media: rc-core.rst: add an introduction for RC core

[linux.git] / include / media / rc-core.h

/*
 * Remote Controller core header
 *
 * Copyright (C) 2009-2010 by Mauro Carvalho Chehab
 *
 * This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation version 2 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 */

#ifndef _RC_CORE
#define _RC_CORE

#include <linux/spinlock.h>
#include <linux/cdev.h>
#include <linux/kfifo.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <media/rc-map.h>

extern int rc_core_debug;
#define IR_dprintk(level, fmt, ...)				\
do {								\
	if (rc_core_debug >= level)				\
		printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__);	\
} while (0)

/**
 * enum rc_driver_type - type of the RC output
 *
 * @RC_DRIVER_SCANCODE:	 Driver or hardware generates a scancode
 * @RC_DRIVER_IR_RAW:	 Driver or hardware generates pulse/space sequences.
 *			 It needs a Infra-Red pulse/space decoder
 * @RC_DRIVER_IR_RAW_TX: Device transmitter only,
 *			 driver requires pulse/space data sequence.
 */
enum rc_driver_type {
	RC_DRIVER_SCANCODE = 0,
	RC_DRIVER_IR_RAW,
	RC_DRIVER_IR_RAW_TX,
};

/**
 * struct rc_scancode_filter - Filter scan codes.
 * @data:	Scancode data to match.
 * @mask:	Mask of bits of scancode to compare.
 */
struct rc_scancode_filter {
	u32 data;
	u32 mask;
};

/**
 * enum rc_filter_type - Filter type constants.
 * @RC_FILTER_NORMAL:	Filter for normal operation.
 * @RC_FILTER_WAKEUP:	Filter for waking from suspend.
 * @RC_FILTER_MAX:	Number of filter types.
 */
enum rc_filter_type {
	RC_FILTER_NORMAL = 0,
	RC_FILTER_WAKEUP,

	RC_FILTER_MAX
};

/**
 * struct lirc_fh - represents an open lirc file
 * @list: list of open file handles
 * @rc: rcdev for this lirc chardev
 * @carrier_low: when setting the carrier range, first the low end must be
 *	set with an ioctl and then the high end with another ioctl
 * @send_timeout_reports: report timeouts in lirc raw IR.
 * @rawir: queue for incoming raw IR
 * @scancodes: queue for incoming decoded scancodes
 * @wait_poll: poll struct for lirc device
 * @send_mode: lirc mode for sending, either LIRC_MODE_SCANCODE or
 *	LIRC_MODE_PULSE
 * @rec_mode: lirc mode for receiving, either LIRC_MODE_SCANCODE or
 *	LIRC_MODE_MODE2
 */
struct lirc_fh {
	struct list_head list;
	struct rc_dev *rc;
	int				carrier_low;
	bool				send_timeout_reports;
	DECLARE_KFIFO_PTR(rawir, unsigned int);
	DECLARE_KFIFO_PTR(scancodes, struct lirc_scancode);
	wait_queue_head_t		wait_poll;
	u8				send_mode;
	u8				rec_mode;
};

/**
 * struct rc_dev - represents a remote control device
 * @dev: driver model's view of this device
 * @managed_alloc: devm_rc_allocate_device was used to create rc_dev
 * @sysfs_groups: sysfs attribute groups
 * @device_name: name of the rc child device
 * @input_phys: physical path to the input child device
 * @input_id: id of the input child device (struct input_id)
 * @driver_name: name of the hardware driver which registered this device
 * @map_name: name of the default keymap
 * @rc_map: current scan/key table
 * @lock: used to ensure we've filled in all protocol details before
 *	anyone can call show_protocols or store_protocols
 * @minor: unique minor remote control device number
 * @raw: additional data for raw pulse/space devices
 * @input_dev: the input child device used to communicate events to userspace
 * @driver_type: specifies if protocol decoding is done in hardware or software
 * @idle: used to keep track of RX state
 * @encode_wakeup: wakeup filtering uses IR encode API, therefore the allowed
 *	wakeup protocols is the set of all raw encoders
 * @allowed_protocols: bitmask with the supported RC_PROTO_BIT_* protocols
 * @enabled_protocols: bitmask with the enabled RC_PROTO_BIT_* protocols
 * @allowed_wakeup_protocols: bitmask with the supported RC_PROTO_BIT_* wakeup
 *	protocols
 * @wakeup_protocol: the enabled RC_PROTO_* wakeup protocol or
 *	RC_PROTO_UNKNOWN if disabled.
 * @scancode_filter: scancode filter
 * @scancode_wakeup_filter: scancode wakeup filters
 * @scancode_mask: some hardware decoders are not capable of providing the full
 *	scancode to the application. As this is a hardware limit, we can't do
 *	anything with it. Yet, as the same keycode table can be used with other
 *	devices, a mask is provided to allow its usage. Drivers should generally
 *	leave this field in blank
 * @users: number of current users of the device
 * @priv: driver-specific data
 * @keylock: protects the remaining members of the struct
 * @keypressed: whether a key is currently pressed
 * @keyup_jiffies: time (in jiffies) when the current keypress should be released
 * @timer_keyup: timer for releasing a keypress
 * @timer_repeat: timer for autorepeat events. This is needed for CEC, which
 *	has non-standard repeats.
 * @last_keycode: keycode of last keypress
 * @last_protocol: protocol of last keypress
 * @last_scancode: scancode of last keypress
 * @last_toggle: toggle value of last command
 * @timeout: optional time after which device stops sending data
 * @min_timeout: minimum timeout supported by device
 * @max_timeout: maximum timeout supported by device
 * @rx_resolution : resolution (in ns) of input sampler
 * @tx_resolution: resolution (in ns) of output sampler
 * @lirc_dev: lirc device
 * @lirc_cdev: lirc char cdev
 * @gap_start: time when gap starts
 * @gap_duration: duration of initial gap
 * @gap: true if we're in a gap
 * @lirc_fh_lock: protects lirc_fh list
 * @lirc_fh: list of open files
 * @registered: set to true by rc_register_device(), false by
 *	rc_unregister_device
 * @change_protocol: allow changing the protocol used on hardware decoders
 * @open: callback to allow drivers to enable polling/irq when IR input device
 *	is opened.
 * @close: callback to allow drivers to disable polling/irq when IR input device
 *	is opened.
 * @s_tx_mask: set transmitter mask (for devices with multiple tx outputs)
 * @s_tx_carrier: set transmit carrier frequency
 * @s_tx_duty_cycle: set transmit duty cycle (0% - 100%)
 * @s_rx_carrier_range: inform driver about carrier it is expected to handle
 * @tx_ir: transmit IR
 * @s_idle: enable/disable hardware idle mode, upon which,
 *	device doesn't interrupt host until it sees IR pulses
 * @s_learning_mode: enable wide band receiver used for learning
 * @s_carrier_report: enable carrier reports
 * @s_filter: set the scancode filter
 * @s_wakeup_filter: set the wakeup scancode filter. If the mask is zero
 *	then wakeup should be disabled. wakeup_protocol will be set to
 *	a valid protocol if mask is nonzero.
 * @s_timeout: set hardware timeout in ns
 */
struct rc_dev {
	struct device			dev;
	bool				managed_alloc;
	const struct attribute_group	*sysfs_groups[5];
	const char			*device_name;
	const char			*input_phys;
	struct input_id			input_id;
	const char			*driver_name;
	const char			*map_name;
	struct rc_map			rc_map;
	struct mutex			lock;
	unsigned int			minor;
	struct ir_raw_event_ctrl	*raw;
	struct input_dev		*input_dev;
	enum rc_driver_type		driver_type;
	bool				idle;
	bool				encode_wakeup;
	u64				allowed_protocols;
	u64				enabled_protocols;
	u64				allowed_wakeup_protocols;
	enum rc_proto			wakeup_protocol;
	struct rc_scancode_filter	scancode_filter;
	struct rc_scancode_filter	scancode_wakeup_filter;
	u32				scancode_mask;
	u32				users;
	void				*priv;
	spinlock_t			keylock;
	bool				keypressed;
	unsigned long			keyup_jiffies;
	struct timer_list		timer_keyup;
	struct timer_list		timer_repeat;
	u32				last_keycode;
	enum rc_proto			last_protocol;
	u32				last_scancode;
	u8				last_toggle;
	u32				timeout;
	u32				min_timeout;
	u32				max_timeout;
	u32				rx_resolution;
	u32				tx_resolution;
#ifdef CONFIG_LIRC
	struct device			lirc_dev;
	struct cdev			lirc_cdev;
	ktime_t				gap_start;
	u64				gap_duration;
	bool				gap;
	spinlock_t			lirc_fh_lock;
	struct list_head		lirc_fh;
#endif
	bool				registered;
	int				(*change_protocol)(struct rc_dev *dev, u64 *rc_proto);
	int				(*open)(struct rc_dev *dev);
	void				(*close)(struct rc_dev *dev);
	int				(*s_tx_mask)(struct rc_dev *dev, u32 mask);
	int				(*s_tx_carrier)(struct rc_dev *dev, u32 carrier);
	int				(*s_tx_duty_cycle)(struct rc_dev *dev, u32 duty_cycle);
	int				(*s_rx_carrier_range)(struct rc_dev *dev, u32 min, u32 max);
	int				(*tx_ir)(struct rc_dev *dev, unsigned *txbuf, unsigned n);
	void				(*s_idle)(struct rc_dev *dev, bool enable);
	int				(*s_learning_mode)(struct rc_dev *dev, int enable);
	int				(*s_carrier_report) (struct rc_dev *dev, int enable);
	int				(*s_filter)(struct rc_dev *dev,
						    struct rc_scancode_filter *filter);
	int				(*s_wakeup_filter)(struct rc_dev *dev,
							   struct rc_scancode_filter *filter);
	int				(*s_timeout)(struct rc_dev *dev,
						     unsigned int timeout);
};

#define to_rc_dev(d) container_of(d, struct rc_dev, dev)

/*
 * From rc-main.c
 * Those functions can be used on any type of Remote Controller. They
 * basically creates an input_dev and properly reports the device as a
 * Remote Controller, at sys/class/rc.
 */

/**
 * rc_allocate_device - Allocates a RC device
 *
 * @rc_driver_type: specifies the type of the RC output to be allocated
 * returns a pointer to struct rc_dev.
 */
struct rc_dev *rc_allocate_device(enum rc_driver_type);

/**
 * devm_rc_allocate_device - Managed RC device allocation
 *
 * @dev: pointer to struct device
 * @rc_driver_type: specifies the type of the RC output to be allocated
 * returns a pointer to struct rc_dev.
 */
struct rc_dev *devm_rc_allocate_device(struct device *dev, enum rc_driver_type);

/**
 * rc_free_device - Frees a RC device
 *
 * @dev: pointer to struct rc_dev.
 */
void rc_free_device(struct rc_dev *dev);

/**
 * rc_register_device - Registers a RC device
 *
 * @dev: pointer to struct rc_dev.
 */
int rc_register_device(struct rc_dev *dev);

/**
 * devm_rc_register_device - Manageded registering of a RC device
 *
 * @parent: pointer to struct device.
 * @dev: pointer to struct rc_dev.
 */
int devm_rc_register_device(struct device *parent, struct rc_dev *dev);

/**
 * rc_unregister_device - Unregisters a RC device
 *
 * @dev: pointer to struct rc_dev.
 */
void rc_unregister_device(struct rc_dev *dev);

void rc_repeat(struct rc_dev *dev);
void rc_keydown(struct rc_dev *dev, enum rc_proto protocol, u32 scancode,
		u8 toggle);
void rc_keydown_notimeout(struct rc_dev *dev, enum rc_proto protocol,
			  u32 scancode, u8 toggle);
void rc_keyup(struct rc_dev *dev);
u32 rc_g_keycode_from_table(struct rc_dev *dev, u32 scancode);

/*
 * From rc-raw.c
 * The Raw interface is specific to InfraRed. It may be a good idea to
 * split it later into a separate header.
 */
struct ir_raw_event {
	union {
		u32             duration;
		u32             carrier;
	};
	u8                      duty_cycle;

	unsigned                pulse:1;
	unsigned                reset:1;
	unsigned                timeout:1;
	unsigned                carrier_report:1;
};

#define DEFINE_IR_RAW_EVENT(event) struct ir_raw_event event = {}

static inline void init_ir_raw_event(struct ir_raw_event *ev)
{
	memset(ev, 0, sizeof(*ev));
}

#define IR_DEFAULT_TIMEOUT	MS_TO_NS(125)
#define IR_MAX_DURATION         500000000	/* 500 ms */
#define US_TO_NS(usec)		((usec) * 1000)
#define MS_TO_US(msec)		((msec) * 1000)
#define MS_TO_NS(msec)		((msec) * 1000 * 1000)

void ir_raw_event_handle(struct rc_dev *dev);
int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev);
int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse);
int ir_raw_event_store_with_filter(struct rc_dev *dev,
				struct ir_raw_event *ev);
void ir_raw_event_set_idle(struct rc_dev *dev, bool idle);
int ir_raw_encode_scancode(enum rc_proto protocol, u32 scancode,
			   struct ir_raw_event *events, unsigned int max);
int ir_raw_encode_carrier(enum rc_proto protocol);

static inline void ir_raw_event_reset(struct rc_dev *dev)
{
	struct ir_raw_event ev = { .reset = true };

	ir_raw_event_store(dev, &ev);
	ir_raw_event_handle(dev);
}

/* extract mask bits out of data and pack them into the result */
static inline u32 ir_extract_bits(u32 data, u32 mask)
{
	u32 vbit = 1, value = 0;

	do {
		if (mask & 1) {
			if (data & 1)
				value |= vbit;
			vbit <<= 1;
		}
		data >>= 1;
	} while (mask >>= 1);

	return value;
}

/* Get NEC scancode and protocol type from address and command bytes */
static inline u32 ir_nec_bytes_to_scancode(u8 address, u8 not_address,
					   u8 command, u8 not_command,
					   enum rc_proto *protocol)
{
	u32 scancode;

	if ((command ^ not_command) != 0xff) {
		/* NEC transport, but modified protocol, used by at
		 * least Apple and TiVo remotes
		 */
		scancode = not_address << 24 |
			address     << 16 |
			not_command <<  8 |
			command;
		*protocol = RC_PROTO_NEC32;
	} else if ((address ^ not_address) != 0xff) {
		/* Extended NEC */
		scancode = address     << 16 |
			   not_address <<  8 |
			   command;
		*protocol = RC_PROTO_NECX;
	} else {
		/* Normal NEC */
		scancode = address << 8 | command;
		*protocol = RC_PROTO_NEC;
	}

	return scancode;
}

#endif /* _RC_CORE */