xref: /linux/include/linux/extcon/extcon-adc-jack.h (revision 4413e16d9d21673bb5048a2e542f1aaa00015c2e)
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 denotes
24  *             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 	 */
63 	const char **cable_names;
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 */
72