hwmon: (pmbus/fsp-3y) Fix FSP-3Y YH-5151E VOUT

After testing new YH-5151E devices, we found out that not all YH-5151E
work the same. The newly tested devices actually report vout correctly
in linear16 (even though they're still YH-5151E). We suspect that it is
because these new devices have a different firmware version, but that is
unconfirmed. The version cannot be queried through PMBus.

The compliant versions of YH-5151E report VOUT_MODE normally, so we turn
on the linear11 workaround only if VOUT_MODE doesn't report anything.

Signed-off-by: Václav Kubernát <kubernat@cesnet.cz>
Link: https://lore.kernel.org/r/20210513201110.313523-1-kubernat@cesnet.cz
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Václav Kubernát 2021-05-13 22:11:10 +02:00 committed by Guenter Roeck
parent 35d470b5fb
commit c2a338c939

View File

@ -37,6 +37,8 @@ struct fsp3y_data {
struct pmbus_driver_info info;
int chip;
int page;
bool vout_linear_11;
};
#define to_fsp3y_data(x) container_of(x, struct fsp3y_data, info)
@ -108,11 +110,9 @@ static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
int rv;
/*
* YH5151-E outputs vout in linear11. The conversion is done when
* reading. Here, we have to inject pmbus_core with the correct
* exponent (it is -6).
* Inject an exponent for non-compliant YH5151-E.
*/
if (data->chip == yh5151e && reg == PMBUS_VOUT_MODE)
if (data->vout_linear_11 && reg == PMBUS_VOUT_MODE)
return 0x1A;
rv = set_page(client, page);
@ -161,10 +161,9 @@ static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase,
return rv;
/*
* YH-5151E is non-compliant and outputs output voltages in linear11
* instead of linear16.
* Handle YH-5151E non-compliant linear11 vout voltage.
*/
if (data->chip == yh5151e && reg == PMBUS_READ_VOUT)
if (data->vout_linear_11 && reg == PMBUS_READ_VOUT)
rv = sign_extend32(rv, 10) & 0xffff;
return rv;
@ -256,6 +255,25 @@ static int fsp3y_probe(struct i2c_client *client)
data->info = fsp3y_info[data->chip];
/*
* YH-5151E sometimes reports vout in linear11 and sometimes in
* linear16. This depends on the exact individual piece of hardware. One
* YH-5151E can use linear16 and another might use linear11 instead.
*
* The format can be recognized by reading VOUT_MODE - if it doesn't
* report a valid exponent, then vout uses linear11. Otherwise, the
* device is compliant and uses linear16.
*/
data->vout_linear_11 = false;
if (data->chip == yh5151e) {
rv = i2c_smbus_read_byte_data(client, PMBUS_VOUT_MODE);
if (rv < 0)
return rv;
if (rv == 0xFF)
data->vout_linear_11 = true;
}
return pmbus_do_probe(client, &data->info);
}