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);
-#define is_newstyle_driver(d) ((d)->probe || (d)->remove)
+#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)
+{
+ while (id->name[0]) {
+ if (strcmp(client->name, id->name) == 0)
+ return id;
+ id++;
+ }
+ return NULL;
+}
+
static int i2c_device_match(struct device *dev, struct device_driver *drv)
{
struct i2c_client *client = to_i2c_client(dev);
if (!is_newstyle_driver(driver))
return 0;
- /* new style drivers use the same kind of driver matching policy
- * as platform devices or SPI: compare device and driver IDs.
- */
- return strcmp(client->driver_name, drv->name) == 0;
+ /* match on an id table if there is one */
+ if (driver->id_table)
+ return i2c_match_id(driver->id_table, client) != NULL;
+
+ return 0;
}
#ifdef CONFIG_HOTPLUG
/* uevent helps with hotplug: modprobe -q $(MODALIAS) */
-static int i2c_device_uevent(struct device *dev, char **envp, int num_envp,
- char *buffer, int buffer_size)
+static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct i2c_client *client = to_i2c_client(dev);
- int i = 0, length = 0;
/* by definition, legacy drivers can't hotplug */
- if (dev->driver || !client->driver_name)
+ if (dev->driver)
return 0;
- if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
- "MODALIAS=%s", client->driver_name))
+ if (add_uevent_var(env, "MODALIAS=%s%s",
+ I2C_MODULE_PREFIX, client->name))
return -ENOMEM;
- envp[i] = NULL;
dev_dbg(dev, "uevent\n");
return 0;
}
{
struct i2c_client *client = to_i2c_client(dev);
struct i2c_driver *driver = to_i2c_driver(dev->driver);
+ int status;
- if (!driver->probe)
+ 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");
- return driver->probe(client);
+
+ 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)
driver->shutdown(to_i2c_client(dev));
}
-static int i2c_device_suspend(struct device * dev, pm_message_t mesg)
+static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
{
struct i2c_driver *driver;
return driver->suspend(to_i2c_client(dev), mesg);
}
-static int i2c_device_resume(struct device * dev)
+static int i2c_device_resume(struct device *dev)
{
struct i2c_driver *driver;
kfree(to_i2c_client(dev));
}
-static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf)
+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);
}
-static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
+static ssize_t
+show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
{
struct i2c_client *client = to_i2c_client(dev);
- return client->driver_name
- ? sprintf(buf, "%s\n", client->driver_name)
- : 0;
+ return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
}
static struct device_attribute i2c_dev_attrs[] = {
};
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
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->driver_name, info->driver_name,
- sizeof(client->driver_name));
strlcpy(client->name, info->type, sizeof(client->name));
/* a new style driver may be bound to this device when we
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);
EXPORT_SYMBOL_GPL(i2c_unregister_device);
+static const struct i2c_device_id dummy_id[] = {
+ { "dummy", 0 },
+ { },
+};
+
+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.
+ */
+struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
+{
+ struct i2c_board_info info = {
+ I2C_BOARD_INFO("dummy", address),
+ };
+
+ return i2c_new_device(adapter, &info);
+}
+EXPORT_SYMBOL_GPL(i2c_new_dummy);
+
/* ------------------------------------------------------------------------- */
/* I2C bus adapters -- one roots each I2C or SMBUS segment */
-void i2c_adapter_dev_release(struct device *dev)
+static void i2c_adapter_dev_release(struct device *dev)
{
struct i2c_adapter *adap = to_i2c_adapter(dev);
complete(&adap->dev_released);
}
-EXPORT_SYMBOL_GPL(i2c_adapter_dev_release); /* exported to i2c-isa */
static ssize_t
show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf)
{ },
};
-struct class i2c_adapter_class = {
+static struct class i2c_adapter_class = {
.owner = THIS_MODULE,
.name = "i2c-adapter",
.dev_attrs = i2c_adapter_attrs,
};
-EXPORT_SYMBOL_GPL(i2c_adapter_class); /* exported to i2c-isa */
static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
{
if (devinfo->busnum == adapter->nr
&& !i2c_new_device(adapter,
&devinfo->board_info))
- printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n",
- i2c_adapter_id(adapter),
+ dev_err(&adapter->dev,
+ "Can't create device at 0x%02x\n",
devinfo->board_info.addr);
}
mutex_unlock(&__i2c_board_lock);
}
+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;
- struct list_head *item;
- struct i2c_driver *driver;
+ int res = 0, dummy;
+
+ /* Can't register until after driver model init */
+ if (unlikely(WARN_ON(!i2c_bus_type.p)))
+ return -EAGAIN;
mutex_init(&adap->bus_lock);
mutex_init(&adap->clist_lock);
INIT_LIST_HEAD(&adap->clients);
- mutex_lock(&core_lists);
- list_add_tail(&adap->list, &adapters);
+ mutex_lock(&core_lock);
/* Add the adapter to the driver core.
* If the parent pointer is not set up,
pr_debug("I2C adapter driver [%s] forgot to specify "
"physical device\n", adap->name);
}
- sprintf(adap->dev.bus_id, "i2c-%d", adap->nr);
+
+ /* 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 (adap->nr < __i2c_first_dynamic_bus_num)
i2c_scan_static_board_info(adap);
- /* let legacy drivers scan this bus for matching devices */
- 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);
- }
+ /* 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:
- list_del(&adap->list);
idr_remove(&i2c_adapter_idr, adap->nr);
goto out_unlock;
}
if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
return -ENOMEM;
- mutex_lock(&core_lists);
+ 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_lists);
+ mutex_unlock(&core_lock);
if (res < 0) {
if (res == -EAGAIN)
* Context: can sleep
*
* This routine is used to declare an I2C adapter when its bus number
- * matters. Example: for I2C adapters from system-on-chip CPUs, or
- * otherwise built in to the system's mainboard, and where i2c_board_info
+ * 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
if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
return -ENOMEM;
- mutex_lock(&core_lists);
+ mutex_lock(&core_lock);
/* "above" here means "above or equal to", sigh;
* we need the "equal to" result to force the result
*/
status = -EBUSY;
idr_remove(&i2c_adapter_idr, id);
}
- mutex_unlock(&core_lists);
+ mutex_unlock(&core_lock);
if (status == -EAGAIN)
goto retry;
}
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
*/
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) {
+ list_for_each_entry_safe_reverse(client, _n, &adap->clients, list) {
struct i2c_driver *driver;
- client = list_entry(item, struct i2c_client, list);
driver = client->driver;
/* new style, follow standard driver model */
/* clean up the sysfs representation */
init_completion(&adap->dev_released);
device_unregister(&adap->dev);
- list_del(&adap->list);
/* wait for sysfs to drop all references */
wait_for_completion(&adap->dev_released);
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);
+
+ 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
{
int res;
+ /* Can't register until after driver model init */
+ 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->attach_adapter || driver->detach_adapter
- || driver->detach_client) {
+ if (driver->detach_adapter || driver->detach_client) {
printk(KERN_WARNING
"i2c-core: driver [%s] is confused\n",
driver->driver.name);
if (res)
return res;
- mutex_lock(&core_lists);
+ mutex_lock(&core_lock);
- list_add_tail(&driver->list,&drivers);
pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
- /* legacy drivers scan i2c busses directly */
- if (driver->attach_adapter) {
- struct i2c_adapter *adapter;
-
- list_for_each_entry(adapter, &adapters, 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);
- mutex_unlock(&core_lists);
+ mutex_unlock(&core_lock);
return 0;
}
EXPORT_SYMBOL(i2c_register_driver);
-/**
- * i2c_del_driver - unregister I2C driver
- * @driver: the driver being unregistered
- * Context: can sleep
- */
-void 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;
-
- mutex_lock(&core_lists);
+ 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);
+ }
- /* new-style driver? */
if (is_newstyle_driver(driver))
- goto unregister;
+ 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.
*/
- list_for_each(item1,&adapters) {
- adap = list_entry(item1, struct i2c_adapter, list);
- if (driver->detach_adapter) {
- if (driver->detach_adapter(adap)) {
- dev_err(&adap->dev, "detach_adapter failed "
- "for driver [%s]\n",
- driver->driver.name);
- }
- } 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 (driver->detach_client(client)) {
- dev_err(&adap->dev, "detach_client "
- "failed for client [%s] at "
- "0x%02x\n", client->name,
- client->addr);
- }
- }
+ 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);
}
}
- unregister:
+ 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);
- mutex_unlock(&core_lists);
+ 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;
-
- mutex_lock(&adapter->clist_lock);
- rval = __i2c_check_addr(adapter, addr);
- mutex_unlock(&adapter->clist_lock);
-
- return rval;
+ return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
}
-EXPORT_SYMBOL(i2c_check_addr);
int i2c_attach_client(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
- int res = 0;
-
- mutex_lock(&adapter->clist_lock);
- if (__i2c_check_addr(client->adapter, client->addr)) {
- res = -EBUSY;
- goto out_unlock;
- }
- list_add_tail(&client->list,&adapter->clients);
+ int res;
- client->usage_count = 0;
+ /* 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 && !is_newstyle_driver(client->driver)) {
client->dev.release = i2c_client_release;
- client->dev.uevent_suppress = 1;
+ dev_set_uevent_suppress(&client->dev, 1);
} else
client->dev.release = i2c_client_dev_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);
+ dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adapter),
+ client->addr);
res = device_register(&client->dev);
if (res)
- goto out_list;
+ 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 "
return 0;
-out_list:
- list_del(&client->list);
+out_err:
dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x "
"(%d)\n", client->name, client->addr, res);
-out_unlock:
- mutex_unlock(&adapter->clist_lock);
return res;
}
EXPORT_SYMBOL(i2c_attach_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);
if (res) {
mutex_lock(&adapter->clist_lock);
list_del(&client->list);
+ mutex_unlock(&adapter->clist_lock);
+
init_completion(&client->released);
device_unregister(&client->dev);
- mutex_unlock(&adapter->clist_lock);
wait_for_completion(&client->released);
out:
}
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;
-}
-EXPORT_SYMBOL(i2c_use_client);
+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;
}
-EXPORT_SYMBOL(i2c_release_client);
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;
- mutex_lock(&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) {
- mutex_unlock(&adap->clist_lock);
- client->driver->command(client,cmd,arg);
- mutex_lock(&adap->clist_lock);
- }
- module_put(client->driver->driver.owner);
- }
- mutex_unlock(&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);
retval = bus_register(&i2c_bus_type);
if (retval)
return retval;
- return class_register(&i2c_adapter_class);
+ retval = class_register(&i2c_adapter_class);
+ if (retval)
+ 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);
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
}
#endif
- mutex_lock_nested(&adap->bus_lock, adap->level);
- ret = adap->algo->master_xfer(adap,msgs,num);
+ 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;
}
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;
}
EXPORT_SYMBOL(i2c_master_recv);
-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_control);
-
/* ----------------------------------------------------
* the i2c address scanning function
* Will not work for 10-bit addresses!
}
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++) {
&& address_data->normal_i2c[0] == I2C_CLIENT_END)
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
}
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,
return NULL;
}
- mutex_lock(&adap->clist_lock);
for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
/* Check address validity */
if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
}
/* Check address availability */
- if (__i2c_check_addr(adap, addr_list[i])) {
+ 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;
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, NULL) >= 0)
+ I2C_SMBUS_BYTE, &data) >= 0)
break;
} else {
if (i2c_smbus_xfer(adap, addr_list[i], 0,
break;
}
}
- mutex_unlock(&adap->clist_lock);
if (addr_list[i] == I2C_CLIENT_END) {
dev_dbg(&adap->dev, "Probing failed, no device found\n");
{
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);
/* The SMBus parts */
#define POLY (0x1070U << 3)
-static u8
-crc8(u16 data)
+static u8 crc8(u16 data)
{
int i;
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);
-}
-EXPORT_SYMBOL(i2c_smbus_write_quick);
-
+/**
+ * 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 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,
}
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 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;
}
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 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;
}
EXPORT_SYMBOL(i2c_smbus_write_word_data);
-/* Returns the number of read bytes */
+/**
+ * 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;
- if (i2c_smbus_xfer(client->adapter, client->addr, client->flags,
- I2C_SMBUS_READ, command,
- I2C_SMBUS_BLOCK_DATA, &data))
- return -1;
+ 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, const u8 *values)
{
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];
};
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 = 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];
num = 2; /* Another special case */
read_write = I2C_SMBUS_READ;
if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
- dev_err(&adapter->dev, "%s called with invalid "
- "block proc call size (%d)\n", __FUNCTION__,
+ dev_err(&adapter->dev,
+ "Invalid block write size %d\n",
data->block[0]);
- return -1;
+ return -EINVAL;
}
msg[0].len = data->block[0] + 2;
for (i = 1; i < msg[0].len; i++)
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
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)
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:
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) {
mutex_lock(&adapter->bus_lock);
- res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write,
- command,size,data);
+
+ /* 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;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff