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[PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value

Finn Thain posted 2 patches 1 week, 3 days ago
[PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Finn Thain 1 week, 3 days ago 
Instead of hard-coded values and ifdefs, store the year offset in the
platform_data struct.

Tested-by: Daniel Palmer <daniel@0x0f.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
---
David, Andreas - with your acknowledgement, I will ask Alexandre to merge
this.
---
I tested this for regressions using qemu-system-sparc64.
Also, Daniel tested the RTC functionality on his MVME147 system.

Changed since v2:
 - Use an int for the year offset in struct m48t59_plat_data.

Changed since v3:
 - Added reviewed-by tag from Geert.
---
 arch/sparc/kernel/time_32.c |  1 +
 arch/sparc/kernel/time_64.c |  1 +
 drivers/rtc/rtc-m48t59.c    | 26 ++++----------------------
 include/linux/rtc/m48t59.h  |  3 +++
 4 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c
index 08bbdc458596..578fd0d49f30 100644
--- a/arch/sparc/kernel/time_32.c
+++ b/arch/sparc/kernel/time_32.c
@@ -255,6 +255,7 @@ static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 static struct m48t59_plat_data m48t59_data = {
 	.read_byte = mostek_read_byte,
 	.write_byte = mostek_write_byte,
+	.yy_offset = 68,
 };
 
 /* resource is set at runtime */
diff --git a/arch/sparc/kernel/time_64.c b/arch/sparc/kernel/time_64.c
index 60f1c8cc5363..b32f27f929d1 100644
--- a/arch/sparc/kernel/time_64.c
+++ b/arch/sparc/kernel/time_64.c
@@ -544,6 +544,7 @@ static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 static struct m48t59_plat_data m48t59_data = {
 	.read_byte	= mostek_read_byte,
 	.write_byte	= mostek_write_byte,
+	.yy_offset	= 68,
 };
 
 static struct platform_device m48t59_rtc = {
diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
index 5d30ce8e13ca..4e608bc8bbd3 100644
--- a/drivers/rtc/rtc-m48t59.c
+++ b/drivers/rtc/rtc-m48t59.c
@@ -71,7 +71,7 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	/* Issue the READ command */
 	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 
-	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR));
+	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
 	/* tm_mon is 0-11 */
 	tm->tm_mon	= bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
 	tm->tm_mday	= bcd2bin(M48T59_READ(M48T59_MDAY));
@@ -82,10 +82,6 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		dev_dbg(dev, "Century bit is enabled\n");
 		tm->tm_year += 100;	/* one century */
 	}
-#ifdef CONFIG_SPARC
-	/* Sun SPARC machines count years since 1968 */
-	tm->tm_year += 68;
-#endif
 
 	tm->tm_wday	= bcd2bin(val & 0x07);
 	tm->tm_hour	= bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
@@ -106,12 +102,7 @@ static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
 	unsigned long flags;
 	u8 val = 0;
-	int year = tm->tm_year;
-
-#ifdef CONFIG_SPARC
-	/* Sun SPARC machines count years since 1968 */
-	year -= 68;
-#endif
+	int year = tm->tm_year - pdata->yy_offset;
 
 	dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
 		year + 1900, tm->tm_mon, tm->tm_mday,
@@ -162,11 +153,7 @@ static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	/* Issue the READ command */
 	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
 
-	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
-#ifdef CONFIG_SPARC
-	/* Sun SPARC machines count years since 1968 */
-	tm->tm_year += 68;
-#endif
+	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
 	/* tm_mon is 0-11 */
 	tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
 
@@ -197,12 +184,7 @@ static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct rtc_time *tm = &alrm->time;
 	u8 mday, hour, min, sec;
 	unsigned long flags;
-	int year = tm->tm_year;
-
-#ifdef CONFIG_SPARC
-	/* Sun SPARC machines count years since 1968 */
-	year -= 68;
-#endif
+	int year = tm->tm_year - pdata->yy_offset;
 
 	/* If no irq, we don't support ALARM */
 	if (m48t59->irq == NO_IRQ)
diff --git a/include/linux/rtc/m48t59.h b/include/linux/rtc/m48t59.h
index 9465d5405fe2..373ba77071c6 100644
--- a/include/linux/rtc/m48t59.h
+++ b/include/linux/rtc/m48t59.h
@@ -56,6 +56,9 @@ struct m48t59_plat_data {
 	void __iomem *ioaddr;
 	/* offset to RTC registers, automatically set according to the type */
 	unsigned int offset;
+
+	/* YY digits (in RTC) are offset, i.e. year is 1900 + yy_offset + YY */
+	int yy_offset;
 };
 
 #endif /* _LINUX_RTC_M48T59_H_ */
-- 
2.44.2
Re: [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Andreas Larsson 1 week ago 
On 2024-11-12 23:32, Finn Thain wrote:
> Instead of hard-coded values and ifdefs, store the year offset in the
> platform_data struct.
> 
> Tested-by: Daniel Palmer <daniel@0x0f.com>
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Finn Thain <fthain@linux-m68k.org>
> ---
> David, Andreas - with your acknowledgement, I will ask Alexandre to merge
> this.
> ---
> I tested this for regressions using qemu-system-sparc64.
> Also, Daniel tested the RTC functionality on his MVME147 system.
> 
> Changed since v2:
>  - Use an int for the year offset in struct m48t59_plat_data.
> 
> Changed since v3:
>  - Added reviewed-by tag from Geert.
> ---
>  arch/sparc/kernel/time_32.c |  1 +
>  arch/sparc/kernel/time_64.c |  1 +
>  drivers/rtc/rtc-m48t59.c    | 26 ++++----------------------
>  include/linux/rtc/m48t59.h  |  3 +++
>  4 files changed, 9 insertions(+), 22 deletions(-)
> 
> diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c
> index 08bbdc458596..578fd0d49f30 100644
> --- a/arch/sparc/kernel/time_32.c
> +++ b/arch/sparc/kernel/time_32.c
> @@ -255,6 +255,7 @@ static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
>  static struct m48t59_plat_data m48t59_data = {
>  	.read_byte = mostek_read_byte,
>  	.write_byte = mostek_write_byte,
> +	.yy_offset = 68,
>  };
>  
>  /* resource is set at runtime */
> diff --git a/arch/sparc/kernel/time_64.c b/arch/sparc/kernel/time_64.c
> index 60f1c8cc5363..b32f27f929d1 100644
> --- a/arch/sparc/kernel/time_64.c
> +++ b/arch/sparc/kernel/time_64.c
> @@ -544,6 +544,7 @@ static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
>  static struct m48t59_plat_data m48t59_data = {
>  	.read_byte	= mostek_read_byte,
>  	.write_byte	= mostek_write_byte,
> +	.yy_offset	= 68,
>  };
>  
>  static struct platform_device m48t59_rtc = {
> diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
> index 5d30ce8e13ca..4e608bc8bbd3 100644
> --- a/drivers/rtc/rtc-m48t59.c
> +++ b/drivers/rtc/rtc-m48t59.c
> @@ -71,7 +71,7 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
>  	/* Issue the READ command */
>  	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
>  
> -	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR));
> +	tm->tm_year	= bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
>  	/* tm_mon is 0-11 */
>  	tm->tm_mon	= bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
>  	tm->tm_mday	= bcd2bin(M48T59_READ(M48T59_MDAY));
> @@ -82,10 +82,6 @@ static int m48t59_rtc_read_time(struct device *dev, struct rtc_time *tm)
>  		dev_dbg(dev, "Century bit is enabled\n");
>  		tm->tm_year += 100;	/* one century */
>  	}
> -#ifdef CONFIG_SPARC
> -	/* Sun SPARC machines count years since 1968 */
> -	tm->tm_year += 68;
> -#endif
>  
>  	tm->tm_wday	= bcd2bin(val & 0x07);
>  	tm->tm_hour	= bcd2bin(M48T59_READ(M48T59_HOUR) & 0x3F);
> @@ -106,12 +102,7 @@ static int m48t59_rtc_set_time(struct device *dev, struct rtc_time *tm)
>  	struct m48t59_private *m48t59 = dev_get_drvdata(dev);
>  	unsigned long flags;
>  	u8 val = 0;
> -	int year = tm->tm_year;
> -
> -#ifdef CONFIG_SPARC
> -	/* Sun SPARC machines count years since 1968 */
> -	year -= 68;
> -#endif
> +	int year = tm->tm_year - pdata->yy_offset;
>  
>  	dev_dbg(dev, "RTC set time %04d-%02d-%02d %02d/%02d/%02d\n",
>  		year + 1900, tm->tm_mon, tm->tm_mday,
> @@ -162,11 +153,7 @@ static int m48t59_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
>  	/* Issue the READ command */
>  	M48T59_SET_BITS(M48T59_CNTL_READ, M48T59_CNTL);
>  
> -	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR));
> -#ifdef CONFIG_SPARC
> -	/* Sun SPARC machines count years since 1968 */
> -	tm->tm_year += 68;
> -#endif
> +	tm->tm_year = bcd2bin(M48T59_READ(M48T59_YEAR)) + pdata->yy_offset;
>  	/* tm_mon is 0-11 */
>  	tm->tm_mon = bcd2bin(M48T59_READ(M48T59_MONTH)) - 1;
>  
> @@ -197,12 +184,7 @@ static int m48t59_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
>  	struct rtc_time *tm = &alrm->time;
>  	u8 mday, hour, min, sec;
>  	unsigned long flags;
> -	int year = tm->tm_year;
> -
> -#ifdef CONFIG_SPARC
> -	/* Sun SPARC machines count years since 1968 */
> -	year -= 68;
> -#endif
> +	int year = tm->tm_year - pdata->yy_offset;
>  
>  	/* If no irq, we don't support ALARM */
>  	if (m48t59->irq == NO_IRQ)
> diff --git a/include/linux/rtc/m48t59.h b/include/linux/rtc/m48t59.h
> index 9465d5405fe2..373ba77071c6 100644
> --- a/include/linux/rtc/m48t59.h
> +++ b/include/linux/rtc/m48t59.h
> @@ -56,6 +56,9 @@ struct m48t59_plat_data {
>  	void __iomem *ioaddr;
>  	/* offset to RTC registers, automatically set according to the type */
>  	unsigned int offset;
> +
> +	/* YY digits (in RTC) are offset, i.e. year is 1900 + yy_offset + YY */
> +	int yy_offset;
>  };
>  
>  #endif /* _LINUX_RTC_M48T59_H_ */

Tested-by: Andreas Larsson <andreas@gaisler.com>
Acked-by: Andreas Larsson <andreas@gaisler.com>

Thanks,
Andreas
Re: (subset) [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Alexandre Belloni 4 days, 22 hours ago 
On Wed, 13 Nov 2024 09:32:15 +1100, Finn Thain wrote:
> Instead of hard-coded values and ifdefs, store the year offset in the
> platform_data struct.
> 
> 

Applied, thanks!

[1/2] rtc: m48t59: Use platform_data struct for year offset value
      https://git.kernel.org/abelloni/c/a06e4a93067c

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Re: (subset) [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Finn Thain 2 days, 13 hours ago 
On Mon, 18 Nov 2024, Alexandre Belloni wrote:

> On Wed, 13 Nov 2024 09:32:15 +1100, Finn Thain wrote:
> > Instead of hard-coded values and ifdefs, store the year offset in the
> > platform_data struct.
> > 
> > 
> 
> Applied, thanks!
> 
> [1/2] rtc: m48t59: Use platform_data struct for year offset value
>       https://git.kernel.org/abelloni/c/a06e4a93067c
> 

Thanks, Alexandre. Would you also take patch 2/2, please? Geert has sent a 
reviewed-by tag for that one too.
Re: (subset) [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Alexandre Belloni 1 day, 18 hours ago 
On 21/11/2024 09:13:32+1100, Finn Thain wrote:
> 
> On Mon, 18 Nov 2024, Alexandre Belloni wrote:
> 
> > On Wed, 13 Nov 2024 09:32:15 +1100, Finn Thain wrote:
> > > Instead of hard-coded values and ifdefs, store the year offset in the
> > > platform_data struct.
> > > 
> > > 
> > 
> > Applied, thanks!
> > 
> > [1/2] rtc: m48t59: Use platform_data struct for year offset value
> >       https://git.kernel.org/abelloni/c/a06e4a93067c
> > 
> 
> Thanks, Alexandre. Would you also take patch 2/2, please? Geert has sent a 
> reviewed-by tag for that one too.

I thought Geert would take it as this only touches arch/m68k

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Re: (subset) [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Finn Thain 1 day, 13 hours ago 
On Thu, 21 Nov 2024, Alexandre Belloni wrote:

> On 21/11/2024 09:13:32+1100, Finn Thain wrote:
> > 
> > On Mon, 18 Nov 2024, Alexandre Belloni wrote:
> > 
> > > On Wed, 13 Nov 2024 09:32:15 +1100, Finn Thain wrote:
> > > > Instead of hard-coded values and ifdefs, store the year offset in the
> > > > platform_data struct.
> > > > 
> > > > 
> > > 
> > > Applied, thanks!
> > > 
> > > [1/2] rtc: m48t59: Use platform_data struct for year offset value
> > >       https://git.kernel.org/abelloni/c/a06e4a93067c
> > > 
> > 
> > Thanks, Alexandre. Would you also take patch 2/2, please? Geert has sent a 
> > reviewed-by tag for that one too.
> 
> I thought Geert would take it as this only touches arch/m68k
> 

That's quite understandable -- I accidentally addressed it "To: Geert". 
Sorry for any confusion caused.

Anyway, would you please pick up patch 2/2 also? After all, patch 2/2 is 
the reason why patch 1/2 exists. Indeed, 1/2 was written several years 
after 2/2, in response to your recent review of 2/2.
Re: (subset) [PATCH v4 1/2] rtc: m48t59: Use platform_data struct for year offset value
Posted by Geert Uytterhoeven 1 day, 17 hours ago 
Hi Alexandre,

On Thu, Nov 21, 2024 at 6:46 PM Alexandre Belloni
<alexandre.belloni@bootlin.com> wrote:
> On 21/11/2024 09:13:32+1100, Finn Thain wrote:
> > On Mon, 18 Nov 2024, Alexandre Belloni wrote:
> > > On Wed, 13 Nov 2024 09:32:15 +1100, Finn Thain wrote:
> > > > Instead of hard-coded values and ifdefs, store the year offset in the
> > > > platform_data struct.
> > >
> > > Applied, thanks!
> > >
> > > [1/2] rtc: m48t59: Use platform_data struct for year offset value
> > >       https://git.kernel.org/abelloni/c/a06e4a93067c
> >
> > Thanks, Alexandre. Would you also take patch 2/2, please? Geert has sent a
> > reviewed-by tag for that one too.
>
> I thought Geert would take it as this only touches arch/m68k

I can do that only after v6.13-rc1 has been released, due to the hard
dependency on the new m48t59_plat_data.yy_offset member.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

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