2021-04-29 08:01:14

by Václav Kubernát

[permalink] [raw]
Subject: [PATCH v3] Fix FSP-3Y YH-5151E non-compliant vout encoding

I didn't properly test the driver for YH-5151E, so it was completely
broken. Firstly, the log/real mapping was incorrect in one case.
Secondly, PMBus specifies that output voltages should be in the linear16
encoding. However, the YH-5151E is non-compliant and uses linear11.
YM-2151E isn't affected by this. Fix this by converting the values
inside the read functions. linear16 gets the exponent from the VOUT_MODE
command. The device doesn't support it, so I have to manually supply the
value for it.

Both supported devices have now been tested to report correct vout
values.

Fixes: 1734b4135a62 ("hwmon: Add driver for fsp-3y PSUs and PDUs")
Signed-off-by: Václav Kubernát <[email protected]>
---
drivers/hwmon/pmbus/fsp-3y.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/pmbus/fsp-3y.c b/drivers/hwmon/pmbus/fsp-3y.c
index 564649e87e34..655690dde4d7 100644
--- a/drivers/hwmon/pmbus/fsp-3y.c
+++ b/drivers/hwmon/pmbus/fsp-3y.c
@@ -57,7 +57,7 @@ static int page_log_to_page_real(int page_log, enum chips chip)
case YH5151E_PAGE_12V_LOG:
return YH5151E_PAGE_12V_REAL;
case YH5151E_PAGE_5V_LOG:
- return YH5151E_PAGE_5V_LOG;
+ return YH5151E_PAGE_5V_REAL;
case YH5151E_PAGE_3V3_LOG:
return YH5151E_PAGE_3V3_REAL;
}
@@ -103,8 +103,18 @@ static int set_page(struct i2c_client *client, int page_log)

static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct fsp3y_data *data = to_fsp3y_data(info);
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).
+ */
+ if (data->chip == yh5151e && reg == PMBUS_VOUT_MODE)
+ return 0x1A;
+
rv = set_page(client, page);
if (rv < 0)
return rv;
@@ -114,6 +124,8 @@ static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)

static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase, int reg)
{
+ const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
+ struct fsp3y_data *data = to_fsp3y_data(info);
int rv;

/*
@@ -144,7 +156,18 @@ static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase,
if (rv < 0)
return rv;

- return i2c_smbus_read_word_data(client, reg);
+ rv = i2c_smbus_read_word_data(client, reg);
+ if (rv < 0)
+ return rv;
+
+ /*
+ * YH-5151E is non-compliant and outputs output voltages in linear11
+ * instead of linear16.
+ */
+ if (data->chip == yh5151e && reg == PMBUS_READ_VOUT)
+ rv = sign_extend32(rv, 10) & 0xffff;
+
+ return rv;
}

struct pmbus_driver_info fsp3y_info[] = {
--
2.31.1


2021-04-30 01:30:13

by Guenter Roeck

[permalink] [raw]
Subject: Re: [PATCH v3] Fix FSP-3Y YH-5151E non-compliant vout encoding

On Thu, Apr 29, 2021 at 09:53:38AM +0200, V?clav Kubern?t wrote:
> I didn't properly test the driver for YH-5151E, so it was completely
> broken. Firstly, the log/real mapping was incorrect in one case.
> Secondly, PMBus specifies that output voltages should be in the linear16
> encoding. However, the YH-5151E is non-compliant and uses linear11.
> YM-2151E isn't affected by this. Fix this by converting the values
> inside the read functions. linear16 gets the exponent from the VOUT_MODE
> command. The device doesn't support it, so I have to manually supply the
> value for it.
>
> Both supported devices have now been tested to report correct vout
> values.
>
> Fixes: 1734b4135a62 ("hwmon: Add driver for fsp-3y PSUs and PDUs")
> Signed-off-by: V?clav Kubern?t <[email protected]>

Applied.

Thanks,
Guenter

> ---
> drivers/hwmon/pmbus/fsp-3y.c | 27 +++++++++++++++++++++++++--
> 1 file changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/fsp-3y.c b/drivers/hwmon/pmbus/fsp-3y.c
> index 564649e87e34..655690dde4d7 100644
> --- a/drivers/hwmon/pmbus/fsp-3y.c
> +++ b/drivers/hwmon/pmbus/fsp-3y.c
> @@ -57,7 +57,7 @@ static int page_log_to_page_real(int page_log, enum chips chip)
> case YH5151E_PAGE_12V_LOG:
> return YH5151E_PAGE_12V_REAL;
> case YH5151E_PAGE_5V_LOG:
> - return YH5151E_PAGE_5V_LOG;
> + return YH5151E_PAGE_5V_REAL;
> case YH5151E_PAGE_3V3_LOG:
> return YH5151E_PAGE_3V3_REAL;
> }
> @@ -103,8 +103,18 @@ static int set_page(struct i2c_client *client, int page_log)
>
> static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
> {
> + const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> + struct fsp3y_data *data = to_fsp3y_data(info);
> 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).
> + */
> + if (data->chip == yh5151e && reg == PMBUS_VOUT_MODE)
> + return 0x1A;
> +
> rv = set_page(client, page);
> if (rv < 0)
> return rv;
> @@ -114,6 +124,8 @@ static int fsp3y_read_byte_data(struct i2c_client *client, int page, int reg)
>
> static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase, int reg)
> {
> + const struct pmbus_driver_info *info = pmbus_get_driver_info(client);
> + struct fsp3y_data *data = to_fsp3y_data(info);
> int rv;
>
> /*
> @@ -144,7 +156,18 @@ static int fsp3y_read_word_data(struct i2c_client *client, int page, int phase,
> if (rv < 0)
> return rv;
>
> - return i2c_smbus_read_word_data(client, reg);
> + rv = i2c_smbus_read_word_data(client, reg);
> + if (rv < 0)
> + return rv;
> +
> + /*
> + * YH-5151E is non-compliant and outputs output voltages in linear11
> + * instead of linear16.
> + */
> + if (data->chip == yh5151e && reg == PMBUS_READ_VOUT)
> + rv = sign_extend32(rv, 10) & 0xffff;
> +
> + return rv;
> }
>
> struct pmbus_driver_info fsp3y_info[] = {