Re: [PATCH v2 2/2] rtc: nuvoton: Compatible with NCT3015Y-R and NCT3018Y-R
From: Paul Menzel
Date: Thu Aug 10 2023 - 04:16:37 EST
Dear Mia,
Thank you for your patch.
It’d be great if you made the commit message summary/title more
specific. Maybe:
Add support for NCT3015Y-R
Am 09.08.23 um 11:51 schrieb Mia Lin:
An introduction what the NCT3015Y-R is and listing the differences to
NCT3018Y-R would be nice.
- 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.
Why? This also looks unrelated to the NCT3015Y-R support. Could you
factor it out into separate patch?
- Use DT compatible to check the chip matches or not.
Could you please add the datasheet name and revision?
Signed-off-by: Mia Lin <mimi05633@xxxxxxxxx>
---
drivers/rtc/rtc-nct3018y.c | 88 +++++++++++++++++++++++++++++++++-----
1 file changed, 78 insertions(+), 10 deletions(-)
diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c
index a4e3f924837e..edc73be3ab59 100644
--- a/drivers/rtc/rtc-nct3018y.c
+++ b/drivers/rtc/rtc-nct3018y.c
@@ -7,6 +7,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
@@ -23,6 +24,7 @@
#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 +39,20 @@
#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_NCT3015Y 0x01
+#define NCT3018Y_REG_PART_NCT3018Y 0x02
+
+struct rtc_data {
+ u8 part_number;
+};
+
+static const struct rtc_data nct3015y_rtc_data = {
+ .part_number = NCT3018Y_REG_PART_NCT3015Y,
+};
+
+static const struct rtc_data nct3018y_rtc_data = {
+ .part_number = NCT3018Y_REG_PART_NCT3018Y,
+};
struct nct3018y {
struct rtc_device *rtc;
@@ -52,7 +68,7 @@ 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 +125,10 @@ 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);
+ }
The two hunks look like unrelated fixes. It’d be great, if you factored
those out into a separate patch.
return 0;
}
@@ -178,7 +196,30 @@ 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;
Why is err now initialized to 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__);
Could you make these distinct error messages, so users are able to
pinpoint the correct location right away? (Or does `dev_dbg` already
provide that information? Maybe the line? (Also more cases below.)
+ 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 +253,18 @@ 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;
}
@@ -456,6 +509,7 @@ static int nct3018y_probe(struct i2c_client *client)
{
struct nct3018y *nct3018y;
int err, flags;
+ const struct rtc_data *data = of_device_get_match_data(&client->dev);
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_BYTE |
@@ -479,11 +533,24 @@ 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) {
+ if (!(flags & data->part_number))
+ dev_warn(&client->dev, "%s: part_num=0x%x but NCT3018Y_REG_PART=0x%x\n",
+ __func__, data->part_number, flags);
+ 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;
+ }
+ } else if (flags & NCT3018Y_REG_PART_NCT3015Y) {
+ if (!(flags & data->part_number))
+ dev_warn(&client->dev, "%s: part_num=0x%x but NCT3018Y_REG_PART=0x%x\n",
+ __func__, data->part_number, flags);
}
flags = 0;
@@ -530,7 +597,8 @@ static const struct i2c_device_id nct3018y_id[] = {
MODULE_DEVICE_TABLE(i2c, nct3018y_id);
static const struct of_device_id nct3018y_of_match[] = {
- { .compatible = "nuvoton,nct3018y" },
+ { .compatible = "nuvoton,nct3015y", .data = &nct3015y_rtc_data },
+ { .compatible = "nuvoton,nct3018y", .data = &nct3018y_rtc_data },
{}
};
MODULE_DEVICE_TABLE(of, nct3018y_of_match);
Kind regards,
Paul