Dear Alexandre,
Thanks for your comments.
The replies are as follow.
Thanks.
Best regard,
Mia
Sent from my iPhone
> On Nov 4, 2023, at 7:16 AM, Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> wrote:
>
> On 13/09/2023 09:37:19+0800, Mia Lin wrote:
>> The NCT3015Y-R and NCT3018Y-R use the same datasheet
>> but have different topologies as follows.
>> - Topology (Only 1st i2c can set TWO bit and HF bit)
>> In NCT3015Y-R,
>> rtc 1st i2c is connected to a host CPU
>> rtc 2nd i2c is connected to a BMC
>> In NCT3018Y-R,
>> rtc 1st i2c is connected to a BMC
>> rtc 2nd i2c is connected to a host CPU
>> In order to be compatible with NCT3015Y-R and NCT3018Y-R,
>> - 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 | 52 +++++++++++++++++++++++++++++++++-----
>> 1 file changed, 46 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/rtc/rtc-nct3018y.c b/drivers/rtc/rtc-nct3018y.c
>> index ed4e606be8e5..b006b58e15e2 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)
>> @@ -37,10 +38,12 @@
>> #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;
>> struct i2c_client *client;
>> + int part_num;
>> #ifdef CONFIG_COMMON_CLK
>> struct clk_hw clkout_hw;
>> #endif
>> @@ -177,8 +180,27 @@ static int nct3018y_rtc_read_time(struct device *dev, struct rtc_time *tm)
>> static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
>> {
>> struct i2c_client *client = to_i2c_client(dev);
>> + struct nct3018y *nct3018y = dev_get_drvdata(dev);
>> unsigned char buf[4] = {0};
>> - int err;
>> + int err, flags;
>> + int restore_flags = 0;
>> +
>> + flags = i2c_smbus_read_byte_data(client, NCT3018Y_REG_CTRL);
>> + if (flags < 0) {
>> + dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_CTRL.\n");
>> + return flags;
>> + }
>> +
>> + /* Check and set TWO bit */
>> + if ((nct3018y->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 +234,18 @@ static int nct3018y_rtc_set_time(struct device *dev, struct rtc_time *tm)
>> return -EIO;
>> }
>>
>> + /* Restore TWO bit */
>> + if (restore_flags) {
>> + if (nct3018y->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 +513,17 @@ 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;
>> + nct3018y->part_num = i2c_smbus_read_byte_data(client, NCT3018Y_REG_PART);
>> + if (nct3018y->part_num < 0) {
>> + dev_dbg(&client->dev, "Failed to read NCT3018Y_REG_PART.\n");
>> + return nct3018y->part_num;
>> + } else if (nct3018y->part_num & NCT3018Y_REG_PART_NCT3018Y) {
>
> This is a weird way to check as this will accept any value of
> NCT3018Y_REG_PART as long as bit 1 is set, is this really what you want?
［Mia] Thanks for your comments. I’ll fix it.
>
>> + 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
>>
>
> --
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com
