Input: ads7846: allow at most 1 read at a time

[pandora-kernel.git] / drivers / input / touchscreen / ads7846.c

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 63cd056..6e123ec 100644 (file)
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -114,6 +114,7 @@ struct ads7846 {
        unsigned                disabled:1;
        unsigned                is_suspended:1;
        unsigned                ext_trigger:1;
+       unsigned                reading:1;
 
        int                     (*filter)(void *data, int data_idx, int *val);
        void                    *filter_data;
@@ -568,9 +569,7 @@ static void ads7846_rx(void *ads)
                pr_debug("%s: ignored %d pressure %d\n",
                        ts->spi->dev.bus_id, ts->tc.ignore, Rt);
 #endif
-               hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-                             HRTIMER_MODE_REL);
-               return;
+               goto out;
        }
 
        /* Maybe check the pendown state before reporting. This discards
@@ -610,6 +609,8 @@ static void ads7846_rx(void *ads)
 #endif
        }
 
+out:
+       ts->reading = 0;
        next_poll = ktime_set(0, ts->ext_trigger ?
                                 TS_FALLBACK_PERIOD : TS_POLL_PERIOD);
        hrtimer_start(&ts->timer, next_poll, HRTIMER_MODE_REL);
@@ -694,18 +695,18 @@ static void ads7846_rx_val(void *ads)
                BUG();
        }
        status = spi_async(ts->spi, m);
-       if (status)
-               dev_err(&ts->spi->dev, "spi_async --> %d\n",
+       if (status) {
+               ts->reading = 0;
+               dev_err(&ts->spi->dev, "spi_async 1 --> %d\n",
                                status);
+       }
 }
 
-static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
+/* Must be called with ts->lock held */
+static void ads7846_next_update(struct ads7846 *ts)
 {
-       struct ads7846  *ts = container_of(handle, struct ads7846, timer);
        int             status = 0;
 
-       spin_lock_irq(&ts->lock);
-
        if (unlikely(!ts->get_pendown_state() ||
                     device_suspended(&ts->spi->dev))) {
                if (ts->pendown) {
@@ -729,13 +730,25 @@ static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
                ts->pending = 0;
        } else {
                /* pen is still down, continue with the measurement */
+               ts->reading = 1;
                ts->msg_idx = 0;
                status = spi_async(ts->spi, &ts->msg[0]);
-               if (status)
-                       dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
+               if (status) {
+                       ts->reading = 0;
+                       dev_err(&ts->spi->dev, "spi_async 2 --> %d\n", status);
+               }
        }
+}
 
+static enum hrtimer_restart ads7846_timer(struct hrtimer *handle)
+{
+       struct ads7846 *ts = container_of(handle, struct ads7846, timer);
+
+       spin_lock_irq(&ts->lock);
+       if (ts->pending && !ts->reading)
+               ads7846_next_update(ts);
        spin_unlock_irq(&ts->lock);
+
        return HRTIMER_NORESTART;
 }
 
@@ -771,10 +784,8 @@ static void omap_vsync_handler(void *arg, u32 mask)
        struct ads7846 *ts = arg;
 
        spin_lock_irq(&ts->lock);
-
-       if (ts->pending)
-               hrtimer_start(&ts->timer, ktime_set(0, 0), HRTIMER_MODE_REL);
-
+       if (ts->pending && !ts->reading)
+               ads7846_next_update(ts);
        spin_unlock_irq(&ts->lock);
 }