RE: [PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC

["Devang Tailor" <dev.tailor@samsung.com>]

Hi Krzysztof,


> -----Original Message-----
> From: Krzysztof Kozlowski <krzk@kernel.org>
> Sent: 07 July 2025 14:54
> To: Devang Tailor <dev.tailor@samsung.com>;
> alexandre.belloni@bootlin.com; robh@kernel.org; krzk+dt@kernel.org;
> conor+dt@kernel.org; alim.akhtar@samsung.com; linux-rtc@vger.kernel.org;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org; inux-arm-
> kernel@lists.infradead.org; linux-samsung-soc@vger.kernel.org;
> faraz.ata@samsung.com
> Subject: Re: [PATCH 2/3] rtc: s3c: support for exynosautov9 on-chip RTC
> 
> On 02/07/2025 07:24, Devang Tailor wrote:
> > The on-chip RTC of this SoC is almost similar to the previous versions
> > of SoC. Hence re-use the existing driver with platform specific change
> > to enable RTC.
> >
> > This has been tested with 'hwclock' & 'date' utilities
> >
> > Signed-off-by: Devang Tailor <dev.tailor@samsung.com>
> > ---
> >  drivers/rtc/rtc-s3c.c | 26 ++++++++++++++++++++++++++
> > drivers/rtc/rtc-s3c.h |  4 ++++
> >  2 files changed, 30 insertions(+)
> >
> > diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c index
> > 5dd575865adf..00686aa805f2 100644
> > --- a/drivers/rtc/rtc-s3c.c
> > +++ b/drivers/rtc/rtc-s3c.c
> > @@ -384,6 +384,23 @@ static void s3c6410_rtc_disable(struct s3c_rtc
> *info)
> >  	writew(con, info->base + S3C2410_RTCCON);  }
> >
> > +static void exynosautov9_rtc_disable(struct s3c_rtc *info) {
> > +	unsigned int con;
> > +
> > +	con = readb(info->base + S3C2410_RTCCON);
> > +	con &= ~S3C2410_RTCCON_RTCEN;
> > +	writeb(con, info->base + S3C2410_RTCCON);
> > +
> > +	con = readb(info->base + EXYNOSAUTOV9_TICCON0);
> > +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> > +	writeb(con, info->base + EXYNOSAUTOV9_TICCON0);
> > +
> > +	con = readb(info->base + EXYNOSAUTOV9_TICCON1);
> > +	con &= ~EXYNOSAUTOV9_TICCON_TICEN;
> > +	writeb(con, info->base + EXYNOSAUTOV9_TICCON1);
> 
> You clear these bits during disable, but why aren't they set during enable?
> Why is this asymmetric? This should be clearly explained, but both commit
> msg and code is completely silent.

OK. I will correct in V2 patch

> 
> > +}
> > +
> >  static void s3c_rtc_remove(struct platform_device *pdev)  {
> >  	struct s3c_rtc *info = platform_get_drvdata(pdev); @@ -574,6 +591,12
> > @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
> >  	.disable		= s3c6410_rtc_disable,
> >  };
> >
> > +static struct s3c_rtc_data const exynosautov9_rtc_data = {
> 
> Please put const after static.

I tried to keep it similar to the existing format, I will correct it in V2 patch.

> 
> 
> 
> Best regards,
> Krzysztof