xref: /linux/include/linux/extcon/extcon-adc-jack.h (revision a75e1c73a46eed0332d036e371f714e76d167c07)

/*
 * include/linux/extcon/extcon-adc-jack.h
 *
 * Analog Jack extcon driver with ADC-based detection capability.
 *
 * Copyright (C) 2012 Samsung Electronics
 * MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#ifndef _EXTCON_ADC_JACK_H_
#define _EXTCON_ADC_JACK_H_ __FILE__

#include <linux/module.h>
#include <linux/extcon.h>

/**
 * struct adc_jack_cond - condition to use an extcon state
 * @state:		the corresponding extcon state (if 0, this struct
 *			denotes the last adc_jack_cond element among the array)
 * @min_adc:		min adc value for this condition
 * @max_adc:		max adc value for this condition
 *
 * For example, if { .state = 0x3, .min_adc = 100, .max_adc = 200}, it means
 * that if ADC value is between (inclusive) 100 and 200, than the cable 0 and
 * 1 are attached (1<<0 | 1<<1 == 0x3)
 *
 * Note that you don't need to describe condition for "no cable attached"
 * because when no adc_jack_cond is met, state = 0 is automatically chosen.
 */
struct adc_jack_cond {
	u32 state;	/* extcon state value. 0 if invalid */
	u32 min_adc;
	u32 max_adc;
};

/**
 * struct adc_jack_pdata - platform data for adc jack device.
 * @name:		name of the extcon device. If null, "adc-jack" is used.
 * @consumer_channel:	Unique name to identify the channel on the consumer
 *			side. This typically describes the channels used within
 *			the consumer. E.g. 'battery_voltage'
 * @cable_names:	array of cable names ending with null.
 * @adc_contitions:	array of struct adc_jack_cond conditions ending
 *			with .state = 0 entry. This describes how to decode
 *			adc values into extcon state.
 * @irq_flags:		irq flags used for the @irq
 * @handling_delay_ms:	in some devices, we need to read ADC value some
 *			milli-seconds after the interrupt occurs. You may
 *			describe such delays with @handling_delay_ms, which
 *			is rounded-off by jiffies.
 */
struct adc_jack_pdata {
	const char *name;
	const char *consumer_channel;

	/* The last entry should be NULL */
	const char **cable_names;

	/* The last entry's state should be 0 */
	struct adc_jack_cond *adc_conditions;

	unsigned long irq_flags;
	unsigned long handling_delay_ms; /* in ms */
};

#endif /* _EXTCON_ADC_JACK_H */