watchdog: ROHM BD96801 PMIC WDG driver

Introduce driver for WDG block on ROHM BD96801 scalable PMIC.

This driver only supports watchdog with I2C feeding and delayed
response detection. Whether the watchdog toggles PRSTB pin or
just causes an interrupt can be configured via device-tree.

The BD96801 PMIC HW supports also window watchdog (too early
feeding detection) and Q&A mode. These are not supported by
this driver.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/bb3a49d606e793a61b0c033170ff2a9f30f3c2a5.1719473802.git.mazziesaccount@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/watchdog/Kconfig

@@ -181,6 +181,19 @@ config BD957XMUF_WATCHDOG
 	  watchdog. Alternatively say M to compile the driver as a module,
 	  which will be called bd9576_wdt.
 
+config BD96801_WATCHDOG
+	tristate "ROHM BD96801 PMIC Watchdog"
+	depends on MFD_ROHM_BD96801
+	select WATCHDOG_CORE
+	help
+	  Support for the watchdog in the ROHM BD96801 PMIC. Watchdog can be
+	  configured to only generate IRQ or to trigger system reset via reset
+	  pin.
+
+	  Say Y here to include support for the ROHM BD96801 watchdog.
+	  Alternatively say M to compile the driver as a module,
+	  which will be called bd96801_wdt.
+
 config CROS_EC_WATCHDOG
 	tristate "ChromeOS EC-based watchdog"
 	select WATCHDOG_CORE

drivers/watchdog/Makefile

@@ -218,6 +218,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o
 
 # Architecture Independent
 obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o
+obj-$(CONFIG_BD96801_WATCHDOG) += bd96801_wdt.o
 obj-$(CONFIG_CROS_EC_WATCHDOG) += cros_ec_wdt.o
 obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o