drivers/rtc/rtc-pcf8563.c: add RTC_VL_READ/RTC_VL_CLR ioctl feature
Changes are based on arch/cris/arch-v10/drivers/pcf8563.c
[akpm@linux-foundation.org: fix sparse warning]
Signed-off-by: Alexander Stein <alexander.stein@systec-electronic.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mikael Starvik <starvik@axis.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index bc0677d..97a3284 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -64,6 +64,7 @@
* 1970...2069.
*/
int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
+ int voltage_low; /* incicates if a low_voltage was detected */
};
/*
@@ -86,9 +87,11 @@
return -EIO;
}
- if (buf[PCF8563_REG_SC] & PCF8563_SC_LV)
+ if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
+ pcf8563->voltage_low = 1;
dev_info(&client->dev,
"low voltage detected, date/time is not reliable.\n");
+ }
dev_dbg(&client->dev,
"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
@@ -173,6 +176,44 @@
return 0;
}
+#ifdef CONFIG_RTC_INTF_DEV
+static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
+ struct rtc_time tm;
+
+ switch (cmd) {
+ case RTC_VL_READ:
+ if (pcf8563->voltage_low)
+ dev_info(dev, "low voltage detected, date/time is not reliable.\n");
+
+ if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
+ sizeof(int)))
+ return -EFAULT;
+ return 0;
+ case RTC_VL_CLR:
+ /*
+ * Clear the VL bit in the seconds register in case
+ * the time has not been set already (which would
+ * have cleared it). This does not really matter
+ * because of the cached voltage_low value but do it
+ * anyway for consistency.
+ */
+ if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
+ pcf8563_set_datetime(to_i2c_client(dev), &tm);
+
+ /* Clear the cached value. */
+ pcf8563->voltage_low = 0;
+
+ return 0;
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+#else
+#define pcf8563_rtc_ioctl NULL
+#endif
+
static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
return pcf8563_get_datetime(to_i2c_client(dev), tm);
@@ -184,6 +225,7 @@
}
static const struct rtc_class_ops pcf8563_rtc_ops = {
+ .ioctl = pcf8563_rtc_ioctl,
.read_time = pcf8563_rtc_read_time,
.set_time = pcf8563_rtc_set_time,
};