[U-Boot] [EXT] Re: [PATCH v3] rtc: Add DM support to ds3231

Chuanhua Han chuanhua.han at nxp.com
Fri Jun 21 06:23:49 UTC 2019



> -----Original Message-----
> From: Lukasz Majewski <lukma at denx.de>
> Sent: 2019年6月21日 13:52
> To: Chuanhua Han <chuanhua.han at nxp.com>
> Cc: Prabhakar Kushwaha <prabhakar.kushwaha at nxp.com>;
> u-boot at lists.denx.de
> Subject: [EXT] Re: [PATCH v3] rtc: Add DM support to ds3231
> 
> On Fri, 21 Jun 2019 12:17:00 +0800
> Chuanhua Han <chuanhua.han at nxp.com> wrote:
> 
> > Add an implementation of the ds3231 driver that uses the driver model
> > i2c APIs.
> >
> > Signed-off-by: Chuanhua Han <chuanhua.han at nxp.com>
> > ---
> > Changes in v3:
> > 	- Update copyright information.
> >
> > Changes in v2:
> >         - Replace "#ifndef CONFIG_DM_RTC" with "#if
> > !CONFIG_IS_ENABLED(DM_RTC)"
> >
> >  drivers/rtc/ds3231.c | 108
> > +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 108
> > insertions(+)
> >
> > diff --git a/drivers/rtc/ds3231.c b/drivers/rtc/ds3231.c index
> > 9352ff87a2..86f1c3e899 100644
> > --- a/drivers/rtc/ds3231.c
> > +++ b/drivers/rtc/ds3231.c
> > @@ -2,6 +2,9 @@
> >  /*
> >   * (C) Copyright 2006
> >   * Markus Klotzbuecher, mk at denx.de
> > + *
> > + * (C) Copyright 2019 NXP
> > + * Chuanhua Han <chuanhua.han at nxp.com>
> >   */
> >
> >  /*
> > @@ -13,6 +16,7 @@
> >
> >  #include <common.h>
> >  #include <command.h>
> > +#include <dm.h>
> >  #include <rtc.h>
> >  #include <i2c.h>
> >
> > @@ -50,6 +54,7 @@
> >  #define RTC_STAT_BIT_EN32KHZ	0x8	/* Enable 32KHz
> > Output  */
> >
> > +#if !CONFIG_IS_ENABLED(DM_RTC)
> >  static uchar rtc_read (uchar reg);
> >  static void rtc_write (uchar reg, uchar val);
> >
> > @@ -164,3 +169,106 @@ static void rtc_write (uchar reg, uchar val)  {
> >  	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);  }
> > +#else
> > +static int ds3231_rtc_get(struct udevice *dev, struct rtc_time *tmp)
> > +{
> > +	int rel = 0;
> > +	uchar sec, min, hour, mday, wday, mon_cent, year, status;
> > +
> > +	status = dm_i2c_reg_read(dev, RTC_STAT_REG_ADDR);
> > +	sec = dm_i2c_reg_read(dev, RTC_SEC_REG_ADDR);
> > +	min = dm_i2c_reg_read(dev, RTC_MIN_REG_ADDR);
> > +	hour = dm_i2c_reg_read(dev, RTC_HR_REG_ADDR);
> > +	wday = dm_i2c_reg_read(dev, RTC_DAY_REG_ADDR);
> > +	mday = dm_i2c_reg_read(dev, RTC_DATE_REG_ADDR);
> > +	mon_cent = dm_i2c_reg_read(dev, RTC_MON_REG_ADDR);
> > +	year = dm_i2c_reg_read(dev, RTC_YR_REG_ADDR);
> > +
> > +	if (status & RTC_STAT_BIT_OSF) {
> > +		printf("### Warning: RTC oscillator has stopped\n");
> > +		/* clear the OSF flag */
> > +		dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
> > +				 dm_i2c_reg_read(dev,
> > RTC_STAT_REG_ADDR)
> > +						& ~RTC_STAT_BIT_OSF);
> > +		rel = -1;
> 
> A few remarks regarding above code:
> 
> 1. By conversion we do use 'ret' instead of 'rel'. Is the 'rel' name itself here
> important?
> 
> 2. The OSF bit - why shall we return from ds3231_rtc_get() with -1 (by
> convention it is an error) if this flag is set?
> 
> 3. The '-1' value does not show the real reason for the error. Maybe some
> standard value (like e.g. -EINVAL, -ENODEV, -EIO) from errno.h would be more
> appropriate?
OK,I will modify!
> 
> > +	}
> > +
> > +	tmp->tm_sec  = bcd2bin(sec & 0x7F);
> > +	tmp->tm_min  = bcd2bin(min & 0x7F);
> > +	tmp->tm_hour = bcd2bin(hour & 0x3F);
> > +	tmp->tm_mday = bcd2bin(mday & 0x3F);
> > +	tmp->tm_mon  = bcd2bin(mon_cent & 0x1F);
> > +	tmp->tm_year = bcd2bin(year) + ((mon_cent & 0x80) ? 2000 :
> > 1900);
> > +	tmp->tm_wday = bcd2bin((wday - 1) & 0x07);
> > +	tmp->tm_yday = 0;
> > +	tmp->tm_isdst = 0;
> > +
> > +	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME:
> > %2d:%02d:%02d\n",
> > +	      tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
> > +	      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
> > +
> > +	return rel;
> > +}
> > +
> > +static int ds3231_rtc_set(struct udevice *dev, const struct rtc_time
> > *tmp) +{
> > +	uchar century;
> > +
> > +	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME:
> > %2d:%02d:%02d\n",
> > +	      tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
> > +	      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
> > +
> > +	dm_i2c_reg_write(dev, RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year
> > % 100)); +
> > +	century = (tmp->tm_year >= 2000) ? 0x80 : 0;
> > +	dm_i2c_reg_write(dev, RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon)
> > | century); +
> > +	dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday
> 1));
> > +	dm_i2c_reg_write(dev, RTC_DATE_REG_ADDR,
> > bin2bcd(tmp->tm_mday));
> > +	dm_i2c_reg_write(dev, RTC_HR_REG_ADDR,
> > bin2bcd(tmp->tm_hour));
> > +	dm_i2c_reg_write(dev, RTC_MIN_REG_ADDR,
> > bin2bcd(tmp->tm_min));
> > +	dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
> > bin2bcd(tmp->tm_sec)); +
> > +	return 0;
> > +}
> > +
> > +static int ds3231_rtc_reset(struct udevice *dev) {
> > +	int ret;
> > +
> > +	ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
> > +			       RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS2);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	return 0;
> > +}
> > +
> > +static int ds3231_probe(struct udevice *dev) {
> > +	i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
> > +			DM_I2C_CHIP_WR_ADDRESS);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct rtc_ops ds3231_rtc_ops = {
> > +	.get = ds3231_rtc_get,
> > +	.set = ds3231_rtc_set,
> > +	.reset = ds3231_rtc_reset,
> > +};
> > +
> > +static const struct udevice_id ds3231_rtc_ids[] = {
> > +	{ .compatible = "dallas,ds3231" },
> > +	{ .compatible = "dallas,ds3232" },
> > +	{ }
> > +};
> > +
> > +U_BOOT_DRIVER(rtc_ds3231) = {
> > +	.name   = "rtc-ds3231",
> > +	.id     = UCLASS_RTC,
> > +	.probe  = ds3231_probe,
> > +	.of_match = ds3231_rtc_ids,
> > +	.ops    = &ds3231_rtc_ops,
> > +};
> > +#endif
> 
> 
> 
> 
> 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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