Input: ads7846: add read on vsync hack

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

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 870b6dc..51cc7c3 100644 (file)
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -27,6 +27,7 @@
 #include <linux/spi/spi.h>
 #include <linux/spi/ads7846.h>
 #include <asm/irq.h>
+#include <mach/display.h>
 
 
 /*
@@ -111,6 +112,7 @@ struct ads7846 {
        unsigned                irq_disabled:1; /* P: lock */
        unsigned                disabled:1;
        unsigned                is_suspended:1;
+       unsigned                ext_trigger:1;
 
        int                     (*filter)(void *data, int data_idx, int *val);
        void                    *filter_data;
@@ -606,8 +608,11 @@ static void ads7846_rx(void *ads)
 #endif
        }
 
-       hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
-                       HRTIMER_MODE_REL);
+       if (!ts->ext_trigger)
+               hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_PERIOD),
+                               HRTIMER_MODE_REL);
+       else
+               ts->pending = 0;
 }
 
 static int ads7846_debounce(void *ads, int data_idx, int *val)
@@ -759,6 +764,21 @@ static irqreturn_t ads7846_irq(int irq, void *handle)
        return IRQ_HANDLED;
 }
 
+static void omap_vsync_handler(void *arg, u32 mask)
+{
+       struct ads7846 *ts = arg;
+
+       spin_lock_irq(&ts->lock);
+
+       if (ts->pendown && !ts->pending && !ts->disabled) {
+               ts->pending = 1;
+               hrtimer_start(&ts->timer, ktime_set(0, 0),
+                               HRTIMER_MODE_REL);
+       }
+
+       spin_unlock_irq(&ts->lock);
+}
+
 /*--------------------------------------------------------------------------*/
 
 /* Must be called with ts->lock held */
@@ -1127,6 +1147,12 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 
        dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
 
+       err = omap_dispc_register_isr(omap_vsync_handler, ts, DISPC_IRQ_VSYNC);
+       if (err == 0) {
+               dev_info(&spi->dev, "using vsync trigger\n");
+               ts->ext_trigger = 1;
+       }
+
        /* take a first sample, leaving nPENIRQ active and vREF off; avoid
         * the touchscreen, in case it's not connected.
         */
@@ -1164,6 +1190,7 @@ static int __devexit ads7846_remove(struct spi_device *spi)
 
        ads784x_hwmon_unregister(spi, ts);
        input_unregister_device(ts->input);
+       omap_dispc_unregister_isr(omap_vsync_handler, ts, DISPC_IRQ_VSYNC);
 
        ads7846_suspend(spi, PMSG_SUSPEND);