Commit 27006416 authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

rtc: pcf2127: fix alarm handling 



Fix multiple issues when handling alarms:
 - Use threaded interrupt to avoid scheduling when atomic
 - Stop matching on week day as it may not be set correctly
 - Avoid parsing the DT interrupt and use what is provided by the i2c or
   spi subsystem
 - Avoid returning IRQ_NONE in case of error in the interrupt handler
 - Never write WDTF as specified in the datasheet
 - Set uie_unsupported, as for the pcf85063, setting alarms every seconds
   is not working correctly and confuses the RTC.

Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200812085114.474903-1-alexandre.belloni@bootlin.com
parent 8a914bac

drivers/rtc/rtc-pcf2127.c

+19 −18
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#define PCF2127_BIT_CTRL2_TSIE			BIT(2)

#define PCF2127_BIT_CTRL2_AF			BIT(4)

#define PCF2127_BIT_CTRL2_TSF2			BIT(5)

#define PCF2127_BIT_CTRL2_WDTF			BIT(6)

/* Control register 3 */

#define PCF2127_REG_CTRL3		0x02

#define PCF2127_BIT_CTRL3_BLIE			BIT(0)
@@ -55,6 +56,7 @@ 
#define PCF2127_REG_ALARM_HR		0x0C

#define PCF2127_REG_ALARM_DM		0x0D

#define PCF2127_REG_ALARM_DW		0x0E

#define PCF2127_BIT_ALARM_AE			BIT(7)

/* Watchdog registers */

#define PCF2127_REG_WD_CTL		0x10

#define PCF2127_BIT_WD_CTL_TF0			BIT(0)
@@ -360,7 +362,6 @@ static int pcf2127_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	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_wday = buf[4] & 0x07;



	return 0;

}
@@ -398,7 +399,7 @@ static int pcf2127_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 
	buf[1] = bin2bcd(alrm->time.tm_min);

	buf[2] = bin2bcd(alrm->time.tm_hour);

	buf[3] = bin2bcd(alrm->time.tm_mday);

	buf[4] = (alrm->time.tm_wday & 0x07);

	buf[4] = PCF2127_BIT_ALARM_AE; /* Do not match on week day */



	ret = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_ALARM_SC, buf,

				sizeof(buf));
@@ -418,16 +419,15 @@ static irqreturn_t pcf2127_rtc_irq(int irq, void *dev) 
	if (ret)

		return IRQ_NONE;



	if (ctrl2 & PCF2127_BIT_CTRL2_AF) {

	if (!(ctrl2 & PCF2127_BIT_CTRL2_AF))

		return IRQ_NONE;



	regmap_write(pcf2127->regmap, PCF2127_REG_CTRL2,

			     ctrl2 & ~PCF2127_BIT_CTRL2_AF);

		     ctrl2 & ~(PCF2127_BIT_CTRL2_AF | PCF2127_BIT_CTRL2_WDTF));



	rtc_update_irq(pcf2127->rtc, 1, RTC_IRQF | RTC_AF);

	}



	ret = pcf2127_wdt_active_ping(&pcf2127->wdd);

	if (ret)

		return IRQ_NONE;

	pcf2127_wdt_active_ping(&pcf2127->wdd);



	return IRQ_HANDLED;

}
@@ -533,10 +533,9 @@ static const struct attribute_group pcf2127_attr_group = { 
};



static int pcf2127_probe(struct device *dev, struct regmap *regmap,

			const char *name, bool has_nvmem)

			 int alarm_irq, const char *name, bool has_nvmem)

{

	struct pcf2127 *pcf2127;

	int alarm_irq = 0;

	u32 wdd_timeout;

	int ret = 0;
@@ -558,10 +557,11 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap, 
	pcf2127->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;

	pcf2127->rtc->range_max = RTC_TIMESTAMP_END_2099;

	pcf2127->rtc->set_start_time = true; /* Sets actual start to 1970 */

	pcf2127->rtc->uie_unsupported = 1;



	alarm_irq = of_irq_get_byname(dev->of_node, "alarm");

	if (alarm_irq >= 0) {

		ret = devm_request_irq(dev, alarm_irq, pcf2127_rtc_irq,

		ret = devm_request_threaded_irq(dev, alarm_irq, NULL,

						pcf2127_rtc_irq,

						IRQF_TRIGGER_LOW | IRQF_ONESHOT,

						dev_name(dev), dev);

		if (ret) {
@@ -792,7 +792,7 @@ static int pcf2127_i2c_probe(struct i2c_client *client, 
		return PTR_ERR(regmap);

	}



	return pcf2127_probe(&client->dev, regmap,

	return pcf2127_probe(&client->dev, regmap, client->irq,

			     pcf2127_i2c_driver.driver.name, id->driver_data);

}
@@ -858,7 +858,8 @@ static int pcf2127_spi_probe(struct spi_device *spi) 
		return PTR_ERR(regmap);

	}



	return pcf2127_probe(&spi->dev, regmap, pcf2127_spi_driver.driver.name,

	return pcf2127_probe(&spi->dev, regmap, spi->irq,

			     pcf2127_spi_driver.driver.name,

			     spi_get_device_id(spi)->driver_data);

}

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