Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 11 May 2023 13:19:58 -0400
From:   Hugo Villeneuve <hugo@hugovil.com>
To:     Hugo Villeneuve <hugo@hugovil.com>
Cc:     Alexandre Belloni <alexandre.belloni@bootlin.com>,
        a.zummo@towertech.it, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-rtc@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Hugo Villeneuve <hvilleneuve@dimonoff.com>, hugo@hugovil.com
Message-Id: <20230511131958.fd82402f8ef43dd8690bee78@hugovil.com>
In-Reply-To: <20230123155240.2d55fc2f5874a50e2e6252d2@hugovil.com>
References: <20221215150214.1109074-1-hugo@hugovil.com>
        <20221215150214.1109074-9-hugo@hugovil.com>
        <Y8rHx8U4peB+fnW8@mail.local>
        <20230123155240.2d55fc2f5874a50e2e6252d2@hugovil.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Subject: Re: [PATCH v3 08/14] rtc: pcf2127: add support for PCF2131
 interrupts on output INT_A
Precedence: bulk

On Mon, 23 Jan 2023 15:52:40 -0500
Hugo Villeneuve <hugo@hugovil.com> wrote:

> On Fri, 20 Jan 2023 17:56:39 +0100
> Alexandre Belloni <alexandre.belloni@bootlin.com> wrote:
> 
> > On 15/12/2022 10:02:09-0500, Hugo Villeneuve wrote:
> > > From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > > 
> > > The PCF2127 and PCF2129 have one output interrupt pin. The PCF2131 has
> > > two, named INT_A and INT_B. The hardware support that any interrupt
> > > source can be routed to either one or both of them.
> > > 
> > > Force all interrupt sources to go to the INT A pin.
> > > 
> > > Support to route any interrupt source to INT A/B pins is not supported
> > > by this driver at the moment.
> > > 
> > 
> > The main issue with this is that this will created a breaking change
> > once someone needs support for INTB
> 
> We already had a discussion about this a while ago:
> 
>     https://lore.kernel.org/linux-rtc/7be3f9541eaed7e17e334267e49665f442b1b458.camel@dimonoff.com/
> 
> What exactly do you suggest? I personnaly don't have any need for INTB at the moment and I would prefer to avoid the great complexity of supporting any combination of routing interrupts to any A ou  pins.

Hi Alexandre,
a few months later, and I am still waiting for your feedback on this (and other questions/interrogations I raised for other patches related to this series) to submit the next version of this patch series.

Can you have a look at it and provide some answers?

Thank you,
Hugo.


> > > Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
> > > ---
> > >  drivers/rtc/rtc-pcf2127.c | 35 +++++++++++++++++++++++++++++++++++
> > >  1 file changed, 35 insertions(+)
> > > 
> > > diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> > > index 4148e135f935..68af4d0438b8 100644
> > > --- a/drivers/rtc/rtc-pcf2127.c
> > > +++ b/drivers/rtc/rtc-pcf2127.c
> > > @@ -191,6 +191,7 @@ struct pcf21xx_config {
> > >  	int max_register;
> > >  	unsigned int has_nvmem:1;
> > >  	unsigned int has_bit_wd_ctl_cd0:1;
> > > +	unsigned int has_int_a_b:1; /* PCF2131 supports two interrupt outputs. */
> > >  	u8 regs_td_base; /* Time/data base registers. */
> > >  	u8 regs_alarm_base; /* Alarm function base registers. */
> > >  	u8 reg_wd_ctl; /* Watchdog control register. */
> > > @@ -879,6 +880,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> > >  		.max_register = 0x1d,
> > >  		.has_nvmem = 1,
> > >  		.has_bit_wd_ctl_cd0 = 1,
> > > +		.has_int_a_b = 0,
> > >  		.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> > >  		.regs_alarm_base = PCF2127_REG_ALARM_BASE,
> > >  		.reg_wd_ctl = PCF2127_REG_WD_CTL,
> > > @@ -902,6 +904,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> > >  		.max_register = 0x19,
> > >  		.has_nvmem = 0,
> > >  		.has_bit_wd_ctl_cd0 = 0,
> > > +		.has_int_a_b = 0,
> > >  		.regs_td_base = PCF2127_REG_TIME_DATE_BASE,
> > >  		.regs_alarm_base = PCF2127_REG_ALARM_BASE,
> > >  		.reg_wd_ctl = PCF2127_REG_WD_CTL,
> > > @@ -925,6 +928,7 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
> > >  		.max_register = 0x36,
> > >  		.has_nvmem = 0,
> > >  		.has_bit_wd_ctl_cd0 = 0,
> > > +		.has_int_a_b = 1,
> > >  		.regs_td_base = PCF2131_REG_TIME_DATE_BASE,
> > >  		.regs_alarm_base = PCF2131_REG_ALARM_BASE,
> > >  		.reg_wd_ctl = PCF2131_REG_WD_CTL,
> > > @@ -1017,6 +1021,28 @@ static int pcf2127_enable_ts(struct device *dev, int ts_id)
> > >  	return ret;
> > >  }
> > >  
> > > +/* Route all interrupt sources to INT A pin. */
> > > +static int pcf2127_configure_interrupt_pins(struct device *dev)
> > > +{
> > > +	struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
> > > +	int ret;
> > > +
> > > +	/* Mask bits need to be cleared to enable corresponding
> > > +	 * interrupt source.
> > > +	 */
> > > +	ret = regmap_write(pcf2127->regmap,
> > > +			   PCF2131_REG_INT_A_MASK1, 0);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	ret = regmap_write(pcf2127->regmap,
> > > +			   PCF2131_REG_INT_A_MASK2, 0);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	return ret;
> > > +}
> > > +
> > >  static int pcf2127_probe(struct device *dev, struct regmap *regmap,
> > >  			 int alarm_irq, const char *name, const struct pcf21xx_config *config)
> > >  {
> > > @@ -1076,6 +1102,15 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
> > >  		set_bit(RTC_FEATURE_ALARM, pcf2127->rtc->features);
> > >  	}
> > >  
> > > +	if (pcf2127->cfg->has_int_a_b) {
> > > +		/* Configure int A/B pins, independently of alarm_irq. */
> > > +		ret = pcf2127_configure_interrupt_pins(dev);
> > > +		if (ret) {
> > > +			dev_err(dev, "failed to configure interrupt pins\n");
> > > +			return ret;
> > > +		}
> > > +	}
> > > +
> > >  	if (pcf2127->cfg->has_nvmem) {
> > >  		struct nvmem_config nvmem_cfg = {
> > >  			.priv = pcf2127,
> > > -- 
> > > 2.30.2
> > > 
> > 
> > -- 
> > Alexandre Belloni, co-owner and COO, Bootlin
> > Embedded Linux and Kernel engineering
> > https://bootlin.com
> > 
> 
> 
> -- 
> Hugo Villeneuve <hugo@hugovil.com>


-- 
Hugo Villeneuve