linux-kernel - Re: [PATCH v3 03/14] rtc: pcf2127: adapt for alarm registers at any offset

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Date:   Fri, 20 Jan 2023 18:10:36 +0100
From:   Alexandre Belloni <alexandre.belloni@...tlin.com>
To:     Hugo Villeneuve <hugo@...ovil.com>
Cc:     a.zummo@...ertech.it, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, linux-rtc@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        Hugo Villeneuve <hvilleneuve@...onoff.com>
Subject: Re: [PATCH v3 03/14] rtc: pcf2127: adapt for alarm registers at any
 offset

On 15/12/2022 10:02:04-0500, Hugo Villeneuve wrote:
> From: Hugo Villeneuve <hvilleneuve@...onoff.com>
> 
> This will simplify the implementation of new variants into this driver.
> 
> Signed-off-by: Hugo Villeneuve <hvilleneuve@...onoff.com>
> ---
>  drivers/rtc/rtc-pcf2127.c | 42 ++++++++++++++++++++++-----------------
>  1 file changed, 24 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> index fb0caacaabee..db0cb784c0c9 100644
> --- a/drivers/rtc/rtc-pcf2127.c
> +++ b/drivers/rtc/rtc-pcf2127.c
> @@ -56,11 +56,14 @@
>  /* Time and date registers bits */
>  #define PCF2127_BIT_SC_OSF			BIT(7)
>  /* Alarm registers */
> -#define PCF2127_REG_ALARM_SC		0x0A
> -#define PCF2127_REG_ALARM_MN		0x0B
> -#define PCF2127_REG_ALARM_HR		0x0C
> -#define PCF2127_REG_ALARM_DM		0x0D
> -#define PCF2127_REG_ALARM_DW		0x0E
> +#define PCF2127_REG_ALARM_BASE		0x0A
> +/* Alarm registers offsets (starting from base register) */
> +#define PCF2127_OFFSET_ALARM_SC		0
> +#define PCF2127_OFFSET_ALARM_MN		1
> +#define PCF2127_OFFSET_ALARM_HR		2
> +#define PCF2127_OFFSET_ALARM_DM		3
> +#define PCF2127_OFFSET_ALARM_DW		4
> +/* Alarm bits */
>  #define PCF2127_BIT_ALARM_AE			BIT(7)
>  /* CLKOUT control register */
>  #define PCF2127_REG_CLKOUT		0x0f
> @@ -110,6 +113,7 @@ struct pcf21xx_config {
>  	unsigned int has_nvmem:1;
>  	unsigned int has_bit_wd_ctl_cd0:1;
>  	u8 regs_td_base; /* Time/data base registers. */
> +	u8 regs_alarm_base; /* Alarm function base registers. */
>  };
>  
>  struct pcf2127 {
> @@ -402,18 +406,18 @@ static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>  	if (ret)
>  		return ret;
>  
> -	ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
> -			       sizeof(buf));
> +	ret = regmap_bulk_read(pcf2127->regmap, pcf2127->cfg->regs_alarm_base,
> +			       buf, sizeof(buf));
>  	if (ret)
>  		return ret;
>  
>  	alrm->enabled = ctrl2 & PCF2127_BIT_CTRL2_AIE;
>  	alrm->pending = ctrl2 & PCF2127_BIT_CTRL2_AF;
>  
> -	alrm->time.tm_sec = bcd2bin(buf[0] & 0x7F);
> -	alrm->time.tm_min = bcd2bin(buf[1] & 0x7F);
> -	alrm->time.tm_hour = bcd2bin(buf[2] & 0x3F);
> -	alrm->time.tm_mday = bcd2bin(buf[3] & 0x3F);
> +	alrm->time.tm_sec = bcd2bin(buf[PCF2127_OFFSET_ALARM_SC] & 0x7F);
> +	alrm->time.tm_min = bcd2bin(buf[PCF2127_OFFSET_ALARM_MN] & 0x7F);
> +	alrm->time.tm_hour = bcd2bin(buf[PCF2127_OFFSET_ALARM_HR] & 0x3F);
> +	alrm->time.tm_mday = bcd2bin(buf[PCF2127_OFFSET_ALARM_DM] & 0x3F);

I feel like this is adding defines for the sake of having defines. I
don't think this is particularly useful.


>  
>  	return 0;
>  }
> @@ -447,14 +451,14 @@ static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>  	if (ret)
>  		return ret;
>  
> -	buf[0] = bin2bcd(alrm->time.tm_sec);
> -	buf[1] = bin2bcd(alrm->time.tm_min);
> -	buf[2] = bin2bcd(alrm->time.tm_hour);
> -	buf[3] = bin2bcd(alrm->time.tm_mday);
> -	buf[4] = PCF2127_BIT_ALARM_AE; /* Do not match on week day */
> +	buf[PCF2127_OFFSET_ALARM_SC] = bin2bcd(alrm->time.tm_sec);
> +	buf[PCF2127_OFFSET_ALARM_MN] = bin2bcd(alrm->time.tm_min);
> +	buf[PCF2127_OFFSET_ALARM_HR] = bin2bcd(alrm->time.tm_hour);
> +	buf[PCF2127_OFFSET_ALARM_DM] = bin2bcd(alrm->time.tm_mday);
> +	buf[PCF2127_OFFSET_ALARM_DW] = PCF2127_BIT_ALARM_AE; /* Do not match on week day */
>  
> -	ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,
> -				sizeof(buf));
> +	ret = regmap_bulk_write(pcf2127->regmap, pcf2127->cfg->regs_alarm_base,
> +				buf, sizeof(buf));
>  	if (ret)
>  		return ret;
>  
> @@ -659,12 +663,14 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
>  		.has_nvmem = 1,
>  		.has_bit_wd_ctl_cd0 = 1,
>  		.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> +		.regs_alarm_base = PCF2127_REG_ALARM_BASE,
>  	},
>  	[PCF2129] = {
>  		.max_register = 0x19,
>  		.has_nvmem = 0,
>  		.has_bit_wd_ctl_cd0 = 0,
>  		.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> +		.regs_alarm_base = PCF2127_REG_ALARM_BASE,
>  	},
>  };
>  
> -- 
> 2.30.2
> 

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