diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index d87f77f790d6..2d3db81be099 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -56,6 +56,7 @@ struct at24_data { struct at24_platform_data chip; struct memory_accessor macc; int use_smbus; + int use_smbus_write; /* * Lock protects against activities from other Linux tasks, @@ -324,7 +325,7 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf, { struct i2c_client *client; struct i2c_msg msg; - ssize_t status; + ssize_t status = 0; unsigned long timeout, write_time; unsigned next_page; @@ -365,9 +366,18 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf, timeout = jiffies + msecs_to_jiffies(write_timeout); do { write_time = jiffies; - if (at24->use_smbus) { - status = i2c_smbus_write_i2c_block_data(client, - offset, count, buf); + if (at24->use_smbus_write) { + switch (at24->use_smbus_write) { + case I2C_SMBUS_I2C_BLOCK_DATA: + status = i2c_smbus_write_i2c_block_data(client, + offset, count, buf); + break; + case I2C_SMBUS_BYTE_DATA: + status = i2c_smbus_write_byte_data(client, + offset, buf[0]); + break; + } + if (status == 0) status = count; } else { @@ -487,6 +497,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) struct at24_platform_data chip; bool writable; int use_smbus = 0; + int use_smbus_write = 0; struct at24_data *at24; int err; unsigned i, num_addresses; @@ -546,6 +557,18 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) } } + /* Use I2C operations unless we're stuck with SMBus extensions. */ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { + use_smbus_write = I2C_SMBUS_I2C_BLOCK_DATA; + } else if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { + use_smbus_write = I2C_SMBUS_BYTE_DATA; + chip.page_size = 1; + } + } + if (chip.flags & AT24_FLAG_TAKE8ADDR) num_addresses = 8; else @@ -559,6 +582,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) mutex_init(&at24->lock); at24->use_smbus = use_smbus; + at24->use_smbus_write = use_smbus_write; at24->chip = chip; at24->num_addresses = num_addresses; @@ -576,8 +600,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) writable = !(chip.flags & AT24_FLAG_READONLY); if (writable) { - if (!use_smbus || i2c_check_functionality(client->adapter, - I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { + if (!use_smbus || use_smbus_write) { unsigned write_max = chip.page_size; |