[PATCH v2] rtc: ia64: allow other architectures to use EFI RTC

From: Mark Salter
Date: Fri Jul 25 2014 - 16:04:42 EST


Currently, the rtc-efi driver is restricted to ia64 only. Newer
architectures with EFI support may want to also use that driver. This
patch moves the platform device setup from ia64 into drivers/rtc and allow
any architecture with CONFIG_EFI=y to use the rtc-efi driver.

This is v2 of the patch to fix a boot problem with kernels building in
rtc-efi but not being booted via EFI. In that case, runtime services are
not available so there is no point in registering the platform device.

Signed-off-by: Mark Salter <msalter@xxxxxxxxxx>
Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/ia64/kernel/time.c | 15 ---------------
drivers/rtc/Kconfig | 2 +-
drivers/rtc/Makefile | 4 ++++
drivers/rtc/rtc-efi-platform.c | 31 +++++++++++++++++++++++++++++++
4 files changed, 36 insertions(+), 16 deletions(-)
create mode 100644 drivers/rtc/rtc-efi-platform.c

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 71c52bc..a149c67 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -384,21 +384,6 @@ static struct irqaction timer_irqaction = {
.name = "timer"
};

-static struct platform_device rtc_efi_dev = {
- .name = "rtc-efi",
- .id = -1,
-};
-
-static int __init rtc_init(void)
-{
- if (platform_device_register(&rtc_efi_dev) < 0)
- printk(KERN_ERR "unable to register rtc device...\n");
-
- /* not necessarily an error */
- return 0;
-}
-module_init(rtc_init);
-
void read_persistent_clock(struct timespec *ts)
{
efi_gettimeofday(ts);
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 0754f5c..4478a59 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -789,7 +789,7 @@ config RTC_DRV_DA9063

config RTC_DRV_EFI
tristate "EFI RTC"
- depends on IA64
+ depends on EFI
help
If you say yes here you will get support for the EFI
Real Time Clock.
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 70347d0..f1dfc36 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -10,6 +10,10 @@ obj-$(CONFIG_RTC_SYSTOHC) += systohc.o
obj-$(CONFIG_RTC_CLASS) += rtc-core.o
rtc-core-y := class.o interface.o

+ifdef CONFIG_RTC_DRV_EFI
+rtc-core-y += rtc-efi-platform.o
+endif
+
rtc-core-$(CONFIG_RTC_INTF_DEV) += rtc-dev.o
rtc-core-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o
rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o
diff --git a/drivers/rtc/rtc-efi-platform.c b/drivers/rtc/rtc-efi-platform.c
new file mode 100644
index 0000000..b40fbe3
--- /dev/null
+++ b/drivers/rtc/rtc-efi-platform.c
@@ -0,0 +1,31 @@
+/*
+ * Moved from arch/ia64/kernel/time.c
+ *
+ * Copyright (C) 1998-2003 Hewlett-Packard Co
+ * Stephane Eranian <eranian@xxxxxxxxxx>
+ * David Mosberger <davidm@xxxxxxxxxx>
+ * Copyright (C) 1999 Don Dugger <don.dugger@xxxxxxxxx>
+ * Copyright (C) 1999-2000 VA Linux Systems
+ * Copyright (C) 1999-2000 Walt Drummond <drummond@xxxxxxxxxxx>
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/efi.h>
+#include <linux/platform_device.h>
+
+static struct platform_device rtc_efi_dev = {
+ .name = "rtc-efi",
+ .id = -1,
+};
+
+static int __init rtc_init(void)
+{
+ if (efi_enabled(EFI_RUNTIME_SERVICES))
+ if (platform_device_register(&rtc_efi_dev) < 0)
+ pr_err("unable to register rtc device...\n");
+
+ /* not necessarily an error */
+ return 0;
+}
+module_init(rtc_init);
--
1.8.3.1



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