hwmon: (pmbus/ltc2978) Fix PMBus polling of MFR_COMMON definitions.

BugLink: https://bugs.launchpad.net/bugs/1868627

commit cf2b012c upstream.

Change 21537dc driver PMBus polling of MFR_COMMON from bits 5/4 to
bits 6/5. This fixs a LTC297X family bug where polling always returns
not busy even when the part is busy. This fixes a LTC388X and
LTM467X bug where polling used PEND and NOT_IN_TRANS, and BUSY was
not polled, which can lead to NACKing of commands. LTC388X and
LTM467X modules now poll BUSY and PEND, increasing reliability by
eliminating NACKing of commands.
Signed-off-by: Mike Jones <michael-a1.jones@analog.com>
Link: https://lore.kernel.org/r/1580234400-2829-2-git-send-email-michael-a1.jones@analog.com
Fixes: e04d1ce9 ("hwmon: (ltc2978) Add polling for chips requiring it")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/hwmon/pmbus/ltc2978.c

@@ -89,8 +89,8 @@ enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882,
 
 #define LTC_POLL_TIMEOUT		100	/* in milli-seconds */
 
-#define LTC_NOT_BUSY			BIT(5)
-#define LTC_NOT_PENDING			BIT(4)
+#define LTC_NOT_BUSY			BIT(6)
+#define LTC_NOT_PENDING			BIT(5)
 
 /*
  * LTC2978 clears peak data whenever the CLEAR_FAULTS command is executed, which