From: Brandon Wyman bjwyman@gmail.com
[ Upstream commit f067d5585cda2de1e47dde914a8a4f151659e0ad ]
The bytes for max_power_out from the ibm-cffps devices differ in byte order for some power supplies.
The Witherspoon power supply returns the bytes in MSB/LSB order.
The Rainier power supply returns the bytes in LSB/MSB order.
The Witherspoon power supply uses version cffps1. The Rainier power supply should use version cffps2. If version is cffps1, swap the bytes before output to max_power_out.
Tested: Witherspoon before: 3148. Witherspoon after: 3148. Rainier before: 53255. Rainier after: 2000.
Signed-off-by: Brandon Wyman bjwyman@gmail.com Reviewed-by: Eddie James eajames@linux.ibm.com Link: https://lore.kernel.org/r/20210928205051.1222815-1-bjwyman@gmail.com [groeck: Replaced yoda programming] Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/pmbus/ibm-cffps.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c index 79bc2032dcb2..da261d32450d 100644 --- a/drivers/hwmon/pmbus/ibm-cffps.c +++ b/drivers/hwmon/pmbus/ibm-cffps.c @@ -171,8 +171,14 @@ static ssize_t ibm_cffps_debugfs_read(struct file *file, char __user *buf, cmd = CFFPS_SN_CMD; break; case CFFPS_DEBUGFS_MAX_POWER_OUT: - rc = i2c_smbus_read_word_swapped(psu->client, - CFFPS_MAX_POWER_OUT_CMD); + if (psu->version == cffps1) { + rc = i2c_smbus_read_word_swapped(psu->client, + CFFPS_MAX_POWER_OUT_CMD); + } else { + rc = i2c_smbus_read_word_data(psu->client, + CFFPS_MAX_POWER_OUT_CMD); + } + if (rc < 0) return rc;