[PATCH 1/3] RTC:s35390a: Add Alarm interrupt support

[PATCH 1/3] RTC:s35390a: Add Alarm interrupt support

[hvaibhav]

From: Vaibhav Hiremath <hvaibhav@ti.com>


Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
---
 drivers/rtc/rtc-s35390a.c |  208 ++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 205 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c
index f789e00..3d34fc5 100644
--- a/drivers/rtc/rtc-s35390a.c
+++ b/drivers/rtc/rtc-s35390a.c
@@ -19,6 +19,8 @@
 #define S35390A_CMD_STATUS1	0
 #define S35390A_CMD_STATUS2	1
 #define S35390A_CMD_TIME1	2
+#define S35390A_CMD_TIME2	3
+#define S35390A_CMD_INT1_REG1	4
 
 #define S35390A_BYTE_YEAR	0
 #define S35390A_BYTE_MONTH	1
@@ -28,12 +30,24 @@
 #define S35390A_BYTE_MINS	5
 #define S35390A_BYTE_SECS	6
 
+#define S35390A_ALRM_BYTE_WDAY	0
+#define S35390A_ALRM_BYTE_HOURS	1
+#define S35390A_ALRM_BYTE_MINS	2
+
 #define S35390A_FLAG_POC	0x01
 #define S35390A_FLAG_BLD	0x02
 #define S35390A_FLAG_24H	0x40
 #define S35390A_FLAG_RESET	0x80
 #define S35390A_FLAG_TEST	0x01
 
+#define S35390A_INT1_MODE_MASK		0xF
+
+#define S35390A_INT1_MODE_NOINTR	0x0
+#define S35390A_INT1_MODE_FREQ		0x1
+#define S35390A_INT1_MODE_PMIN_EDG	0x2
+#define S35390A_INT1_MODE_PMIN_STDY	0x3
+#define S35390A_INT1_MODE_ALARM		0x4
+
 static const struct i2c_device_id s35390a_id[] = {
 	{ "s35390a", 0 },
 	{ }
@@ -44,6 +58,8 @@ struct s35390a {
 	struct i2c_client *client[8];
 	struct rtc_device *rtc;
 	int twentyfourhour;
+	struct work_struct work;
+	struct rtc_wkalrm alarm;
 };
 
 static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len)
@@ -194,9 +210,179 @@ static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	return s35390a_set_datetime(to_i2c_client(dev), tm);
 }
 
+static int s35390a_alarm_irq_enable(struct i2c_client *client, unsigned enabled)
+{
+	struct s35390a *s35390a = i2c_get_clientdata(client);
+	struct rtc_wkalrm *alm;
+	char buf[3], sts;
+	int err, i;
+
+	err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
+	if (err) {
+		dev_err(&client->dev, "%s: failed to read STS2 reg\n",
+								__func__);
+		return err;
+	}
+
+	/* This chip returns the bits of each byte in reverse order */
+	sts = bitrev8(sts);
+
+	sts &= ~S35390A_INT1_MODE_MASK;
+
+	if (enabled)
+		sts |= S35390A_INT1_MODE_ALARM;
+	else
+		sts |= S35390A_INT1_MODE_NOINTR;
+
+	/* This chip expects the bits of each byte in reverse order */
+	sts = bitrev8(sts);
+
+	err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
+	if (err) {
+		dev_err(&client->dev, "%s: failed to set STS2 reg\n", __func__);
+		return err;
+	}
+
+	alm = &s35390a->alarm;
+
+	if (alm->time.tm_wday != -1)
+		buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80;
+
+	buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a,
+			alm->time.tm_hour) | 0x80;
+	buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80;
+
+	if (alm->time.tm_hour >= 12)
+		buf[S35390A_ALRM_BYTE_HOURS] |= 0x40;
+
+	/* This chip expects the bits of each byte to be in reverse order */
+	for (i = 0; i < 3; ++i)
+		buf[i] = bitrev8(buf[i]);
+
+	return s35390a_set_reg(s35390a, S35390A_CMD_INT1_REG1, buf,
+								sizeof(buf));
+}
+
+static int s35390a_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
+{
+	return s35390a_alarm_irq_enable(to_i2c_client(dev), enabled);
+}
+
+static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
+{
+	struct s35390a *s35390a = i2c_get_clientdata(client);
+
+	dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "
+		"mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec,
+		alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday,
+		alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday);
+
+	/* Copy Alarm time */
+	memcpy(&s35390a->alarm, alm, sizeof(s35390a->alarm));
+
+	return 0;
+}
+
+static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	return s35390a_set_alarm(to_i2c_client(dev), alm);
+}
+
+static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm)
+{
+	struct s35390a *s35390a = i2c_get_clientdata(client);
+	char buf[3], sts;
+	int i, err;
+
+	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts,
+							sizeof(sts)) < 0)
+		return -EIO;
+
+	/* This chip returns the bits of each byte in reverse order */
+	sts = bitrev8(sts);
+
+	s35390a_alarm_irq_enable(client, 1);
+	err = s35390a_get_reg(s35390a, S35390A_CMD_INT1_REG1, buf, sizeof(buf));
+	if (err < 0)
+		return err;
+
+	/* This chip returns the bits of each byte in reverse order */
+	for (i = 0; i < 3; ++i) {
+		buf[i] = bitrev8(buf[i]);
+		buf[i] &= ~0x80;
+	}
+
+	alm->time.tm_wday = bcd2bin(buf[S35390A_ALRM_BYTE_WDAY]);
+	alm->time.tm_hour = s35390a_reg2hr(s35390a,
+					buf[S35390A_ALRM_BYTE_HOURS]);
+	alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS]);
+
+	dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n",
+			__func__, alm->time.tm_min, alm->time.tm_hour,
+			alm->time.tm_wday);
+
+	if (!(sts & BIT(2)))
+		s35390a_alarm_irq_enable(client, 0);
+
+	return 0;
+}
+
+static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	return s35390a_read_alarm(to_i2c_client(dev), alm);
+}
+
+static void s35390a_work(struct work_struct *work)
+{
+	struct s35390a *s35390a;
+	struct i2c_client *client;
+	char buf[1];
+
+	s35390a = container_of(work, struct s35390a, work);
+	if (!s35390a)
+		return;
+
+	client = s35390a->client[0];
+
+	if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0)
+		goto out;
+
+	/* This chip returns the bits of each byte in reverse order */
+	buf[0] = bitrev8(buf[0]);
+
+	/* Notify RTC core on event if any */
+	if (buf[0] & BIT(2)) {
+		rtc_update_irq(s35390a->rtc, 1, RTC_IRQF | RTC_AF);
+		s35390a_alarm_irq_enable(client, 0);
+	}
+
+	enable_irq(client->irq);
+out:
+	return;
+}
+
+static irqreturn_t s35390a_irq(int irq, void *client)
+{
+	struct s35390a *s35390a;
+
+	if (!client)
+		return IRQ_HANDLED;
+
+	s35390a = i2c_get_clientdata((struct i2c_client *)client);
+
+	disable_irq_nosync(irq);
+	schedule_work(&s35390a->work);
+
+	return IRQ_HANDLED;
+}
+
 static const struct rtc_class_ops s35390a_rtc_ops = {
-	.read_time	= s35390a_rtc_read_time,
-	.set_time	= s35390a_rtc_set_time,
+	.read_time		= s35390a_rtc_read_time,
+	.set_time		= s35390a_rtc_set_time,
+	.alarm_irq_enable	= s35390a_rtc_alarm_irq_enable,
+	.set_alarm		= s35390a_rtc_set_alarm,
+	.read_alarm		= s35390a_rtc_read_alarm,
+
 };
 
 static struct i2c_driver s35390a_driver;
@@ -261,15 +447,30 @@ static int s35390a_probe(struct i2c_client *client,
 	if (s35390a_get_datetime(client, &tm) < 0)
 		dev_warn(&client->dev, "clock needs to be set\n");
 
+	INIT_WORK(&s35390a->work, s35390a_work);
+
+	if (client->irq > 0) {
+		err = request_irq(client->irq, s35390a_irq, IRQF_TRIGGER_LOW,
+				client->name, client);
+		if (err) {
+			dev_err(&client->dev, "unable to request IRQ\n");
+			goto exit_dummy;
+		}
+	}
+
 	s35390a->rtc = rtc_device_register(s35390a_driver.driver.name,
 				&client->dev, &s35390a_rtc_ops, THIS_MODULE);
 
 	if (IS_ERR(s35390a->rtc)) {
 		err = PTR_ERR(s35390a->rtc);
-		goto exit_dummy;
+		goto exit_intr;
 	}
+
 	return 0;
 
+exit_intr:
+	free_irq(client->irq, client);
+
 exit_dummy:
 	for (i = 1; i < 8; ++i)
 		if (s35390a->client[i])
@@ -290,6 +491,7 @@ static int s35390a_remove(struct i2c_client *client)
 			i2c_unregister_device(s35390a->client[i]);
 
 	rtc_device_unregister(s35390a->rtc);
+	free_irq(client->irq, client);
 	kfree(s35390a);
 
 	return 0;
-- 
1.6.2.4

Re: [PATCH 1/3] RTC:s35390a: Add Alarm interrupt support

[Felipe Balbi]

On Tue, Aug 17, 2010 at 10:48:39AM +0200, ext hvaibhav@ti.com wrote:
>From: Vaibhav Hiremath <hvaibhav@ti.com>

you need a description here.

>Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>

[snip]

>+static void s35390a_work(struct work_struct *work)
>+{
>+	struct s35390a *s35390a;
>+	struct i2c_client *client;
>+	char buf[1];
>+
>+	s35390a = container_of(work, struct s35390a, work);
>+	if (!s35390a)
>+		return;

container_of() will never return NULL. You can remove this check. You 
won't need this, actually after converting to threaded_irq, see below.

>+static irqreturn_t s35390a_irq(int irq, void *client)
>+{
>+	struct s35390a *s35390a;

all the other drivers will do:

static irqreturn_t s35390a_irq(int irq, void *_s35390a)
{
	struct s35390a	*s35390a = _s35390a

	[...]

>+	if (!client)
>+		return IRQ_HANDLED;

if client is NULL, you should let this oops.

>+	schedule_work(&s35390a->work);

please don't use workqueue. Use threaded IRQ.

>@@ -261,15 +447,30 @@ static int s35390a_probe(struct i2c_client *client,
> 	if (s35390a_get_datetime(client, &tm) < 0)
> 		dev_warn(&client->dev, "clock needs to be set\n");
>
>+	INIT_WORK(&s35390a->work, s35390a_work);
>+
>+	if (client->irq > 0) {

irq 0 is a valid number.

>+		err = request_irq(client->irq, s35390a_irq, IRQF_TRIGGER_LOW,
>+				client->name, client);

instead of the i2c client, you can pass s35390. Also use 
request_threaded_irq();

-- 
balbi

DefectiveByDesign.org

RE: [PATCH 1/3] RTC:s35390a: Add Alarm interrupt support

[Hiremath, Vaibhav]

> -----Original Message-----
> From: Felipe Balbi [mailto:felipe.balbi@nokia.com]
> Sent: Tuesday, August 17, 2010 2:59 PM
> To: Hiremath, Vaibhav
> Cc: linux-kernel@vger.kernel.org; akpm@linux-foundation.org;
> byron.bbradley@gmail.com; linux-omap@vger.kernel.org
> Subject: Re: [PATCH 1/3] RTC:s35390a: Add Alarm interrupt support
> 
> On Tue, Aug 17, 2010 at 10:48:39AM +0200, ext hvaibhav@ti.com wrote:
> >From: Vaibhav Hiremath <hvaibhav@ti.com>
> 
> you need a description here.
> 
[Hiremath, Vaibhav] Frankly, I deliberately removed the description thinking its duplication of subject line and subject like should be enough to explain about the patch.

I will add description in the next version.

> >Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
> 
> [snip]
> 
> >+static void s35390a_work(struct work_struct *work)
> >+{
> >+	struct s35390a *s35390a;
> >+	struct i2c_client *client;
> >+	char buf[1];
> >+
> >+	s35390a = container_of(work, struct s35390a, work);
> >+	if (!s35390a)
> >+		return;
> 
> container_of() will never return NULL. You can remove this check. You
> won't need this, actually after converting to threaded_irq, see below.
> 
[Hiremath, Vaibhav] Ok, will remove in next version.

> >+static irqreturn_t s35390a_irq(int irq, void *client)
> >+{
> >+	struct s35390a *s35390a;
> 
> all the other drivers will do:
> 
> static irqreturn_t s35390a_irq(int irq, void *_s35390a)
> {
> 	struct s35390a	*s35390a = _s35390a
> 
> 	[...]
> 
> >+	if (!client)
> >+		return IRQ_HANDLED;
> 
> if client is NULL, you should let this oops.
> 
[Hiremath, Vaibhav] Ok, will remove in next version.

> >+	schedule_work(&s35390a->work);
> 
> please don't use workqueue. Use threaded IRQ.
> 
[Hiremath, Vaibhav] Ok, will migrate to threaded irq and submit it again.


Thanks,
Vaibhav

> >@@ -261,15 +447,30 @@ static int s35390a_probe(struct i2c_client *client,
> > 	if (s35390a_get_datetime(client, &tm) < 0)
> > 		dev_warn(&client->dev, "clock needs to be set\n");
> >
> >+	INIT_WORK(&s35390a->work, s35390a_work);
> >+
> >+	if (client->irq > 0) {
> 
> irq 0 is a valid number.
> 
> >+		err = request_irq(client->irq, s35390a_irq, IRQF_TRIGGER_LOW,
> >+				client->name, client);
> 
> instead of the i2c client, you can pass s35390. Also use
> request_threaded_irq();
> 
> --
> balbi
> 
> DefectiveByDesign.org