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authorMarcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>2010-12-16 21:31:32 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-12-21 14:53:43 +0000
commitd2ccb52d88dcb7eb3539d0e0c77a7028b8d46037 (patch)
tree335bde43defe6cb2916ebb92b23b85cb1d6c3712 /drivers/rtc
parent47bb3b31ab2c95e275b850a291794a29aaaa31cd (diff)
downloadlinux-2.6.38-lt-ux500-d2ccb52d88dcb7eb3539d0e0c77a7028b8d46037.tar.gz
ARM: 6455/2: Better use of the RTC framework for sa11xx.
This patch uses the RTC framework to treat some common ioctl. In particular, it fixes the behaviour of rtc_irq_set_freq(), which did not work as expected because the timer was not beeing retriggered. Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-sa1100.c98
1 files changed, 74 insertions, 24 deletions
diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
index b0985f72707..88ea52b8647 100644
--- a/drivers/rtc/rtc-sa1100.c
+++ b/drivers/rtc/rtc-sa1100.c
@@ -42,7 +42,7 @@
#define RTC_DEF_DIVIDER (32768 - 1)
#define RTC_DEF_TRIM 0
-static unsigned long rtc_freq = 1024;
+static const unsigned long RTC_FREQ = 1024;
static unsigned long timer_freq;
static struct rtc_time rtc_alarm;
static DEFINE_SPINLOCK(sa1100_rtc_lock);
@@ -156,8 +156,58 @@ 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 int sa1100_irq_set_state(struct device *dev, int enabled)
+{
+ spin_lock_irq(&sa1100_rtc_lock);
+ if (enabled) {
+ struct rtc_device *rtc = (struct rtc_device *)dev;
+
+ OSMR1 = timer_freq / rtc->irq_freq + OSCR;
+ OIER |= OIER_E1;
+ rtc_timer1_count = 1;
+ } else {
+ OIER &= ~OIER_E1;
+ }
+ spin_unlock_irq(&sa1100_rtc_lock);
+
+ return 0;
+}
+
+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);
@@ -175,7 +225,11 @@ static irqreturn_t timer1_interrupt(int irq, void *dev_id)
rtc_update_irq(rtc, rtc_timer1_count, RTC_PF | RTC_IRQF);
if (rtc_timer1_count == 1)
- rtc_timer1_count = (rtc_freq * ((1 << 30) / (timer_freq >> 2)));
+ rtc_timer1_count =
+ (rtc->irq_freq * ((1 << 30) / (timer_freq >> 2)));
+
+ /* retrigger. */
+ sa1100_timer1_retrigger(rtc);
return IRQ_HANDLED;
}
@@ -183,8 +237,10 @@ static irqreturn_t timer1_interrupt(int irq, void *dev_id)
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_freq;
+ unsigned long period = timer_freq / rtc->irq_freq;
unsigned long oscr = OSCR;
unsigned long osmr1 = OSMR1;
unsigned long missed = (oscr - osmr1)/period;
@@ -207,6 +263,7 @@ static int sa1100_rtc_read_callback(struct device *dev, int data)
static int sa1100_rtc_open(struct device *dev)
{
int ret;
+ struct rtc_device *rtc = (struct rtc_device *)dev;
ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, IRQF_DISABLED,
"rtc 1Hz", dev);
@@ -226,6 +283,9 @@ static int sa1100_rtc_open(struct device *dev)
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);
+
return 0;
fail_pi:
@@ -274,25 +334,6 @@ static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
RTSR |= RTSR_HZE;
spin_unlock_irq(&sa1100_rtc_lock);
return 0;
- case RTC_PIE_OFF:
- spin_lock_irq(&sa1100_rtc_lock);
- OIER &= ~OIER_E1;
- spin_unlock_irq(&sa1100_rtc_lock);
- return 0;
- case RTC_PIE_ON:
- spin_lock_irq(&sa1100_rtc_lock);
- OSMR1 = timer_freq / rtc_freq + OSCR;
- OIER |= OIER_E1;
- rtc_timer1_count = 1;
- spin_unlock_irq(&sa1100_rtc_lock);
- return 0;
- case RTC_IRQP_READ:
- return put_user(rtc_freq, (unsigned long *)arg);
- case RTC_IRQP_SET:
- if (arg < 1 || arg > timer_freq)
- return -EINVAL;
- rtc_freq = arg;
- return 0;
}
return -ENOIOCTLCMD;
}
@@ -344,12 +385,14 @@ static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
{
+ struct rtc_device *rtc = (struct rtc_device *)dev;
+
seq_printf(seq, "trim/divider\t: 0x%08x\n", (u32) RTTR);
seq_printf(seq, "update_IRQ\t: %s\n",
(RTSR & RTSR_HZE) ? "yes" : "no");
seq_printf(seq, "periodic_IRQ\t: %s\n",
(OIER & OIER_E1) ? "yes" : "no");
- seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq);
+ seq_printf(seq, "periodic_freq\t: %d\n", rtc->irq_freq);
seq_printf(seq, "RTSR\t\t: 0x%08x\n", (u32)RTSR);
return 0;
@@ -365,6 +408,8 @@ static const struct rtc_class_ops sa1100_rtc_ops = {
.read_alarm = sa1100_rtc_read_alarm,
.set_alarm = sa1100_rtc_set_alarm,
.proc = sa1100_rtc_proc,
+ .irq_set_freq = sa1100_irq_set_freq,
+ .irq_set_state = sa1100_irq_set_state,
};
static int sa1100_rtc_probe(struct platform_device *pdev)
@@ -391,13 +436,18 @@ static int sa1100_rtc_probe(struct platform_device *pdev)
device_init_wakeup(&pdev->dev, 1);
rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
- THIS_MODULE);
+ THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
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().
*