[PATCH 09/10] RTC: sa1100: Update the sa1100 RTC driver.

From: John Stultz
Date: Mon Feb 21 2011 - 18:57:44 EST


From: Marcelo Roberto Jimenez <mroberto@xxxxxxxxxxxxxxxxxxxxx>

Since PIE interrupts are now emulated, this patch removes the previous
code that used the hardware counters.

The removal of read_callback() also fixes a wrong user space behaviour
of this driver, which was not returning the right value to read().

[john.stultz: Merge fixups]

CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CC: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
CC: Marcelo Roberto Jimenez <mroberto@xxxxxxxxxxxxxxxxxxxxx>
CC: rtc-linux@xxxxxxxxxxxxxxxx
Signed-off-by: Marcelo Roberto Jimenez <mroberto@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
drivers/rtc/rtc-sa1100.c | 111 +--------------------------------------------
1 files changed, 3 insertions(+), 108 deletions(-)

diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index 9ece7be..febde00 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -43,7 +43,6 @@
#define RTC_DEF_TRIM 0

static const unsigned long RTC_FREQ = 1024;
-static unsigned long timer_freq;
static struct rtc_time rtc_alarm;
static DEFINE_SPINLOCK(sa1100_rtc_lock);

@@ -156,97 +155,11 @@ static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

-static int sa1100_irq_set_freq(struct device *dev, int freq)
-{
- if (freq < 1 || freq > timer_freq) {
- return -EINVAL;
- } else {
- struct rtc_device *rtc = (struct rtc_device *)dev;
-
- rtc->irq_freq = freq;
-
- return 0;
- }
-}
-
-static int rtc_timer1_count;
-
-static inline int sa1100_timer1_retrigger(struct rtc_device *rtc)
-{
- unsigned long diff;
- unsigned long period = timer_freq / rtc->irq_freq;
-
- spin_lock_irq(&sa1100_rtc_lock);
-
- do {
- OSMR1 += period;
- diff = OSMR1 - OSCR;
- /* If OSCR > OSMR1, diff is a very large number (unsigned
- * math). This means we have a lost interrupt. */
- } while (diff > period);
- OIER |= OIER_E1;
-
- spin_unlock_irq(&sa1100_rtc_lock);
-
- return 0;
-}
-
-static irqreturn_t timer1_interrupt(int irq, void *dev_id)
-{
- struct platform_device *pdev = to_platform_device(dev_id);
- struct rtc_device *rtc = platform_get_drvdata(pdev);
-
- /*
- * If we match for the first time, rtc_timer1_count will be 1.
- * Otherwise, we wrapped around (very unlikely but
- * still possible) so compute the amount of missed periods.
- * The match reg is updated only when the data is actually retrieved
- * to avoid unnecessary interrupts.
- */
- OSSR = OSSR_M1; /* clear match on timer1 */
-
- rtc_update_irq(rtc, rtc_timer1_count, RTC_PF | RTC_IRQF);
-
- if (rtc_timer1_count == 1)
- rtc_timer1_count =
- (rtc->irq_freq * ((1 << 30) / (timer_freq >> 2)));
-
- /* retrigger. */
- sa1100_timer1_retrigger(rtc);
-
- return IRQ_HANDLED;
-}
-
-static int sa1100_rtc_read_callback(struct device *dev, int data)
-{
- if (data & RTC_PF) {
- struct rtc_device *rtc = (struct rtc_device *)dev;
-
- /* interpolate missed periods and set match for the next */
- unsigned long period = timer_freq / rtc->irq_freq;
- unsigned long oscr = OSCR;
- unsigned long osmr1 = OSMR1;
- unsigned long missed = (oscr - osmr1)/period;
- data += missed << 8;
- OSSR = OSSR_M1; /* clear match on timer 1 */
- OSMR1 = osmr1 + (missed + 1)*period;
- /* Ensure we didn't miss another match in the mean time.
- * Here we compare (match - OSCR) 8 instead of 0 --
- * see comment in pxa_timer_interrupt() for explanation.
- */
- while ((signed long)((osmr1 = OSMR1) - OSCR) <= 8) {
- data += 0x100;
- OSSR = OSSR_M1; /* clear match on timer 1 */
- OSMR1 = osmr1 + period;
- }
- }
- return data;
-}
-
static int sa1100_rtc_open(struct device *dev)
{
int ret;
- struct rtc_device *rtc = (struct rtc_device *)dev;
+ struct platform_device *plat_dev = to_platform_device(dev);
+ struct rtc_device *rtc = platform_get_drvdata(plat_dev);

ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
"rtc 1Hz", dev);
@@ -260,19 +173,11 @@ static int sa1100_rtc_open(struct device *dev)
dev_err(dev, "IRQ %d already in use.\n", IRQ_RTCAlrm);
goto fail_ai;
}
- ret = request_irq(IRQ_OST1, timer1_interrupt, IRQF_DISABLED,
- "rtc timer", dev);
- if (ret) {
- dev_err(dev, "IRQ %d already in use.\n", IRQ_OST1);
- goto fail_pi;
- }
rtc->max_user_freq = RTC_FREQ;
- sa1100_irq_set_freq(dev, RTC_FREQ);
+ rtc_irq_set_freq(rtc, NULL, RTC_FREQ);

return 0;

- fail_pi:
- free_irq(IRQ_RTCAlrm, dev);
fail_ai:
free_irq(IRQ_RTC1Hz, dev);
fail_ui:
@@ -287,12 +192,10 @@ static void sa1100_rtc_release(struct device *dev)
OSSR = OSSR_M1;
spin_unlock_irq(&sa1100_rtc_lock);

- free_irq(IRQ_OST1, dev);
free_irq(IRQ_RTCAlrm, dev);
free_irq(IRQ_RTC1Hz, dev);
}

-
static int sa1100_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
spin_lock_irq(&sa1100_rtc_lock);
@@ -348,7 +251,6 @@ static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)

static const struct rtc_class_ops sa1100_rtc_ops = {
.open = sa1100_rtc_open,
- .read_callback = sa1100_rtc_read_callback,
.release = sa1100_rtc_release,
.read_time = sa1100_rtc_read_time,
.set_time = sa1100_rtc_set_time,
@@ -361,8 +263,6 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;

- timer_freq = get_clock_tick_rate();
-
/*
* According to the manual we should be able to let RTTR be zero
* and then a default diviser for a 32.768KHz clock is used.
@@ -388,11 +288,6 @@ static int sa1100_rtc_probe(struct platform_device *pdev)

platform_set_drvdata(pdev, rtc);

- /* Set the irq_freq */
- /*TODO: Find out who is messing with this value after we initialize
- * it here.*/
- rtc->irq_freq = RTC_FREQ;
-
/* Fix for a nasty initialization problem the in SA11xx RTSR register.
* See also the comments in sa1100_rtc_interrupt().
*
--
1.7.3.2.146.gca209

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