include/linux/extcon/extcon-adc-jack.h

   1 /*
   2  * include/linux/extcon/extcon-adc-jack.h
   3  *
   4  * Analog Jack extcon driver with ADC-based detection capability.
   5  *
   6  * Copyright (C) 2012 Samsung Electronics
   7  * MyungJoo Ham <myungjoo.ham@samsung.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  */
  14
  15 #ifndef _EXTCON_ADC_JACK_H_
  16 #define _EXTCON_ADC_JACK_H_ __FILE__
  17
  18 #include <linux/module.h>
  19 #include <linux/extcon.h>
  20
  21 /**
  22  * struct adc_jack_cond - condition to use an extcon state
  23  * @state:              the corresponding extcon state (if 0, this struct
  24  *                      denotes the last adc_jack_cond element among the array)
  25  * @min_adc:            min adc value for this condition
  26  * @max_adc:            max adc value for this condition
  27  *
  28  * For example, if { .state = 0x3, .min_adc = 100, .max_adc = 200}, it means
  29  * that if ADC value is between (inclusive) 100 and 200, than the cable 0 and
  30  * 1 are attached (1<<0 | 1<<1 == 0x3)
  31  *
  32  * Note that you don't need to describe condition for "no cable attached"
  33  * because when no adc_jack_cond is met, state = 0 is automatically chosen.
  34  */
  35 struct adc_jack_cond {
  36         u32 state;      /* extcon state value. 0 if invalid */
  37         u32 min_adc;
  38         u32 max_adc;
  39 };
  40
  41 /**
  42  * struct adc_jack_pdata - platform data for adc jack device.
  43  * @name:               name of the extcon device. If null, "adc-jack" is used.
  44  * @consumer_channel:   Unique name to identify the channel on the consumer
  45  *                      side. This typically describes the channels used within
  46  *                      the consumer. E.g. 'battery_voltage'
  47  * @cable_names:        array of cable names ending with null.
  48  * @adc_contitions:     array of struct adc_jack_cond conditions ending
  49  *                      with .state = 0 entry. This describes how to decode
  50  *                      adc values into extcon state.
  51  * @irq_flags:          irq flags used for the @irq
  52  * @handling_delay_ms:  in some devices, we need to read ADC value some
  53  *                      milli-seconds after the interrupt occurs. You may
  54  *                      describe such delays with @handling_delay_ms, which
  55  *                      is rounded-off by jiffies.
  56  */
  57 struct adc_jack_pdata {
  58         const char *name;
  59         const char *consumer_channel;
  60
  61         /* The last entry should be NULL */
  62         const char **cable_names;
  63
  64         /* The last entry's state should be 0 */
  65         struct adc_jack_cond *adc_conditions;
  66
  67         unsigned long irq_flags;
  68         unsigned long handling_delay_ms; /* in ms */
  69 };
  70
  71 #endif /* _EXTCON_ADC_JACK_H */