rtc: pcf85063: add RTC_VL_READ/RTC_VL_CLR support

Allow reading the oscillator status bit. Also allow clearing it even if
that makes little sense and can't be done in a race free way.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index ed7f171253655eabc9fbcc3d4663b868f0c36404..1afa6d9fa9fb26126a0ad6691f7f9765a36bab71 100644 (file)
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -277,11 +277,45 @@ static int pcf85063_set_offset(struct device *dev, long offset)
        return regmap_write(pcf85063->regmap, PCF85063_REG_OFFSET, reg);
 }
 
+static int pcf85063_ioctl(struct device *dev, unsigned int cmd,
+                         unsigned long arg)
+{
+       struct pcf85063 *pcf85063 = dev_get_drvdata(dev);
+       int status, ret = 0;
+
+       switch (cmd) {
+       case RTC_VL_READ:
+               ret = regmap_read(pcf85063->regmap, PCF85063_REG_SC, &status);
+               if (ret < 0)
+                       return ret;
+
+               if (status & PCF85063_REG_SC_OS)
+                       dev_warn(&pcf85063->rtc->dev, "Voltage low, data loss detected.\n");
+
+               status &= PCF85063_REG_SC_OS;
+
+               if (copy_to_user((void __user *)arg, &status, sizeof(int)))
+                       return -EFAULT;
+
+               return 0;
+
+       case RTC_VL_CLR:
+               ret = regmap_update_bits(pcf85063->regmap, PCF85063_REG_SC,
+                                        PCF85063_REG_SC_OS, 0);
+
+               return ret;
+
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+
 static const struct rtc_class_ops pcf85063_rtc_ops = {
        .read_time      = pcf85063_rtc_read_time,
        .set_time       = pcf85063_rtc_set_time,
        .read_offset    = pcf85063_read_offset,
        .set_offset     = pcf85063_set_offset,
+       .ioctl          = pcf85063_ioctl,
 };
 
 static const struct rtc_class_ops pcf85063_rtc_ops_alarm = {
@@ -292,6 +326,7 @@ static const struct rtc_class_ops pcf85063_rtc_ops_alarm = {
        .read_alarm     = pcf85063_rtc_read_alarm,
        .set_alarm      = pcf85063_rtc_set_alarm,
        .alarm_irq_enable = pcf85063_rtc_alarm_irq_enable,
+       .ioctl          = pcf85063_ioctl,
 };
 
 static int pcf85063_nvmem_read(void *priv, unsigned int offset,