gpiolib: export descriptor-based GPIO interface

This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:

- gpio works with integers, whereas gpiod operates on opaque handlers
  which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
  the new interface, whereas chips drivers will use
  <linux/gpio/driver.h>

The legacy gpio API is now built as inline functions on top of gpiod.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index a06ec3e85ba3..c691df044458 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -16,14 +16,17 @@
 #define GPIOF_OUT_INIT_LOW      (GPIOF_DIR_OUT | GPIOF_INIT_LOW)
 #define GPIOF_OUT_INIT_HIGH     (GPIOF_DIR_OUT | GPIOF_INIT_HIGH)
 
+/* Gpio pin is active-low */
+#define GPIOF_ACTIVE_LOW        (1 << 2)
+
 /* Gpio pin is open drain */
-#define GPIOF_OPEN_DRAIN        (1 << 2)
+#define GPIOF_OPEN_DRAIN        (1 << 3)
 
 /* Gpio pin is open source */
-#define GPIOF_OPEN_SOURCE       (1 << 3)
+#define GPIOF_OPEN_SOURCE       (1 << 4)
 
-#define GPIOF_EXPORT            (1 << 4)
-#define GPIOF_EXPORT_CHANGEABLE (1 << 5)
+#define GPIOF_EXPORT            (1 << 5)
+#define GPIOF_EXPORT_CHANGEABLE (1 << 6)
 #define GPIOF_EXPORT_DIR_FIXED  (GPIOF_EXPORT)
 #define GPIOF_EXPORT_DIR_CHANGEABLE (GPIOF_EXPORT | GPIOF_EXPORT_CHANGEABLE)