[PATCH 5.19 0081/1157] rtc: rx8025: fix 12/24 hour mode detection on RX-8035

Greg Kroah-Hartman
2022-08-15T22:09:01Z

From: Mathew McBride <matt@traverse.com.au>

commit 71af91565052214ad86f288e0d8ffb165f790995 upstream.

The 12/24hr flag in the RX-8035 can be found in the hour register,
instead of the CTRL1 on the RX-8025. This was overlooked when
support for the RX-8035 was added, and was causing read errors when
the hour register 'overflowed'.

To deal with the relevant register not always being visible in
the relevant functions, determine the 12/24 mode at startup and
store it in the driver state.

Signed-off-by: Mathew McBride <matt@traverse.com.au>
Fixes: f120e2e33ac8 ("rtc: rx8025: implement RX-8035 support")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220706074236.24011-1-matt@traverse.com.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/rtc/rtc-rx8025.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)

--- a/drivers/rtc/rtc-rx8025.c
+++ b/drivers/rtc/rtc-rx8025.c
@@ -55,6 +55,8 @@
#define RX8025_BIT_CTRL2_XST BIT(5)
#define RX8025_BIT_CTRL2_VDET BIT(6)

+#define RX8035_BIT_HOUR_1224 BIT(7)
+
/* Clock precision adjustment */
#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
#define RX8025_ADJ_DATA_MAX 62
@@ -78,6 +80,7 @@ struct rx8025_data {
struct rtc_device *rtc;
enum rx_model model;
u8 ctrl1;
+ int is_24;
};

static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
@@ -226,7 +229,7 @@ static int rx8025_get_time(struct device

dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
- if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
+ if (rx8025->is_24)
dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
else
dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
@@ -254,7 +257,7 @@ static int rx8025_set_time(struct device
*/
date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
- if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
+ if (rx8025->is_24)
date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
else
date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
@@ -279,6 +282,7 @@ static int rx8025_init_client(struct i2c
struct rx8025_data *rx8025 = i2c_get_clientdata(client);
u8 ctrl[2], ctrl2;
int need_clear = 0;
+ int hour_reg;
int err;

err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
@@ -303,6 +307,16 @@ static int rx8025_init_client(struct i2c

err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
}
+
+ if (rx8025->model == model_rx_8035) {
+ /* In RX-8035, 12/24 flag is in the hour register */
+ hour_reg = rx8025_read_reg(client, RX8025_REG_HOUR);
+ if (hour_reg < 0)
+ return hour_reg;
+ rx8025->is_24 = (hour_reg & RX8035_BIT_HOUR_1224);
+ } else {
+ rx8025->is_24 = (ctrl[1] & RX8025_BIT_CTRL1_1224);
+ }
out:
return err;
}
@@ -329,7 +343,7 @@ static int rx8025_read_alarm(struct devi
/* Hardware alarms precision is 1 minute! */
t->time.tm_sec = 0;
t->time.tm_min = bcd2bin(ald[0] & 0x7f);
- if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
+ if (rx8025->is_24)
t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
else
t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
@@ -350,7 +364,7 @@ static int rx8025_set_alarm(struct devic
int err;

ald[0] = bin2bcd(t->time.tm_min);
- if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
+ if (rx8025->is_24)
ald[1] = bin2bcd(t->time.tm_hour);
else
ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)