[PATCH v11 41/56] input: atmel_mxt_ts: export GPIO reset line via sysfs

[Jiada Wang]

From: "George G. Davis" <george_da...@mentor.com>

N.B. Modifying the atmel_mxt_ts GPIO reset line during operation will
cause problems with normal driver operation.  This feature is provided
as a diagnostic debug aid.  It does not take into consideration any
pending operations which may be in progress.  Modifying the atmel_mxt_ts
GPIO reset line at any time will inevitably cause the driver to fail.

Signed-off-by: George G. Davis <george_da...@mentor.com>
Signed-off-by: Rajeev Kumar <rajeev_ku...@mentor.com>
Signed-off-by: Jiada Wang <jiada_w...@mentor.com>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c 
b/drivers/input/touchscreen/atmel_mxt_ts.c
index 75329f87927b..ceb14b4a8d4d 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -4080,6 +4080,19 @@ static int mxt_probe(struct i2c_client *client, const 
struct i2c_device_id *id)
                return error;
        }
 
+       if (data->reset_gpio) {
+               error = gpiod_export(data->reset_gpio, 0);
+               if (error)
+                       return error;
+
+               error = gpiod_export_link(&client->dev, "reset",
+                                         data->reset_gpio);
+               if (error) {
+                       gpiod_unexport(data->reset_gpio);
+                       return error;
+               }
+       }
+
        if (data->suspend_mode == MXT_SUSPEND_REGULATOR) {
                enable_irq(data->irq);
 
@@ -4110,6 +4123,10 @@ static int mxt_probe(struct i2c_client *client, const 
struct i2c_device_id *id)
 err_free_object:
        mxt_free_input_device(data);
        mxt_free_object_table(data);
+       if (data->reset_gpio) {
+               sysfs_remove_link(&client->dev.kobj, "reset");
+               gpiod_unexport(data->reset_gpio);
+       }
        return error;
 }
 
@@ -4119,6 +4136,10 @@ static int mxt_remove(struct i2c_client *client)
 
        disable_irq(data->irq);
        sysfs_remove_group(&client->dev.kobj, &mxt_fw_attr_group);
+       if (data->reset_gpio) {
+               sysfs_remove_link(&client->dev.kobj, "reset");
+               gpiod_unexport(data->reset_gpio);
+       }
        mxt_debug_msg_remove(data);
        mxt_sysfs_remove(data);
        mxt_free_input_device(data);
-- 
2.17.1