Input: ad7879 - support auxiliary GPIOs via gpiolib

Drop the simple fancy sysfs hooks for the aux GPIOs and expose these via
the gpiolib interface so that other drivers can use them.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/spi/ad7879.h b/include/linux/spi/ad7879.h
index 4231104..6334cee 100644
--- a/include/linux/spi/ad7879.h
+++ b/include/linux/spi/ad7879.h
@@ -28,8 +28,12 @@
 	 * 1 = 4, 2 = 8, 3 = 16 (median > averaging)
 	 */
 	u8	median;
-	/* 1 = AUX/VBAT/GPIO set to GPIO Output */
-	u8	gpio_output;
-	/* Initial GPIO pin state (valid if gpio_output = 1) */
-	u8	gpio_default;
+	/* 1 = AUX/VBAT/GPIO export GPIO to gpiolib
+	 * requires CONFIG_GPIOLIB
+	 */
+	bool	gpio_export;
+	/* identifies the first GPIO number handled by this chip;
+	 * or, if negative, requests dynamic ID allocation.
+	 */
+	s32	gpio_base;
 };