Edit File: pcf857x.h
#ifndef __LINUX_PCF857X_H #define __LINUX_PCF857X_H /** * struct pcf857x_platform_data - data to set up pcf857x driver * @gpio_base: number of the chip's first GPIO * @n_latch: optional bit-inverse of initial register value; if * you leave this initialized to zero the driver will act * like the chip was just reset * @setup: optional callback issued once the GPIOs are valid * @teardown: optional callback issued before the GPIOs are invalidated * @context: optional parameter passed to setup() and teardown() * * In addition to the I2C_BOARD_INFO() state appropriate to each chip, * the i2c_board_info used with the pcf875x driver must provide its * platform_data (pointer to one of these structures) with at least * the gpio_base value initialized. * * The @setup callback may be used with the kind of board-specific glue * which hands the (now-valid) GPIOs to other drivers, or which puts * devices in their initial states using these GPIOs. * * These GPIO chips are only "quasi-bidirectional"; read the chip specs * to understand the behavior. They don't have separate registers to * record which pins are used for input or output, record which output * values are driven, or provide access to input values. That must be * inferred by reading the chip's value and knowing the last value written * to it. If you leave n_latch initialized to zero, that last written * value is presumed to be all ones (as if the chip were just reset). */ struct pcf857x_platform_data { unsigned gpio_base; unsigned n_latch; int (*setup)(struct i2c_client *client, int gpio, unsigned ngpio, void *context); int (*teardown)(struct i2c_client *client, int gpio, unsigned ngpio, void *context); void *context; }; #endif /* __LINUX_PCF857X_H */