watchdog: andes: atcwdt200: Andes support for ATCWDT200 (torvalds#203)

Reformed from the following patches on RISCV-Linux-5.4:
- (ff42294) riscv: Porting Watch dog driver
- Remove vendor SBI call sbi_andes_set_reset_vector(), directly
  program SMU reset vector, thus it needs CONFIG_ATCSMU as dependency
- Add readl_fixup to work around dts probe when hardware is not present

Reformed from the following patches on ast-v5_4_0-branch:
- (852a286) watchdog: andes: atcwdt200: Integrate driver with watchdog framework (torvalds#243)
- (d50f7ff) watchdog: andes: atcwdt200: Use div64_s64 for 64-bit division to avoid link error with 32-bit toolchain (torvalds#246)
- (352d0db) watchdog: andes: atcwdt200: Add support for automatic detection of interrupt timer type (torvalds#248)

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Signed-off-by: Randolph <randolph@andestech.com>
Co-authored-by: Randolph <randolph@andestech.com>
Reviewed-on: https://gitea.andestech.com/RD-SW/linux/pulls/203
Reviewed-by: CL Chin-Long Wang <cl634@andestech.com>
Reviewed-by: randolph <randolph@andestech.com>

Author: 2 people

arch/riscv/configs/andes-support.config

@@ -31,3 +31,5 @@ CONFIG_FFB_MODE_RGB=y
 CONFIG_FFB_MODE_16BPP=y
 
 CONFIG_RTC_DRV_ATCRTC100=y
+
+CONFIG_ATCWDT200_WATCHDOG=y

arch/riscv/configs/andes_defconfig

@@ -210,6 +210,9 @@ CONFIG_RTC_INTF_SYSFS=y
 CONFIG_RTC_INTF_PROC=y
 CONFIG_RTC_INTF_DEV=y
 
+CONFIG_WATCHDOG=y
+CONFIG_WATCHDOG_CORE=y
+
 CONFIG_ZSMALLOC=y
 CONFIG_ZRAM=y
 CONFIG_CRYPTO_LZO=y

drivers/watchdog/Kconfig

@@ -47,6 +47,12 @@ config WATCHDOG_NOWAYOUT
 	  get killed. If you say Y here, the watchdog cannot be stopped once
 	  it has been started.
 
+config WATCHDOG_DEBUG
+	bool "Hang in watch dog interrupt handler"
+	help
+	  When system failed, it will hang in watch dog interrupt handler for
+	  debugging.
+
 config WATCHDOG_HANDLE_BOOT_ENABLED
 	bool "Update boot-enabled watchdog until userspace takes over"
 	default y
@@ -528,6 +534,13 @@ config FTWDT010_WATCHDOG
 	  To compile this driver as a module, choose M here: the
 	  module will be called ftwdt010_wdt.
 
+config ATCWDT200_WATCHDOG
+	tristate "ATCWDT200_WATCHDOG"
+	depends on RISCV && ARCH_ANDES && ANDES_ATCSMU
+	help
+	  Support for Andes atcwdt200 watchdog. The driver needs SMU to
+	  program reset vector before triggering software reset.
+
 config IXP4XX_WATCHDOG
 	tristate "IXP4xx Watchdog"
 	depends on ARCH_IXP4XX || (ARM && COMPILE_TEST)

drivers/watchdog/Makefile

@@ -49,6 +49,7 @@ obj-$(CONFIG_TWL4030_WATCHDOG) += twl4030_wdt.o
 obj-$(CONFIG_21285_WATCHDOG) += wdt285.o
 obj-$(CONFIG_977_WATCHDOG) += wdt977.o
 obj-$(CONFIG_FTWDT010_WATCHDOG) += ftwdt010_wdt.o
+obj-$(CONFIG_ATCWDT200_WATCHDOG) += atcwdt200_wdt.o
 obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
 obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
 obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o