• Haavard Skinnemoen's avatar
    i2c: Bitbanging I2C bus driver using the GPIO API · 1c23af90
    Haavard Skinnemoen authored
    This is a very simple bitbanging I2C bus driver utilizing the new
    arch-neutral GPIO API. Useful for chips that don't have a built-in
    I2C controller, additional I2C busses, or testing purposes.
    
    To use, include something similar to the following in the
    board-specific setup code:
    
      #include <linux/i2c-gpio.h>
    
      static struct i2c_gpio_platform_data i2c_gpio_data = {
    	.sda_pin	= GPIO_PIN_FOO,
    	.scl_pin	= GPIO_PIN_BAR,
      };
      static struct platform_device i2c_gpio_device = {
    	.name		= "i2c-gpio",
    	.id		= 0,
    	.dev		= {
    		.platform_data	= &i2c_gpio_data,
    	},
      };
    
    Register this platform_device, set up the I2C pins as GPIO if
    required and you're ready to go. This will use default values for
    udelay and timeout, and will work with GPIO hardware that does not
    support open drain mode, but allows sensing of the SDA and SCL lines
    even when they are being driven.
    Signed-off-by: 's avatarHaavard Skinnemoen <hskinnemoen@atmel.com>
    Signed-off-by: 's avatarJean Delvare <khali@linux-fr.org>
    1c23af90
i2c-gpio.h 1.31 KB