aspeed: Watchdog Timer Driver

This driver supports ast2500 and ast2400 SoCs.
Only ast2500 supports reset_mask and thus the option of resettting
individual peripherals using WDT.

Signed-off-by: Maxim Sloyko <maxims@google.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 49 insertions, 4 deletions

diff --git a/arch/arm/include/asm/arch-aspeed/wdt.h b/arch/arm/include/asm/arch-aspeed/wdt.h
index b292a0e..981fa05 100644
--- a/arch/arm/include/asm/arch-aspeed/wdt.h
+++ b/arch/arm/include/asm/arch-aspeed/wdt.h
@@ -67,15 +67,60 @@ struct ast_wdt {
 	u32 timeout_status;
 	u32 clr_timeout_status;
 	u32 reset_width;
-#ifdef CONFIG_ASPEED_AST2500
+	/* On pre-ast2500 SoCs this register is reserved. */
 	u32 reset_mask;
-#else
-	u32 reserved0;
-#endif
 };
 
+/**
+ * Given flags parameter passed to wdt_reset or wdt_start uclass functions,
+ * gets Reset Mode value from it.
+ *
+ * @flags: flags parameter passed into wdt_reset or wdt_start
+ * @return Reset Mode value
+ */
+u32 ast_reset_mode_from_flags(ulong flags);
+
+/**
+ * Given flags parameter passed to wdt_reset or wdt_start uclass functions,
+ * gets Reset Mask value from it. Reset Mask is only supported on ast2500
+ *
+ * @flags: flags parameter passed into wdt_reset or wdt_start
+ * @return Reset Mask value
+ */
+u32 ast_reset_mask_from_flags(ulong flags);
+
+/**
+ * Given Reset Mask and Reset Mode values, converts them to flags,
+ * suitable for passing into wdt_start or wdt_reset uclass functions.
+ *
+ * On ast2500 Reset Mask is 25 bits wide and Reset Mode is 2 bits wide, so they
+ * can both be packed into single 32 bits wide value.
+ *
+ * @reset_mode: Reset Mode
+ * @reset_mask: Reset Mask
+ */
+ulong ast_flags_from_reset_mode_mask(u32 reset_mode, u32 reset_mask);
+
+#ifndef CONFIG_WDT
+/**
+ * Stop WDT
+ *
+ * @wdt: watchdog to stop
+ *
+ * When using driver model this function has different signature
+ */
 void wdt_stop(struct ast_wdt *wdt);
+
+/**
+ * Stop WDT
+ *
+ * @wdt: watchdog to start
+ * @timeout	watchdog timeout in number of clock ticks
+ *
+ * When using driver model this function has different signature
+ */
 void wdt_start(struct ast_wdt *wdt, u32 timeout);
+#endif  /* CONFIG_WDT */
 
 /**
  * Reset peripherals specified by mask