This patch implements 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.
Signed-off-by: Jesper Nilsson <jesper.nils...@axis.com>
---
diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c
index be05a64..62905fb 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 +252,36 @@ static int pcf8523_rtc_set_time(struct device *dev, struct
rtc_time *tm)
return pcf8523_start_rtc(client);
}
+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 err;
+ int ret = 0;
+
+ 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;
+ }
+}
+
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,
/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nils...@axis.com
--
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