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Diffstat (limited to 'include/linux/gpio/driver.h')
-rw-r--r--include/linux/gpio/driver.h15
1 files changed, 10 insertions, 5 deletions
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index fabe2baf7b50..17511434ed07 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -20,6 +20,8 @@
#include <asm/msi.h>
#endif
+#include "defs.h"
+
struct device;
struct irq_chip;
struct irq_data;
@@ -42,9 +44,6 @@ union gpio_irq_fwspec {
#endif
};
-#define GPIO_LINE_DIRECTION_IN 1
-#define GPIO_LINE_DIRECTION_OUT 0
-
/**
* struct gpio_irq_chip - GPIO interrupt controller
*/
@@ -344,11 +343,17 @@ struct gpio_irq_chip {
* @direction_output: configures signal "offset" as output, returns 0 on
* success or a negative error number. This can be omitted on input-only
* or output-only gpio chips.
- * @get: returns value for signal "offset", 0=low, 1=high, or negative error
+ * @get: returns value for signal "offset", 0=low, 1=high, or negative error.
+ * the low and high values are defined as physical low on the line
+ * in/out to the connector such as a physical pad, pin or rail. The GPIO
+ * library has internal logic to handle lines that are active low, such
+ * as indicated by overstrike or #name in a schematic, and the driver
+ * should not try to second-guess the logic value of a line.
* @get_multiple: reads values for multiple signals defined by "mask" and
* stores them in "bits", returns 0 on success or negative error
* @set: assigns output value for signal "offset", returns 0 on success or
- * negative error value
+ * negative error value. The output value follows the same semantic
+ * rules as for @get.
* @set_multiple: assigns output values for multiple signals defined by
* "mask", returns 0 on success or negative error value
* @set_config: optional hook for all kinds of settings. Uses the same