1 files changed, 79 insertions, 1 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 1c9069cd3bae..96581d08774f 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -95,7 +95,7 @@ struct ads7846 {
         u16                     dummy;          /* for the pwrdown read */
         struct ts_event         tc;
 
-        struct spi_transfer     xfer[10];
+        struct spi_transfer     xfer[18];
         struct spi_message      msg[5];
         struct spi_message      *last_msg;
         int                     msg_idx;
@@ -107,6 +107,8 @@ struct ads7846 {
         u16                     debounce_tol;
         u16                     debounce_rep;
 
+        u16                     penirq_recheck_delay_usecs;
+
         spinlock_t              lock;
         struct hrtimer          timer;
         unsigned                pendown:1;      /* P: lock */
@@ -553,6 +555,15 @@ static void ads7846_rx(void *ads)
                 return;
         }
 
+        /* Maybe check the pendown state before reporting. This discards
+         * false readings when the pen is lifted.
+         */
+        if (ts->penirq_recheck_delay_usecs) {
+                udelay(ts->penirq_recheck_delay_usecs);
+                if (!ts->get_pendown_state())
+                        Rt = 0;
+        }
+
         /* NOTE: We can't rely on the pressure to determine the pen down
          * state, even this controller has a pressure sensor.  The pressure
          * value can fluctuate for quite a while after lifting the pen and
@@ -896,6 +907,10 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 ts->filter = ads7846_no_filter;
         ts->get_pendown_state = pdata->get_pendown_state;
 
+        if (pdata->penirq_recheck_delay_usecs)
+                ts->penirq_recheck_delay_usecs =
+                                pdata->penirq_recheck_delay_usecs;
+
         snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
 
         input_dev->name = "ADS784x Touchscreen";
@@ -936,6 +951,24 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         x->len = 2;
         spi_message_add_tail(x, m);
 
+        /* the first sample after switching drivers can be low quality;
+         * optionally discard it, using a second one after the signals
+         * have had enough time to stabilize.
+         */
+        if (pdata->settle_delay_usecs) {
+                x->delay_usecs = pdata->settle_delay_usecs;
+
+                x++;
+                x->tx_buf = &ts->read_y;
+                x->len = 1;
+                spi_message_add_tail(x, m);
+
+                x++;
+                x->rx_buf = &ts->tc.y;
+                x->len = 2;
+                spi_message_add_tail(x, m);
+        }
+
         m->complete = ads7846_rx_val;
         m->context = ts;
 
@@ -954,6 +987,21 @@ static int __devinit ads7846_probe(struct spi_device *spi)
         x->len = 2;
         spi_message_add_tail(x, m);
 
+        /* ... maybe discard first sample ... */
+        if (pdata->settle_delay_usecs) {
+                x->delay_usecs = pdata->settle_delay_usecs;
+
+                x++;
+                x->tx_buf = &ts->read_x;
+                x->len = 1;
+                spi_message_add_tail(x, m);
+
+                x++;
+                x->rx_buf = &ts->tc.x;
+                x->len = 2;
+                spi_message_add_tail(x, m);
+        }
+
         m->complete = ads7846_rx_val;
         m->context = ts;
 
@@ -973,6 +1021,21 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 x->len = 2;
                 spi_message_add_tail(x, m);
 
+                /* ... maybe discard first sample ... */
+                if (pdata->settle_delay_usecs) {
+                        x->delay_usecs = pdata->settle_delay_usecs;
+
+                        x++;
+                        x->tx_buf = &ts->read_z1;
+                        x->len = 1;
+                        spi_message_add_tail(x, m);
+
+                        x++;
+                        x->rx_buf = &ts->tc.z1;
+                        x->len = 2;
+                        spi_message_add_tail(x, m);
+                }
+
                 m->complete = ads7846_rx_val;
                 m->context = ts;
 
@@ -990,6 +1053,21 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 x->len = 2;
                 spi_message_add_tail(x, m);
 
+                /* ... maybe discard first sample ... */
+                if (pdata->settle_delay_usecs) {
+                        x->delay_usecs = pdata->settle_delay_usecs;
+
+                        x++;
+                        x->tx_buf = &ts->read_z2;
+                        x->len = 1;
+                        spi_message_add_tail(x, m);
+
+                        x++;
+                        x->rx_buf = &ts->tc.z2;
+                        x->len = 2;
+                        spi_message_add_tail(x, m);
+                }
+
                 m->complete = ads7846_rx_val;
                 m->context = ts;
         }