Commit 2d101db3 authored by Václav Kubernát's avatar Václav Kubernát Committed by Guenter Roeck
Browse files

hwmon: (pmbus/fsp-3y) 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: 1734b413 ("hwmon: Add driver for fsp-3y PSUs and PDUs")
Signed-off-by: default avatarVáclav Kubernát <kubernat@cesnet.cz>
Link: https://lore.kernel.org/r/20210429075337.110502-1-kubernat@cesnet.cz


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 5216dff2

drivers/hwmon/pmbus/fsp-3y.c

+25 −2
Original line number Diff line number Diff line
@@ -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;

}



static struct pmbus_driver_info fsp3y_info[] = {