watchdog: pic32-dmt: Add PIC32 deadman timer driver

Adds support for the deadman timer peripheral found on PIC32 class devices.

The primary function of the deadman timer (DMT) is to reset the processor
in the event of a software malfunction. The DMT is a free-running
instruction fetch timer, which is clocked whenever an instruction fetch
occurs until a count match occurs. Instructions are not fetched when
the processor is in sleep mode.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Signed-off-by: Joshua Henderson <joshua.henderson@microchip.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12703/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 42408a61255c..9c4143112e6c 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -1488,6 +1488,19 @@ config PIC32_WDT
           To compile this driver as a loadable module, choose M here.
           The module will be called pic32-wdt.
 
+config PIC32_DMT
+        tristate "Microchip PIC32 Deadman Timer"
+        select WATCHDOG_CORE
+        depends on MACH_PIC32
+        help
+          Watchdog driver for PIC32 instruction fetch counting timer. This specific
+          timer is typically be used in misson critical and safety critical
+          applications, where any single failure of the software functionality
+          and sequencing must be detected.
+
+          To compile this driver as a loadable module, choose M here.
+          The module will be called pic32-dmt.
+
 # PARISC Architecture
 
 # POWERPC Architecture