Merge tag 'rtc-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "This includes new ioctls to get and set parameters and in particular
  the backup switch mode that is needed for some RTCs to actually enable
  the backup voltage (and have a useful RTC).

  The same interface can also be used to get the actual features
  supported by the RTC so userspace has a better way than trying and
  failing.

  Summary:

  Subsystem:
   - Add new ioctl to get and set extra RTC parameters, this includes
     backup switch mode
   - Expose available features to userspace, in particular, when alarmas
     have a resolution of one minute instead of a second.
   - Let the core handle those alarms with a minute resolution

  New driver:
   - MSTAR MSC313 RTC

  Drivers:
   - Add SPI ID table where necessary
   - Add BSM support for rv3028, rv3032 and pcf8523
   - s3c: set RTC range
   - rx8025: set range, implement .set_offset and .read_offset"

* tag 'rtc-5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (50 commits)
  rtc: rx8025: use .set_offset/.read_offset
  rtc: rx8025: use rtc_add_group
  rtc: rx8025: clear RTC_FEATURE_ALARM when alarm are not supported
  rtc: rx8025: set range
  rtc: rx8025: let the core handle the alarm resolution
  rtc: rx8025: switch to devm_rtc_allocate_device
  rtc: ab8500: let the core handle the alarm resolution
  rtc: ab-eoz9: support UIE when available
  rtc: ab-eoz9: use RTC_FEATURE_UPDATE_INTERRUPT
  rtc: rv3032: let the core handle the alarm resolution
  rtc: s35390a: let the core handle the alarm resolution
  rtc: handle alarms with a minute resolution
  rtc: pcf85063: silence cppcheck warning
  rtc: rv8803: fix writing back ctrl in flag register
  rtc: s3c: Add time range
  rtc: s3c: Extract read/write IO into separate functions
  rtc: s3c: Remove usage of devm_rtc_device_register()
  rtc: tps80031: Remove driver
  rtc: sun6i: Allow probing without an early clock provider
  rtc: pcf8523: add BSM support
  ...

1 files changed, 65 insertions, 0 deletions

diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
index 5b8ebe86124a..e104972a28fd 100644
--- a/drivers/rtc/dev.c
+++ b/drivers/rtc/dev.c
@@ -208,6 +208,7 @@ static long rtc_dev_ioctl(struct file *file,
 	const struct rtc_class_ops *ops = rtc->ops;
 	struct rtc_time tm;
 	struct rtc_wkalrm alarm;
+	struct rtc_param param;
 	void __user *uarg = (void __user *)arg;
 
 	err = mutex_lock_interruptible(&rtc->ops_lock);
@@ -221,6 +222,7 @@ static long rtc_dev_ioctl(struct file *file,
 	switch (cmd) {
 	case RTC_EPOCH_SET:
 	case RTC_SET_TIME:
+	case RTC_PARAM_SET:
 		if (!capable(CAP_SYS_TIME))
 			err = -EACCES;
 		break;
@@ -382,6 +384,69 @@ static long rtc_dev_ioctl(struct file *file,
 			err = -EFAULT;
 		return err;
 
+	case RTC_PARAM_GET:
+		if (copy_from_user(&param, uarg, sizeof(param))) {
+			mutex_unlock(&rtc->ops_lock);
+			return -EFAULT;
+		}
+
+		switch(param.param) {
+			long offset;
+		case RTC_PARAM_FEATURES:
+			if (param.index != 0)
+				err = -EINVAL;
+			param.uvalue = rtc->features[0];
+			break;
+
+		case RTC_PARAM_CORRECTION:
+			mutex_unlock(&rtc->ops_lock);
+			if (param.index != 0)
+				return -EINVAL;
+			err = rtc_read_offset(rtc, &offset);
+			mutex_lock(&rtc->ops_lock);
+			if (err == 0)
+				param.svalue = offset;
+			break;
+
+		default:
+			if (rtc->ops->param_get)
+				err = rtc->ops->param_get(rtc->dev.parent, &param);
+			else
+				err = -EINVAL;
+		}
+
+		if (!err)
+			if (copy_to_user(uarg, &param, sizeof(param)))
+				err = -EFAULT;
+
+		break;
+
+	case RTC_PARAM_SET:
+		if (copy_from_user(&param, uarg, sizeof(param))) {
+			mutex_unlock(&rtc->ops_lock);
+			return -EFAULT;
+		}
+
+		switch(param.param) {
+		case RTC_PARAM_FEATURES:
+			err = -EINVAL;
+			break;
+
+		case RTC_PARAM_CORRECTION:
+			mutex_unlock(&rtc->ops_lock);
+			if (param.index != 0)
+				return -EINVAL;
+			return rtc_set_offset(rtc, param.svalue);
+
+		default:
+			if (rtc->ops->param_set)
+				err = rtc->ops->param_set(rtc->dev.parent, &param);
+			else
+				err = -EINVAL;
+		}
+
+		break;
+
 	default:
 		/* Finally try the driver's ioctl interface */
 		if (ops->ioctl) {