[PATCH v3 1/1] rtc: nuvoton: Compatible with NCT3015Y-R and NCT3018Y-R

From: Mia Lin
Date: Thu Aug 10 2023 - 05:43:37 EST


- In probe,
If part number is NCT3018Y-R, only set HF bit to 24-Hour format.
Else, do nothing
- In set_time,
If part number is NCT3018Y-R && TWO bit is 0,
change TWO bit to 1, and restore TWO bit after updating time.

Signed-off-by: Mia Lin <mimi05633@xxxxxxxxx>
---
drivers/rtc/rtc-nct3018y.c | 63 ++++++++++++++++++++++++++++++++------
1 file changed, 54 insertions(+), 9 deletions(-)

diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c
index a4e3f924837e..bac1e3fbbbcd 100644
--- a/drivers/rtc/rtc-nct3018y.c
+++ b/drivers/rtc/rtc-nct3018y.c
@@ -23,6 +23,7 @@
#define NCT3018Y_REG_CTRL 0x0A /* timer control */
#define NCT3018Y_REG_ST 0x0B /* status */
#define NCT3018Y_REG_CLKO 0x0C /* clock out */
+#define NCT3018Y_REG_PART 0x21 /* part info */

#define NCT3018Y_BIT_AF BIT(7)
#define NCT3018Y_BIT_ST BIT(7)
@@ -37,6 +38,7 @@
#define NCT3018Y_REG_BAT_MASK 0x07
#define NCT3018Y_REG_CLKO_F_MASK 0x03 /* frequenc mask */
#define NCT3018Y_REG_CLKO_CKE 0x80 /* clock out enabled */
+#define NCT3018Y_REG_PART_NCT3018Y 0x02

struct nct3018y {
struct rtc_device *rtc;
@@ -52,7 +54,7 @@ static int nct3018y_set_alarm_mode(struct i2c_client *client, bool on)

dev_dbg(&client->dev, "%s:on:%d\n", __func__, on);

- flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
+ flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
if (flags < 0) {
dev_dbg(&client->dev,
"Failed to read NCT3018Y_REG_CTRL\n");
@@ -109,8 +111,10 @@ static int nct3018y_get_alarm_mode(struct i2c_client *client, unsigned char *ala
*alarm_flag = flags & NCT3018Y_BIT_AF;
}

- dev_dbg(&client->dev, "%s:alarm_enable:%x alarm_flag:%x\n",
- __func__, *alarm_enable, *alarm_flag);
+ if (alarm_enable && alarm_flag) {
+ dev_dbg(&client->dev, "%s:alarm_enable:%x alarm_flag:%x\n",
+ __func__, *alarm_enable, *alarm_flag);
+ }

return 0;
}
@@ -178,7 +182,30 @@ static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct i2c_client *client = to_i2c_client(dev);
unsigned char buf[4] = {0};
- int err;
+ int err, part_num, flags, restore_flags = 0;
+
+ part_num = i2c_smbus_read_byte_data(client, NCT3018Y_REG_PART);
+ if (part_num < 0) {
+ dev_dbg(&client->dev, "%s: read error\n", __func__);
+ return part_num;
+ }
+
+ flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
+ if (flags < 0) {
+ dev_dbg(&client->dev, "%s: read error\n", __func__);
+ return flags;
+ }
+
+ /* Check and set TWO bit */
+ if ((part_num & NCT3018Y_REG_PART_NCT3018Y) && !(flags & NCT3018Y_BIT_TWO)) {
+ restore_flags = 1;
+ flags |= NCT3018Y_BIT_TWO;
+ err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
+ return err;
+ }
+ }

buf[0] = bin2bcd(tm->tm_sec);
err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_SC, buf[0]);
@@ -212,6 +239,18 @@ static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
return -EIO;
}

+ /* Restore TWO bit */
+ if (restore_flags) {
+ if (part_num & NCT3018Y_REG_PART_NCT3018Y)
+ flags &= ~NCT3018Y_BIT_TWO;
+
+ err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
+ return err;
+ }
+ }
+
return err;
}

@@ -479,11 +518,17 @@ static int nct3018y_probe(struct i2c_client *client)
dev_dbg(&client->dev, "%s: NCT3018Y_BIT_TWO is set\n", __func__);
}

- flags = NCT3018Y_BIT_TWO;
- err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
- if (err < 0) {
- dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
- return err;
+ flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_PART);
+ if (flags < 0) {
+ dev_dbg(&client->dev, "%s: read error\n", __func__);
+ return flags;
+ } else if (flags & NCT3018Y_REG_PART_NCT3018Y) {
+ flags = NCT3018Y_BIT_HF;
+ err = i2c_smbus_write_byte_data(client, NCT3018Y_REG_CTRL, flags);
+ if (err < 0) {
+ dev_dbg(&client->dev, "Unable to write NCT3018Y_REG_CTRL\n");
+ return err;
+ }
}

flags = 0;
--
2.17.1