[PATCH 1/3] rtc: pcf85363: add .max_register in regmap_config

[PATCH 1/3] rtc: pcf85363: add .max_register in regmap_config

[Alexandre Belloni]

This helps debugging as it allows reading registers from debugfs.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-pcf85363.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 64573cccf7fe..3c5e5e1a5ead 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -157,6 +157,7 @@ static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
 static const struct regmap_config regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
+	.max_register = 0x7f,
 };
 
 static int pcf85363_probe(struct i2c_client *client,
-- 
2.16.1

[PATCH] rtc: pcf85363: set time accurately

[Alexandre Belloni]

As per 8.2.6 Setting and reading the time in RTC mode, first stop the clok,
then reset it before setting the date and time registers. Finally, start
the clock.

This uses register address wrap around from 0x2f to 0x00 for efficiency.

This allows to set the clock with a millisecond accuracy (drift is not
corrected in this example):

RTC        System
1325388767 1325388767.000029180
1325388768 1325388768.000018362
1325388769 1325388769.000006544
1325388770 1325388769.999992725
1325388771 1325388770.999974544

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-pcf85363.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 3fa5bda59987..c04a1edcd571 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -106,6 +106,10 @@
 #define PIN_IO_INTA_OUT	2
 #define PIN_IO_INTA_HIZ	3
 
+#define STOP_EN_STOP	BIT(0)
+
+#define RESET_CPR	0xa4
+
 #define NVRAM_SIZE	0x40
 
 static struct i2c_driver pcf85363_driver;
@@ -148,8 +152,12 @@ static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
-	unsigned char buf[DT_YEARS + 1];
-	int len = sizeof(buf);
+	unsigned char tmp[11];
+	unsigned char *buf = &tmp[2];
+	int ret;
+
+	tmp[0] = STOP_EN_STOP;
+	tmp[1] = RESET_CPR;
 
 	buf[DT_100THS] = 0;
 	buf[DT_SECS] = bin2bcd(tm->tm_sec);
@@ -160,8 +168,12 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
 	buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
 
-	return regmap_bulk_write(pcf85363->regmap, DT_100THS,
-				 buf, len);
+	ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
+				tmp, sizeof(tmp));
+	if (ret)
+		return ret;
+
+	return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0);
 }
 
 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
-- 
2.16.1

[PATCH 2/3] rtc: pcf85363: add alarm support

[Alexandre Belloni]

From: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Handle alarms, currently only on INTA

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
---
 drivers/rtc/rtc-pcf85363.c | 159 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)

diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 3c5e5e1a5ead..3fa5bda59987 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -73,6 +73,39 @@
 #define CTRL_RESETS	0x2f
 #define CTRL_RAM	0x40
 
+#define ALRM_SEC_A1E	BIT(0)
+#define ALRM_MIN_A1E	BIT(1)
+#define ALRM_HR_A1E	BIT(2)
+#define ALRM_DAY_A1E	BIT(3)
+#define ALRM_MON_A1E	BIT(4)
+#define ALRM_MIN_A2E	BIT(5)
+#define ALRM_HR_A2E	BIT(6)
+#define ALRM_DAY_A2E	BIT(7)
+
+#define INT_WDIE	BIT(0)
+#define INT_BSIE	BIT(1)
+#define INT_TSRIE	BIT(2)
+#define INT_A2IE	BIT(3)
+#define INT_A1IE	BIT(4)
+#define INT_OIE		BIT(5)
+#define INT_PIE		BIT(6)
+#define INT_ILP		BIT(7)
+
+#define FLAGS_TSR1F	BIT(0)
+#define FLAGS_TSR2F	BIT(1)
+#define FLAGS_TSR3F	BIT(2)
+#define FLAGS_BSF	BIT(3)
+#define FLAGS_WDF	BIT(4)
+#define FLAGS_A1F	BIT(5)
+#define FLAGS_A2F	BIT(6)
+#define FLAGS_PIF	BIT(7)
+
+#define PIN_IO_INTAPM	GENMASK(1, 0)
+#define PIN_IO_INTA_CLK	0
+#define PIN_IO_INTA_BAT	1
+#define PIN_IO_INTA_OUT	2
+#define PIN_IO_INTA_HIZ	3
+
 #define NVRAM_SIZE	0x40
 
 static struct i2c_driver pcf85363_driver;
@@ -131,11 +164,123 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 				 buf, len);
 }
 
+static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+	unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
+	unsigned int val;
+	int ret;
+
+	ret = regmap_bulk_read(pcf85363->regmap, DT_SECOND_ALM1, buf,
+			       sizeof(buf));
+	if (ret)
+		return ret;
+
+	alrm->time.tm_sec = bcd2bin(buf[0]);
+	alrm->time.tm_min = bcd2bin(buf[1]);
+	alrm->time.tm_hour = bcd2bin(buf[2]);
+	alrm->time.tm_mday = bcd2bin(buf[3]);
+	alrm->time.tm_mon = bcd2bin(buf[4]) - 1;
+
+	ret = regmap_read(pcf85363->regmap, CTRL_INTA_EN, &val);
+	if (ret)
+		return ret;
+
+	alrm->enabled =  !!(val & INT_A1IE);
+
+	return 0;
+}
+
+static int _pcf85363_rtc_alarm_irq_enable(struct pcf85363 *pcf85363, unsigned
+					  int enabled)
+{
+	unsigned int alarm_flags = ALRM_SEC_A1E | ALRM_MIN_A1E | ALRM_HR_A1E |
+				   ALRM_DAY_A1E | ALRM_MON_A1E;
+	int ret;
+
+	ret = regmap_update_bits(pcf85363->regmap, DT_ALARM_EN, alarm_flags,
+				 enabled ? alarm_flags : 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(pcf85363->regmap, CTRL_INTA_EN,
+				 INT_A1IE, enabled ? INT_A1IE : 0);
+
+	if (ret || enabled)
+		return ret;
+
+	/* clear current flags */
+	return regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
+}
+
+static int pcf85363_rtc_alarm_irq_enable(struct device *dev,
+					 unsigned int enabled)
+{
+	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+
+	return _pcf85363_rtc_alarm_irq_enable(pcf85363, enabled);
+}
+
+static int pcf85363_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
+	unsigned char buf[DT_MONTH_ALM1 - DT_SECOND_ALM1 + 1];
+	int 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] = bin2bcd(alrm->time.tm_mon + 1);
+
+	/*
+	 * Disable the alarm interrupt before changing the value to avoid
+	 * spurious interrupts
+	 */
+	ret = _pcf85363_rtc_alarm_irq_enable(pcf85363, 0);
+	if (ret)
+		return ret;
+
+	ret = regmap_bulk_write(pcf85363->regmap, DT_SECOND_ALM1, buf,
+				sizeof(buf));
+	if (ret)
+		return ret;
+
+	return _pcf85363_rtc_alarm_irq_enable(pcf85363, alrm->enabled);
+}
+
+static irqreturn_t pcf85363_rtc_handle_irq(int irq, void *dev_id)
+{
+	struct pcf85363 *pcf85363 = i2c_get_clientdata(dev_id);
+	unsigned int flags;
+	int err;
+
+	err = regmap_read(pcf85363->regmap, CTRL_FLAGS, &flags);
+	if (err)
+		return IRQ_NONE;
+
+	if (flags & FLAGS_A1F) {
+		rtc_update_irq(pcf85363->rtc, 1, RTC_IRQF | RTC_AF);
+		regmap_update_bits(pcf85363->regmap, CTRL_FLAGS, FLAGS_A1F, 0);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
 static const struct rtc_class_ops rtc_ops = {
 	.read_time	= pcf85363_rtc_read_time,
 	.set_time	= pcf85363_rtc_set_time,
 };
 
+static const struct rtc_class_ops rtc_ops_alarm = {
+	.read_time	= pcf85363_rtc_read_time,
+	.set_time	= pcf85363_rtc_set_time,
+	.read_alarm	= pcf85363_rtc_read_alarm,
+	.set_alarm	= pcf85363_rtc_set_alarm,
+	.alarm_irq_enable = pcf85363_rtc_alarm_irq_enable,
+};
+
 static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
 			       size_t bytes)
 {
@@ -197,6 +342,20 @@ static int pcf85363_probe(struct i2c_client *client,
 
 	pcf85363->rtc->ops = &rtc_ops;
 
+	if (client->irq > 0) {
+		regmap_write(pcf85363->regmap, CTRL_FLAGS, 0);
+		regmap_update_bits(pcf85363->regmap, CTRL_PIN_IO,
+				   PIN_IO_INTA_OUT, PIN_IO_INTAPM);
+		ret = devm_request_threaded_irq(pcf85363->dev, client->irq,
+						NULL, pcf85363_rtc_handle_irq,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"pcf85363", client);
+		if (ret)
+			dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
+		else
+			pcf85363->rtc->ops = &rtc_ops_alarm;
+	}
+
 	ret = rtc_register_device(pcf85363->rtc);
 
 	nvmem_cfg.priv = pcf85363;
-- 
2.16.1

[PATCH 3/3] rtc: pcf85363: set time accurately

[Alexandre Belloni]

As per 8.2.6 Setting and reading the time in RTC mode, first stop the clok,
then reset it before setting the date and time registers. Finally, start
the clock.

This uses register address wrap around from 0x2f to 0x00 for efficiency.

This allows to set the clock with a millisecond accuracy (drift is not
corrected in this example):

RTC        System
1325388767 1325388767.000029180
1325388768 1325388768.000018362
1325388769 1325388769.000006544
1325388770 1325388769.999992725
1325388771 1325388770.999974544

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-pcf85363.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 3fa5bda59987..c04a1edcd571 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -106,6 +106,10 @@
 #define PIN_IO_INTA_OUT	2
 #define PIN_IO_INTA_HIZ	3
 
+#define STOP_EN_STOP	BIT(0)
+
+#define RESET_CPR	0xa4
+
 #define NVRAM_SIZE	0x40
 
 static struct i2c_driver pcf85363_driver;
@@ -148,8 +152,12 @@ static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
-	unsigned char buf[DT_YEARS + 1];
-	int len = sizeof(buf);
+	unsigned char tmp[11];
+	unsigned char *buf = &tmp[2];
+	int ret;
+
+	tmp[0] = STOP_EN_STOP;
+	tmp[1] = RESET_CPR;
 
 	buf[DT_100THS] = 0;
 	buf[DT_SECS] = bin2bcd(tm->tm_sec);
@@ -160,8 +168,12 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	buf[DT_MONTHS] = bin2bcd(tm->tm_mon + 1);
 	buf[DT_YEARS] = bin2bcd(tm->tm_year % 100);
 
-	return regmap_bulk_write(pcf85363->regmap, DT_100THS,
-				 buf, len);
+	ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN,
+				tmp, sizeof(tmp));
+	if (ret)
+		return ret;
+
+	return regmap_write(pcf85363->regmap, CTRL_STOP_EN, 0);
 }
 
 static int pcf85363_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
-- 
2.16.1