From c60fe56c169eb552113a4711db3a5f99e3acd4c1 Mon Sep 17 00:00:00 2001 From: Konstantin Aladyshev Date: Fri, 26 Jan 2024 23:57:14 +0300 Subject: [PATCH] hwmon: (pmbus/mp2975) Fix driver initialization for MP2975 device The commit 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") has introduced a bug that makes it impossible to initialize MP2975 device: """ mp2975 5-0020: Failed to identify chip capabilities i2c i2c-5: new_device: Instantiated device mp2975 at 0x20 i2c i2c-5: delete_device: Deleting device mp2975 at 0x20 """ Since the 'read_byte_data' function was removed from the 'pmbus_driver_info ' structure the driver no longer reports correctly that VOUT mode is direct. Therefore 'pmbus_identify_common' fails with error, making it impossible to initialize the device. Restore 'read_byte_data' function to fix the issue. Tested: - before: it is not possible to initialize MP2975 device with the 'mp2975' driver, - after: 'mp2975' correctly initializes MP2975 device and all sensor data is correct. Fixes: 1feb31e810b0 ("hwmon: (pmbus/mp2975) Simplify VOUT code") Signed-off-by: Konstantin Aladyshev Link: https://lore.kernel.org/r/20240126205714.2363-1-aladyshev22@gmail.com Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/mp2975.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/hwmon/pmbus/mp2975.c b/drivers/hwmon/pmbus/mp2975.c index b9bb469e2d8fe..5bbfdacb61a76 100644 --- a/drivers/hwmon/pmbus/mp2975.c +++ b/drivers/hwmon/pmbus/mp2975.c @@ -126,6 +126,22 @@ static const struct regulator_desc __maybe_unused mp2975_reg_desc[] = { #define to_mp2975_data(x) container_of(x, struct mp2975_data, info) +static int mp2975_read_byte_data(struct i2c_client *client, int page, int reg) +{ + switch (reg) { + case PMBUS_VOUT_MODE: + /* + * Enforce VOUT direct format, since device allows to set the + * different formats for the different rails. Conversion from + * VID to direct provided by driver internally, in case it is + * necessary. + */ + return PB_VOUT_MODE_DIRECT; + default: + return -ENODATA; + } +} + static int mp2975_read_word_helper(struct i2c_client *client, int page, int phase, u8 reg, u16 mask) @@ -869,6 +885,7 @@ static struct pmbus_driver_info mp2975_info = { PMBUS_HAVE_IIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_POUT | PMBUS_HAVE_PIN | PMBUS_HAVE_STATUS_INPUT | PMBUS_PHASE_VIRTUAL, + .read_byte_data = mp2975_read_byte_data, .read_word_data = mp2975_read_word_data, #if IS_ENABLED(CONFIG_SENSORS_MP2975_REGULATOR) .num_regulators = 1, -- 2.30.2