| /* i2c-core.c - a device driver for the iic-bus interface */ |
| /* ------------------------------------------------------------------------- */ |
| /* Copyright (C) 1995-99 Simon G. Vogl |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| /* ------------------------------------------------------------------------- */ |
| |
| /* 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/module.h> |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/slab.h> |
| #include <linux/i2c.h> |
| #include <linux/init.h> |
| #include <linux/idr.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 DEFINE_MUTEX(core_lock); |
| static DEFINE_IDR(i2c_adapter_idr); |
| |
| static int i2c_check_addr(struct i2c_adapter *adapter, int addr); |
| 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); |
| struct i2c_driver *driver = to_i2c_driver(drv); |
| |
| /* 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, struct kobj_uevent_env *env) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| |
| 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) |
| { |
| 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) |
| { |
| struct i2c_client *client = to_i2c_client(dev); |
| struct i2c_driver *driver; |
| int status; |
| |
| if (!dev->driver) |
| return 0; |
| |
| 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; |
| } |
| |
| static void i2c_device_shutdown(struct device *dev) |
| { |
| struct i2c_driver *driver; |
| |
| if (!dev->driver) |
| return; |
| driver = to_i2c_driver(dev->driver); |
| if (driver->shutdown) |
| driver->shutdown(to_i2c_client(dev)); |
| } |
| |
| static int i2c_device_suspend(struct device *dev, pm_message_t mesg) |
| { |
| 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 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_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); |
| } |
| |
| 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 |
| * @adap: the adapter managing the device |
| * @info: describes one I2C device; bus_num is ignored |
| * Context: can sleep |
| * |
| * Create an i2c device. Binding is handled through driver model |
| * probe()/remove() methods. A driver may be bound to this device when we |
| * return from this function, or any later moment (e.g. maybe hotplugging will |
| * load the driver module). This call is not appropriate for use by mainboard |
| * initialization logic, which usually runs during an arch_initcall() long |
| * before any i2c_adapter could exist. |
| * |
| * This returns the new i2c client, which may be saved for later use with |
| * i2c_unregister_device(); or NULL to indicate an error. |
| */ |
| 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)); |
| |
| /* Check for address business */ |
| status = i2c_check_addr(adap, client->addr); |
| if (status) |
| goto out_err; |
| |
| client->dev.parent = &client->adapter->dev; |
| client->dev.bus = &i2c_bus_type; |
| client->dev.release = i2c_client_dev_release; |
| |
| dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
| client->addr); |
| status = device_register(&client->dev); |
| if (status) |
| goto out_err; |
| |
| dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
| client->name, dev_name(&client->dev)); |
| |
| return client; |
| |
| out_err: |
| dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " |
| "(%d)\n", client->name, client->addr, status); |
| kfree(client); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(i2c_new_device); |
| |
| |
| /** |
| * 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) |
| { |
| device_unregister(&client->dev); |
| } |
| 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 */ |
| |
| 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); |
| } |
| |
| 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; |
| |
| mutex_init(&adap->bus_lock); |
| |
| mutex_lock(&core_lock); |
| |
| /* 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); |
| |
| /* create pre-declared device nodes */ |
| 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_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; |
| } |
| |
| static int __unregister_client(struct device *dev, void *dummy) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| if (client) |
| i2c_unregister_device(client); |
| return 0; |
| } |
| |
| /** |
| * i2c_del_adapter - unregister I2C adapter |
| * @adap: the adapter being unregistered |
| * 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) |
| { |
| int res = 0; |
| |
| mutex_lock(&core_lock); |
| |
| /* First make sure that this adapter was ever added */ |
| 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; |
| } |
| |
| /* 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 can't fail, thus we do not |
| checking the returned value. */ |
| res = device_for_each_child(&adap->dev, NULL, __unregister_client); |
| |
| /* clean up the sysfs representation */ |
| init_completion(&adap->dev_released); |
| device_unregister(&adap->dev); |
| |
| /* wait for sysfs to drop all references */ |
| wait_for_completion(&adap->dev_released); |
| |
| /* 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_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. |
| */ |
| |
| int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
| { |
| int res; |
| |
| /* Can't register until after driver model init */ |
| if (unlikely(WARN_ON(!i2c_bus_type.p))) |
| return -EAGAIN; |
| |
| /* add the driver to the list of i2c drivers in the driver core */ |
| driver->driver.owner = owner; |
| driver->driver.bus = &i2c_bus_type; |
| |
| /* When registration returns, the driver core |
| * will have called probe() for all matching-but-unbound devices. |
| */ |
| res = driver_register(&driver->driver); |
| if (res) |
| return res; |
| |
| mutex_lock(&core_lock); |
| |
| pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
| |
| INIT_LIST_HEAD(&driver->clients); |
| /* Walk the adapters that are already present */ |
| class_for_each_device(&i2c_adapter_class, NULL, driver, |
| __attach_adapter); |
| |
| mutex_unlock(&core_lock); |
| return 0; |
| } |
| EXPORT_SYMBOL(i2c_register_driver); |
| |
| static int __detach_adapter(struct device *dev, void *data) |
| { |
| 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); |
| } |
| |
| if (driver->detach_adapter) { |
| if (driver->detach_adapter(adapter)) |
| dev_err(&adapter->dev, |
| "detach_adapter failed for driver [%s]\n", |
| driver->driver.name); |
| } |
| |
| 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); |
| pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
| |
| mutex_unlock(&core_lock); |
| } |
| EXPORT_SYMBOL(i2c_del_driver); |
| |
| /* ------------------------------------------------------------------------- */ |
| |
| static int __i2c_check_addr(struct device *dev, void *addrp) |
| { |
| struct i2c_client *client = i2c_verify_client(dev); |
| int addr = *(int *)addrp; |
| |
| if (client && client->addr == addr) |
| return -EBUSY; |
| return 0; |
| } |
| |
| static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
| { |
| return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
| } |
| |
| /** |
| * 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 (client && get_device(&client->dev)) |
| return client; |
| return NULL; |
| } |
| EXPORT_SYMBOL(i2c_use_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) |
| { |
| if (client) |
| put_device(&client->dev); |
| } |
| EXPORT_SYMBOL(i2c_release_client); |
| |
| struct i2c_cmd_arg { |
| unsigned cmd; |
| void *arg; |
| }; |
| |
| static int i2c_cmd(struct device *dev, void *_arg) |
| { |
| 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 i2c_cmd_arg cmd_arg; |
| |
| 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) |
| { |
| int retval; |
| |
| retval = bus_register(&i2c_bus_type); |
| if (retval) |
| return retval; |
| 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); |
| } |
| |
| /* 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); |
| |
| /* ---------------------------------------------------- |
| * the functional interface to the i2c busses. |
| * ---------------------------------------------------- |
| */ |
| |
| /** |
| * 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) |
| { |
| 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%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 |
| |
| 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 -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; |
| struct i2c_adapter *adap=client->adapter; |
| struct i2c_msg msg; |
| |
| msg.addr = client->addr; |
| 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; |
| struct i2c_msg msg; |
| int ret; |
| |
| msg.addr = client->addr; |
| msg.flags = client->flags & I2C_M_TEN; |
| msg.flags |= I2C_M_RD; |
| msg.len = count; |
| msg.buf = 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_recv); |
| |
| /* ---------------------------------------------------- |
| * the i2c address scanning function |
| * Will not work for 10-bit addresses! |
| * ---------------------------------------------------- |
| */ |
| |
| 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_lock); |
| adapter = idr_find(&i2c_adapter_idr, id); |
| if (adapter && !try_module_get(adapter->owner)) |
| adapter = NULL; |
| |
| 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) |
| { |
| int i; |
| |
| for(i = 0; i < 8; i++) { |
| if (data & 0x8000) |
| data = data ^ POLY; |
| data = data << 1; |
| } |
| return (u8)(data >> 8); |
| } |
| |
| /* Incremental CRC8 over count bytes in the array pointed to by p */ |
| static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) |
| { |
| int i; |
| |
| for(i = 0; i < count; i++) |
| crc = crc8((crc ^ p[i]) << 8); |
| return crc; |
| } |
| |
| /* Assume a 7-bit address, which is reasonable for SMBus */ |
| static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) |
| { |
| /* The address will be sent first */ |
| u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); |
| pec = i2c_smbus_pec(pec, &addr, 1); |
| |
| /* The data buffer follows */ |
| return i2c_smbus_pec(pec, msg->buf, msg->len); |
| } |
| |
| /* Used for write only transactions */ |
| static inline void i2c_smbus_add_pec(struct i2c_msg *msg) |
| { |
| msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
| msg->len++; |
| } |
| |
| /* Return <0 on CRC error |
| If there was a write before this read (most cases) we need to take the |
| partial CRC from the write part into account. |
| Note that this function does modify the message (we need to decrease the |
| message length to hide the CRC byte from the caller). */ |
| static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) |
| { |
| u8 rpec = msg->buf[--msg->len]; |
| cpec = i2c_smbus_msg_pec(cpec, msg); |
| |
| if (rpec != cpec) { |
| pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", |
| rpec, cpec); |
| return -EBADMSG; |
| } |
| 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; |
| 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; |
| 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; |
| data.byte = value; |
| return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
| 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; |
| 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; |
| data.word = value; |
| return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
| 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, const u8 *values) |
| { |
| union i2c_smbus_data data; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| data.block[0] = length; |
| memcpy(&data.block[1], values, length); |
| return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
| 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 length, u8 *values) |
| { |
| union i2c_smbus_data data; |
| int status; |
| |
| 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, const u8 *values) |
| { |
| union i2c_smbus_data data; |
| |
| if (length > I2C_SMBUS_BLOCK_MAX) |
| length = I2C_SMBUS_BLOCK_MAX; |
| data.block[0] = length; |
| memcpy(data.block + 1, values, length); |
| return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
| 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 |
| No checking of parameters is done! */ |
| static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
| unsigned short flags, |
| 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 |
| need to use only one message; when reading, we need two. We initialize |
| most things with sane defaults, to keep the code below somewhat |
| simpler. */ |
| 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 }, |
| { 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); |
| num = 1; |
| break; |
| case I2C_SMBUS_BYTE: |
| if (read_write == I2C_SMBUS_READ) { |
| /* Special case: only a read! */ |
| msg[0].flags = I2C_M_RD | flags; |
| num = 1; |
| } |
| break; |
| case I2C_SMBUS_BYTE_DATA: |
| if (read_write == I2C_SMBUS_READ) |
| msg[1].len = 1; |
| else { |
| msg[0].len = 2; |
| msgbuf0[1] = data->byte; |
| } |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| if (read_write == I2C_SMBUS_READ) |
| msg[1].len = 2; |
| else { |
| msg[0].len=3; |
| msgbuf0[1] = data->word & 0xff; |
| msgbuf0[2] = data->word >> 8; |
| } |
| break; |
| case I2C_SMBUS_PROC_CALL: |
| num = 2; /* Special case */ |
| read_write = I2C_SMBUS_READ; |
| msg[0].len = 3; |
| msg[1].len = 2; |
| msgbuf0[1] = data->word & 0xff; |
| msgbuf0[2] = data->word >> 8; |
| break; |
| case I2C_SMBUS_BLOCK_DATA: |
| if (read_write == I2C_SMBUS_READ) { |
| 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, |
| "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: |
| 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 = data->block[0]; |
| } else { |
| msg[0].len = data->block[0] + 1; |
| if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 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, "Unsupported transaction %d\n", size); |
| return -EOPNOTSUPP; |
| } |
| |
| i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
| && size != I2C_SMBUS_I2C_BLOCK_DATA); |
| if (i) { |
| /* Compute PEC if first message is a write */ |
| if (!(msg[0].flags & I2C_M_RD)) { |
| 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++; |
| } |
| |
| 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)) { |
| status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
| if (status < 0) |
| return status; |
| } |
| |
| if (read_write == I2C_SMBUS_READ) |
| switch(size) { |
| case I2C_SMBUS_BYTE: |
| data->byte = msgbuf0[0]; |
| break; |
| case I2C_SMBUS_BYTE_DATA: |
| data->byte = msgbuf1[0]; |
| break; |
| case I2C_SMBUS_WORD_DATA: |
| case I2C_SMBUS_PROC_CALL: |
| data->word = msgbuf1[0] | (msgbuf1[1] << 8); |
| break; |
| case I2C_SMBUS_I2C_BLOCK_DATA: |
| 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; |
| } |
| |
| /** |
| * 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); |
| |
| /* 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, protocol, data); |
| |
| return res; |
| } |
| EXPORT_SYMBOL(i2c_smbus_xfer); |
| |
| MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |
| MODULE_DESCRIPTION("I2C-Bus main module"); |
| MODULE_LICENSE("GPL"); |