root/include/media/rc-core.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Remote Controller core header
 *
 * Copyright (C) 2009-2010 by Mauro Carvalho Chehab
 */

#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>

/**
 * enum rc_driver_type - type of the RC driver.
 *
 * @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
 * @rawir: queue for incoming raw IR
 * @scancodes: queue for incoming decoded scancodes
 * @wait_poll: poll struct for lirc device
 * @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_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;
        DECLARE_KFIFO_PTR(rawir, unsigned int);
        DECLARE_KFIFO_PTR(scancodes, struct lirc_scancode);
        wait_queue_head_t               wait_poll;
        u32                             carrier_low;
        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
 * @registered: set to true by rc_register_device(), false by
 *      rc_unregister_device
 * @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
 * @minor: unique minor remote control device number
 * @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
 * @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
 * @users: number of current users of the device
 * @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
 * @priv: driver-specific data
 * @keylock: protects the remaining members of the struct
 * @keypressed: whether a key is currently pressed
 * @last_toggle: toggle value of last command
 * @last_keycode: keycode of last keypress
 * @last_protocol: protocol of last keypress
 * @last_scancode: scancode of last keypress
 * @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.
 * @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 us) of input sampler
 * @lirc_dev: lirc device
 * @lirc_cdev: lirc char cdev
 * @gap_start: start time for gap after timeout if non-zero
 * @lirc_fh_lock: protects lirc_fh list
 * @lirc_fh: list of open files
 * @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_wideband_receiver: 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 us
 */
struct rc_dev {
        struct device                   dev;
        bool                            managed_alloc;
        bool                            registered;
        bool                            idle;
        bool                            encode_wakeup;
        unsigned int                    minor;
        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;
        struct ir_raw_event_ctrl        *raw;
        struct input_dev                *input_dev;
        enum rc_driver_type             driver_type;
        u32                             users;
        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;
        void                            *priv;
        spinlock_t                      keylock;
        bool                            keypressed;
        u8                              last_toggle;
        u32                             last_keycode;
        enum rc_proto                   last_protocol;
        u64                             last_scancode;
        unsigned long                   keyup_jiffies;
        struct timer_list               timer_keyup;
        struct timer_list               timer_repeat;
        u32                             timeout;
        u32                             min_timeout;
        u32                             max_timeout;
        u32                             rx_resolution;
#ifdef CONFIG_LIRC
        struct device                   lirc_dev;
        struct cdev                     lirc_cdev;
        ktime_t                         gap_start;
        spinlock_t                      lirc_fh_lock;
        struct list_head                lirc_fh;
#endif
        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_wideband_receiver)(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, u64 scancode,
                u8 toggle);
void rc_keydown_notimeout(struct rc_dev *dev, enum rc_proto protocol,
                          u64 scancode, u8 toggle);
void rc_keyup(struct rc_dev *dev);
u32 rc_g_keycode_from_table(struct rc_dev *dev, u64 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                overflow:1;
        unsigned                timeout:1;
        unsigned                carrier_report:1;
};

#define US_TO_NS(usec)          ((usec) * 1000)
#define MS_TO_US(msec)          ((msec) * 1000)
#define IR_MAX_DURATION         MS_TO_US(500)
#define IR_DEFAULT_TIMEOUT      MS_TO_US(125)
#define IR_MAX_TIMEOUT          LIRC_VALUE_MASK

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);
int ir_raw_event_store_with_timeout(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_overflow(struct rc_dev *dev)
{
        ir_raw_event_store(dev, &((struct ir_raw_event) { .overflow = true }));
        dev->idle = true;
        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 */