From: [email protected] <[email protected]>
Date: Mon Jul 3 21:34:16 2006 +0300
Input: ads7846: switch to hrtimer
Use hrtimer instead of the normal timer, since it provides better
sampling resolution. This will:
- avoid a problem where we have a 1 jiffy poll period and
dynamic tick on
- utilize high resolution HW clocks when they are added to
the hrtimer framework
Signed-off-by: Imre Deak <[email protected]>
Signed-off-by: Juha Yrjola <[email protected]>
Signed-off-by: David Brownell <[email protected]>
Index: osk/drivers/input/touchscreen/ads7846.c
===================================================================
--- osk.orig/drivers/input/touchscreen/ads7846.c 2006-12-22 11:08:44.000000000 -0800
+++ osk/drivers/input/touchscreen/ads7846.c 2006-12-22 11:08:45.000000000 -0800
@@ -55,7 +55,8 @@
* files.
*/
-#define TS_POLL_PERIOD msecs_to_jiffies(10)
+#define TS_POLL_DELAY (1 * 1000000) /* ns delay before the first sample */
+#define TS_POLL_PERIOD (5 * 1000000) /* ns delay between samples */
/* this driver doesn't aim at the peak continuous sample rate */
#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
@@ -101,7 +102,7 @@ struct ads7846 {
u16 debounce_rep;
spinlock_t lock;
- struct timer_list timer; /* P: lock */
+ struct hrtimer timer;
unsigned pendown:1; /* P: lock */
unsigned pending:1; /* P: lock */
// FIXME remove "irq_disabled"
@@ -470,10 +471,12 @@ static void ads7846_rx(void *ads)
Rt = 0;
/* Sample found inconsistent by debouncing or pressure is beyond
- * the maximum. Don't report it to user space, repeat at least
- * once more the measurement */
+ * the maximum. Don't report it to user space, repeat at least
+ * once more the measurement
+ */
if (ts->tc.ignore || Rt > ts->pressure_max) {
- mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+ hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+ HRTIMER_REL);
return;
}
@@ -515,7 +518,7 @@ static void ads7846_rx(void *ads)
spin_lock_irqsave(&ts->lock, flags);
ts->pendown = (Rt != 0);
- mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
+ hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD), HRTIMER_REL);
spin_unlock_irqrestore(&ts->lock, flags);
}
@@ -606,9 +609,9 @@ static void ads7846_rx_val(void *ads)
status);
}
-static void ads7846_timer(unsigned long handle)
+static int ads7846_timer(struct hrtimer *handle)
{
- struct ads7846 *ts = (void *)handle;
+ struct ads7846 *ts = container_of(handle, struct ads7846, timer);
int status = 0;
spin_lock_irq(&ts->lock);
@@ -630,6 +633,7 @@ static void ads7846_timer(unsigned long
}
spin_unlock_irq(&ts->lock);
+ return HRTIMER_NORESTART;
}
static irqreturn_t ads7846_irq(int irq, void *handle)
@@ -648,7 +652,8 @@ static irqreturn_t ads7846_irq(int irq,
ts->irq_disabled = 1;
disable_irq(ts->spi->irq);
ts->pending = 1;
- mod_timer(&ts->timer, jiffies);
+ hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
+ HRTIMER_REL);
}
}
spin_unlock_irqrestore(&ts->lock, flags);
@@ -790,8 +795,7 @@ static int __devinit ads7846_probe(struc
ts->spi = spi;
ts->input = input_dev;
- init_timer(&ts->timer);
- ts->timer.data = (unsigned long) ts;
+ hrtimer_init(&ts->timer, CLOCK_MONOTONIC, HRTIMER_REL);
ts->timer.function = ads7846_timer;
spin_lock_init(&ts->lock);
-
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