[PATCH v6 1/1] rtc: nuvoton: Compatible with NCT3015Y-R and NCT3018Y-R

[Mining Lin]

Dear Alexandre,

I will add change log next patch.

Thanks.
Best regard,
Mia

Sent from my iPhone

> On Nov 4, 2023, at 7:17 AM, Alexandre Belloni <alexandre.belloni at bootlin.com> wrote:
> 
> On 04/11/2023 00:16:40+0100, Alexandre Belloni 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 at gmail.com>
>>> ---
> 
> I forgot to add, please include a changelog here, this will make my
> reviews easier (and faster).
> 
>>> 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?
>> 
>>> +        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
> 
> -- 
> Alexandre Belloni, co-owner and COO, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com