rtc: rs5c372: Add RTC_VL_READ, RTC_VL_CLR ioctls

In order to make it possible to get battery voltage status, this commit
adds RTC_VL_READ, RTC_VL_CLR ioctl commands to rtc-rs5c372.

Signed-off-by: Camel Guo <camelg@axis.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211111083625.10216-1-camel.guo@axis.com

diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 8098041..9555135 100644 (file)
--- a/drivers/rtc/rtc-rs5c372.c
+++ b/drivers/rtc/rtc-rs5c372.c
@@ -485,6 +485,60 @@ static int rs5c372_rtc_proc(struct device *dev, struct seq_file *seq)
 #define        rs5c372_rtc_proc        NULL
 #endif
 
+#ifdef CONFIG_RTC_INTF_DEV
+static int rs5c372_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+       struct rs5c372  *rs5c = i2c_get_clientdata(to_i2c_client(dev));
+       unsigned char   ctrl2;
+       int             addr;
+       unsigned int    flags;
+
+       dev_dbg(dev, "%s: cmd=%x\n", __func__, cmd);
+
+       addr = RS5C_ADDR(RS5C_REG_CTRL2);
+       ctrl2 = i2c_smbus_read_byte_data(rs5c->client, addr);
+
+       switch (cmd) {
+       case RTC_VL_READ:
+               flags = 0;
+
+               switch (rs5c->type) {
+               case rtc_r2025sd:
+               case rtc_r2221tl:
+                       if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) ||
+                               (rs5c->type == rtc_r2221tl &&  (ctrl2 & R2x2x_CTRL2_XSTP))) {
+                               flags |= RTC_VL_DATA_INVALID;
+                       }
+                       if (ctrl2 & R2x2x_CTRL2_VDET)
+                               flags |= RTC_VL_BACKUP_LOW;
+                       break;
+               default:
+                       if (ctrl2 & RS5C_CTRL2_XSTP)
+                               flags |= RTC_VL_DATA_INVALID;
+                       break;
+               }
+
+               return put_user(flags, (unsigned int __user *)arg);
+       case RTC_VL_CLR:
+               /* clear VDET bit */
+               if (rs5c->type == rtc_r2025sd || rs5c->type == rtc_r2221tl) {
+                       ctrl2 &= ~R2x2x_CTRL2_VDET;
+                       if (i2c_smbus_write_byte_data(rs5c->client, addr, ctrl2) < 0) {
+                               dev_dbg(&rs5c->client->dev, "%s: write error in line %i\n",
+                                               __func__, __LINE__);
+                               return -EIO;
+                       }
+               }
+               return 0;
+       default:
+               return -ENOIOCTLCMD;
+       }
+       return 0;
+}
+#else
+#define rs5c372_ioctl  NULL
+#endif
+
 static const struct rtc_class_ops rs5c372_rtc_ops = {
        .proc           = rs5c372_rtc_proc,
        .read_time      = rs5c372_rtc_read_time,
@@ -492,6 +546,7 @@ static const struct rtc_class_ops rs5c372_rtc_ops = {
        .read_alarm     = rs5c_read_alarm,
        .set_alarm      = rs5c_set_alarm,
        .alarm_irq_enable = rs5c_rtc_alarm_irq_enable,
+       .ioctl          = rs5c372_ioctl,
 };
 
 #if IS_ENABLED(CONFIG_RTC_INTF_SYSFS)