Input: ili210x - optionally show calibrate sysfs attribute

Only show the 'calibrate' sysfs attribute on chip flavours
which support calibration by writing to a calibration register.

Do this by adding a flag to the chip operations structure.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Link: https://lore.kernel.org/r/20191112210148.3535-2-TheSven73@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
index 6861ac4355b26bf29f882d2df33f9451f2530938..4a17096e83e11679a26579148daba4cc17330d6b 100644 (file)
--- a/drivers/input/touchscreen/ili210x.c
+++ b/drivers/input/touchscreen/ili210x.c
@@ -33,6 +33,7 @@ struct ili2xxx_chip {
        bool (*continue_polling)(const u8 *data, bool touch);
        unsigned int max_touches;
        unsigned int resolution;
+       bool has_calibrate_reg;
 };
 
 struct ili210x {
@@ -103,6 +104,7 @@ static const struct ili2xxx_chip ili210x_chip = {
        .parse_touch_data       = ili210x_touchdata_to_coords,
        .continue_polling       = ili210x_check_continue_polling,
        .max_touches            = 2,
+       .has_calibrate_reg      = true,
 };
 
 static int ili211x_read_touch_data(struct i2c_client *client, u8 *data)
@@ -228,6 +230,7 @@ static const struct ili2xxx_chip ili251x_chip = {
        .parse_touch_data       = ili251x_touchdata_to_coords,
        .continue_polling       = ili251x_check_continue_polling,
        .max_touches            = 10,
+       .has_calibrate_reg      = true,
 };
 
 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
@@ -311,8 +314,19 @@ static struct attribute *ili210x_attributes[] = {
        NULL,
 };
 
+static umode_t ili210x_calibrate_visible(struct kobject *kobj,
+                                         struct attribute *attr, int index)
+{
+       struct device *dev = kobj_to_dev(kobj);
+       struct i2c_client *client = to_i2c_client(dev);
+       struct ili210x *priv = i2c_get_clientdata(client);
+
+       return priv->chip->has_calibrate_reg;
+}
+
 static const struct attribute_group ili210x_attr_group = {
        .attrs = ili210x_attributes,
+       .is_visible = ili210x_calibrate_visible,
 };
 
 static void ili210x_power_down(void *data)