From: Brandon Wyman <bjwyman@xxxxxxxxx>
[ 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@xxxxxxxxx>
Reviewed-by: Eddie James <eajames@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210928205051.1222815-1-bjwyman@xxxxxxxxx
[groeck: Replaced yoda programming]
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 df712ce4b164..53f7d1418bc9 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;
--
2.33.0
