From c8a06c1ef0bc45915fc45a170c7c60426971304c Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Wed, 17 Jun 2009 16:28:15 -0700 Subject: w1-gpio: add external pull-up enable callback On embedded devices, sleep mode conditions can be tricky to handle, Especially when processors tend to pull-down the w1 bus during sleep. Bus slaves (such as the ds2760) may interpret this as a reason for power-down conditions and entirely switch off the device. This patch adds a callback function pointer to let users switch on and off the external pull-up resistor. This lets the outside world know whether the processor is currently actively driving the bus or not. When this callback is not provided, the code behaviour won't change. Signed-off-by: Daniel Mack Acked-by: Ville Syrjala Acked-by: Evgeniy Polyakov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/w1-gpio.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h index 9797fec7748a..3adeff82212f 100644 --- a/include/linux/w1-gpio.h +++ b/include/linux/w1-gpio.h @@ -18,6 +18,7 @@ struct w1_gpio_platform_data { unsigned int pin; unsigned int is_open_drain:1; + void (*enable_external_pullup)(int enable); }; #endif /* _LINUX_W1_GPIO_H */ -- cgit v1.2.2