| Message ID | 1454519804-13770-2-git-send-email-stillcompiling@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
A really small nitpick below On 03/02/2016 at 09:16:43 -0800, Joshua Clayton wrote : > clock offset may be set and read in decimal parts per billion > attribute is /sys/class/rtc/rtcN/offset > The attribute is only visible for rtcs that have set_offset implemented. > > Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> > --- > Documentation/rtc.txt | 6 ++++++ > drivers/rtc/rtc-sysfs.c | 35 ++++++++++++++++++++++++++++++++++- > 2 files changed, 40 insertions(+), 1 deletion(-) > > diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt > index 8446f1e..ddc3660 100644 > --- a/Documentation/rtc.txt > +++ b/Documentation/rtc.txt > @@ -157,6 +157,12 @@ wakealarm: The time at which the clock will generate a system wakeup > the epoch by default, or if there's a leading +, seconds in the > future, or if there is a leading +=, seconds ahead of the current > alarm. > +offset: The amount which the rtc clock has been adjusted in firmware. > + Visible only if the driver supports clock offset adjustment. > + The unit is parts per billion, i.e. The number of clock ticks > + which are added to or removed from the rtc's base clock per > + billion ticks. A positive value makes a day pass more slowly, > + longer, and a negative value makes a day pass more quickly. > > IOCTL INTERFACE > --------------- > diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c > index 463e286..f8d7f8d 100644 > --- a/drivers/rtc/rtc-sysfs.c > +++ b/drivers/rtc/rtc-sysfs.c > @@ -218,6 +218,34 @@ 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) This is not properly aligned. > +{ > + 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, > @@ -226,6 +254,7 @@ static struct attribute *rtc_attrs[] = { > &dev_attr_max_user_freq.attr, > &dev_attr_hctosys.attr, > &dev_attr_wakealarm.attr, > + &dev_attr_offset.attr, > NULL, > }; > > @@ -249,9 +278,13 @@ static umode_t rtc_attr_is_visible(struct kobject *kobj, > struct rtc_device *rtc = to_rtc_device(dev); > umode_t mode = attr->mode; > > - if (attr == &dev_attr_wakealarm.attr) > + if (attr == &dev_attr_wakealarm.attr) { > if (!rtc_does_wakealarm(rtc)) > mode = 0; > + } else if (attr == &dev_attr_offset.attr) { > + if (!rtc->ops->set_offset) > + mode = 0; > + } > > return mode; > } > -- > 2.5.0 >
diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt index 8446f1e..ddc3660 100644 --- a/Documentation/rtc.txt +++ b/Documentation/rtc.txt @@ -157,6 +157,12 @@ wakealarm: The time at which the clock will generate a system wakeup the epoch by default, or if there's a leading +, seconds in the future, or if there is a leading +=, seconds ahead of the current alarm. +offset: The amount which the rtc clock has been adjusted in firmware. + Visible only if the driver supports clock offset adjustment. + The unit is parts per billion, i.e. The number of clock ticks + which are added to or removed from the rtc's base clock per + billion ticks. A positive value makes a day pass more slowly, + longer, and a negative value makes a day pass more quickly. IOCTL INTERFACE --------------- diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 463e286..f8d7f8d 100644 --- a/drivers/rtc/rtc-sysfs.c +++ b/drivers/rtc/rtc-sysfs.c @@ -218,6 +218,34 @@ 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, @@ -226,6 +254,7 @@ static struct attribute *rtc_attrs[] = { &dev_attr_max_user_freq.attr, &dev_attr_hctosys.attr, &dev_attr_wakealarm.attr, + &dev_attr_offset.attr, NULL, }; @@ -249,9 +278,13 @@ static umode_t rtc_attr_is_visible(struct kobject *kobj, struct rtc_device *rtc = to_rtc_device(dev); umode_t mode = attr->mode; - if (attr == &dev_attr_wakealarm.attr) + if (attr == &dev_attr_wakealarm.attr) { if (!rtc_does_wakealarm(rtc)) mode = 0; + } else if (attr == &dev_attr_offset.attr) { + if (!rtc->ops->set_offset) + mode = 0; + } return mode; }
clock offset may be set and read in decimal parts per billion attribute is /sys/class/rtc/rtcN/offset The attribute is only visible for rtcs that have set_offset implemented. Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> --- Documentation/rtc.txt | 6 ++++++ drivers/rtc/rtc-sysfs.c | 35 ++++++++++++++++++++++++++++++++++- 2 files changed, 40 insertions(+), 1 deletion(-)