[PATCH 4/7] rtc-cmos: allow strictly MMIO based configurations

[Marc Zyngier <marc.zyngier@arm.com>]

For those new fancy architectures lacking any kind of I/O ports,
and unwilling to emulate them, introduce the new config symbol
RTC_DRV_CMOS_MMIO_STRICT, which provides default (and explosive)
legacy I/O port accessors.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/rtc/Kconfig    | 4 ++++
 drivers/rtc/rtc-cmos.c | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 7e88866..10974f7 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -680,6 +680,10 @@ config RTC_DRV_CMOS
 config RTC_DRV_CMOS_MMIO
 	bool
 
+config RTC_DRV_CMOS_MMIO_STRICT
+	select RTC_DRV_CMOS_MMIO
+	bool
+
 config RTC_DRV_ALPHA
 	bool "Alpha PC-style CMOS"
 	depends on ALPHA
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index d535e72..e2d1338 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -70,6 +70,11 @@ static const char driver_name[] = "rtc_cmos";
 #ifdef CONFIG_RTC_DRV_CMOS_MMIO
 static void __iomem *rtc_cmos_base;
 
+#ifdef CONFIG_RTC_DRV_CMOS_MMIO_STRICT
+#define CMOS_READ(reg)		({BUG(); 0;})
+#define CMOS_WRITE(val,reg)	BUG();
+#endif
+
 static u8 do_cmos_read(u8 reg)
 {
 	u8 val;
-- 
1.8.3.4