Commit d4ef9306 authored by Guenter Roeck's avatar Guenter Roeck Committed by Mark Brown

regmap-i2c: Use i2c block command only if register value width is 8 bit

Chips with 16-bit registers don't usually work well with I2C block
commands. For example, neither the LM75 datasheet nor the TMP102 datasheet
mentions block command support, and in fact it does not work for any of
those chips. Also, it is not clear how the block command would handle
16-bit SMBus operations in the fist place, since the data format associated
with those commands is either little endian or big endian, which requires
some kind of conversion to or from host byte order.

Only use i2c block commands if both register and value width is 8 bit.
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 1a695a90
......@@ -259,7 +259,7 @@ static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
{
if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C))
return &regmap_i2c;
else if (config->reg_bits == 8 &&
else if (config->val_bits == 8 && config->reg_bits == 8 &&
i2c_check_functionality(i2c->adapter,
I2C_FUNC_SMBUS_I2C_BLOCK))
return &regmap_i2c_smbus_i2c_block;
......
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