rtc: abx80x: Implement RTC_VL_READ,CLR ioctls

Implement standard ioctls for polling the battery status and clearing
the battery low indication from userspace.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index d8e94ed..4d24f72 100644 (file)
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -38,6 +38,7 @@
 
 #define ABX8XX_REG_STATUS      0x0f
 #define ABX8XX_STATUS_AF       BIT(2)
+#define ABX8XX_STATUS_BLF      BIT(4)
 #define ABX8XX_STATUS_WDT      BIT(6)
 
 #define ABX8XX_REG_CTRL1       0x10
@@ -507,12 +508,49 @@ static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
        return err;
 }
 
+static int abx80x_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+       struct i2c_client *client = to_i2c_client(dev);
+       int status, tmp;
+
+       switch (cmd) {
+       case RTC_VL_READ:
+               status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
+               if (status < 0)
+                       return status;
+
+               tmp = !!(status & ABX8XX_STATUS_BLF);
+
+               if (copy_to_user((void __user *)arg, &tmp, sizeof(int)))
+                       return -EFAULT;
+
+               return 0;
+
+       case RTC_VL_CLR:
+               status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
+               if (status < 0)
+                       return status;
+
+               status &= ~ABX8XX_STATUS_BLF;
+
+               tmp = i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
+               if (tmp < 0)
+                       return tmp;
+
+               return 0;
+
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+
 static const struct rtc_class_ops abx80x_rtc_ops = {
        .read_time      = abx80x_rtc_read_time,
        .set_time       = abx80x_rtc_set_time,
        .read_alarm     = abx80x_read_alarm,
        .set_alarm      = abx80x_set_alarm,
        .alarm_irq_enable = abx80x_alarm_irq_enable,
+       .ioctl          = abx80x_ioctl,
 };
 
 static int abx80x_dt_trickle_cfg(struct device_node *np)