rtc: rtc-sh: SH-2A support.

Trivial support for the SH-2A on-chip RTC.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/rtc/Kconfig

@@ -404,7 +404,7 @@ config RTC_DRV_SA1100
 
 config RTC_DRV_SH
 	tristate "SuperH On-Chip RTC"
-	depends on RTC_CLASS && (CPU_SH3 || CPU_SH4 || CPU_SH5)
+	depends on RTC_CLASS && SUPERH
 	help
 	  Say Y here to enable support for the on-chip RTC found in
 	  most SuperH processors.

drivers/rtc/rtc-sh.c

@@ -26,9 +26,13 @@
 #include <asm/rtc.h>
 
 #define DRV_NAME	"sh-rtc"
-#define DRV_VERSION	"0.1.4"
+#define DRV_VERSION	"0.1.5"
 
-#ifdef CONFIG_CPU_SH3
+#ifdef CONFIG_CPU_SH2A
+#define rtc_reg_size		sizeof(u16)
+#define RTC_BIT_INVERTED	0
+#define RTC_DEF_CAPABILITIES	RTC_CAP_4_DIGIT_YEAR
+#elif defined(CONFIG_CPU_SH3)
 #define rtc_reg_size		sizeof(u16)
 #define RTC_BIT_INVERTED	0	/* No bug on SH7708, SH7709A */
 #define RTC_DEF_CAPABILITIES	0UL
@@ -62,6 +66,18 @@
 #define RCR1		RTC_REG(14)	/* Control */
 #define RCR2		RTC_REG(15)	/* Control */
 
+/*
+ * Note on RYRAR and RCR3: Up until this point most of the register
+ * definitions are consistent across all of the available parts. However,
+ * the placement of the optional RYRAR and RCR3 (the RYRAR control
+ * register used to control RYRCNT/RYRAR compare) varies considerably
+ * across various parts, occasionally being mapped in to a completely
+ * unrelated address space. For proper RYRAR support a separate resource
+ * would have to be handed off, but as this is purely optional in
+ * practice, we simply opt not to support it, thereby keeping the code
+ * quite a bit more simplified.
+ */
+
 /* ALARM Bits - or with BCD encoded value */
 #define AR_ENB		0x80	/* Enable for alarm cmp   */