Input: ad7877 - use attribute group to control visibility of attributes

Instead of manually creating one set of attributes or another set up
is_visible method in attribute group structure to control whether
aux3 or gpio3 attribute is presented to userspace.

Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 29 insertions, 20 deletions

diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c
index b7de78e82737..326d7336a372 100644
--- a/drivers/input/touchscreen/ad7877.c
+++ b/drivers/input/touchscreen/ad7877.c
@@ -206,8 +206,8 @@ struct ad7877 {
         u16 conversion_data[AD7877_NR_SENSE] ____cacheline_aligned;
 };
 
-static int gpio3;
-module_param(gpio3, int, 0);
+static bool gpio3;
+module_param(gpio3, bool, 0);
 MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
 
 /*
@@ -471,7 +471,7 @@ static void ad7877_enable(struct ad7877 *ts)
 #define SHOW(name) static ssize_t \
 name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
 { \
-        struct ad7877   *ts = dev_get_drvdata(dev); \
+        struct ad7877 *ts = dev_get_drvdata(dev); \
         ssize_t v = ad7877_read_adc(ts->spi, \
                         AD7877_READ_CHAN(name)); \
         if (v < 0) \
@@ -491,7 +491,7 @@ SHOW(temp2)
 static ssize_t ad7877_disable_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        struct ad7877   *ts = dev_get_drvdata(dev);
+        struct ad7877 *ts = dev_get_drvdata(dev);
 
         return sprintf(buf, "%u\n", ts->disabled);
 }
@@ -521,7 +521,7 @@ static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
 static ssize_t ad7877_dac_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        struct ad7877   *ts = dev_get_drvdata(dev);
+        struct ad7877 *ts = dev_get_drvdata(dev);
 
         return sprintf(buf, "%u\n", ts->dac);
 }
@@ -551,7 +551,7 @@ static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
 static ssize_t ad7877_gpio3_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        struct ad7877   *ts = dev_get_drvdata(dev);
+        struct ad7877 *ts = dev_get_drvdata(dev);
 
         return sprintf(buf, "%u\n", ts->gpio3);
 }
@@ -582,7 +582,7 @@ static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
 static ssize_t ad7877_gpio4_show(struct device *dev,
                                      struct device_attribute *attr, char *buf)
 {
-        struct ad7877   *ts = dev_get_drvdata(dev);
+        struct ad7877 *ts = dev_get_drvdata(dev);
 
         return sprintf(buf, "%u\n", ts->gpio4);
 }
@@ -615,16 +615,35 @@ static struct attribute *ad7877_attributes[] = {
         &dev_attr_temp2.attr,
         &dev_attr_aux1.attr,
         &dev_attr_aux2.attr,
+        &dev_attr_aux3.attr,
         &dev_attr_bat1.attr,
         &dev_attr_bat2.attr,
         &dev_attr_disable.attr,
         &dev_attr_dac.attr,
+        &dev_attr_gpio3.attr,
         &dev_attr_gpio4.attr,
         NULL
 };
 
+static mode_t ad7877_attr_is_visible(struct kobject *kobj,
+                                     struct attribute *attr, int n)
+{
+        mode_t mode = attr->mode;
+
+        if (attr == &dev_attr_aux3.attr) {
+                if (gpio3)
+                        mode = 0;
+        } else if (attr == &dev_attr_gpio3.attr) {
+                if (!gpio3)
+                        mode = 0;
+        }
+
+        return mode;
+}
+
 static const struct attribute_group ad7877_attr_group = {
-        .attrs = ad7877_attributes,
+        .is_visible     = ad7877_attr_is_visible,
+        .attrs          = ad7877_attributes,
 };
 
 static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
@@ -787,20 +806,12 @@ static int __devinit ad7877_probe(struct spi_device *spi)
         if (err)
                 goto err_free_irq;
 
-        err = device_create_file(&spi->dev,
-                                 gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
-        if (err)
-                goto err_remove_attr_group;
-
         err = input_register_device(input_dev);
         if (err)
-                goto err_remove_attr;
+                goto err_remove_attr_group;
 
         return 0;
 
-err_remove_attr:
-        device_remove_file(&spi->dev,
-                           gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 err_remove_attr_group:
         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
 err_free_irq:
@@ -814,11 +825,9 @@ err_free_mem:
 
 static int __devexit ad7877_remove(struct spi_device *spi)
 {
-        struct ad7877           *ts = dev_get_drvdata(&spi->dev);
+        struct ad7877 *ts = dev_get_drvdata(&spi->dev);
 
         sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
-        device_remove_file(&spi->dev,
-                           gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
 
         ad7877_disable(ts);
         free_irq(ts->spi->irq, ts);