regmap write operations on i801 controllers were observed to fail with -ENXIO errors. It appears that the i801 controller and/or at least some spd5118 compatible chips do not support the I2C_FUNC_SMBUS_I2C_BLOCK operation used by the regmap-i2c core if I2C_FUNC_SMBUS_I2C_BLOCK is supported by the I2C/SMBus controller. Stop using the regmap-i2c core and always use basic SMBus operations instead. Reported-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx> Closes: https://lore.kernel.org/linux-hwmon/33f369c1-1098-458e-9398-30037bd8c5aa@xxxxxxxxxxxxx/ Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> --- v2: Added patch drivers/hwmon/Kconfig | 2 +- drivers/hwmon/spd5118.c | 28 +++++++++++++++++++++++++++- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index d5eced417fc3..fdfa778a965d 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -2184,7 +2184,7 @@ config SENSORS_INA3221 config SENSORS_SPD5118 tristate "SPD5118 Compliant Temperature Sensors" depends on I2C - select REGMAP_I2C + select REGMAP help If you say yes here you get support for SPD5118 (JEDEC JESD300) compliant temperature sensors. Such sensors are found on DDR5 memory diff --git a/drivers/hwmon/spd5118.c b/drivers/hwmon/spd5118.c index d405c5ef755d..995c45e2a997 100644 --- a/drivers/hwmon/spd5118.c +++ b/drivers/hwmon/spd5118.c @@ -489,6 +489,31 @@ static bool spd5118_volatile_reg(struct device *dev, unsigned int reg) } } +static int spd5118_regmap_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + int ret; + + ret = i2c_smbus_read_byte_data(context, reg); + if (ret < 0) + return ret; + + *val = ret; + + return 0; +} + +static int spd5118_regmap_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + return i2c_smbus_write_byte_data(context, reg, val); +} + +static const struct regmap_bus spd5118_regmap_bus = { + .reg_write = spd5118_regmap_reg_write, + .reg_read = spd5118_regmap_reg_read, +}; + static const struct regmap_range_cfg spd5118_regmap_range_cfg[] = { { .selector_reg = SPD5118_REG_I2C_LEGACY_MODE, @@ -526,7 +551,8 @@ static int spd5118_probe(struct i2c_client *client) if (!data) return -ENOMEM; - regmap = devm_regmap_init_i2c(client, &spd5118_regmap_config); + regmap = devm_regmap_init(dev, &spd5118_regmap_bus, client, + &spd5118_regmap_config); if (IS_ERR(regmap)) return dev_err_probe(dev, PTR_ERR(regmap), "regmap init failed\n"); -- 2.39.2
