[PATCH v2 2/5] rtc: gamecube: Report low battery as invalid data

From: Emmanuel Gil Peyrot
Date: Wed Oct 27 2021 - 18:35:36 EST


I haven’t been able to test this patch as all of my consoles have a
working RTC battery, but according to the documentation it should work
like that.

Signed-off-by: Emmanuel Gil Peyrot <linkmauve@xxxxxxxxxxxx>
---
drivers/rtc/rtc-gamecube.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/drivers/rtc/rtc-gamecube.c b/drivers/rtc/rtc-gamecube.c
index e8260c82c07d..1932c6fe1301 100644
--- a/drivers/rtc/rtc-gamecube.c
+++ b/drivers/rtc/rtc-gamecube.c
@@ -83,6 +83,10 @@
#define RTC_CONTROL0 0x21000c
#define RTC_CONTROL1 0x21000d

+/* RTC flags */
+#define RTC_CONTROL0_UNSTABLE_POWER 0x00000800
+#define RTC_CONTROL0_LOW_BATTERY 0x00000200
+
struct priv {
struct regmap *regmap;
void __iomem *iob;
@@ -182,9 +186,35 @@ static int gamecube_rtc_set_time(struct device *dev, struct rtc_time *t)
return regmap_write(d->regmap, RTC_COUNTER, timestamp - d->rtc_bias);
}

+static int gamecube_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
+{
+ struct priv *d = dev_get_drvdata(dev);
+ int value;
+ int control0;
+ int ret;
+
+ switch (cmd) {
+ case RTC_VL_READ:
+ ret = regmap_read(d->regmap, RTC_CONTROL0, &control0);
+ if (ret)
+ return ret;
+
+ value = 0;
+ if (control0 & RTC_CONTROL0_UNSTABLE_POWER)
+ value |= RTC_VL_DATA_INVALID;
+ if (control0 & RTC_CONTROL0_LOW_BATTERY)
+ value |= RTC_VL_DATA_INVALID;
+ return put_user(value, (unsigned int __user *)arg);
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
static const struct rtc_class_ops gamecube_rtc_ops = {
.read_time = gamecube_rtc_read_time,
.set_time = gamecube_rtc_set_time,
+ .ioctl = gamecube_rtc_ioctl,
};

static int gamecube_rtc_read_offset_from_sram(struct priv *d)
--
2.33.1