diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 579 |
1 files changed, 452 insertions, 127 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index d0175f4f8fc6..7608df83d6d1 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -29,13 +29,11 @@ #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 <linux/semaphore.h> #include <asm/uaccess.h> #include "i2c-core.h" @@ -44,7 +42,9 @@ 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); /* ------------------------------------------------------------------------- */ @@ -103,19 +103,14 @@ 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); - const struct i2c_device_id *id; int status; - if (!driver->probe) + if (!driver->probe || !driver->id_table) return -ENODEV; client->driver = driver; dev_dbg(dev, "probe\n"); - if (driver->id_table) - id = i2c_match_id(driver->id_table, client); - else - id = NULL; - status = driver->probe(client, id); + status = driver->probe(client, i2c_match_id(driver->id_table, client)); if (status) client->driver = NULL; return status; @@ -208,7 +203,7 @@ static struct device_attribute i2c_dev_attrs[] = { { }, }; -static struct bus_type i2c_bus_type = { +struct bus_type i2c_bus_type = { .name = "i2c", .dev_attrs = i2c_dev_attrs, .match = i2c_device_match, @@ -219,6 +214,7 @@ static struct bus_type i2c_bus_type = { .suspend = i2c_device_suspend, .resume = i2c_device_resume, }; +EXPORT_SYMBOL_GPL(i2c_bus_type); /** @@ -306,6 +302,14 @@ void i2c_unregister_device(struct i2c_client *client) 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); @@ -416,6 +420,10 @@ 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); @@ -455,7 +463,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); - /* let legacy drivers scan this bus for matching devices */ + /* Notify drivers */ dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, i2c_do_add_adapter); @@ -561,8 +569,19 @@ 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 */ + 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); @@ -582,8 +601,7 @@ static int i2c_do_del_adapter(struct device_driver *d, void *data) */ int i2c_del_adapter(struct i2c_adapter *adap) { - struct list_head *item, *_n; - struct i2c_client *client; + struct i2c_client *client, *_n; int res = 0; mutex_lock(&core_lock); @@ -604,10 +622,9 @@ int i2c_del_adapter(struct i2c_adapter *adap) /* 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(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 */ @@ -637,6 +654,10 @@ int i2c_del_adapter(struct i2c_adapter *adap) 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; @@ -646,6 +667,20 @@ 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 @@ -685,72 +720,70 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) 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; - - down(&i2c_adapter_class.sem); - list_for_each_entry(adapter, &i2c_adapter_class.devices, - dev.node) { - driver->attach_adapter(adapter); - } - up(&i2c_adapter_class.sem); - } + INIT_LIST_HEAD(&driver->clients); + /* Walk the adapters that are already present */ + class_for_each_device(&i2c_adapter_class, driver, __attach_adapter); 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 *item2, *_n; - struct i2c_client *client; - struct i2c_adapter *adap; + struct i2c_adapter *adapter = to_i2c_adapter(dev); + struct i2c_driver *driver = data; + struct i2c_client *client, *_n; - mutex_lock(&core_lock); + 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. */ - down(&i2c_adapter_class.sem); - list_for_each_entry(adap, &i2c_adapter_class.devices, dev.node) { - 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); } } - up(&i2c_adapter_class.sem); - 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, driver, __detach_adapter); + driver_unregister(&driver->driver); pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); @@ -863,8 +896,9 @@ EXPORT_SYMBOL(i2c_detach_client); */ struct i2c_client *i2c_use_client(struct i2c_client *client) { - get_device(&client->dev); - return client; + if (client && get_device(&client->dev)) + return client; + return NULL; } EXPORT_SYMBOL(i2c_use_client); @@ -876,7 +910,8 @@ EXPORT_SYMBOL(i2c_use_client); */ void i2c_release_client(struct i2c_client *client) { - put_device(&client->dev); + if (client) + put_device(&client->dev); } EXPORT_SYMBOL(i2c_release_client); @@ -942,10 +977,39 @@ module_exit(i2c_exit); * ---------------------------------------------------- */ +/** + * 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; + /* 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++) { @@ -971,11 +1035,19 @@ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) 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; @@ -995,6 +1067,14 @@ int i2c_master_send(struct i2c_client *client,const char *buf ,int count) } 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; @@ -1103,7 +1183,7 @@ int i2c_probe(struct i2c_adapter *adapter, dev_warn(&adapter->dev, "SMBus Quick command not supported, " "can't probe for chips\n"); - return -1; + return -EOPNOTSUPP; } /* Probe entries are done second, and are not affected by ignore @@ -1157,6 +1237,179 @@ int i2c_probe(struct i2c_adapter *adapter, } 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 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; + } + + /* Stop here if the classes do not match */ + if (!(adapter->class & driver->class)) + 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, @@ -1295,29 +1548,38 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) 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, @@ -1325,17 +1587,35 @@ s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) } 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; @@ -1346,17 +1626,35 @@ s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) } 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; @@ -1368,15 +1666,14 @@ s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) EXPORT_SYMBOL(i2c_smbus_write_word_data); /** - * i2c_smbus_read_block_data - SMBus block read request + * i2c_smbus_read_block_data - SMBus "block read" protocol * @client: Handle to slave device - * @command: Command byte issued to let the slave know what data should - * be returned + * @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. * - * Returns the number of bytes read in the slave's response, else a - * negative number to indicate some kind of error. + * 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 @@ -1387,17 +1684,29 @@ 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) { @@ -1418,14 +1727,16 @@ 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; - if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,command, - I2C_SMBUS_I2C_BLOCK_DATA,&data)) - return -1; + 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]; @@ -1466,6 +1777,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, }; int i; u8 partial_pec = 0; + int status; msgbuf0[0] = command; switch(size) { @@ -1515,10 +1827,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } 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]; @@ -1528,10 +1840,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, 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", __func__, + 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++) @@ -1546,19 +1858,18 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } 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 @@ -1576,13 +1887,15 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, 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) @@ -1610,9 +1923,21 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, 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 size, + char read_write, u8 command, int protocol, union i2c_smbus_data * data) { s32 res; @@ -1622,11 +1947,11 @@ s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, if (adapter->algo->smbus_xfer) { mutex_lock(&adapter->bus_lock); res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, - command,size,data); + command, protocol, data); mutex_unlock(&adapter->bus_lock); } else res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, - command,size,data); + command, protocol, data); return res; } |