[PATCH resubmit] rtc: ds1307: Detect oscillator fail on mcp794xx

[PATCH resubmit] rtc: ds1307: Detect oscillator fail on mcp794xx

[Csókás, Bence]

This patch enables the detection of the oscillator failure
on mcp794xx chips.

Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
---
 drivers/rtc/rtc-ds1307.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 506b7d1c2397..bdb7b201a160 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -65,6 +65,7 @@ enum ds_type {
 #	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
 #	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
 #define DS1307_REG_WDAY		0x03	/* 01-07 */
+#	define MCP794XX_BIT_OSCRUN	BIT(5)
 #	define MCP794XX_BIT_VBATEN	0x08
 #define DS1307_REG_MDAY		0x04	/* 01-31 */
 #define DS1307_REG_MONTH	0x05	/* 01-12 */
@@ -242,6 +243,10 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
 	    regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
 		dev_warn_once(dev, "oscillator failed, set time!\n");
 		return -EINVAL;
+	} else if (ds1307->type == mcp794xx &&
+	    !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_OSCRUN)) {
+		dev_warn_once(dev, "oscillator failed, set time!\n");
+		return -EINVAL;
 	}
 
 	tmp = regs[DS1307_REG_SECS];
-- 
2.34.1

Re: [PATCH resubmit] rtc: ds1307: Detect oscillator fail on mcp794xx

[Alexandre Belloni]

Hello,

It is not clear to me why your resent this one but not the other one,
can you elaborate?

On 21/06/2024 10:05:13+0200, Csókás, Bence wrote:
> This patch enables the detection of the oscillator failure
> on mcp794xx chips.
> 
> Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
> Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
> Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>
> ---
>  drivers/rtc/rtc-ds1307.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
> index 506b7d1c2397..bdb7b201a160 100644
> --- a/drivers/rtc/rtc-ds1307.c
> +++ b/drivers/rtc/rtc-ds1307.c
> @@ -65,6 +65,7 @@ enum ds_type {
>  #	define DS1340_BIT_CENTURY_EN	0x80	/* in REG_HOUR */
>  #	define DS1340_BIT_CENTURY	0x40	/* in REG_HOUR */
>  #define DS1307_REG_WDAY		0x03	/* 01-07 */
> +#	define MCP794XX_BIT_OSCRUN	BIT(5)
>  #	define MCP794XX_BIT_VBATEN	0x08
>  #define DS1307_REG_MDAY		0x04	/* 01-31 */
>  #define DS1307_REG_MONTH	0x05	/* 01-12 */
> @@ -242,6 +243,10 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t)
>  	    regs[DS1307_REG_MIN] & M41T0_BIT_OF) {
>  		dev_warn_once(dev, "oscillator failed, set time!\n");
>  		return -EINVAL;
> +	} else if (ds1307->type == mcp794xx &&
> +	    !(regs[DS1307_REG_WDAY] & MCP794XX_BIT_OSCRUN)) {
> +		dev_warn_once(dev, "oscillator failed, set time!\n");
> +		return -EINVAL;
>  	}
>  
>  	tmp = regs[DS1307_REG_SECS];
> -- 
> 2.34.1
> 
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH resubmit] rtc: ds1307: Detect oscillator fail on mcp794xx

[Csókás Bence]

Hi!

On 6/28/24 00:37, Alexandre Belloni wrote:
> Hello,
> 
> It is not clear to me why your resent this one but not the other one,
> can you elaborate?

It was kind of an unrelated patch, I'll send it after I get this one 
merged. But so far, there hasn't been any movements on this series at all.

> On 21/06/2024 10:05:13+0200, Csókás, Bence wrote:
>> This patch enables the detection of the oscillator failure
>> on mcp794xx chips.
>>
>> Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
>> Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
>> Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>

The "other one", I assume, refers to this:

On 6/11/24 09:24, Csókás, Bence wrote:
 > `tm_year` may go up to 299 if the device supports the
 > century bit. Therefore, subtracting may not give us
 > a valid 2-digit number, but modulo does.
 >
 > Co-developed-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
 > Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@prolan.hu>
 > Signed-off-by: Csókás, Bence <csokas.bence@prolan.hu>

And the only thing they had in common is that they were in the same 
file, which my colleague, Tamás, put into one commit in our tree, that I 
split for upstreaming purposes. But really, they are not really related 
or interdependent on one another.

Bence