HID: cp2112: fix setter callbacks return value

Since commit 6485543488a6 ("HID: cp2112: use new line value setter
callbacks"), setting a GPIO value always fails with error -EBADE.

That's because the returned value by the setter callbacks is the
returned value by the hid_hw_raw_request() function which is the number of
bytes sent on success or a negative value on error. The function
gpiochip_set() returns -EBADE if the setter callbacks return a value >
0.

Fix this by making the setter callbacks return 0 on success or a negative
value on error.

While at it, use the returned value by cp2112_gpio_set_unlocked() in the
direction_output callback.

Fixes: 6485543488a6 ("HID: cp2112: use new line value setter callbacks")
Signed-off-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c
index 234fa82eab0795be4de9f5ba1a4ab6c16c6bff4c..b5f2b6356f512aa2520bf20095135e850a0ac605 100644 (file)
--- a/drivers/hid/hid-cp2112.c
+++ b/drivers/hid/hid-cp2112.c
@@ -229,10 +229,12 @@ static int cp2112_gpio_set_unlocked(struct cp2112_device *dev,
        ret = hid_hw_raw_request(hdev, CP2112_GPIO_SET, buf,
                                 CP2112_GPIO_SET_LENGTH, HID_FEATURE_REPORT,
                                 HID_REQ_SET_REPORT);
-       if (ret < 0)
+       if (ret != CP2112_GPIO_SET_LENGTH) {
                hid_err(hdev, "error setting GPIO values: %d\n", ret);
+               return ret < 0 ? ret : -EIO;
+       }
 
-       return ret;
+       return 0;
 }
 
 static int cp2112_gpio_set(struct gpio_chip *chip, unsigned int offset,
@@ -309,9 +311,7 @@ static int cp2112_gpio_direction_output(struct gpio_chip *chip,
         * Set gpio value when output direction is already set,
         * as specified in AN495, Rev. 0.2, cpt. 4.4
         */
-       cp2112_gpio_set_unlocked(dev, offset, value);
-
-       return 0;
+       return cp2112_gpio_set_unlocked(dev, offset, value);
 }
 
 static int cp2112_hid_get(struct hid_device *hdev, unsigned char report_number,