hwmon: (pmbus/bpa-rs600) Add workaround for incorrect Pin max

BPD-RS600 modules running firmware v5.70 misreport the MFR_PIN_MAX.
The indicate a maximum of 1640W instead of 700W. Detect the invalid
reading and return a sensible value instead.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20210812014000.26293-3-chris.packham@alliedtelesis.co.nz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Chris Packham 2021-08-12 13:40:00 +12:00 committed by Guenter Roeck
parent 7a8c68c57f
commit 1125bacbf3

View File

@ -65,6 +65,26 @@ static int bpa_rs600_read_vin(struct i2c_client *client)
return ret;
}
/*
* Firmware V5.70 incorrectly reports 1640W for MFR_PIN_MAX.
* Deal with this by returning a sensible value.
*/
static int bpa_rs600_read_pin_max(struct i2c_client *client)
{
int ret;
ret = pmbus_read_word_data(client, 0, 0xff, PMBUS_MFR_PIN_MAX);
if (ret < 0)
return ret;
/* Detect invalid 1640W (linear encoding) */
if (ret == 0x0b34)
/* Report 700W (linear encoding) */
return 0x095e;
return ret;
}
static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int phase, int reg)
{
int ret;
@ -91,6 +111,9 @@ static int bpa_rs600_read_word_data(struct i2c_client *client, int page, int pha
case PMBUS_READ_VIN:
ret = bpa_rs600_read_vin(client);
break;
case PMBUS_MFR_PIN_MAX:
ret = bpa_rs600_read_pin_max(client);
break;
default:
if (reg >= PMBUS_VIRT_BASE)
ret = -ENXIO;