[PATCH v3] rtc: rs5c372: Add RTC_VL_READ, RTC_VL_CLR ioctls

From: Camel Guo
Date: Thu Nov 11 2021 - 03:36:33 EST


From: Camel Guo <camelg@xxxxxxxx>

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@xxxxxxxx>
---

Notes:
v2: Set RTC_VL_BACKUP_LOW if VDET is set. Do not clear PON, XSTP in
RTC_VL_CLR ioctl

v3: Avoid setting registers in RTC_VL_CLR when unnecessary

drivers/rtc/rtc-rs5c372.c | 55 +++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/drivers/rtc/rtc-rs5c372.c b/drivers/rtc/rtc-rs5c372.c
index 80980414890c..955513514179 100644
--- 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)
--
2.20.1