Messages in this thread Patch in this message | | | From | Joshua Clayton <> | Subject | [PATCH v2 7/8] rtc: implement a sysfs interface for clock offset | Date | Mon, 4 Jan 2016 10:31:25 -0800 |
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The file is called "offset", and may be set and read in decimal. For rtcs that do not have read_offset or set_offset implemented, read always returns zero and write will return -EINVAL.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> --- drivers/rtc/interface.c | 2 +- drivers/rtc/rtc-sysfs.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 57cd928..c064eb9 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -959,7 +959,7 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset) return -ENODEV; if (!rtc->ops->set_offset) { - offset = 0; + *offset = 0; return 0; } diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 7273855..622a0dc 100644 --- a/drivers/rtc/rtc-sysfs.c +++ b/drivers/rtc/rtc-sysfs.c @@ -211,6 +211,34 @@ wakealarm_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RW(wakealarm); +static ssize_t +offset_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + ssize_t retval; + long offset; + + retval = rtc_read_offset(to_rtc_device(dev), &offset); + if (retval == 0) + retval = sprintf(buf, "%ld\n", offset); + + return retval; +} + +static ssize_t +offset_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + ssize_t retval; + long offset; + + retval = kstrtol(buf, 10, &offset); + if (retval == 0) + retval = rtc_set_offset(to_rtc_device(dev), offset); + + return (retval < 0) ? retval : n; +} +static DEVICE_ATTR_RW(offset); + static struct attribute *rtc_attrs[] = { &dev_attr_name.attr, &dev_attr_date.attr, @@ -219,6 +247,7 @@ static struct attribute *rtc_attrs[] = { &dev_attr_max_user_freq.attr, &dev_attr_hctosys.attr, &dev_attr_wakealarm.attr, + &dev_attr_offset.attr, NULL, }; -- 2.5.0
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