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authorJesper Nilsson <jesper.nilsson@axis.com>2013-02-21 16:44:27 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-21 17:22:27 -0800
commitf32bc70d5f938cfef3e534c9db6d38a3759eac6d (patch)
tree2b3772a6c6923871136d6285bb28e3898c6fea42 /drivers
parentfca1dd031a28da74db3df4921dc36fa78941c99f (diff)
rtc-pcf8523: add low battery voltage support
Implement reading of the battery voltage low signal for rtc-pcf8523. The bit is read-only and cannot be cleared by software, so no clear function is implemented. [akpm@linux-foundation.org: omit pcf8563_rtc_ioctl() if CONFIG_RTC_INTF_DEV=n] Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com> Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/rtc/rtc-pcf8523.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
index be05a645f99e..889e3160e701 100644
--- a/drivers/rtc/rtc-pcf8523.c
+++ b/drivers/rtc/rtc-pcf8523.c
@@ -23,6 +23,7 @@
#define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */
#define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */
#define REG_CONTROL3_PM_MASK 0xe0
+#define REG_CONTROL3_BLF (1 << 2) /* battery low bit, read-only */
#define REG_SECONDS 0x03
#define REG_SECONDS_OS (1 << 7)
@@ -250,9 +251,39 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm)
return pcf8523_start_rtc(client);
}
+#ifdef CONFIG_RTC_INTF_DEV
+static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
+ unsigned long arg)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ u8 value;
+ int ret = 0, err;
+
+ switch (cmd) {
+ case RTC_VL_READ:
+ err = pcf8523_read(client, REG_CONTROL3, &value);
+ if (err < 0)
+ return err;
+
+ if (value & REG_CONTROL3_BLF)
+ ret = 1;
+
+ if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
+ return -EFAULT;
+
+ return 0;
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+#else
+#define pcf8523_rtc_ioctl NULL
+#endif
+
static const struct rtc_class_ops pcf8523_rtc_ops = {
.read_time = pcf8523_rtc_read_time,
.set_time = pcf8523_rtc_set_time,
+ .ioctl = pcf8523_rtc_ioctl,
};
static int pcf8523_probe(struct i2c_client *client,