[PATCH v1 3/3] Input: ili210x - optionally hide calibrate sysfs attribute

[Sven Van Asbroeck <thesven73@gmail.com>]

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.

Link: https://lore.kernel.org/lkml/20191111181657.GA57214@dtor-ws/
Cc: Marek Vasut <marex@denx.de>
Cc: Adam Ford <aford173@gmail.com>
Cc: <linux-kernel@vger.kernel.org>
Cc: linux-input@vger.kernel.org
Tree: https://git.kernel.org/pub/scm/linux/kernel/git/dtor/input.git/log/?h=next
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
---
 drivers/input/touchscreen/ili210x.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
index 4321f0d676cc..810770ad02e2 100644
--- a/drivers/input/touchscreen/ili210x.c
+++ b/drivers/input/touchscreen/ili210x.c
@@ -32,6 +32,7 @@ struct ili2xxx_chip {
 	bool (*continue_polling)(const u8 *data, bool touch);
 	unsigned int max_touches;
 	unsigned int resolution;
+	bool no_calibrate_reg;
 };
 
 struct ili210x {
@@ -162,6 +163,7 @@ static const struct ili2xxx_chip ili211x_chip = {
 	.continue_polling	= ili211x_decline_polling,
 	.max_touches		= 10,
 	.resolution		= 2048,
+	.no_calibrate_reg	= true,
 };
 
 static int ili251x_read_reg(struct i2c_client *client,
@@ -310,8 +312,19 @@ 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->no_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)
-- 
2.17.1