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

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Date: Fri, 28 Jun 2024 00:37:03 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Csókás, Bence <csokas.bence@...lan.hu>
Cc: linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
	Szentendrei, Tamás <szentendrei.tamas@...lan.hu>
Subject: Re: [PATCH resubmit] rtc: ds1307: Detect oscillator fail on mcp794xx

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@...lan.hu>
> Signed-off-by: Szentendrei, Tamás <szentendrei.tamas@...lan.hu>
> Signed-off-by: Csókás, Bence <csokas.bence@...lan.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