/* 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 . All SMBus-related things are written by Frodo Looijaard SMBus 2.0 support by Mark Studebaker */ #include #include #include #include #include #include #include #include #include static LIST_HEAD(adapters); static LIST_HEAD(drivers); static DECLARE_MUTEX(core_lists); static DEFINE_IDR(i2c_adapter_idr); static int i2c_device_match(struct device *dev, struct device_driver *drv) { return 1; } static int i2c_bus_suspend(struct device * dev, pm_message_t state) { int rc = 0; if (dev->driver && dev->driver->suspend) rc = dev->driver->suspend(dev,state,0); return rc; } static int i2c_bus_resume(struct device * dev) { int rc = 0; if (dev->driver && dev->driver->resume) rc = dev->driver->resume(dev,0); return rc; } struct bus_type i2c_bus_type = { .name = "i2c", .match = i2c_device_match, .suspend = i2c_bus_suspend, .resume = i2c_bus_resume, }; static int i2c_device_probe(struct device *dev) { return -ENODEV; } static int i2c_device_remove(struct device *dev) { return 0; } void i2c_adapter_dev_release(struct device *dev) { struct i2c_adapter *adap = dev_to_i2c_adapter(dev); complete(&adap->dev_released); } struct device_driver i2c_adapter_driver = { .name = "i2c_adapter", .bus = &i2c_bus_type, .probe = i2c_device_probe, .remove = i2c_device_remove, }; static void i2c_adapter_class_dev_release(struct class_device *dev) { struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev); complete(&adap->class_dev_released); } struct class i2c_adapter_class = { .name = "i2c-adapter", .release =&i2c_adapter_class_dev_release, }; static ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_adapter *adap = dev_to_i2c_adapter(dev); return sprintf(buf, "%s\n", adap->name); } static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); static void i2c_client_release(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); complete(&client->released); } static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); return sprintf(buf, "%s\n", client->name); } /* * We can't use the DEVICE_ATTR() macro here as we want the same filename for a * different type of a device. So beware if the DEVICE_ATTR() macro ever * changes, this definition will also have to change. */ static struct device_attribute dev_attr_client_name = { .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE }, .show = &show_client_name, }; /* --------------------------------------------------- * registering functions * --------------------------------------------------- */ /* ----- * i2c_add_adapter is called from within the algorithm layer, * when a new hw adapter registers. A new device is register to be * available for clients. */ int i2c_add_adapter(struct i2c_adapter *adap) { int id, res = 0; struct list_head *item; struct i2c_driver *driver; down(&core_lists); if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) { res = -ENOMEM; goto out_unlock; } res = idr_get_new(&i2c_adapter_idr, adap, &id); if (res < 0) { if (res == -EAGAIN) res = -ENOMEM; goto out_unlock; } adap->nr = id & MAX_ID_MASK; init_MUTEX(&adap->bus_lock); init_MUTEX(&adap->clist_lock); list_add_tail(&adap->list,&adapters); INIT_LIST_HEAD(&adap->clients); /* Add the adapter to the driver core. * If the parent pointer is not set up, * we add this adapter to the host bus. */ if (adap->dev.parent == NULL) adap->dev.parent = &platform_bus; sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); adap->dev.driver = &i2c_adapter_driver; adap->dev.release = &i2c_adapter_dev_release; device_register(&adap->dev); device_create_file(&adap->dev, &dev_attr_name); /* Add this adapter to the i2c_adapter class */ memset(&adap->class_dev, 0x00, sizeof(struct class_device)); adap->class_dev.dev = &adap->dev; adap->class_dev.class = &i2c_adapter_class; strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE); class_device_register(&adap->class_dev); dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); /* inform drivers of new adapters */ list_for_each(item,&drivers) { driver = list_entry(item, struct i2c_driver, list); if (driver->flags & I2C_DF_NOTIFY) /* We ignore the return code; if it fails, too bad */ driver->attach_adapter(adap); } out_unlock: up(&core_lists); return res; } 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; int res = 0; down(&core_lists); /* 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) { 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->name); goto out_unlock; } } /* detach any active clients. This must be done first, because * it can fail; in which case we give up. */ list_for_each_safe(item, _n, &adap->clients) { client = list_entry(item, struct i2c_client, list); /* detaching devices is unconditional of the set notify * flag, as _all_ clients that reside on the adapter * must be deleted, as this would cause invalid states. */ if ((res=client->driver->detach_client(client))) { dev_err(&adap->dev, "detach_client failed for client " "[%s] at address 0x%02x\n", client->name, client->addr); goto out_unlock; } } /* clean up the sysfs representation */ init_completion(&adap->dev_released); init_completion(&adap->class_dev_released); class_device_unregister(&adap->class_dev); device_remove_file(&adap->dev, &dev_attr_name); device_unregister(&adap->dev); list_del(&adap->list); /* wait for sysfs to drop all references */ wait_for_completion(&adap->dev_released); wait_for_completion(&adap->class_dev_released); /* free dynamically allocated bus id */ idr_remove(&i2c_adapter_idr, adap->nr); dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); out_unlock: up(&core_lists); return res; } /* ----- * What follows is the "upwards" interface: commands for talking to clients, * which implement the functions to access the physical information of the * chips. */ int i2c_add_driver(struct i2c_driver *driver) { struct list_head *item; struct i2c_adapter *adapter; int res = 0; down(&core_lists); /* add the driver to the list of i2c drivers in the driver core */ driver->driver.name = driver->name; driver->driver.bus = &i2c_bus_type; driver->driver.probe = i2c_device_probe; driver->driver.remove = i2c_device_remove; res = driver_register(&driver->driver); if (res) goto out_unlock; list_add_tail(&driver->list,&drivers); pr_debug("i2c-core: driver [%s] registered\n", driver->name); /* now look for instances of driver on our adapters */ if (driver->flags & I2C_DF_NOTIFY) { list_for_each(item,&adapters) { adapter = list_entry(item, struct i2c_adapter, list); driver->attach_adapter(adapter); } } out_unlock: up(&core_lists); return res; } int i2c_del_driver(struct i2c_driver *driver) { struct list_head *item1, *item2, *_n; struct i2c_client *client; struct i2c_adapter *adap; int res = 0; down(&core_lists); /* 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. * * Removing clients does not depend on the notify flag, else * invalid operation might (will!) result, when using stale client * pointers. */ list_for_each(item1,&adapters) { adap = list_entry(item1, struct i2c_adapter, list); if (driver->detach_adapter) { if ((res = driver->detach_adapter(adap))) { dev_err(&adap->dev, "detach_adapter failed " "for driver [%s]\n", driver->name); goto out_unlock; } } else { list_for_each_safe(item2, _n, &adap->clients) { client = list_entry(item2, struct i2c_client, list); if (client->driver != driver) continue; dev_dbg(&adap->dev, "detaching client [%s] " "at 0x%02x\n", client->name, client->addr); if ((res = driver->detach_client(client))) { dev_err(&adap->dev, "detach_client " "failed for client [%s] at " "0x%02x\n", client->name, client->addr); goto out_unlock; } } } } driver_unregister(&driver->driver); list_del(&driver->list); pr_debug("i2c-core: driver [%s] unregistered\n", driver->name); out_unlock: up(&core_lists); return 0; } static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr) { struct list_head *item; struct i2c_client *client; list_for_each(item,&adapter->clients) { client = list_entry(item, struct i2c_client, list); if (client->addr == addr) return -EBUSY; } return 0; } int i2c_check_addr(struct i2c_adapter *adapter, int addr) { int rval; down(&adapter->clist_lock); rval = __i2c_check_addr(adapter, addr); up(&adapter->clist_lock); return rval; } int i2c_attach_client(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; down(&adapter->clist_lock); if (__i2c_check_addr(client->adapter, client->addr)) { up(&adapter->clist_lock); return -EBUSY; } list_add_tail(&client->list,&adapter->clients); up(&adapter->clist_lock); if (adapter->client_register) { if (adapter->client_register(client)) { dev_dbg(&adapter->dev, "client_register " "failed for client [%s] at 0x%02x\n", client->name, client->addr); } } if (client->flags & I2C_CLIENT_ALLOW_USE) client->usage_count = 0; client->dev.parent = &client->adapter->dev; client->dev.driver = &client->driver->driver; client->dev.bus = &i2c_bus_type; client->dev.release = &i2c_client_release; snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), "%d-%04x", i2c_adapter_id(adapter), client->addr); dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", client->name, client->dev.bus_id); device_register(&client->dev); device_create_file(&client->dev, &dev_attr_client_name); return 0; } int i2c_detach_client(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; int res = 0; if ((client->flags & I2C_CLIENT_ALLOW_USE) && (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) { dev_err(&client->dev, "client_unregister [%s] failed, " "client not detached\n", client->name); goto out; } } down(&adapter->clist_lock); list_del(&client->list); init_completion(&client->released); device_remove_file(&client->dev, &dev_attr_client_name); device_unregister(&client->dev); up(&adapter->clist_lock); wait_for_completion(&client->released); out: return res; } static int i2c_inc_use_client(struct i2c_client *client) { if (!try_module_get(client->driver->owner)) return -ENODEV; if (!try_module_get(client->adapter->owner)) { module_put(client->driver->owner); return -ENODEV; } return 0; } static void i2c_dec_use_client(struct i2c_client *client) { module_put(client->driver->owner); module_put(client->adapter->owner); } int i2c_use_client(struct i2c_client *client) { int ret; ret = i2c_inc_use_client(client); if (ret) return ret; if (client->flags & I2C_CLIENT_ALLOW_USE) { if (client->flags & I2C_CLIENT_ALLOW_MULTIPLE_USE) client->usage_count++; else if (client->usage_count > 0) goto busy; else client->usage_count++; } return 0; busy: i2c_dec_use_client(client); return -EBUSY; } int i2c_release_client(struct i2c_client *client) { if(client->flags & I2C_CLIENT_ALLOW_USE) { if(client->usage_count>0) client->usage_count--; else { pr_debug("i2c-core: %s used one too many times\n", __FUNCTION__); return -EPERM; } } i2c_dec_use_client(client); return 0; } void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) { struct list_head *item; struct i2c_client *client; down(&adap->clist_lock); list_for_each(item,&adap->clients) { client = list_entry(item, struct i2c_client, list); if (!try_module_get(client->driver->owner)) continue; if (NULL != client->driver->command) { up(&adap->clist_lock); client->driver->command(client,cmd,arg); down(&adap->clist_lock); } module_put(client->driver->owner); } up(&adap->clist_lock); } static int __init i2c_init(void) { int retval; retval = bus_register(&i2c_bus_type); if (retval) return retval; retval = driver_register(&i2c_adapter_driver); if (retval) return retval; return class_register(&i2c_adapter_class); } static void __exit i2c_exit(void) { class_unregister(&i2c_adapter_class); driver_unregister(&i2c_adapter_driver); bus_unregister(&i2c_bus_type); } subsys_initcall(i2c_init); module_exit(i2c_exit); /* ---------------------------------------------------- * the functional interface to the i2c busses. * ---------------------------------------------------- */ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) { int ret; if (adap->algo->master_xfer) { #ifdef DEBUG for (ret = 0; ret < num; ret++) { dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ? 'R' : 'W', msgs[ret].addr, msgs[ret].len); } #endif down(&adap->bus_lock); ret = adap->algo->master_xfer(adap,msgs,num); up(&adap->bus_lock); return ret; } else { dev_dbg(&adap->dev, "I2C level transfers not supported\n"); return -ENOSYS; } } 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; } 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; } 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; } /* ---------------------------------------------------- * the i2c address scanning function * Will not work for 10-bit addresses! * ---------------------------------------------------- */ static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, int (*found_proc) (struct i2c_adapter *, int, int)) { int err; /* Make sure the address is valid */ if (addr < 0x03 || addr > 0x77) { dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", addr); return -EINVAL; } /* Skip if already in use */ if (i2c_check_addr(adapter, addr)) return 0; /* Make sure there is something at this address, unless forced */ if (kind < 0) { if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0) return 0; /* prevent 24RF08 corruption */ if ((addr & ~0x0f) == 0x50) i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL); } /* Finally call the custom detection function */ err = found_proc(adapter, addr, kind); /* -ENODEV can be returned if there is a chip at the given address but it isn't supported by this chip driver. We catch it here as this isn't an error. */ return (err == -ENODEV) ? 0 : err; } int i2c_probe(struct i2c_adapter *adapter, struct i2c_client_address_data *address_data, int (*found_proc) (struct i2c_adapter *, int, int)) { int i, err; int adap_id = i2c_adapter_id(adapter); /* Forget it if we can't probe using SMBUS_QUICK */ if (! i2c_check_functionality(adapter,I2C_FUNC_SMBUS_QUICK)) return -1; /* Force entries are done first, and are not affected by ignore entries */ if (address_data->forces) { unsigned short **forces = address_data->forces; int kind; for (kind = 0; forces[kind]; kind++) { for (i = 0; forces[kind][i] != I2C_CLIENT_END; i += 2) { if (forces[kind][i] == adap_id || forces[kind][i] == ANY_I2C_BUS) { dev_dbg(&adapter->dev, "found force " "parameter for adapter %d, " "addr 0x%02x, kind %d\n", adap_id, forces[kind][i + 1], kind); err = i2c_probe_address(adapter, forces[kind][i + 1], kind, found_proc); if (err) return err; } } } } /* Probe entries are done second, and are not affected by ignore entries either */ for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { if (address_data->probe[i] == adap_id || address_data->probe[i] == ANY_I2C_BUS) { dev_dbg(&adapter->dev, "found probe parameter for " "adapter %d, addr 0x%02x\n", adap_id, address_data->probe[i + 1]); err = i2c_probe_address(adapter, address_data->probe[i + 1], -1, found_proc); if (err) return err; } } /* Normal entries are done last, unless shadowed by an ignore entry */ for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { int j, ignore; ignore = 0; for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; j += 2) { if ((address_data->ignore[j] == adap_id || address_data->ignore[j] == ANY_I2C_BUS) && address_data->ignore[j + 1] == address_data->normal_i2c[i]) { dev_dbg(&adapter->dev, "found ignore " "parameter for adapter %d, " "addr 0x%02x\n", adap_id, address_data->ignore[j + 1]); } ignore = 1; break; } if (ignore) continue; dev_dbg(&adapter->dev, "found normal entry for adapter %d, " "addr 0x%02x\n", adap_id, address_data->normal_i2c[i]); err = i2c_probe_address(adapter, address_data->normal_i2c[i], -1, found_proc); if (err) return err; } return 0; } struct i2c_adapter* i2c_get_adapter(int id) { struct i2c_adapter *adapter; down(&core_lists); adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); if (adapter && !try_module_get(adapter->owner)) adapter = NULL; up(&core_lists); return adapter; } void i2c_put_adapter(struct i2c_adapter *adap) { module_put(adap->owner); } /* 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); } /* CRC over count bytes in the first array plus the bytes in the rest array if it is non-null. rest[0] is the (length of rest) - 1 and is included. */ static u8 i2c_smbus_partial_pec(u8 crc, int count, u8 *first, u8 *rest) { int i; for(i = 0; i < count; i++) crc = crc8((crc ^ first[i]) << 8); if(rest != NULL) for(i = 0; i <= rest[0]; i++) crc = crc8((crc ^ rest[i]) << 8); return crc; } static u8 i2c_smbus_pec(int count, u8 *first, u8 *rest) { return i2c_smbus_partial_pec(0, count, first, rest); } /* Returns new "size" (transaction type) Note that we convert byte to byte_data and byte_data to word_data rather than invent new xxx_PEC transactions. */ static int i2c_smbus_add_pec(u16 addr, u8 command, int size, union i2c_smbus_data *data) { u8 buf[3]; buf[0] = addr << 1; buf[1] = command; switch(size) { case I2C_SMBUS_BYTE: data->byte = i2c_smbus_pec(2, buf, NULL); size = I2C_SMBUS_BYTE_DATA; break; case I2C_SMBUS_BYTE_DATA: buf[2] = data->byte; data->word = buf[2] || (i2c_smbus_pec(3, buf, NULL) << 8); size = I2C_SMBUS_WORD_DATA; break; case I2C_SMBUS_WORD_DATA: /* unsupported */ break; case I2C_SMBUS_BLOCK_DATA: data->block[data->block[0] + 1] = i2c_smbus_pec(2, buf, data->block); size = I2C_SMBUS_BLOCK_DATA_PEC; break; } return size; } static int i2c_smbus_check_pec(u16 addr, u8 command, int size, u8 partial, union i2c_smbus_data *data) { u8 buf[3], rpec, cpec; buf[1] = command; switch(size) { case I2C_SMBUS_BYTE_DATA: buf[0] = (addr << 1) | 1; cpec = i2c_smbus_pec(2, buf, NULL); rpec = data->byte; break; case I2C_SMBUS_WORD_DATA: buf[0] = (addr << 1) | 1; buf[2] = data->word & 0xff; cpec = i2c_smbus_pec(3, buf, NULL); rpec = data->word >> 8; break; case I2C_SMBUS_WORD_DATA_PEC: /* unsupported */ cpec = rpec = 0; break; case I2C_SMBUS_PROC_CALL_PEC: /* unsupported */ cpec = rpec = 0; break; case I2C_SMBUS_BLOCK_DATA_PEC: buf[0] = (addr << 1); buf[2] = (addr << 1) | 1; cpec = i2c_smbus_pec(3, buf, data->block); rpec = data->block[data->block[0] + 1]; break; case I2C_SMBUS_BLOCK_PROC_CALL_PEC: buf[0] = (addr << 1) | 1; rpec = i2c_smbus_partial_pec(partial, 1, buf, data->block); cpec = data->block[data->block[0] + 1]; break; default: cpec = rpec = 0; break; } if (rpec != cpec) { pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec); return -1; } 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); } s32 i2c_smbus_read_byte(struct i2c_client *client) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data)) return -1; else return 0x0FF & data.byte; } s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) { union i2c_smbus_data data; /* only for PEC */ return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,value, I2C_SMBUS_BYTE,&data); } s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data)) return -1; else return 0x0FF & data.byte; } 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); } s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) { union i2c_smbus_data data; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data)) return -1; else return 0x0FFFF & data.word; } 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); } s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; int i; if (length > I2C_SMBUS_BLOCK_MAX) length = I2C_SMBUS_BLOCK_MAX; for (i = 1; i <= length; i++) data.block[i] = values[i-1]; data.block[0] = length; return i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_WRITE,command, I2C_SMBUS_BLOCK_DATA,&data); } /* Returns the number of read bytes */ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, u8 *values) { union i2c_smbus_data data; int i; if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, I2C_SMBUS_READ,command, I2C_SMBUS_I2C_BLOCK_DATA,&data)) return -1; else { for (i = 1; i <= data.block[0]; i++) values[i-1] = data.block[i]; return data.block[0]; } } /* 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[34]; unsigned char msgbuf1[34]; 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; 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) & 0xff; } 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) & 0xff; break; case I2C_SMBUS_BLOCK_DATA: case I2C_SMBUS_BLOCK_DATA_PEC: if (read_write == I2C_SMBUS_READ) { dev_err(&adapter->dev, "Block read not supported " "under I2C emulation!\n"); return -1; } 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; } if(size == I2C_SMBUS_BLOCK_DATA_PEC) (msg[0].len)++; for (i = 1; i <= msg[0].len; i++) msgbuf0[i] = data->block[i-1]; } break; case I2C_SMBUS_BLOCK_PROC_CALL: case I2C_SMBUS_BLOCK_PROC_CALL_PEC: dev_dbg(&adapter->dev, "Block process call not supported " "under I2C emulation!\n"); return -1; case I2C_SMBUS_I2C_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { msg[1].len = I2C_SMBUS_I2C_BLOCK_MAX; } else { msg[0].len = data->block[0] + 1; if (msg[0].len > I2C_SMBUS_I2C_BLOCK_MAX + 1) { dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with " "invalid block write size (%d)\n", data->block[0]); return -1; } 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; } if (i2c_transfer(adapter, msg, num) < 0) return -1; 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: /* fixed at 32 for now */ data->block[0] = I2C_SMBUS_I2C_BLOCK_MAX; for (i = 0; i < I2C_SMBUS_I2C_BLOCK_MAX; i++) data->block[i+1] = msgbuf1[i]; break; } return 0; } s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, char read_write, u8 command, int size, union i2c_smbus_data * data) { s32 res; int swpec = 0; u8 partial = 0; flags &= I2C_M_TEN | I2C_CLIENT_PEC; if((flags & I2C_CLIENT_PEC) && !(i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HWPEC_CALC))) { swpec = 1; if(read_write == I2C_SMBUS_READ && size == I2C_SMBUS_BLOCK_DATA) size = I2C_SMBUS_BLOCK_DATA_PEC; else if(size == I2C_SMBUS_PROC_CALL) size = I2C_SMBUS_PROC_CALL_PEC; else if(size == I2C_SMBUS_BLOCK_PROC_CALL) { i2c_smbus_add_pec(addr, command, I2C_SMBUS_BLOCK_DATA, data); partial = data->block[data->block[0] + 1]; size = I2C_SMBUS_BLOCK_PROC_CALL_PEC; } else if(read_write == I2C_SMBUS_WRITE && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA) size = i2c_smbus_add_pec(addr, command, size, data); } if (adapter->algo->smbus_xfer) { down(&adapter->bus_lock); res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, command,size,data); up(&adapter->bus_lock); } else res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, command,size,data); if(res >= 0 && swpec && size != I2C_SMBUS_QUICK && size != I2C_SMBUS_I2C_BLOCK_DATA && (read_write == I2C_SMBUS_READ || size == I2C_SMBUS_PROC_CALL_PEC || size == I2C_SMBUS_BLOCK_PROC_CALL_PEC)) { if(i2c_smbus_check_pec(addr, command, size, partial, data)) return -1; } return res; } /* Next four are needed by i2c-isa */ EXPORT_SYMBOL_GPL(i2c_adapter_dev_release); EXPORT_SYMBOL_GPL(i2c_adapter_driver); EXPORT_SYMBOL_GPL(i2c_adapter_class); EXPORT_SYMBOL_GPL(i2c_bus_type); EXPORT_SYMBOL(i2c_add_adapter); EXPORT_SYMBOL(i2c_del_adapter); EXPORT_SYMBOL(i2c_add_driver); EXPORT_SYMBOL(i2c_del_driver); EXPORT_SYMBOL(i2c_attach_client); EXPORT_SYMBOL(i2c_detach_client); EXPORT_SYMBOL(i2c_use_client); EXPORT_SYMBOL(i2c_release_client); EXPORT_SYMBOL(i2c_clients_command); EXPORT_SYMBOL(i2c_check_addr); EXPORT_SYMBOL(i2c_master_send); EXPORT_SYMBOL(i2c_master_recv); EXPORT_SYMBOL(i2c_control); EXPORT_SYMBOL(i2c_transfer); EXPORT_SYMBOL(i2c_get_adapter); EXPORT_SYMBOL(i2c_put_adapter); EXPORT_SYMBOL(i2c_probe); EXPORT_SYMBOL(i2c_smbus_xfer); EXPORT_SYMBOL(i2c_smbus_write_quick); EXPORT_SYMBOL(i2c_smbus_read_byte); EXPORT_SYMBOL(i2c_smbus_write_byte); EXPORT_SYMBOL(i2c_smbus_read_byte_data); EXPORT_SYMBOL(i2c_smbus_write_byte_data); EXPORT_SYMBOL(i2c_smbus_read_word_data); EXPORT_SYMBOL(i2c_smbus_write_word_data); EXPORT_SYMBOL(i2c_smbus_write_block_data); EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); MODULE_AUTHOR("Simon G. Vogl "); MODULE_DESCRIPTION("I2C-Bus main module"); MODULE_LICENSE("GPL");