From 2d101db3e5be3bbee6001d4227705cec70ecb82e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?V=C3=A1clav=20Kubern=C3=A1t?= Date: Thu, 29 Apr 2021 09:53:38 +0200 Subject: [PATCH] hwmon: (pmbus/fsp-3y) Fix FSP-3Y YH-5151E non-compliant vout encoding MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Link: https://lore.kernel.org/r/20210429075337.110502-1-kubernat@cesnet.cz Signed-off-by: Guenter Roeck --- 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 b177987286ae..e24842475254 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; } static struct pmbus_driver_info fsp3y_info[] = {