[U-Boot] [PATCH 2/2] rtc: pcf2127: Fixed bug with rtc settings and getting error time

[Lukasz Majewski]

Hi Chuanhua,

> The previous pcf2127 RTC chip could not read and set the correct time.
> When reading the data of internal registers, the read address was the
> value of register plus 1. This is because this chip requires the host
> to send a stop signal after setting the register address and before
> reading the register data.
> 
> This patch sets the DM_I2C_CHIP_ADDR_STOP flag in order to
> generate a stop signal and fixes the bug of the original read and
> write time.

Thank you for the patch. It now looks far more better than the previous
versions.

It is not using generic flag and can be reused by other ICs with
similar issues.

Let's wait for Heiko's opinion.

Reviewed-by: Lukasz Majewski <lukma at denx.de>

> 
> Signed-off-by: Biwen Li <biwen.li at nxp.com>
> Signed-off-by: Chuanhua Han <chuanhua.han at nxp.com>
> ---
> Changes in v4:
> 	- Replace DM_I2C_CHIP_RD_NO_I2C_SETUP_OFFSET with
> DM_I2C_CHIP_ADDR_STOP.
> 
> Changes in v3:
> 	- When the rtc time is obtained, the address of the set
> register is separated from the read data.
> 
> Changes in v2: 
>         - Split the original patch into 3 patches
>         - Add detailed description information for each patch
> 
>  drivers/rtc/pcf2127.c | 20 ++++++++++++++------
>  1 file changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/rtc/pcf2127.c b/drivers/rtc/pcf2127.c
> index dcf0340b4d..65794b98e6 100644
> --- a/drivers/rtc/pcf2127.c
> +++ b/drivers/rtc/pcf2127.c
> @@ -24,12 +24,9 @@
>  
>  static int pcf2127_rtc_set(struct udevice *dev, const struct
> rtc_time *tm) {
> -	uchar buf[8];
> +	uchar buf[7] = {0};
>  	int i = 0, ret;
>  
> -	/* start register address */
> -	buf[i++] = PCF2127_REG_SC;
> -
>  	/* hours, minutes and seconds */
>  	buf[i++] = bin2bcd(tm->tm_sec);
>  	buf[i++] = bin2bcd(tm->tm_min);
> @@ -44,7 +41,7 @@ static int pcf2127_rtc_set(struct udevice *dev,
> const struct rtc_time *tm) buf[i++] = bin2bcd(tm->tm_year % 100);
>  
>  	/* write register's data */
> -	ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
> +	ret = dm_i2c_write(dev, PCF2127_REG_SC, buf, i);
>  
>  	return ret;
>  }
> @@ -54,9 +51,12 @@ static int pcf2127_rtc_get(struct udevice *dev,
> struct rtc_time *tm) int ret = 0;
>  	uchar buf[10] = { PCF2127_REG_CTRL1 };
>  
> -	ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, buf, 1);
> +	/* Set the address of the start register to be read */
> +	ret = dm_i2c_write(dev, PCF2127_REG_CTRL1, NULL, 0);
>  	if (ret < 0)
>  		return ret;
> +
> +	/* Read register's data */
>  	ret = dm_i2c_read(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
>  	if (ret < 0)
>  		return ret;
> @@ -90,6 +90,13 @@ static int pcf2127_rtc_reset(struct udevice *dev)
>  	return 0;
>  }
>  
> +static int pcf2127_probe(struct udevice *dev)
> +{
> +	i2c_set_chip_flags(dev, DM_I2C_CHIP_ADDR_STOP);
> +
> +	return 0;
> +}
> +
>  static const struct rtc_ops pcf2127_rtc_ops = {
>  	.get = pcf2127_rtc_get,
>  	.set = pcf2127_rtc_set,
> @@ -104,6 +111,7 @@ static const struct udevice_id pcf2127_rtc_ids[]
> = { U_BOOT_DRIVER(rtc_pcf2127) = {
>  	.name	= "rtc-pcf2127",
>  	.id	= UCLASS_RTC,
> +	.probe	= pcf2127_probe,
>  	.of_match = pcf2127_rtc_ids,
>  	.ops	= &pcf2127_rtc_ops,
>  };




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma at denx.de
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