Input: ads7846 - do not allow altering platform data

Tested-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

2 files changed, 20 insertions, 17 deletions

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 69210cb56c54..a3771607ead5 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -878,14 +878,15 @@ static int __devinit setup_pendown(struct spi_device *spi, struct ads7846 *ts)
 
 static int __devinit ads7846_probe(struct spi_device *spi)
 {
-        struct ads7846                  *ts;
-        struct ads7846_packet           *packet;
-        struct input_dev                *input_dev;
-        struct ads7846_platform_data    *pdata = spi->dev.platform_data;
-        struct spi_message              *m;
-        struct spi_transfer             *x;
-        int                             vref;
-        int                             err;
+        struct ads7846 *ts;
+        struct ads7846_packet *packet;
+        struct input_dev *input_dev;
+        const struct ads7846_platform_data *pdata = spi->dev.platform_data;
+        struct spi_message *m;
+        struct spi_transfer *x;
+        unsigned long irq_flags;
+        int vref;
+        int err;
 
         if (!spi->irq) {
                 dev_dbg(&spi->dev, "no IRQ?\n");
@@ -1174,20 +1175,22 @@ static int __devinit ads7846_probe(struct spi_device *spi)
                 goto err_put_regulator;
         }
 
-        if (!pdata->irq_flags)
-                pdata->irq_flags = IRQF_TRIGGER_FALLING;
+        irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
 
-        if (request_irq(spi->irq, ads7846_irq, pdata->irq_flags,
-                        spi->dev.driver->name, ts)) {
+        err = request_irq(spi->irq, ads7846_irq, irq_flags,
+                          spi->dev.driver->name, ts);
+
+        if (err && !pdata->irq_flags) {
                 dev_info(&spi->dev,
                         "trying pin change workaround on irq %d\n", spi->irq);
                 err = request_irq(spi->irq, ads7846_irq,
                                   IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
                                   spi->dev.driver->name, ts);
-                if (err) {
-                        dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
-                        goto err_disable_regulator;
-                }
+        }
+
+        if (err) {
+                dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
+                goto err_disable_regulator;
         }
 
         err = ads784x_hwmon_register(spi, ts);
diff --git a/include/linux/spi/ads7846.h b/include/linux/spi/ads7846.h
index 95d36bfb34bc..92bd0839d5b4 100644
--- a/include/linux/spi/ads7846.h
+++ b/include/linux/spi/ads7846.h
@@ -48,7 +48,7 @@ struct ads7846_platform_data {
                                          * state if get_pendown_state == NULL
                                          */
         int     (*get_pendown_state)(void);
-        int     (*filter_init)  (struct ads7846_platform_data *pdata,
+        int     (*filter_init)  (const struct ads7846_platform_data *pdata,
                                  void **filter_data);
         int     (*filter)       (void *filter_data, int data_idx, int *val);
         void    (*filter_cleanup)(void *filter_data);