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@xxxxxxxxx>
---
drivers/hwmon/pmbus/fsp-3y.c | 32 +++++++++++++++++++++++++-------
1 file changed, 25 insertions(+), 7 deletions(-)
diff --git a/drivers/hwmon/pmbus/fsp-3y.c b/drivers/hwmon/pmbus/fsp-3y.c
index 46252b17c008..073d960a0af5 100644
--- a/drivers/hwmon/pmbus/fsp-3y.c
+++ b/drivers/hwmon/pmbus/fsp-3y.c
@@ -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);
}
--
2.31.1
