unload support

[ms2-kexec] / headphone_cons.c

/*
 * Provide kernel console on headphone jack
 */

#include <linux/module.h>
#include <linux/gpio_mapping.h>
#include <linux/gpio.h>

static int hs_switch = -1;

/*
 * int add_preferred_console(char *name, int idx, char *options)
 * c0069208 T add_preferred_console
 */

static int (*add_preferred_console)(char *, int, char*) = (int (*)(char*, int, char*))0xc0069208;

static int __init headphone_cons_init(void)
{
	/* Get the headset switch gpio number from devtree */
	hs_switch = get_gpio_by_name("headset_uart_switch");
	if (hs_switch < 0)
		return -EINVAL;

	printk(KERN_INFO "headset_uart_switch: %d\n", hs_switch);

	printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));

#if 0
	/* configure headset switch gpio as output and
	   direction based on devtree setting */
	if (gpio_request(hs_switch, "mapphone audio headset uart switch") < 0)
		return -ENODEV;
#endif

	/* route kernel uart out headset jack */
	gpio_direction_output(hs_switch, 0);
	printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));

	add_preferred_console("ttyS", 0, "115200");
	return 0;
}

static void __exit headphone_cons_exit(void)
{
	if (hs_switch < 0)
		return;

	printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
	gpio_direction_output(hs_switch, 1);
	printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
}


module_init(headphone_cons_init);
module_exit(headphone_cons_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Michael Gernoth <michael@gernoth.net>");