Input: ads7846 - add pen_down sysfs attribute

It's handy for userspace diagnostics to see the pen down status, to
see whether the touchscreen is "stuck" (shortcircuited).

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Juha Yrjola <juha.yrjola@nokia.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 46d1fec2cfd8..7f384a694d80 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -233,6 +233,21 @@ SHOW(temp1)
 SHOW(vaux)
 SHOW(vbatt)
 
+static int is_pen_down(struct device *dev)
+{
+        struct ads7846          *ts = dev_get_drvdata(dev);
+
+        return ts->pendown;
+}
+
+static ssize_t ads7846_pen_down_show(struct device *dev,
+                                     struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%u\n", is_pen_down(dev));
+}
+
+static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
+
 /*--------------------------------------------------------------------------*/
 
 /*
@@ -559,6 +574,8 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 device_create_file(&spi->dev, &dev_attr_vbatt);
         device_create_file(&spi->dev, &dev_attr_vaux);
 
+        device_create_file(&spi->dev, &dev_attr_pen_down);
+
         err = input_register_device(input_dev);
         if (err)
                 goto err_free_irq;
@@ -582,6 +599,8 @@ static int __devexit ads7846_remove(struct spi_device *spi)
         if (ts->irq_disabled)
                 enable_irq(ts->spi->irq);
 
+        device_remove_file(&spi->dev, &dev_attr_pen_down);
+
         if (ts->model == 7846) {
                 device_remove_file(&spi->dev, &dev_attr_temp0);
                 device_remove_file(&spi->dev, &dev_attr_temp1);