBOL(i2c_register_driver);
-int i2c_del_driver(struct i2c_driver *driver)
+static int __detach_adapter(struct device *dev, void *data)
{
- struct list_head *item1, *item2, *_n;
- struct i2c_client *client;
- struct i2c_adapter *adap;
-
- int res = 0;
+ struct i2c_adapter *adapter = to_i2c_adapter(dev);
+ struct i2c_driver *driver = data;
+ struct i2c_client *client, *_n;
+
+ /* Remove the devices we created ourselves as the result of hardware
+ * probing (using a driver's detect method) */
+ list_for_each_entry_safe(client, _n, &driver->clients, detected) {
+ dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
+ client->name, client->addr);
+ list_del(&client->detected);
+ i2c_unregister_device(client);
+ }
- mutex_lock(&core_lists);
+ 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
+ * attached. If so, detach them to be able to kill the driver
* afterwards.
*/
- list_for_each(item1,&adapters) {
- adap = list_entry(item1, struct i2c_adapter, list);
- if (driver->detach_adapter) {
- if ((res = driver->detach_adapter(adap))) {
- dev_err(&adap->dev, "detach_adapter failed "
- "for driver [%s]\n",
- driver->driver.name);
- goto out_unlock;
- }
- } else {
- list_for_each_safe(item2, _n, &adap->clients) {
- client = list_entry(item2, struct i2c_client, list);
- if (client->driver != driver)
- continue;
- dev_dbg(&adap->dev, "detaching client [%s] "
- "at 0x%02x\n", client->name,
- client->addr);
- if ((res = driver->detach_client(client))) {
- dev_err(&adap->dev, "detach_client "
- "failed for client [%s] at "
- "0x%02x\n", client->name,
- client->addr);
- goto out_unlock;
- }
- }
+ 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;
+}
+
+/**
+ * i2c_del_driver - unregister I2C driver
+ * @driver: the driver being unregistered
+ * Context: can sleep
+ */
+void i2c_del_driver(struct i2c_driver *driver)
+{
+ mutex_lock(&core_lock);
+
+ class_for_each_device(&i2c_adapter_class, NULL, driver,
+ __detach_adapter);
+
driver_unregister(&driver->driver);
- list_del(&driver->list);
pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
- out_unlock:
- mutex_unlock(&core_lists);
- return 0;
+ mutex_unlock(&core_lock);
}
+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;
}
-int i2c_check_addr(struct i2c_adapter *adapter, int addr)
+static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
{
- int rval;
-
- down(&adapter->clist_lock);
- rval = __i2c_check_addr(adapter, addr);
- up(&adapter->clist_lock);
-
- return rval;
+ 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));
- down(&adapter->clist_lock);
- if (__i2c_check_addr(client->adapter, client->addr)) {
- up(&adapter->clist_lock);
- return -EBUSY;
- }
- list_add_tail(&client->list,&adapter->clients);
- up(&adapter->clist_lock);
-
if (adapter->client_register) {
- if (adapter->client_register(client)) {
+ if (adapter->client_register(client)) {
dev_dbg(&adapter->dev, "client_register "
"failed for client [%s] at 0x%02x\n",
client->name, client->addr);
}
}
- client->usage_count = 0;
-
- client->dev.parent = &client->adapter->dev;
- client->dev.driver = &client->driver->driver;
- client->dev.bus = &i2c_bus_type;
- client->dev.release = &i2c_client_release;
-
- snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id),
- "%d-%04x", i2c_adapter_id(adapter), client->addr);
- dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n",
- client->name, client->dev.bus_id);
- device_register(&client->dev);
- device_create_file(&client->dev, &dev_attr_client_name);
-
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 (client->usage_count > 0) {
- dev_warn(&client->dev, "Client [%s] still busy, "
- "can't detach\n", client->name);
- return -EBUSY;
- }
if (adapter->client_unregister) {
res = adapter->client_unregister(client);
}
}
- down(&adapter->clist_lock);
+ mutex_lock(&adapter->clist_lock);
list_del(&client->list);
+ mutex_unlock(&adapter->clist_lock);
+
init_completion(&client->released);
- device_remove_file(&client->dev, &dev_attr_client_name);
device_unregister(&client->dev);
- up(&adapter->clist_lock);
wait_for_completion(&client->released);
out:
return res;
}
+EXPORT_SYMBOL(i2c_detach_client);
-static int i2c_inc_use_client(struct i2c_client *client)
+/**
+ * i2c_use_client - increments the reference count of the i2c client structure
+ * @client: the client being referenced
+ *
+ * Each live reference to a client should be refcounted. The driver model does
+ * that automatically as part of driver binding, so that most drivers don't
+ * need to do this explicitly: they hold a reference until they're unbound
+ * from the device.
+ *
+ * A pointer to the client with the incremented reference counter is returned.
+ */
+struct i2c_client *i2c_use_client(struct i2c_client *client)
{
-
- if (!try_module_get(client->driver->driver.owner))
- return -ENODEV;
- if (!try_module_get(client->adapter->owner)) {
- module_put(client->driver->driver.owner);
- return -ENODEV;
- }
-
- return 0;
+ if (client && get_device(&client->dev))
+ return client;
+ return NULL;
}
+EXPORT_SYMBOL(i2c_use_client);
-static void i2c_dec_use_client(struct i2c_client *client)
+/**
+ * i2c_release_client - release a use of the i2c client structure
+ * @client: the client being no longer referenced
+ *
+ * Must be called when a user of a client is finished with it.
+ */
+void i2c_release_client(struct i2c_client *client)
{
- module_put(client->driver->driver.owner);
- module_put(client->adapter->owner);
+ if (client)
+ put_device(&client->dev);
}
+EXPORT_SYMBOL(i2c_release_client);
-int i2c_use_client(struct i2c_client *client)
-{
- int ret;
-
- ret = i2c_inc_use_client(client);
- if (ret)
- return ret;
-
- client->usage_count++;
-
- return 0;
-}
+struct i2c_cmd_arg {
+ unsigned cmd;
+ void *arg;
+};
-int i2c_release_client(struct i2c_client *client)
+static int i2c_cmd(struct device *dev, void *_arg)
{
- if (!client->usage_count) {
- pr_debug("i2c-core: %s used one too many times\n",
- __FUNCTION__);
- return -EPERM;
- }
-
- client->usage_count--;
- i2c_dec_use_client(client);
-
+ 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;
- down(&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) {
- up(&adap->clist_lock);
- client->driver->command(client,cmd,arg);
- down(&adap->clist_lock);
- }
- module_put(client->driver->driver.owner);
- }
- up(&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);
static int __init i2c_init(void)
{
retval = bus_register(&i2c_bus_type);
if (retval)
return retval;
- retval = driver_register(&i2c_adapter_driver);
+ retval = class_register(&i2c_adapter_class);
if (retval)
- return retval;
- return class_register(&i2c_adapter_class);
+ goto bus_err;
+ retval = i2c_add_driver(&dummy_driver);
+ if (retval)
+ goto class_err;
+ return 0;
+
+class_err:
+ class_unregister(&i2c_adapter_class);
+bus_err:
+ bus_unregister(&i2c_bus_type);
+ return retval;
}
static void __exit i2c_exit(void)
{
+ i2c_del_driver(&dummy_driver);
class_unregister(&i2c_adapter_class);
- driver_unregister(&i2c_adapter_driver);
bus_unregister(&i2c_bus_type);
}
-subsys_initcall(i2c_init);
+/* We must initialize early, because some subsystems register i2c drivers
+ * in subsys_initcall() code, but are linked (and initialized) before i2c.
+ */
+postcore_initcall(i2c_init);
module_exit(i2c_exit);
/* ----------------------------------------------------
* ----------------------------------------------------
*/
-int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num)
+/**
+ * i2c_transfer - execute a single or combined I2C message
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ * terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Note that there is no requirement that each message be sent to
+ * the same slave address, although that is the most common model.
+ */
+int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
- int ret;
+ unsigned long orig_jiffies;
+ int ret, try;
+
+ /* REVISIT the fault reporting model here is weak:
+ *
+ * - When we get an error after receiving N bytes from a slave,
+ * there is no way to report "N".
+ *
+ * - When we get a NAK after transmitting N bytes to a slave,
+ * there is no way to report "N" ... or to let the master
+ * continue executing the rest of this combined message, if
+ * that's the appropriate response.
+ *
+ * - When for example "num" is two and we successfully complete
+ * the first message but get an error part way through the
+ * second, it's unclear whether that should be reported as
+ * one (discarding status on the second message) or errno
+ * (discarding status on the first one).
+ */
if (adap->algo->master_xfer) {
#ifdef DEBUG
for (ret = 0; ret < num; ret++) {
dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
- "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ?
- 'R' : 'W', msgs[ret].addr, msgs[ret].len);
+ "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
+ ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
+ (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
}
#endif
- down(&adap->bus_lock);
- ret = adap->algo->master_xfer(adap,msgs,num);
- up(&adap->bus_lock);
+ if (in_atomic() || irqs_disabled()) {
+ ret = mutex_trylock(&adap->bus_lock);
+ if (!ret)
+ /* I2C activity is ongoing. */
+ return -EAGAIN;
+ } else {
+ mutex_lock_nested(&adap->bus_lock, adap->level);
+ }
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (ret = 0, try = 0; try <= adap->retries; try++) {
+ ret = adap->algo->master_xfer(adap, msgs, num);
+ if (ret != -EAGAIN)
+ break;
+ if (time_after(jiffies, orig_jiffies + adap->timeout))
+ break;
+ }
+ mutex_unlock(&adap->bus_lock);
return ret;
} else {
dev_dbg(&adap->dev, "I2C level transfers not supported\n");
- return -ENOSYS;
+ return -EOPNOTSUPP;
}
}
+EXPORT_SYMBOL(i2c_transfer);
+/**
+ * i2c_master_send - issue a single I2C message in master transmit mode
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave
+ * @count: How many bytes to write
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
{
int ret;
msg.flags = client->flags & I2C_M_TEN;
msg.len = count;
msg.buf = (char *)buf;
-
+
ret = i2c_transfer(adap, &msg, 1);
/* If everything went ok (i.e. 1 msg transmitted), return #bytes
transmitted, else error code. */
return (ret == 1) ? count : ret;
}
+EXPORT_SYMBOL(i2c_master_send);
+/**
+ * i2c_master_recv - issue a single I2C message in master receive mode
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave
+ * @count: How many bytes to read
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
{
struct i2c_adapter *adap=client->adapter;
transmitted, else error code. */
return (ret == 1) ? count : ret;
}
-
-
-int i2c_control(struct i2c_client *client,
- unsigned int cmd, unsigned long arg)
-{
- int ret = 0;
- struct i2c_adapter *adap = client->adapter;
-
- dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg);
- switch (cmd) {
- case I2C_RETRIES:
- adap->retries = arg;
- break;
- case I2C_TIMEOUT:
- adap->timeout = arg;
- break;
- default:
- if (adap->algo->algo_control!=NULL)
- ret = adap->algo->algo_control(adap,cmd,arg);
- }
- return ret;
-}
+EXPORT_SYMBOL(i2c_master_recv);
/* ----------------------------------------------------
* the i2c address scanning function
/* 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. */
- return (err == -ENODEV) ? 0 : err;
+ 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,
- struct i2c_client_address_data *address_data,
+ const struct i2c_client_address_data *address_data,
int (*found_proc) (struct i2c_adapter *, int, int))
{
int i, err;
/* Force entries are done first, and are not affected by ignore
entries */
if (address_data->forces) {
- unsigned short **forces = address_data->forces;
+ const unsigned short * const *forces = address_data->forces;
int kind;
for (kind = 0; forces[kind]; kind++) {
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;
+ return 0;
- dev_warn(&adapter->dev, "SMBus Quick command not supported, "
- "can't probe for chips\n");
- return -1;
+ 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
"parameter for adapter %d, "
"addr 0x%02x\n", adap_id,
address_data->ignore[j + 1]);
+ ignore = 1;
+ break;
}
- ignore = 1;
- break;
}
if (ignore)
continue;
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)
+{
+ struct i2c_board_info info;
+ struct i2c_adapter *adapter = temp_client->adapter;
+ int addr = temp_client->addr;
+ 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 */
+ memset(&info, 0, sizeof(struct i2c_board_info));
+ info.addr = addr;
+ err = driver->detect(temp_client, kind, &info);
+ if (err) {
+ /* -ENODEV is returned if the detection fails. We catch it
+ here as this isn't an error. */
+ return err == -ENODEV ? 0 : err;
+ }
+
+ /* Consistency check */
+ if (info.type[0] == '\0') {
+ dev_err(&adapter->dev, "%s detection function provided "
+ "no name for 0x%x\n", driver->driver.name,
+ addr);
+ } else {
+ struct i2c_client *client;
+
+ /* Detection succeeded, instantiate the device */
+ dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
+ info.type, info.addr);
+ client = i2c_new_device(adapter, &info);
+ if (client)
+ list_add_tail(&client->detected, &driver->clients);
+ else
+ dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
+ info.type, info.addr);
+ }
+ return 0;
+}
+
+static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
+{
+ const struct i2c_client_address_data *address_data;
+ struct i2c_client *temp_client;
+ int i, err = 0;
+ int adap_id = i2c_adapter_id(adapter);
+
+ address_data = driver->address_data;
+ if (!driver->detect || !address_data)
+ return 0;
+
+ /* Set up a temporary client to help detect callback */
+ temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
+ if (!temp_client)
+ return -ENOMEM;
+ temp_client->adapter = 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);
+ temp_client->addr = forces[kind][i + 1];
+ err = i2c_detect_address(temp_client,
+ kind, driver);
+ if (err)
+ goto exit_free;
+ }
+ }
+ }
+ }
+
+ /* Stop here if the classes do not match */
+ if (!(adapter->class & driver->class))
+ goto exit_free;
+
+ /* 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)
+ goto exit_free;
+
+ dev_warn(&adapter->dev, "SMBus Quick command not supported, "
+ "can't probe for chips\n");
+ err = -EOPNOTSUPP;
+ goto exit_free;
+ }
+
+ /* 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]);
+ temp_client->addr = address_data->probe[i + 1];
+ err = i2c_detect_address(temp_client, -1, driver);
+ if (err)
+ goto exit_free;
+ }
+ }
+
+ /* 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]);
+ temp_client->addr = address_data->normal_i2c[i];
+ err = i2c_detect_address(temp_client, -1, driver);
+ if (err)
+ goto exit_free;
+ }
+
+ exit_free:
+ kfree(temp_client);
+ return err;
+}
+
+struct i2c_client *
+i2c_new_probed_device(struct i2c_adapter *adap,
+ struct i2c_board_info *info,
+ unsigned short const *addr_list)
+{
+ int i;
+
+ /* Stop here if the bus doesn't support probing */
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
+ dev_err(&adap->dev, "Probing not supported\n");
+ return NULL;
+ }
+
+ for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
+ /* Check address validity */
+ if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
+ dev_warn(&adap->dev, "Invalid 7-bit address "
+ "0x%02x\n", addr_list[i]);
+ continue;
+ }
+
+ /* Check address availability */
+ 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;
+ }
+
+ /* Test address responsiveness
+ The default probe method is a quick write, but it is known
+ to corrupt the 24RF08 EEPROMs due to a state machine bug,
+ and could also irreversibly write-protect some EEPROMs, so
+ for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
+ read instead. Also, some bus drivers don't implement
+ quick write, so we fallback to a byte read it that case
+ too. */
+ if ((addr_list[i] & ~0x07) == 0x30
+ || (addr_list[i] & ~0x0f) == 0x50
+ || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
+ union i2c_smbus_data data;
+
+ if (i2c_smbus_xfer(adap, addr_list[i], 0,
+ I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &data) >= 0)
+ break;
+ } else {
+ if (i2c_smbus_xfer(adap, addr_list[i], 0,
+ I2C_SMBUS_WRITE, 0,
+ I2C_SMBUS_QUICK, NULL) >= 0)
+ break;
+ }
+ }
+
+ if (addr_list[i] == I2C_CLIENT_END) {
+ dev_dbg(&adap->dev, "Probing failed, no device found\n");
+ return NULL;
+ }
+
+ info->addr = addr_list[i];
+ return i2c_new_device(adap, info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_probed_device);
struct i2c_adapter* i2c_get_adapter(int id)
{
struct i2c_adapter *adapter;
-
- mutex_lock(&core_lists);
- adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id);
+
+ mutex_lock(&core_lock);
+ adapter = idr_find(&i2c_adapter_idr, id);
if (adapter && !try_module_get(adapter->owner))
adapter = NULL;
- mutex_unlock(&core_lists);
+ mutex_unlock(&core_lock);
return adapter;
}
+EXPORT_SYMBOL(i2c_get_adapter);
void i2c_put_adapter(struct i2c_adapter *adap)
{
module_put(adap->owner);
}
+EXPORT_SYMBOL(i2c_put_adapter);
/* The SMBus parts */
-#define POLY (0x1070U << 3)
-static u8
-crc8(u16 data)
+#define POLY (0x1070U << 3)
+static u8 crc8(u16 data)
{
int i;
-
+
for(i = 0; i < 8; i++) {
- if (data & 0x8000)
+ if (data & 0x8000)
data = data ^ POLY;
data = data << 1;
}
if (rpec != cpec) {
pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
rpec, cpec);
- return -1;
+ return -EBADMSG;
}
- return 0;
-}
-
-s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value)
-{
- return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- value,0,I2C_SMBUS_QUICK,NULL);
+ return 0;
}
+/**
+ * i2c_smbus_read_byte - SMBus "receive byte" protocol
+ * @client: Handle to slave device
+ *
+ * This executes the SMBus "receive byte" protocol, returning negative errno
+ * else the byte received from the device.
+ */
s32 i2c_smbus_read_byte(struct i2c_client *client)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data))
- return -1;
- else
- return 0x0FF & data.byte;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, 0,
+ I2C_SMBUS_BYTE, &data);
+ return (status < 0) ? status : data.byte;
}
+EXPORT_SYMBOL(i2c_smbus_read_byte);
+/**
+ * i2c_smbus_write_byte - SMBus "send byte" protocol
+ * @client: Handle to slave device
+ * @value: Byte to be sent
+ *
+ * This executes the SMBus "send byte" protocol, returning negative errno
+ * else zero on success.
+ */
s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
{
return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
}
+EXPORT_SYMBOL(i2c_smbus_write_byte);
+/**
+ * i2c_smbus_read_byte_data - SMBus "read byte" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ *
+ * This executes the SMBus "read byte" protocol, returning negative errno
+ * else a data byte received from the device.
+ */
s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data))
- return -1;
- else
- return 0x0FF & data.byte;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BYTE_DATA, &data);
+ return (status < 0) ? status : data.byte;
}
+EXPORT_SYMBOL(i2c_smbus_read_byte_data);
+/**
+ * i2c_smbus_write_byte_data - SMBus "write byte" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: Byte being written
+ *
+ * This executes the SMBus "write byte" protocol, returning negative errno
+ * else zero on success.
+ */
s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
{
union i2c_smbus_data data;
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BYTE_DATA,&data);
}
+EXPORT_SYMBOL(i2c_smbus_write_byte_data);
+/**
+ * i2c_smbus_read_word_data - SMBus "read word" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ *
+ * This executes the SMBus "read word" protocol, returning negative errno
+ * else a 16-bit unsigned "word" received from the device.
+ */
s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
{
union i2c_smbus_data data;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data))
- return -1;
- else
- return 0x0FFFF & data.word;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_WORD_DATA, &data);
+ return (status < 0) ? status : data.word;
}
+EXPORT_SYMBOL(i2c_smbus_read_word_data);
+/**
+ * i2c_smbus_write_word_data - SMBus "write word" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: 16-bit "word" being written
+ *
+ * This executes the SMBus "write word" protocol, returning negative errno
+ * else zero on success.
+ */
s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
{
union i2c_smbus_data data;
I2C_SMBUS_WRITE,command,
I2C_SMBUS_WORD_DATA,&data);
}
+EXPORT_SYMBOL(i2c_smbus_write_word_data);
+
+/**
+ * i2c_smbus_process_call - SMBus "process call" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @value: 16-bit "word" being written
+ *
+ * This executes the SMBus "process call" protocol, returning negative errno
+ * else a 16-bit unsigned "word" received from the device.
+ */
+s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
+{
+ union i2c_smbus_data data;
+ int status;
+ data.word = value;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_WRITE, command,
+ I2C_SMBUS_PROC_CALL, &data);
+ return (status < 0) ? status : data.word;
+}
+EXPORT_SYMBOL(i2c_smbus_process_call);
+
+/**
+ * i2c_smbus_read_block_data - SMBus "block read" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @values: Byte array into which data will be read; big enough to hold
+ * the data returned by the slave. SMBus allows at most 32 bytes.
+ *
+ * This executes the SMBus "block read" protocol, returning negative errno
+ * else the number of data bytes in the slave's response.
+ *
+ * Note that using this function requires that the client's adapter support
+ * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
+ * support this; its emulation through I2C messaging relies on a specific
+ * mechanism (I2C_M_RECV_LEN) which may not be implemented.
+ */
+s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
+ u8 *values)
+{
+ union i2c_smbus_data data;
+ int status;
+
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_BLOCK_DATA, &data);
+ if (status)
+ return status;
+ memcpy(values, &data.block[1], data.block[0]);
+ return data.block[0];
+}
+EXPORT_SYMBOL(i2c_smbus_read_block_data);
+
+/**
+ * i2c_smbus_write_block_data - SMBus "block write" protocol
+ * @client: Handle to slave device
+ * @command: Byte interpreted by slave
+ * @length: Size of data block; SMBus allows at most 32 bytes
+ * @values: Byte array which will be written.
+ *
+ * This executes the SMBus "block write" protocol, returning negative errno
+ * else zero on success.
+ */
s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
- u8 length, u8 *values)
+ u8 length, const u8 *values)
{
union i2c_smbus_data data;
I2C_SMBUS_WRITE,command,
I2C_SMBUS_BLOCK_DATA,&data);
}
+EXPORT_SYMBOL(i2c_smbus_write_block_data);
/* Returns the number of read bytes */
-s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values)
+s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
+ u8 length, u8 *values)
{
union i2c_smbus_data data;
+ int status;
- if (i2c_smbus_xfer(client->adapter,client->addr,client->flags,
- I2C_SMBUS_READ,command,
- I2C_SMBUS_I2C_BLOCK_DATA,&data))
- return -1;
+ if (length > I2C_SMBUS_BLOCK_MAX)
+ length = I2C_SMBUS_BLOCK_MAX;
+ data.block[0] = length;
+ status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
+ I2C_SMBUS_READ, command,
+ I2C_SMBUS_I2C_BLOCK_DATA, &data);
+ if (status < 0)
+ return status;
memcpy(values, &data.block[1], data.block[0]);
return data.block[0];
}
+EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
- u8 length, u8 *values)
+ u8 length, const u8 *values)
{
union i2c_smbus_data data;
I2C_SMBUS_WRITE, command,
I2C_SMBUS_I2C_BLOCK_DATA, &data);
}
+EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
-/* Simulate a SMBus command using the i2c protocol
+/* Simulate a SMBus command using the i2c protocol
No checking of parameters is done! */
-static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
+static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
unsigned short flags,
- char read_write, u8 command, int size,
+ char read_write, u8 command, int size,
union i2c_smbus_data * data)
{
/* So we need to generate a series of msgs. In the case of writing, we
unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
int num = read_write == I2C_SMBUS_READ?2:1;
- struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
+ struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
{ addr, flags | I2C_M_RD, 0, msgbuf1 }
};
int i;
u8 partial_pec = 0;
+ int status;
msgbuf0[0] = command;
switch(size) {
case I2C_SMBUS_QUICK:
msg[0].len = 0;
/* Special case: The read/write field is used as data */
- msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0;
+ msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
+ I2C_M_RD : 0);
num = 1;
break;
case I2C_SMBUS_BYTE:
else {
msg[0].len=3;
msgbuf0[1] = data->word & 0xff;
- msgbuf0[2] = (data->word >> 8) & 0xff;
+ msgbuf0[2] = data->word >> 8;
}
break;
case I2C_SMBUS_PROC_CALL:
msg[0].len = 3;
msg[1].len = 2;
msgbuf0[1] = data->word & 0xff;
- msgbuf0[2] = (data->word >> 8) & 0xff;
+ msgbuf0[2] = data->word >> 8;
break;
case I2C_SMBUS_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
- dev_err(&adapter->dev, "Block read not supported "
- "under I2C emulation!\n");
- return -1;
+ msg[1].flags |= I2C_M_RECV_LEN;
+ msg[1].len = 1; /* block length will be added by
+ the underlying bus driver */
} else {
msg[0].len = data->block[0] + 2;
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
- dev_err(&adapter->dev, "smbus_access called with "
- "invalid block write size (%d)\n",
- data->block[0]);
- return -1;
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
}
for (i = 1; i < msg[0].len; i++)
msgbuf0[i] = data->block[i-1];
}
break;
case I2C_SMBUS_BLOCK_PROC_CALL:
- dev_dbg(&adapter->dev, "Block process call not supported "
- "under I2C emulation!\n");
- return -1;
+ num = 2; /* Another special case */
+ read_write = I2C_SMBUS_READ;
+ if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
+ }
+ msg[0].len = data->block[0] + 2;
+ for (i = 1; i < msg[0].len; i++)
+ msgbuf0[i] = data->block[i-1];
+ msg[1].flags |= I2C_M_RECV_LEN;
+ msg[1].len = 1; /* block length will be added by
+ the underlying bus driver */
+ break;
case I2C_SMBUS_I2C_BLOCK_DATA:
if (read_write == I2C_SMBUS_READ) {
- msg[1].len = I2C_SMBUS_BLOCK_MAX;
+ msg[1].len = data->block[0];
} else {
msg[0].len = data->block[0] + 1;
if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
- dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with "
- "invalid block write size (%d)\n",
- data->block[0]);
- return -1;
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
+ data->block[0]);
+ return -EINVAL;
}
for (i = 1; i <= data->block[0]; i++)
msgbuf0[i] = data->block[i];
}
break;
default:
- dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n",
- size);
- return -1;
+ dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
+ return -EOPNOTSUPP;
}
i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
if (i) {
/* Compute PEC if first message is a write */
if (!(msg[0].flags & I2C_M_RD)) {
- if (num == 1) /* Write only */
+ if (num == 1) /* Write only */
i2c_smbus_add_pec(&msg[0]);
else /* Write followed by read */
partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
}
/* Ask for PEC if last message is a read */
if (msg[num-1].flags & I2C_M_RD)
- msg[num-1].len++;
+ msg[num-1].len++;
}
- if (i2c_transfer(adapter, msg, num) < 0)
- return -1;
+ status = i2c_transfer(adapter, msg, num);
+ if (status < 0)
+ return status;
/* Check PEC if last message is a read */
if (i && (msg[num-1].flags & I2C_M_RD)) {
- if (i2c_smbus_check_pec(partial_pec, &msg[num-1]) < 0)
- return -1;
+ status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
+ if (status < 0)
+ return status;
}
if (read_write == I2C_SMBUS_READ)
case I2C_SMBUS_BYTE_DATA:
data->byte = msgbuf1[0];
break;
- case I2C_SMBUS_WORD_DATA:
+ case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
data->word = msgbuf1[0] | (msgbuf1[1] << 8);
break;
case I2C_SMBUS_I2C_BLOCK_DATA:
- /* fixed at 32 for now */
- data->block[0] = I2C_SMBUS_BLOCK_MAX;
- for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++)
+ for (i = 0; i < data->block[0]; i++)
data->block[i+1] = msgbuf1[i];
break;
+ case I2C_SMBUS_BLOCK_DATA:
+ case I2C_SMBUS_BLOCK_PROC_CALL:
+ for (i = 0; i < msgbuf1[0] + 1; i++)
+ data->block[i] = msgbuf1[i];
+ break;
}
return 0;
}
-
-s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags,
- char read_write, u8 command, int size,
- union i2c_smbus_data * data)
+/**
+ * i2c_smbus_xfer - execute SMBus protocol operations
+ * @adapter: Handle to I2C bus
+ * @addr: Address of SMBus slave on that bus
+ * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
+ * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
+ * @command: Byte interpreted by slave, for protocols which use such bytes
+ * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
+ * @data: Data to be read or written
+ *
+ * This executes an SMBus protocol operation, and returns a negative
+ * errno code else zero on success.
+ */
+s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
+ char read_write, u8 command, int protocol,
+ union i2c_smbus_data *data)
{
+ unsigned long orig_jiffies;
+ int try;
s32 res;
flags &= I2C_M_TEN | I2C_CLIENT_PEC;
if (adapter->algo->smbus_xfer) {
- down(&adapter->bus_lock);
- res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
- command,size,data);
- up(&adapter->bus_lock);
+ mutex_lock(&adapter->bus_lock);
+
+ /* Retry automatically on arbitration loss */
+ orig_jiffies = jiffies;
+ for (res = 0, try = 0; try <= adapter->retries; try++) {
+ res = adapter->algo->smbus_xfer(adapter, addr, flags,
+ read_write, command,
+ protocol, data);
+ if (res != -EAGAIN)
+ break;
+ if (time_after(jiffies,
+ orig_jiffies + adapter->timeout))
+ break;
+ }
+ mutex_unlock(&adapter->bus_lock);
} else
res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
- command,size,data);
+ command, protocol, data);
return res;
}
-
-
-/* Next four are needed by i2c-isa */
-EXPORT_SYMBOL_GPL(i2c_adapter_dev_release);
-EXPORT_SYMBOL_GPL(i2c_adapter_driver);
-EXPORT_SYMBOL_GPL(i2c_adapter_class);
-EXPORT_SYMBOL_GPL(i2c_bus_type);
-
-EXPORT_SYMBOL(i2c_add_adapter);
-EXPORT_SYMBOL(i2c_del_adapter);
-EXPORT_SYMBOL(i2c_del_driver);
-EXPORT_SYMBOL(i2c_attach_client);
-EXPORT_SYMBOL(i2c_detach_client);
-EXPORT_SYMBOL(i2c_use_client);
-EXPORT_SYMBOL(i2c_release_client);
-EXPORT_SYMBOL(i2c_clients_command);
-EXPORT_SYMBOL(i2c_check_addr);
-
-EXPORT_SYMBOL(i2c_master_send);
-EXPORT_SYMBOL(i2c_master_recv);
-EXPORT_SYMBOL(i2c_control);
-EXPORT_SYMBOL(i2c_transfer);
-EXPORT_SYMBOL(i2c_get_adapter);
-EXPORT_SYMBOL(i2c_put_adapter);
-EXPORT_SYMBOL(i2c_probe);
-
EXPORT_SYMBOL(i2c_smbus_xfer);
-EXPORT_SYMBOL(i2c_smbus_write_quick);
-EXPORT_SYMBOL(i2c_smbus_read_byte);
-EXPORT_SYMBOL(i2c_smbus_write_byte);
-EXPORT_SYMBOL(i2c_smbus_read_byte_data);
-EXPORT_SYMBOL(i2c_smbus_write_byte_data);
-EXPORT_SYMBOL(i2c_smbus_read_word_data);
-EXPORT_SYMBOL(i2c_smbus_write_word_data);
-EXPORT_SYMBOL(i2c_smbus_write_block_data);
-EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
-EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
MODULE_DESCRIPTION("I2C-Bus main module");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff