ping 2014-10-28 17:51 GMT+01:00 Christian Gmeiner <christian.gmeiner@xxxxxxxxx>: > ping > -- > Christian Gmeiner, MSc > > https://soundcloud.com/christian-gmeiner > > > 2014-10-09 11:07 GMT+02:00 Christian Gmeiner <christian.gmeiner@xxxxxxxxx>: >> I have a at24 EEPROM connected via i2c bus provided by ISCH i2c >> bus driver. This bus driver does not support >> I2C_FUNC_SMBUS_WRITE_I2C_BLOCK and so I was looking for a way >> to be able to write the eeprom. This patch adds support for >> I2C_SMBUS_BYTE_DATA writing via i2c_smbus_write_byte_data. >> It is quite slow, but it works. >> >> Signed-off-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx> >> --- >> drivers/misc/eeprom/at24.c | 35 +++++++++++++++++++++++++++++------ >> 1 file changed, 29 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c >> index d87f77f..f51daac 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_smbuse_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_smbuse_write) { >> + switch (at24->use_smbuse_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_smbuse_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; >> >> -- >> 1.9.3 >> -- Christian Gmeiner, MSc https://soundcloud.com/christian-gmeiner -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
