@@ -119,8 +119,9 @@ three different userspace interfaces:
* /sys/class/rtc/rtcN ... sysfs attributes support readonly
access to some RTC attributes.
- * /proc/driver/rtc ... the first RTC (rtc0) may expose itself
- using a procfs interface. More information is (currently) shown
+ * /proc/driver/rtc ... the system clock RTC may expose itself
+ using a procfs interface. If there is no RTC for the system clock,
+ rtc0 is used by default. More information is (currently) shown
here than through sysfs.
The RTC Class framework supports a wide variety of RTCs, ranging from those
@@ -69,13 +69,15 @@ config RTC_INTF_SYSFS
If unsure, say Y.
config RTC_INTF_PROC
- boolean "/proc/driver/rtc (procfs for rtc0)"
+ boolean "/proc/driver/rtc (procfs for rtcN)"
depends on PROC_FS
default RTC_CLASS
help
- Say yes here if you want to use your first RTC through the proc
- interface, /proc/driver/rtc. Other RTCs will not be available
- through that API.
+ Say yes here if you want to use your system clock RTC through
+ the proc interface, /proc/driver/rtc.
+ Other RTCs will not be available through that API.
+ If there is no RTC for the system clock, then the first RTC(rtc0)
+ is used by default.
If unsure, say Y.
@@ -18,6 +18,26 @@
#include "rtc-core.h"
+#define NAME_SIZE 10
+
+#if defined(CONFIG_RTC_HCTOSYS_DEVICE)
+static bool is_rtc_hctosys(struct rtc_device *rtc)
+{
+ int size;
+ char name[NAME_SIZE];
+
+ size = scnprintf(name, NAME_SIZE, "rtc%d", rtc->id);
+ if (size > NAME_SIZE)
+ return false;
+
+ return !strncmp(name, CONFIG_RTC_HCTOSYS_DEVICE, NAME_SIZE);
+}
+#else
+static bool is_rtc_hctosys(struct rtc_device *rtc)
+{
+ return (rtc->id == 0);
+}
+#endif
static int rtc_proc_show(struct seq_file *seq, void *offset)
{
@@ -117,12 +137,12 @@ static const struct file_operations rtc_proc_fops = {
void rtc_proc_add_device(struct rtc_device *rtc)
{
- if (rtc->id == 0)
+ if (is_rtc_hctosys(rtc))
proc_create_data("driver/rtc", 0, NULL, &rtc_proc_fops, rtc);
}
void rtc_proc_del_device(struct rtc_device *rtc)
{
- if (rtc->id == 0)
+ if (is_rtc_hctosys(rtc))
remove_proc_entry("driver/rtc", NULL);
}
To get time information via /proc/driver/rtc, only the first device (rtc0) is used. If the rtcN (eg. rtc1 or rtc2) is used for the system clock, there is no way to get information of rtcN via /proc/driver/rtc. With this patch, the time data can be retrieved from the system clock RTC. If the RTC_HCTOSYS_DEVICE is not defined, then rtc0 is used by default. Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com> --- Documentation/rtc.txt | 5 +++-- drivers/rtc/Kconfig | 10 ++++++---- drivers/rtc/rtc-proc.c | 24 ++++++++++++++++++++++-- 3 files changed, 31 insertions(+), 8 deletions(-)