git.zerfleddert.de Git - ms2-kexec/blob - headphone_cons.c

   1 /*
   2  * Provide kernel console on headphone jack
   3  */
   4
   5 #include <linux/module.h>
   6 #include <linux/gpio_mapping.h>
   7 #include <linux/gpio.h>
   8
   9 static int hs_switch = -1;
  10
  11 /*
  12  * int add_preferred_console(char *name, int idx, char *options)
  13  * c0069208 T add_preferred_console
  14  */
  15
  16 static int (*add_preferred_console)(char *, int, char*) = (int (*)(char*, int, char*))0xc0069208;
  17
  18 static int __init headphone_cons_init(void)
  19 {
  20         /* Get the headset switch gpio number from devtree */
  21         hs_switch = get_gpio_by_name("headset_uart_switch");
  22         if (hs_switch < 0)
  23                 return -EINVAL;
  24
  25         printk(KERN_INFO "headset_uart_switch: %d\n", hs_switch);
  26
  27         printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
  28
  29 #if 0
  30         /* configure headset switch gpio as output and
  31            direction based on devtree setting */
  32         if (gpio_request(hs_switch, "mapphone audio headset uart switch") < 0)
  33                 return -ENODEV;
  34 #endif
  35
  36         /* route kernel uart out headset jack */
  37         gpio_direction_output(hs_switch, 0);
  38         printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
  39
  40         add_preferred_console("ttyS", 0, "115200");
  41         return 0;
  42 }
  43
  44 static void __exit headphone_cons_exit(void)
  45 {
  46         if (hs_switch < 0)
  47                 return;
  48
  49         printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
  50         gpio_direction_output(hs_switch, 1);
  51         printk(KERN_INFO "value: %d\n", gpio_get_value(hs_switch));
  52 }
  53
  54
  55 module_init(headphone_cons_init);
  56 module_exit(headphone_cons_exit);
  57
  58 MODULE_LICENSE("GPL");
  59 MODULE_AUTHOR("Michael Gernoth <michael@gernoth.net>");