Input: ads7846 - add support for the ads7843 touchscreen

The ads7843 support has now become almost trivial since the last
rework.

Signed-off-by: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 15 insertions, 13 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 0a26e0663542..2f5fc8043366 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -39,7 +39,8 @@
 /*
  * This code has been heavily tested on a Nokia 770, and lightly
  * tested on other ads7846 devices (OSK/Mistral, Lubbock).
- * Support for ads7843 and ads7845 has only been stubbed in.
+ * Support for ads7843 tested on Atmel at91sam926x-EK.
+ * Support for ads7845 has only been stubbed in.
  *
  * IRQ handling needs a workaround because of a shortcoming in handling
  * edge triggered IRQs on some platforms like the OMAP1/2. These
@@ -246,18 +247,16 @@ static int ads7846_read12_ser(struct device *dev, unsigned command)
 
         /* REVISIT:  take a few more samples, and compare ... */
 
-        /* maybe off internal vREF */
-        if (use_internal) {
-                req->ref_off = REF_OFF;
-                req->xfer[4].tx_buf = &req->ref_off;
-                req->xfer[4].len = 1;
-                spi_message_add_tail(&req->xfer[4], &req->msg);
-
-                req->xfer[5].rx_buf = &req->scratch;
-                req->xfer[5].len = 2;
-                CS_CHANGE(req->xfer[5]);
-                spi_message_add_tail(&req->xfer[5], &req->msg);
-        }
+        /* converter in low power mode & enable PENIRQ */
+        req->ref_off = PWRDOWN;
+        req->xfer[4].tx_buf = &req->ref_off;
+        req->xfer[4].len = 1;
+        spi_message_add_tail(&req->xfer[4], &req->msg);
+
+        req->xfer[5].rx_buf = &req->scratch;
+        req->xfer[5].len = 2;
+        CS_CHANGE(req->xfer[5]);
+        spi_message_add_tail(&req->xfer[5], &req->msg);
 
         ts->irq_disabled = 1;
         disable_irq(spi->irq);
@@ -536,6 +535,9 @@ static void ads7846_rx(void *ads)
         } else
                 Rt = 0;
 
+        if (ts->model == 7843)
+                Rt = ts->pressure_max / 2;
+
         /* 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