[PATCH 0/7] Blackfin On-Chip RTC driver updates

[PATCH 0/7] Blackfin On-Chip RTC driver updates

[Bryan Wu]

 Mainly updates from Mike.

[PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |   24 +++++++++++++++++-------
 1 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index 1aa709d..303ed6e 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -72,7 +72,7 @@ struct bfin_rtc {
 #define SEC_BITS_OFF    0
 
 /* Some helper functions to convert between the common RTC notion of time
- * and the internal Blackfin notion that is stored in 32bits.
+ * and the internal Blackfin notion that is encoded in 32bits.
  */
 static inline u32 rtc_time_to_bfin(unsigned long now)
 {
@@ -112,6 +112,11 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
  * If anyone can point out the obvious solution here, i'm listening :).  This
  * shouldn't be an issue on an SMP or preempt system as this function should
  * only be called with the rtc lock held.
+ *
+ * Other options:
+ *  - disable PREN so the sync happens at 32.768kHZ ... but this changes the
+ *    inc rate for all RTC registers from 1HZ to 32.768kHZ ...
+ *  - use the write complete IRQ
  */
 static void rtc_bfin_sync_pending(void)
 {
@@ -356,12 +361,18 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
 	return 0;
 }
 
+/**
+ *	bfin_irq_set_freq - make sure hardware supports requested freq
+ *	@dev: pointer to RTC device structure
+ *	@freq: requested frequency rate
+ *
+ *	The Blackfin RTC can only generate periodic events at 1 per
+ *	second (1 Hz), so reject any attempt at changing it.
+ */
 static int bfin_irq_set_freq(struct device *dev, int freq)
 {
-	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	stampit();
-	rtc->rtc_dev->irq_freq = freq;
-	return 0;
+	return -ENOTTY;
 }
 
 static struct rtc_class_ops bfin_rtc_ops = {
@@ -394,14 +405,13 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev)
 		ret = PTR_ERR(rtc->rtc_dev);
 		goto err;
 	}
-	rtc->rtc_dev->irq_freq = 0;
-	rtc->rtc_dev->max_user_freq = (2 << 16); /* stopwatch is an unsigned 16 bit reg */
+	rtc->rtc_dev->irq_freq = 1;
 
 	platform_set_drvdata(pdev, rtc);
 
 	return 0;
 
-err:
+ err:
 	kfree(rtc);
 	return ret;
 }
-- 
1.5.3.4

Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Alessandro Zummo]

On Fri, 23 Nov 2007 18:08:26 +0800
Bryan Wu <bryan.wu@analog.com> wrote:

 Hi, I fannly got some time to review the patches. Seems ok, the
 only question is...

> static int bfin_irq_set_freq(struct device *dev, int freq)
>  {
> -	struct bfin_rtc *rtc = dev_get_drvdata(dev);
>  	stampit();
> -	rtc->rtc_dev->irq_freq = freq;
> -	return 0;
> +	return -ENOTTY;
>  }

 .. why ENOTTY here?

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Mike Frysinger]

On Dec 4, 2007 11:26 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> Bryan Wu <bryan.wu@analog.com> wrote:
>
>  Hi, I fannly got some time to review the patches. Seems ok, the
>  only question is...
>
> > static int bfin_irq_set_freq(struct device *dev, int freq)
> >  {
> > -     struct bfin_rtc *rtc = dev_get_drvdata(dev);
> >       stampit();
> > -     rtc->rtc_dev->irq_freq = freq;
> > -     return 0;
> > +     return -ENOTTY;
> >  }
>
>  .. why ENOTTY here?

blah, hit "reply" in previous e-mail ...

that's what the documentation says to do as does every other rtc driver ?
-mike

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Alessandro Zummo]

On Tue, 4 Dec 2007 11:29:11 -0500
"Mike Frysinger" <vapier.adi@gmail.com> wrote:

> 
> On Dec 4, 2007 11:26 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> > Bryan Wu <bryan.wu@analog.com> wrote:
> >
> >  Hi, I fannly got some time to review the patches. Seems ok, the
> >  only question is...
> >
> > > static int bfin_irq_set_freq(struct device *dev, int freq)
> > >  {
> > > -     struct bfin_rtc *rtc = dev_get_drvdata(dev);
> > >       stampit();
> > > -     rtc->rtc_dev->irq_freq = freq;
> > > -     return 0;
> > > +     return -ENOTTY;
> > >  }
> >
> >  .. why ENOTTY here?
> 
> blah, hit "reply" in previous e-mail ...
> 
> that's what the documentation says to do as does every other rtc driver ?
> -mike

 it should be EINVAL. at least it is wat rtc-cmos does when the value
 is invalid.

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Mike Frysinger]

On Dec 4, 2007 11:41 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> On Tue, 4 Dec 2007 11:29:11 -0500 "Mike Frysinger" <vapier.adi@gmail.com> wrote:
> > On Dec 4, 2007 11:26 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> > > Bryan Wu <bryan.wu@analog.com> wrote:
> > >
> > >  Hi, I fannly got some time to review the patches. Seems ok, the
> > >  only question is...
> > >
> > > > static int bfin_irq_set_freq(struct device *dev, int freq)
> > > >  {
> > > > -     struct bfin_rtc *rtc = dev_get_drvdata(dev);
> > > >       stampit();
> > > > -     rtc->rtc_dev->irq_freq = freq;
> > > > -     return 0;
> > > > +     return -ENOTTY;
> > > >  }
> > >
> > >  .. why ENOTTY here?
> >
> > that's what the documentation says to do as does every other rtc driver ?
>
>  it should be EINVAL. at least it is wat rtc-cmos does when the value
>  is invalid.

the return of ENOTTY is to say "changing of freq isnt supported", not
that the value is invalid.  but i can get the same behavior by
deleting the function as the rtc-dev layer will take care of returning
ENOTTY.

so the behavior is for the RTC_IRQP_SET ioctl:
 - return ENOTTY if you cannot change freq
   - the rtc-dev layer will do this for you if you do not set irq_set_freq
 - return EINVAL if the requested freq is not within the capabilities
of the hardware

sound about right ?
-mike

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Alessandro Zummo]

On Tue, 4 Dec 2007 11:47:56 -0500
"Mike Frysinger" <vapier.adi@gmail.com> wrote:

> 
> the return of ENOTTY is to say "changing of freq isnt supported", not
> that the value is invalid.  but i can get the same behavior by
> deleting the function as the rtc-dev layer will take care of returning
> ENOTTY.
> 
> so the behavior is for the RTC_IRQP_SET ioctl:
>  - return ENOTTY if you cannot change freq
>    - the rtc-dev layer will do this for you if you do not set irq_set_freq
>  - return EINVAL if the requested freq is not within the capabilities
> of the hardware
> 
> sound about right ?

 yes, it is. I agree about deleting it.


-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Mike Frysinger]

On Dec 4, 2007 11:49 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> On Tue, 4 Dec 2007 11:47:56 -0500
> "Mike Frysinger" <vapier.adi@gmail.com> wrote:
> > the return of ENOTTY is to say "changing of freq isnt supported", not
> > that the value is invalid.  but i can get the same behavior by
> > deleting the function as the rtc-dev layer will take care of returning
> > ENOTTY.
> >
> > so the behavior is for the RTC_IRQP_SET ioctl:
> >  - return ENOTTY if you cannot change freq
> >    - the rtc-dev layer will do this for you if you do not set irq_set_freq
> >  - return EINVAL if the requested freq is not within the capabilities
> > of the hardware
> >
> > sound about right ?
>
>  yes, it is. I agree about deleting it.

so, merge this patch and i'll follow up with another to delete the
func and update the documentation ?
-mike

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Alessandro Zummo]

On Tue, 4 Dec 2007 11:56:54 -0500
"Mike Frysinger" <vapier.adi@gmail.com> wrote:

> On Dec 4, 2007 11:49 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
> > On Tue, 4 Dec 2007 11:47:56 -0500
> > "Mike Frysinger" <vapier.adi@gmail.com> wrote:
> > > the return of ENOTTY is to say "changing of freq isnt supported", not
> > > that the value is invalid.  but i can get the same behavior by
> > > deleting the function as the rtc-dev layer will take care of returning
> > > ENOTTY.
> > >
> > > so the behavior is for the RTC_IRQP_SET ioctl:
> > >  - return ENOTTY if you cannot change freq
> > >    - the rtc-dev layer will do this for you if you do not set irq_set_freq
> > >  - return EINVAL if the requested freq is not within the capabilities
> > > of the hardware
> > >
> > > sound about right ?
> >
> >  yes, it is. I agree about deleting it.
> 
> so, merge this patch and i'll follow up with another to delete the
> func and update the documentation ?

 ok. You have my 

 Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>

 on the whole patch set.

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it

Re: [rtc-linux] Re: [PATCH 1/7] Blackfin RTC driver: the frequency function is in units of Hz, not units of seconds, so lock our driver down to 1 Hz

[Mike Frysinger]

On Dec 4, 2007 11:41 AM, Alessandro Zummo <alessandro.zummo@towertech.it> wrote:
>  it should be EINVAL. at least it is wat rtc-cmos does when the value
>  is invalid.

in the example rtc test code (Documentation/rtc.txt), would it be
useful to handle EINVAL ?  if the freq isnt supported, just say
"hardware does not support frequency %i" and continue on to try the
next freq ?  the current code just does:
perror("RTC_IRQP_SET ioctl");
exit(errno);
-mike

[PATCH 2/7] Blackfin RTC driver: we pass in a (struct device*) to the irq handler, not a (struct platform_device*), so fix the irq handler

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index 303ed6e..2a801f2 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -144,8 +144,8 @@ static void rtc_bfin_reset(struct bfin_rtc *rtc)
 
 static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
 {
-	struct platform_device *pdev = to_platform_device(dev_id);
-	struct bfin_rtc *rtc = platform_get_drvdata(pdev);
+	struct device *dev = dev_id;
+	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	unsigned long events = 0;
 	u16 rtc_istat;
 
-- 
1.5.3.4

[PATCH 3/7] Blackfin RTC driver: cleanup proc handler (we dont need RTC reg dump now that we have MMR filesystem in sysfs)

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |   26 ++++++++++++--------------
 1 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index 2a801f2..343f284 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -45,7 +45,7 @@
 
 #include <asm/blackfin.h>
 
-#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __FUNCTION__, __LINE__, ## args)
+#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
 #define stampit() stamp("here i am")
 
 struct bfin_rtc {
@@ -343,22 +343,20 @@ static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 
 static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
 {
-#define yesno(x) (x ? "yes" : "no")
+#define yesno(x) ((x) ? "yes" : "no")
 	u16 ictl = bfin_read_RTC_ICTL();
 	stampit();
-	seq_printf(seq, "alarm_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_ALARM));
-	seq_printf(seq, "wkalarm_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_ALARM_DAY));
-	seq_printf(seq, "seconds_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_SEC));
-	seq_printf(seq, "periodic_IRQ\t: %s\n", yesno(ictl & RTC_ISTAT_STOPWATCH));
-#ifdef DEBUG
-	seq_printf(seq, "RTC_STAT\t: 0x%08X\n", bfin_read_RTC_STAT());
-	seq_printf(seq, "RTC_ICTL\t: 0x%04X\n", bfin_read_RTC_ICTL());
-	seq_printf(seq, "RTC_ISTAT\t: 0x%04X\n", bfin_read_RTC_ISTAT());
-	seq_printf(seq, "RTC_SWCNT\t: 0x%04X\n", bfin_read_RTC_SWCNT());
-	seq_printf(seq, "RTC_ALARM\t: 0x%08X\n", bfin_read_RTC_ALARM());
-	seq_printf(seq, "RTC_PREN\t: 0x%04X\n", bfin_read_RTC_PREN());
-#endif
+	seq_printf(seq,
+		"alarm_IRQ\t: %s\n"
+		"wkalarm_IRQ\t: %s\n"
+		"seconds_IRQ\t: %s\n"
+		"periodic_IRQ\t: %s\n",
+		yesno(ictl & RTC_ISTAT_ALARM),
+		yesno(ictl & RTC_ISTAT_ALARM_DAY),
+		yesno(ictl & RTC_ISTAT_SEC),
+		yesno(ictl & RTC_ISTAT_STOPWATCH));
 	return 0;
+#undef yesno
 }
 
 /**
-- 
1.5.3.4

[PATCH 4/7] Blackfin RTC driver: use dev_dbg() rather than pr_stamp()

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |   48 ++++++++++++++++++++++--------------------------
 1 files changed, 22 insertions(+), 26 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index 343f284..b14a9c4 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -45,8 +45,7 @@
 
 #include <asm/blackfin.h>
 
-#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
-#define stampit() stamp("here i am")
+#define dev_dbg_stamp(dev) dev_dbg(dev, "%s:%i: here i am\n", __func__, __LINE__)
 
 struct bfin_rtc {
 	struct rtc_device *rtc_dev;
@@ -120,7 +119,6 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
  */
 static void rtc_bfin_sync_pending(void)
 {
-	stampit();
 	while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE)) {
 		if (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING))
 			break;
@@ -128,8 +126,9 @@ static void rtc_bfin_sync_pending(void)
 	bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
 }
 
-static void rtc_bfin_reset(struct bfin_rtc *rtc)
+static void rtc_bfin_reset(struct device *dev)
 {
+	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	/* Initialize the RTC. Enable pre-scaler to scale RTC clock
 	 * to 1Hz and clear interrupt/status registers. */
 	spin_lock_irq(&rtc->lock);
@@ -149,7 +148,7 @@ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
 	unsigned long events = 0;
 	u16 rtc_istat;
 
-	stampit();
+	dev_dbg_stamp(dev);
 
 	spin_lock_irq(&rtc->lock);
 
@@ -180,10 +179,9 @@ static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
 
 static int bfin_rtc_open(struct device *dev)
 {
-	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	int ret;
 
-	stampit();
+	dev_dbg_stamp(dev);
 
 	ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_DISABLED, "rtc-bfin", dev);
 	if (unlikely(ret)) {
@@ -191,16 +189,15 @@ static int bfin_rtc_open(struct device *dev)
 		return ret;
 	}
 
-	rtc_bfin_reset(rtc);
+	rtc_bfin_reset(dev);
 
 	return ret;
 }
 
 static void bfin_rtc_release(struct device *dev)
 {
-	struct bfin_rtc *rtc = dev_get_drvdata(dev);
-	stampit();
-	rtc_bfin_reset(rtc);
+	dev_dbg_stamp(dev);
+	rtc_bfin_reset(dev);
 	free_irq(IRQ_RTC, dev);
 }
 
@@ -208,11 +205,11 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 
-	stampit();
+	dev_dbg_stamp(dev);
 
 	switch (cmd) {
 	case RTC_PIE_ON:
-		stampit();
+		dev_dbg_stamp(dev);
 		spin_lock_irq(&rtc->lock);
 		rtc_bfin_sync_pending();
 		bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH);
@@ -221,7 +218,7 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 		spin_unlock_irq(&rtc->lock);
 		return 0;
 	case RTC_PIE_OFF:
-		stampit();
+		dev_dbg_stamp(dev);
 		spin_lock_irq(&rtc->lock);
 		rtc_bfin_sync_pending();
 		bfin_write_RTC_SWCNT(0);
@@ -230,7 +227,7 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 		return 0;
 
 	case RTC_UIE_ON:
-		stampit();
+		dev_dbg_stamp(dev);
 		spin_lock_irq(&rtc->lock);
 		rtc_bfin_sync_pending();
 		bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
@@ -238,7 +235,7 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 		spin_unlock_irq(&rtc->lock);
 		return 0;
 	case RTC_UIE_OFF:
-		stampit();
+		dev_dbg_stamp(dev);
 		spin_lock_irq(&rtc->lock);
 		rtc_bfin_sync_pending();
 		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~RTC_ISTAT_SEC);
@@ -250,7 +247,7 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 		u16 which_alarm;
 		int ret = 0;
 
-		stampit();
+		dev_dbg_stamp(dev);
 
 		spin_lock_irq(&rtc->lock);
 
@@ -278,7 +275,7 @@ static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long ar
 		return ret;
 	}
 	case RTC_AIE_OFF:
-		stampit();
+		dev_dbg_stamp(dev);
 		spin_lock_irq(&rtc->lock);
 		rtc_bfin_sync_pending();
 		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
@@ -293,7 +290,7 @@ static int bfin_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 
-	stampit();
+	dev_dbg_stamp(dev);
 
 	spin_lock_irq(&rtc->lock);
 	rtc_bfin_sync_pending();
@@ -309,7 +306,7 @@ static int bfin_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	int ret;
 	unsigned long now;
 
-	stampit();
+	dev_dbg_stamp(dev);
 
 	spin_lock_irq(&rtc->lock);
 
@@ -327,7 +324,7 @@ static int bfin_rtc_set_time(struct device *dev, struct rtc_time *tm)
 static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
-	stampit();
+	dev_dbg_stamp(dev);
 	memcpy(&alrm->time, &rtc->rtc_alarm, sizeof(struct rtc_time));
 	alrm->pending = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
 	return 0;
@@ -336,7 +333,7 @@ static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
-	stampit();
+	dev_dbg_stamp(dev);
 	memcpy(&rtc->rtc_alarm, &alrm->time, sizeof(struct rtc_time));
 	return 0;
 }
@@ -345,7 +342,7 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
 {
 #define yesno(x) ((x) ? "yes" : "no")
 	u16 ictl = bfin_read_RTC_ICTL();
-	stampit();
+	dev_dbg_stamp(dev);
 	seq_printf(seq,
 		"alarm_IRQ\t: %s\n"
 		"wkalarm_IRQ\t: %s\n"
@@ -369,7 +366,7 @@ static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
  */
 static int bfin_irq_set_freq(struct device *dev, int freq)
 {
-	stampit();
+	dev_dbg_stamp(dev);
 	return -ENOTTY;
 }
 
@@ -390,7 +387,7 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev)
 	struct bfin_rtc *rtc;
 	int ret = 0;
 
-	stampit();
+	dev_dbg_stamp(&pdev->dev);
 
 	rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
 	if (unlikely(!rtc))
@@ -436,7 +433,6 @@ static struct platform_driver bfin_rtc_driver = {
 
 static int __init bfin_rtc_init(void)
 {
-	stampit();
 	return platform_driver_register(&bfin_rtc_driver);
 }
 
-- 
1.5.3.4

[PATCH 5/7] Blackfin RTC driver: read_alarm() checks the enabled field, not the pending field.

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

also, dont bother using memcpy since we can just do an assignment of the same structure.

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index b14a9c4..a4ed2f8 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -326,7 +326,7 @@ static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	dev_dbg_stamp(dev);
 	memcpy(&alrm->time, &rtc->rtc_alarm, sizeof(struct rtc_time));
-	alrm->pending = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
+	alrm->enabled = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
 	return 0;
 }
 
@@ -334,7 +334,7 @@ static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	dev_dbg_stamp(dev);
-	memcpy(&rtc->rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+	rtc->rtc_alarm = alrm->time;
 	return 0;
 }
 
-- 
1.5.3.4

[PATCH 6/7] Blackfin RTC driver: shave off another memcpy() by using assignment.

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index a4ed2f8..69810a2 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -325,7 +325,7 @@ static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	dev_dbg_stamp(dev);
-	memcpy(&alrm->time, &rtc->rtc_alarm, sizeof(struct rtc_time));
+	alrm->time = rtc->rtc_alarm;
 	alrm->enabled = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
 	return 0;
 }
-- 
1.5.3.4

[PATCH 7/7] Blackfin RTC driver: convert sync wait to use the irq write complete notice

[Bryan Wu]

From: Mike Frysinger <michael.frysinger@analog.com>

 - thus clearing out the need for spin locks
 - add a small optimization for reading of the rtc field

Signed-off-by: Mike Frysinger <michael.frysinger@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
---
 drivers/rtc/rtc-bfin.c |  249 ++++++++++++++++++++++++++----------------------
 1 files changed, 136 insertions(+), 113 deletions(-)

diff --git a/drivers/rtc/rtc-bfin.c b/drivers/rtc/rtc-bfin.c
index 69810a2..d90ba86 100644
--- a/drivers/rtc/rtc-bfin.c
+++ b/drivers/rtc/rtc-bfin.c
@@ -1,6 +1,6 @@
 /*
  * Blackfin On-Chip Real Time Clock Driver
- *  Supports BF53[123]/BF53[467]/BF54[2489]
+ *  Supports BF52[257]/BF53[123]/BF53[467]/BF54[24789]
  *
  * Copyright 2004-2007 Analog Devices Inc.
  *
@@ -32,16 +32,16 @@
  * writes to clear status registers complete immediately.
  */
 
-#include <linux/module.h>
-#include <linux/kernel.h>
 #include <linux/bcd.h>
-#include <linux/rtc.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
 #include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/rtc.h>
 #include <linux/seq_file.h>
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/delay.h>
 
 #include <asm/blackfin.h>
 
@@ -50,7 +50,7 @@
 struct bfin_rtc {
 	struct rtc_device *rtc_dev;
 	struct rtc_time rtc_alarm;
-	spinlock_t lock;
+	u16 rtc_wrote_regs;
 };
 
 /* Bit values for the ISTAT / ICTL registers */
@@ -96,7 +96,10 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
 	rtc_time_to_tm(rtc_bfin_to_time(rtc_bfin), tm);
 }
 
-/* Wait for the previous write to a RTC register to complete.
+/**
+ *	bfin_rtc_sync_pending - make sure pending writes have complete
+ *
+ * Wait for the previous write to a RTC register to complete.
  * Unfortunately, we can't sleep here as that introduces a race condition when
  * turning on interrupt events.  Consider this:
  *  - process sets alarm
@@ -117,64 +120,102 @@ static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
  *    inc rate for all RTC registers from 1HZ to 32.768kHZ ...
  *  - use the write complete IRQ
  */
-static void rtc_bfin_sync_pending(void)
+/*
+static void bfin_rtc_sync_pending_polled(void)
 {
-	while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE)) {
+	while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE))
 		if (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING))
 			break;
-	}
 	bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
 }
+*/
+static DECLARE_COMPLETION(bfin_write_complete);
+static void bfin_rtc_sync_pending(struct device *dev)
+{
+	dev_dbg_stamp(dev);
+	while (bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING)
+		wait_for_completion_timeout(&bfin_write_complete, HZ * 5);
+	dev_dbg_stamp(dev);
+}
 
-static void rtc_bfin_reset(struct device *dev)
+/**
+ *	bfin_rtc_reset - set RTC to sane/known state
+ *
+ * Initialize the RTC.  Enable pre-scaler to scale RTC clock
+ * to 1Hz and clear interrupt/status registers.
+ */
+static void bfin_rtc_reset(struct device *dev)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
-	/* Initialize the RTC. Enable pre-scaler to scale RTC clock
-	 * to 1Hz and clear interrupt/status registers. */
-	spin_lock_irq(&rtc->lock);
-	rtc_bfin_sync_pending();
+	dev_dbg_stamp(dev);
+	bfin_rtc_sync_pending(dev);
 	bfin_write_RTC_PREN(0x1);
-	bfin_write_RTC_ICTL(0);
+	bfin_write_RTC_ICTL(RTC_ISTAT_WRITE_COMPLETE);
 	bfin_write_RTC_SWCNT(0);
 	bfin_write_RTC_ALARM(0);
 	bfin_write_RTC_ISTAT(0xFFFF);
-	spin_unlock_irq(&rtc->lock);
+	rtc->rtc_wrote_regs = 0;
 }
 
+/**
+ *	bfin_rtc_interrupt - handle interrupt from RTC
+ *
+ * Since we handle all RTC events here, we have to make sure the requested
+ * interrupt is enabled (in RTC_ICTL) as the event status register (RTC_ISTAT)
+ * always gets updated regardless of the interrupt being enabled.  So when one
+ * even we care about (e.g. stopwatch) goes off, we don't want to turn around
+ * and say that other events have happened as well (e.g. second).  We do not
+ * have to worry about pending writes to the RTC_ICTL register as interrupts
+ * only fire if they are enabled in the RTC_ICTL register.
+ */
 static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
 {
 	struct device *dev = dev_id;
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	unsigned long events = 0;
-	u16 rtc_istat;
+	bool write_complete = false;
+	u16 rtc_istat, rtc_ictl;
 
 	dev_dbg_stamp(dev);
 
-	spin_lock_irq(&rtc->lock);
-
 	rtc_istat = bfin_read_RTC_ISTAT();
+	rtc_ictl = bfin_read_RTC_ICTL();
 
-	if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
-		bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY);
-		events |= RTC_AF | RTC_IRQF;
+	if (rtc_istat & RTC_ISTAT_WRITE_COMPLETE) {
+		bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
+		write_complete = true;
+		complete(&bfin_write_complete);
 	}
 
-	if (rtc_istat & RTC_ISTAT_STOPWATCH) {
-		bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH);
-		events |= RTC_PF | RTC_IRQF;
-		bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq);
+	if (rtc_ictl & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
+		if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
+			bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY);
+			events |= RTC_AF | RTC_IRQF;
+		}
 	}
 
-	if (rtc_istat & RTC_ISTAT_SEC) {
-		bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
-		events |= RTC_UF | RTC_IRQF;
+	if (rtc_ictl & RTC_ISTAT_STOPWATCH) {
+		if (rtc_istat & RTC_ISTAT_STOPWATCH) {
+			bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH);
+			events |= RTC_PF | RTC_IRQF;
+			bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq);
+		}
 	}
 
-	rtc_update_irq(rtc->rtc_dev, 1, events);
+	if (rtc_ictl & RTC_ISTAT_SEC) {
+		if (rtc_istat & RTC_ISTAT_SEC) {
+			bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
+			events |= RTC_UF | RTC_IRQF;
+		}
+	}
 
-	spin_unlock_irq(&rtc->lock);
+	if (events)
+		rtc_update_irq(rtc->rtc_dev, 1, events);
 
-	return IRQ_HANDLED;
+	if (write_complete || events)
+		return IRQ_HANDLED;
+	else
+		return IRQ_NONE;
 }
 
 static int bfin_rtc_open(struct device *dev)
@@ -183,13 +224,9 @@ static int bfin_rtc_open(struct device *dev)
 
 	dev_dbg_stamp(dev);
 
-	ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_DISABLED, "rtc-bfin", dev);
-	if (unlikely(ret)) {
-		dev_err(dev, "request RTC IRQ failed with %d\n", ret);
-		return ret;
-	}
-
-	rtc_bfin_reset(dev);
+	ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_SHARED, to_platform_device(dev)->name, dev);
+	if (!ret)
+		bfin_rtc_reset(dev);
 
 	return ret;
 }
@@ -197,93 +234,70 @@ static int bfin_rtc_open(struct device *dev)
 static void bfin_rtc_release(struct device *dev)
 {
 	dev_dbg_stamp(dev);
-	rtc_bfin_reset(dev);
+	bfin_rtc_reset(dev);
 	free_irq(IRQ_RTC, dev);
 }
 
+static void bfin_rtc_int_set(struct bfin_rtc *rtc, u16 rtc_int)
+{
+	bfin_write_RTC_ISTAT(rtc_int);
+	bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | rtc_int);
+}
+static void bfin_rtc_int_clear(struct bfin_rtc *rtc, u16 rtc_int)
+{
+	bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & rtc_int);
+}
+static void bfin_rtc_int_set_alarm(struct bfin_rtc *rtc)
+{
+	/* Blackfin has different bits for whether the alarm is
+	 * more than 24 hours away.
+	 */
+	bfin_rtc_int_set(rtc, (rtc->rtc_alarm.tm_yday == -1 ? RTC_ISTAT_ALARM : RTC_ISTAT_ALARM_DAY));
+}
 static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
+	int ret = 0;
 
 	dev_dbg_stamp(dev);
 
+	bfin_rtc_sync_pending(dev);
+
 	switch (cmd) {
 	case RTC_PIE_ON:
 		dev_dbg_stamp(dev);
-		spin_lock_irq(&rtc->lock);
-		rtc_bfin_sync_pending();
-		bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH);
+		bfin_rtc_int_set(rtc, RTC_ISTAT_STOPWATCH);
 		bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq);
-		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | RTC_ISTAT_STOPWATCH);
-		spin_unlock_irq(&rtc->lock);
-		return 0;
+		break;
 	case RTC_PIE_OFF:
 		dev_dbg_stamp(dev);
-		spin_lock_irq(&rtc->lock);
-		rtc_bfin_sync_pending();
-		bfin_write_RTC_SWCNT(0);
-		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~RTC_ISTAT_STOPWATCH);
-		spin_unlock_irq(&rtc->lock);
-		return 0;
+		bfin_rtc_int_clear(rtc, ~RTC_ISTAT_STOPWATCH);
+		break;
 
 	case RTC_UIE_ON:
 		dev_dbg_stamp(dev);
-		spin_lock_irq(&rtc->lock);
-		rtc_bfin_sync_pending();
-		bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
-		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | RTC_ISTAT_SEC);
-		spin_unlock_irq(&rtc->lock);
-		return 0;
+		bfin_rtc_int_set(rtc, RTC_ISTAT_SEC);
+		break;
 	case RTC_UIE_OFF:
 		dev_dbg_stamp(dev);
-		spin_lock_irq(&rtc->lock);
-		rtc_bfin_sync_pending();
-		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~RTC_ISTAT_SEC);
-		spin_unlock_irq(&rtc->lock);
-		return 0;
-
-	case RTC_AIE_ON: {
-		unsigned long rtc_alarm;
-		u16 which_alarm;
-		int ret = 0;
+		bfin_rtc_int_clear(rtc, ~RTC_ISTAT_SEC);
+		break;
 
+	case RTC_AIE_ON:
 		dev_dbg_stamp(dev);
-
-		spin_lock_irq(&rtc->lock);
-
-		rtc_bfin_sync_pending();
-		if (rtc->rtc_alarm.tm_yday == -1) {
-			struct rtc_time now;
-			rtc_bfin_to_tm(bfin_read_RTC_STAT(), &now);
-			now.tm_sec = rtc->rtc_alarm.tm_sec;
-			now.tm_min = rtc->rtc_alarm.tm_min;
-			now.tm_hour = rtc->rtc_alarm.tm_hour;
-			ret = rtc_tm_to_time(&now, &rtc_alarm);
-			which_alarm = RTC_ISTAT_ALARM;
-		} else {
-			ret = rtc_tm_to_time(&rtc->rtc_alarm, &rtc_alarm);
-			which_alarm = RTC_ISTAT_ALARM_DAY;
-		}
-		if (ret == 0) {
-			bfin_write_RTC_ISTAT(which_alarm);
-			bfin_write_RTC_ALARM(rtc_time_to_bfin(rtc_alarm));
-			bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | which_alarm);
-		}
-
-		spin_unlock_irq(&rtc->lock);
-
-		return ret;
-	}
+		bfin_rtc_int_set_alarm(rtc);
+		break;
 	case RTC_AIE_OFF:
 		dev_dbg_stamp(dev);
-		spin_lock_irq(&rtc->lock);
-		rtc_bfin_sync_pending();
-		bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
-		spin_unlock_irq(&rtc->lock);
-		return 0;
+		bfin_rtc_int_clear(rtc, ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
+		break;
+
+	default:
+		dev_dbg_stamp(dev);
+		ret = -ENOIOCTLCMD;
 	}
 
-	return -ENOIOCTLCMD;
+	return ret;
 }
 
 static int bfin_rtc_read_time(struct device *dev, struct rtc_time *tm)
@@ -292,10 +306,10 @@ static int bfin_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
 	dev_dbg_stamp(dev);
 
-	spin_lock_irq(&rtc->lock);
-	rtc_bfin_sync_pending();
+	if (rtc->rtc_wrote_regs & 0x1)
+		bfin_rtc_sync_pending(dev);
+
 	rtc_bfin_to_tm(bfin_read_RTC_STAT(), tm);
-	spin_unlock_irq(&rtc->lock);
 
 	return 0;
 }
@@ -308,16 +322,14 @@ static int bfin_rtc_set_time(struct device *dev, struct rtc_time *tm)
 
 	dev_dbg_stamp(dev);
 
-	spin_lock_irq(&rtc->lock);
-
 	ret = rtc_tm_to_time(tm, &now);
 	if (ret == 0) {
-		rtc_bfin_sync_pending();
+		if (rtc->rtc_wrote_regs & 0x1)
+			bfin_rtc_sync_pending(dev);
 		bfin_write_RTC_STAT(rtc_time_to_bfin(now));
+		rtc->rtc_wrote_regs = 0x1;
 	}
 
-	spin_unlock_irq(&rtc->lock);
-
 	return ret;
 }
 
@@ -326,6 +338,7 @@ static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
 	dev_dbg_stamp(dev);
 	alrm->time = rtc->rtc_alarm;
+	bfin_rtc_sync_pending(dev);
 	alrm->enabled = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
 	return 0;
 }
@@ -333,8 +346,20 @@ static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct bfin_rtc *rtc = dev_get_drvdata(dev);
+	unsigned long rtc_alarm;
+
 	dev_dbg_stamp(dev);
+
+	if (rtc_tm_to_time(&alrm->time, &rtc_alarm))
+		return -EINVAL;
+
 	rtc->rtc_alarm = alrm->time;
+
+	bfin_rtc_sync_pending(dev);
+	bfin_write_RTC_ALARM(rtc_time_to_bfin(rtc_alarm));
+	if (alrm->enabled)
+		bfin_rtc_int_set_alarm(rtc);
+
 	return 0;
 }
 
@@ -393,8 +418,6 @@ static int __devinit bfin_rtc_probe(struct platform_device *pdev)
 	if (unlikely(!rtc))
 		return -ENOMEM;
 
-	spin_lock_init(&rtc->lock);
-
 	rtc->rtc_dev = rtc_device_register(pdev->name, &pdev->dev, &bfin_rtc_ops, THIS_MODULE);
 	if (unlikely(IS_ERR(rtc))) {
 		ret = PTR_ERR(rtc->rtc_dev);
-- 
1.5.3.4