// SPDX-License-Identifier: GPL-2.0+
//
// handle em28xx IR remotes via linux kernel input layer.
//
// Copyright (C) 2005 Ludovico Cavedon <cavedon@sssup.it>
//                    Markus Rechberger <mrechberger@gmail.com>
//                    Mauro Carvalho Chehab <mchehab@kernel.org>
//                    Sascha Sommer <saschasommer@freenet.de>
//
// 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; either version 2 of the License, or
// (at your option) any later version.
//
// 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.

#include "em28xx.h"

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/usb.h>
#include <linux/usb/input.h>
#include <linux/slab.h>
#include <linux/bitrev.h>

#define EM28XX_SNAPSHOT_KEY                             KEY_CAMERA
#define EM28XX_BUTTONS_DEBOUNCED_QUERY_INTERVAL         500 /* [ms] */
#define EM28XX_BUTTONS_VOLATILE_QUERY_INTERVAL          100 /* [ms] */

static unsigned int ir_debug;
module_param(ir_debug, int, 0644);
MODULE_PARM_DESC(ir_debug, "enable debug messages [IR]");

#define MODULE_NAME "em28xx"

#define dprintk(fmt, arg...) do {                                       \
        if (ir_debug)                                                   \
                dev_printk(KERN_DEBUG, &ir->dev->intf->dev,             \
                           "input: %s: " fmt, __func__, ## arg);        \
} while (0)

/*
 * Polling structure used by em28xx IR's
 */

struct em28xx_ir_poll_result {
        unsigned int toggle_bit:1;
        unsigned int read_count:7;

        enum rc_proto protocol;
        u32 scancode;
};

struct em28xx_IR {
        struct em28xx *dev;
        struct rc_dev *rc;
        char phys[32];

        /* poll decoder */
        int polling;
        struct delayed_work work;
        unsigned int full_code:1;
        unsigned int last_readcount;
        u64 rc_proto;

        struct i2c_client *i2c_client;

        int  (*get_key_i2c)(struct i2c_client *ir, enum rc_proto *protocol,
                            u32 *scancode);
        int  (*get_key)(struct em28xx_IR *ir, struct em28xx_ir_poll_result *r);
};

/*
 * I2C IR based get keycodes - should be used with ir-kbd-i2c
 */

static int em28xx_get_key_terratec(struct i2c_client *i2c_dev,
                                   enum rc_proto *protocol, u32 *scancode)
{
        int rc;
        unsigned char b;

        /* poll IR chip */
        rc = i2c_master_recv(i2c_dev, &b, 1);
        if (rc != 1) {
                if (rc < 0)
                        return rc;
                return -EIO;
        }

        /*
         * it seems that 0xFE indicates that a button is still hold
         * down, while 0xff indicates that no button is hold down.
         */

        if (b == 0xff)
                return 0;

        if (b == 0xfe)
                /* keep old data */
                return 1;

        *protocol = RC_PROTO_UNKNOWN;
        *scancode = b;
        return 1;
}

static int em28xx_get_key_em_haup(struct i2c_client *i2c_dev,
                                  enum rc_proto *protocol, u32 *scancode)
{
        unsigned char buf[2];
        int size;

        /* poll IR chip */
        size = i2c_master_recv(i2c_dev, buf, sizeof(buf));

        if (size != 2)
                return -EIO;

        /* Does eliminate repeated parity code */
        if (buf[1] == 0xff)
                return 0;

        /*
         * Rearranges bits to the right order.
         * The bit order were determined experimentally by using
         * The original Hauppauge Grey IR and another RC5 that uses addr=0x08
         * The RC5 code has 14 bits, but we've experimentally determined
         * the meaning for only 11 bits.
         * So, the code translation is not complete. Yet, it is enough to
         * work with the provided RC5 IR.
         */
        *protocol = RC_PROTO_RC5;
        *scancode = (bitrev8(buf[1]) & 0x1f) << 8 | bitrev8(buf[0]) >> 2;
        return 1;
}

static int em28xx_get_key_pinnacle_usb_grey(struct i2c_client *i2c_dev,
                                            enum rc_proto *protocol,
                                            u32 *scancode)
{
        unsigned char buf[3];

        /* poll IR chip */

        if (i2c_master_recv(i2c_dev, buf, 3) != 3)
                return -EIO;

        if (buf[0] != 0x00)
                return 0;

        *protocol = RC_PROTO_UNKNOWN;
        *scancode = buf[2] & 0x3f;
        return 1;
}

static int em28xx_get_key_winfast_usbii_deluxe(struct i2c_client *i2c_dev,
                                               enum rc_proto *protocol,
                                               u32 *scancode)
{
        unsigned char subaddr, keydetect, key;

        struct i2c_msg msg[] = {
                {
                        .addr = i2c_dev->addr,
                        .flags = 0,
                        .buf = &subaddr, .len = 1
                }, {
                        .addr = i2c_dev->addr,
                        .flags = I2C_M_RD,
                        .buf = &keydetect,
                        .len = 1
                }
        };

        subaddr = 0x10;
        if (i2c_transfer(i2c_dev->adapter, msg, 2) != 2)
                return -EIO;
        if (keydetect == 0x00)
                return 0;

        subaddr = 0x00;
        msg[1].buf = &key;
        if (i2c_transfer(i2c_dev->adapter, msg, 2) != 2)
                return -EIO;
        if (key == 0x00)
                return 0;

        *protocol = RC_PROTO_UNKNOWN;
        *scancode = key;
        return 1;
}

/*
 * Poll based get keycode functions
 */

/* This is for the em2860/em2880 */
static int default_polling_getkey(struct em28xx_IR *ir,
                                  struct em28xx_ir_poll_result *poll_result)
{
        struct em28xx *dev = ir->dev;
        int rc;
        u8 msg[3] = { 0, 0, 0 };

        /*
         * Read key toggle, brand, and key code
         * on registers 0x45, 0x46 and 0x47
         */
        rc = dev->em28xx_read_reg_req_len(dev, 0, EM28XX_R45_IR,
                                          msg, sizeof(msg));
        if (rc < 0)
                return rc;

        /* Infrared toggle (Reg 0x45[7]) */
        poll_result->toggle_bit = (msg[0] >> 7);

        /* Infrared read count (Reg 0x45[6:0] */
        poll_result->read_count = (msg[0] & 0x7f);

        /* Remote Control Address/Data (Regs 0x46/0x47) */
        switch (ir->rc_proto) {
        case RC_PROTO_BIT_RC5:
                poll_result->protocol = RC_PROTO_RC5;
                poll_result->scancode = RC_SCANCODE_RC5(msg[1], msg[2]);
                break;

        case RC_PROTO_BIT_NEC:
                poll_result->protocol = RC_PROTO_NEC;
                poll_result->scancode = RC_SCANCODE_NEC(msg[1], msg[2]);
                break;

        default:
                poll_result->protocol = RC_PROTO_UNKNOWN;
                poll_result->scancode = msg[1] << 8 | msg[2];
                break;
        }

        return 0;
}

static int em2874_polling_getkey(struct em28xx_IR *ir,
                                 struct em28xx_ir_poll_result *poll_result)
{
        struct em28xx *dev = ir->dev;
        int rc;
        u8 msg[5] = { 0, 0, 0, 0, 0 };

        /*
         * Read key toggle, brand, and key code
         * on registers 0x51-55
         */
        rc = dev->em28xx_read_reg_req_len(dev, 0, EM2874_R51_IR,
                                          msg, sizeof(msg));
        if (rc < 0)
                return rc;

        /* Infrared toggle (Reg 0x51[7]) */
        poll_result->toggle_bit = (msg[0] >> 7);

        /* Infrared read count (Reg 0x51[6:0] */
        poll_result->read_count = (msg[0] & 0x7f);

        /*
         * Remote Control Address (Reg 0x52)
         * Remote Control Data (Reg 0x53-0x55)
         */
        switch (ir->rc_proto) {
        case RC_PROTO_BIT_RC5:
                poll_result->protocol = RC_PROTO_RC5;
                poll_result->scancode = RC_SCANCODE_RC5(msg[1], msg[2]);
                break;

        case RC_PROTO_BIT_NEC:
                poll_result->scancode = ir_nec_bytes_to_scancode(msg[1], msg[2], msg[3], msg[4],
                                                                 &poll_result->protocol);
                break;

        case RC_PROTO_BIT_RC6_0:
                poll_result->protocol = RC_PROTO_RC6_0;
                poll_result->scancode = RC_SCANCODE_RC6_0(msg[1], msg[2]);
                break;

        default:
                poll_result->protocol = RC_PROTO_UNKNOWN;
                poll_result->scancode = (msg[1] << 24) | (msg[2] << 16) |
                                        (msg[3] << 8)  | msg[4];
                break;
        }

        return 0;
}

/*
 * Polling code for em28xx
 */

static int em28xx_i2c_ir_handle_key(struct em28xx_IR *ir)
{
        static u32 scancode;
        enum rc_proto protocol;
        int rc;

        rc = ir->get_key_i2c(ir->i2c_client, &protocol, &scancode);
        if (rc < 0) {
                dprintk("ir->get_key_i2c() failed: %d\n", rc);
                return rc;
        }

        if (rc) {
                dprintk("%s: proto = 0x%04x, scancode = 0x%04x\n",
                        __func__, protocol, scancode);
                rc_keydown(ir->rc, protocol, scancode, 0);
        }
        return 0;
}

static void em28xx_ir_handle_key(struct em28xx_IR *ir)
{
        int result;
        struct em28xx_ir_poll_result poll_result;

        /* read the registers containing the IR status */
        result = ir->get_key(ir, &poll_result);
        if (unlikely(result < 0)) {
                dprintk("ir->get_key() failed: %d\n", result);
                return;
        }

        if (unlikely(poll_result.read_count != ir->last_readcount)) {
                dprintk("%s: toggle: %d, count: %d, key 0x%04x\n", __func__,
                        poll_result.toggle_bit, poll_result.read_count,
                        poll_result.scancode);
                if (ir->full_code)
                        rc_keydown(ir->rc,
                                   poll_result.protocol,
                                   poll_result.scancode,
                                   poll_result.toggle_bit);
                else
                        rc_keydown(ir->rc,
                                   RC_PROTO_UNKNOWN,
                                   poll_result.scancode & 0xff,
                                   poll_result.toggle_bit);

                if (ir->dev->chip_id == CHIP_ID_EM2874 ||
                    ir->dev->chip_id == CHIP_ID_EM2884)
                        /*
                         * The em2874 clears the readcount field every time the
                         * register is read.  The em2860/2880 datasheet says
                         * that it is supposed to clear the readcount, but it
                         * doesn't. So with the em2874, we are looking for a
                         * non-zero read count as opposed to a readcount
                         * that is incrementing
                         */
                        ir->last_readcount = 0;
                else
                        ir->last_readcount = poll_result.read_count;
        }
}

static void em28xx_ir_work(struct work_struct *work)
{
        struct em28xx_IR *ir = container_of(work, struct em28xx_IR, work.work);

        if (ir->i2c_client) /* external i2c device */
                em28xx_i2c_ir_handle_key(ir);
        else /* internal device */
                em28xx_ir_handle_key(ir);
        schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
}

static int em28xx_ir_start(struct rc_dev *rc)
{
        struct em28xx_IR *ir = rc->priv;

        INIT_DELAYED_WORK(&ir->work, em28xx_ir_work);
        schedule_delayed_work(&ir->work, 0);

        return 0;
}

static void em28xx_ir_stop(struct rc_dev *rc)
{
        struct em28xx_IR *ir = rc->priv;

        cancel_delayed_work_sync(&ir->work);
}

static int em2860_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_proto)
{
        struct em28xx_IR *ir = rc_dev->priv;
        struct em28xx *dev = ir->dev;

        /* Adjust xclk based on IR table for RC5/NEC tables */
        if (*rc_proto & RC_PROTO_BIT_RC5) {
                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
                ir->full_code = 1;
                *rc_proto = RC_PROTO_BIT_RC5;
        } else if (*rc_proto & RC_PROTO_BIT_NEC) {
                dev->board.xclk &= ~EM28XX_XCLK_IR_RC5_MODE;
                ir->full_code = 1;
                *rc_proto = RC_PROTO_BIT_NEC;
        } else if (*rc_proto & RC_PROTO_BIT_UNKNOWN) {
                *rc_proto = RC_PROTO_BIT_UNKNOWN;
        } else {
                *rc_proto = ir->rc_proto;
                return -EINVAL;
        }
        em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, dev->board.xclk,
                              EM28XX_XCLK_IR_RC5_MODE);

        ir->rc_proto = *rc_proto;

        return 0;
}

static int em2874_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_proto)
{
        struct em28xx_IR *ir = rc_dev->priv;
        struct em28xx *dev = ir->dev;
        u8 ir_config = EM2874_IR_RC5;

        /* Adjust xclk and set type based on IR table for RC5/NEC/RC6 tables */
        if (*rc_proto & RC_PROTO_BIT_RC5) {
                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
                ir->full_code = 1;
                *rc_proto = RC_PROTO_BIT_RC5;
        } else if (*rc_proto & RC_PROTO_BIT_NEC) {
                dev->board.xclk &= ~EM28XX_XCLK_IR_RC5_MODE;
                ir_config = EM2874_IR_NEC | EM2874_IR_NEC_NO_PARITY;
                ir->full_code = 1;
                *rc_proto = RC_PROTO_BIT_NEC;
        } else if (*rc_proto & RC_PROTO_BIT_RC6_0) {
                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
                ir_config = EM2874_IR_RC6_MODE_0;
                ir->full_code = 1;
                *rc_proto = RC_PROTO_BIT_RC6_0;
        } else if (*rc_proto & RC_PROTO_BIT_UNKNOWN) {
                *rc_proto = RC_PROTO_BIT_UNKNOWN;
        } else {
                *rc_proto = ir->rc_proto;
                return -EINVAL;
        }
        em28xx_write_regs(dev, EM2874_R50_IR_CONFIG, &ir_config, 1);
        em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, dev->board.xclk,
                              EM28XX_XCLK_IR_RC5_MODE);

        ir->rc_proto = *rc_proto;

        return 0;
}

static int em28xx_ir_change_protocol(struct rc_dev *rc_dev, u64 *rc_proto)
{
        struct em28xx_IR *ir = rc_dev->priv;
        struct em28xx *dev = ir->dev;

        /* Setup the proper handler based on the chip */
        switch (dev->chip_id) {
        case CHIP_ID_EM2860:
        case CHIP_ID_EM2883:
                return em2860_ir_change_protocol(rc_dev, rc_proto);
        case CHIP_ID_EM2884:
        case CHIP_ID_EM2874:
        case CHIP_ID_EM28174:
        case CHIP_ID_EM28178:
                return em2874_ir_change_protocol(rc_dev, rc_proto);
        default:
                dev_err(&ir->dev->intf->dev,
                        "Unrecognized em28xx chip id 0x%02x: IR not supported\n",
                        dev->chip_id);
                return -EINVAL;
        }
}

static int em28xx_probe_i2c_ir(struct em28xx *dev)
{
        int i = 0;
        /*
         * Leadtek winfast tv USBII deluxe can find a non working IR-device
         * at address 0x18, so if that address is needed for another board in
         * the future, please put it after 0x1f.
         */
        static const unsigned short addr_list[] = {
                 0x1f, 0x30, 0x47, I2C_CLIENT_END
        };

        while (addr_list[i] != I2C_CLIENT_END) {
                if (i2c_probe_func_quick_read(&dev->i2c_adap[dev->def_i2c_bus],
                                              addr_list[i]) == 1)
                        return addr_list[i];
                i++;
        }

        return -ENODEV;
}

/*
 * Handle buttons
 */

static void em28xx_query_buttons(struct work_struct *work)
{
        struct em28xx *dev =
                container_of(work, struct em28xx, buttons_query_work.work);
        u8 i, j;
        int regval;
        bool is_pressed, was_pressed;
        const struct em28xx_led *led;

        /* Poll and evaluate all addresses */
        for (i = 0; i < dev->num_button_polling_addresses; i++) {
                /* Read value from register */
                regval = em28xx_read_reg(dev, dev->button_polling_addresses[i]);
                if (regval < 0)
                        continue;
                /* Check states of the buttons and act */
                j = 0;
                while (dev->board.buttons[j].role >= 0 &&
                       dev->board.buttons[j].role < EM28XX_NUM_BUTTON_ROLES) {
                        const struct em28xx_button *button;

                        button = &dev->board.buttons[j];

                        /* Check if button uses the current address */
                        if (button->reg_r != dev->button_polling_addresses[i]) {
                                j++;
                                continue;
                        }
                        /* Determine if button is and was pressed last time */
                        is_pressed = regval & button->mask;
                        was_pressed = dev->button_polling_last_values[i]
                                       & button->mask;
                        if (button->inverted) {
                                is_pressed = !is_pressed;
                                was_pressed = !was_pressed;
                        }
                        /* Clear button state (if needed) */
                        if (is_pressed && button->reg_clearing)
                                em28xx_write_reg(dev, button->reg_clearing,
                                                 (~regval & button->mask)
                                                    | (regval & ~button->mask));
                        /* Handle button state */
                        if (!is_pressed || was_pressed) {
                                j++;
                                continue;
                        }
                        switch (button->role) {
                        case EM28XX_BUTTON_SNAPSHOT:
                                /* Emulate the keypress */
                                input_report_key(dev->sbutton_input_dev,
                                                 EM28XX_SNAPSHOT_KEY, 1);
                                /* Unpress the key */
                                input_report_key(dev->sbutton_input_dev,
                                                 EM28XX_SNAPSHOT_KEY, 0);
                                break;
                        case EM28XX_BUTTON_ILLUMINATION:
                                led = em28xx_find_led(dev,
                                                      EM28XX_LED_ILLUMINATION);
                                /* Switch illumination LED on/off */
                                if (led)
                                        em28xx_toggle_reg_bits(dev,
                                                               led->gpio_reg,
                                                               led->gpio_mask);
                                break;
                        default:
                                WARN_ONCE(1, "BUG: unhandled button role.");
                        }
                        /* Next button */
                        j++;
                }
                /* Save current value for comparison during the next polling */
                dev->button_polling_last_values[i] = regval;
        }
        /* Schedule next poll */
        schedule_delayed_work(&dev->buttons_query_work,
                              msecs_to_jiffies(dev->button_polling_interval));
}

static int em28xx_register_snapshot_button(struct em28xx *dev)
{
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        struct input_dev *input_dev;
        int err;

        dev_info(&dev->intf->dev, "Registering snapshot button...\n");
        input_dev = input_allocate_device();
        if (!input_dev)
                return -ENOMEM;

        usb_make_path(udev, dev->snapshot_button_path,
                      sizeof(dev->snapshot_button_path));
        strlcat(dev->snapshot_button_path, "/sbutton",
                sizeof(dev->snapshot_button_path));

        input_dev->name = "em28xx snapshot button";
        input_dev->phys = dev->snapshot_button_path;
        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP);
        set_bit(EM28XX_SNAPSHOT_KEY, input_dev->keybit);
        input_dev->keycodesize = 0;
        input_dev->keycodemax = 0;
        usb_to_input_id(udev, &input_dev->id);
        input_dev->dev.parent = &dev->intf->dev;

        err = input_register_device(input_dev);
        if (err) {
                dev_err(&dev->intf->dev, "input_register_device failed\n");
                input_free_device(input_dev);
                return err;
        }

        dev->sbutton_input_dev = input_dev;
        return 0;
}

static void em28xx_init_buttons(struct em28xx *dev)
{
        u8  i = 0, j = 0;
        bool addr_new = false;

        dev->button_polling_interval = EM28XX_BUTTONS_DEBOUNCED_QUERY_INTERVAL;
        while (dev->board.buttons[i].role >= 0 &&
               dev->board.buttons[i].role < EM28XX_NUM_BUTTON_ROLES) {
                const struct em28xx_button *button = &dev->board.buttons[i];

                /* Check if polling address is already on the list */
                addr_new = true;
                for (j = 0; j < dev->num_button_polling_addresses; j++) {
                        if (button->reg_r == dev->button_polling_addresses[j]) {
                                addr_new = false;
                                break;
                        }
                }
                /* Check if max. number of polling addresses is exceeded */
                if (addr_new && dev->num_button_polling_addresses
                                           >= EM28XX_NUM_BUTTON_ADDRESSES_MAX) {
                        WARN_ONCE(1, "BUG: maximum number of button polling addresses exceeded.");
                        goto next_button;
                }
                /* Button role specific checks and actions */
                if (button->role == EM28XX_BUTTON_SNAPSHOT) {
                        /* Register input device */
                        if (em28xx_register_snapshot_button(dev) < 0)
                                goto next_button;
                } else if (button->role == EM28XX_BUTTON_ILLUMINATION) {
                        /* Check sanity */
                        if (!em28xx_find_led(dev, EM28XX_LED_ILLUMINATION)) {
                                dev_err(&dev->intf->dev,
                                        "BUG: illumination button defined, but no illumination LED.\n");
                                goto next_button;
                        }
                }
                /* Add read address to list of polling addresses */
                if (addr_new) {
                        unsigned int index = dev->num_button_polling_addresses;

                        dev->button_polling_addresses[index] = button->reg_r;
                        dev->num_button_polling_addresses++;
                }
                /* Reduce polling interval if necessary */
                if (!button->reg_clearing)
                        dev->button_polling_interval =
                                         EM28XX_BUTTONS_VOLATILE_QUERY_INTERVAL;
next_button:
                /* Next button */
                i++;
        }

        /* Start polling */
        if (dev->num_button_polling_addresses) {
                memset(dev->button_polling_last_values, 0,
                       EM28XX_NUM_BUTTON_ADDRESSES_MAX);
                schedule_delayed_work(&dev->buttons_query_work,
                                      msecs_to_jiffies(dev->button_polling_interval));
        }
}

static void em28xx_shutdown_buttons(struct em28xx *dev)
{
        /* Cancel polling */
        cancel_delayed_work_sync(&dev->buttons_query_work);
        /* Clear polling addresses list */
        dev->num_button_polling_addresses = 0;
        /* Deregister input devices */
        if (dev->sbutton_input_dev) {
                dev_info(&dev->intf->dev, "Deregistering snapshot button\n");
                input_unregister_device(dev->sbutton_input_dev);
                dev->sbutton_input_dev = NULL;
        }
}

static int em28xx_ir_init(struct em28xx *dev)
{
        struct usb_device *udev = interface_to_usbdev(dev->intf);
        struct em28xx_IR *ir;
        struct rc_dev *rc;
        int err = -ENOMEM;
        u64 rc_proto;
        u16 i2c_rc_dev_addr = 0;

        if (dev->is_audio_only) {
                /* Shouldn't initialize IR for this interface */
                return 0;
        }

        kref_get(&dev->ref);
        INIT_DELAYED_WORK(&dev->buttons_query_work, em28xx_query_buttons);

        if (dev->board.buttons)
                em28xx_init_buttons(dev);

        if (dev->board.has_ir_i2c) {
                i2c_rc_dev_addr = em28xx_probe_i2c_ir(dev);
                if (!i2c_rc_dev_addr) {
                        dev->board.has_ir_i2c = 0;
                        dev_warn(&dev->intf->dev,
                                 "No i2c IR remote control device found.\n");
                        err = -ENODEV;
                        goto ref_put;
                }
        }

        if (!dev->board.ir_codes && !dev->board.has_ir_i2c) {
                /* No remote control support */
                dev_warn(&dev->intf->dev,
                         "Remote control support is not available for this card.\n");
                return 0;
        }

        dev_info(&dev->intf->dev, "Registering input extension\n");

        ir = kzalloc(sizeof(*ir), GFP_KERNEL);
        if (!ir)
                goto ref_put;
        rc = rc_allocate_device(RC_DRIVER_SCANCODE);
        if (!rc)
                goto error;

        /* record handles to ourself */
        ir->dev = dev;
        dev->ir = ir;
        ir->rc = rc;

        rc->priv = ir;
        rc->open = em28xx_ir_start;
        rc->close = em28xx_ir_stop;

        if (dev->board.has_ir_i2c) {    /* external i2c device */
                switch (dev->model) {
                case EM2800_BOARD_TERRATEC_CINERGY_200:
                case EM2820_BOARD_TERRATEC_CINERGY_250:
                        rc->map_name = RC_MAP_EM_TERRATEC;
                        ir->get_key_i2c = em28xx_get_key_terratec;
                        break;
                case EM2820_BOARD_PINNACLE_USB_2:
                        rc->map_name = RC_MAP_PINNACLE_GREY;
                        ir->get_key_i2c = em28xx_get_key_pinnacle_usb_grey;
                        break;
                case EM2820_BOARD_HAUPPAUGE_WINTV_USB_2:
                        rc->map_name = RC_MAP_HAUPPAUGE;
                        ir->get_key_i2c = em28xx_get_key_em_haup;
                        rc->allowed_protocols = RC_PROTO_BIT_RC5;
                        break;
                case EM2820_BOARD_LEADTEK_WINFAST_USBII_DELUXE:
                        rc->map_name = RC_MAP_WINFAST_USBII_DELUXE;
                        ir->get_key_i2c = em28xx_get_key_winfast_usbii_deluxe;
                        break;
                default:
                        err = -ENODEV;
                        goto error;
                }

                ir->i2c_client = kzalloc(sizeof(*ir->i2c_client), GFP_KERNEL);
                if (!ir->i2c_client)
                        goto error;
                ir->i2c_client->adapter = &ir->dev->i2c_adap[dev->def_i2c_bus];
                ir->i2c_client->addr = i2c_rc_dev_addr;
                ir->i2c_client->flags = 0;
                /* NOTE: all other fields of i2c_client are unused */
        } else {        /* internal device */
                switch (dev->chip_id) {
                case CHIP_ID_EM2860:
                case CHIP_ID_EM2883:
                        rc->allowed_protocols = RC_PROTO_BIT_RC5 |
                                                RC_PROTO_BIT_NEC;
                        ir->get_key = default_polling_getkey;
                        break;
                case CHIP_ID_EM2884:
                case CHIP_ID_EM2874:
                case CHIP_ID_EM28174:
                case CHIP_ID_EM28178:
                        ir->get_key = em2874_polling_getkey;
                        rc->allowed_protocols = RC_PROTO_BIT_RC5 |
                                RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX |
                                RC_PROTO_BIT_NEC32 | RC_PROTO_BIT_RC6_0;
                        break;
                default:
                        err = -ENODEV;
                        goto error;
                }

                rc->change_protocol = em28xx_ir_change_protocol;
                rc->map_name = dev->board.ir_codes;

                /* By default, keep protocol field untouched */
                rc_proto = RC_PROTO_BIT_UNKNOWN;
                err = em28xx_ir_change_protocol(rc, &rc_proto);
                if (err)
                        goto error;
        }

        /* This is how often we ask the chip for IR information */
        ir->polling = 100; /* ms */

        usb_make_path(udev, ir->phys, sizeof(ir->phys));
        strlcat(ir->phys, "/input0", sizeof(ir->phys));

        rc->device_name = em28xx_boards[dev->model].name;
        rc->input_phys = ir->phys;
        usb_to_input_id(udev, &rc->input_id);
        rc->dev.parent = &dev->intf->dev;
        rc->driver_name = MODULE_NAME;

        /* all done */
        err = rc_register_device(rc);
        if (err)
                goto error;

        dev_info(&dev->intf->dev, "Input extension successfully initialized\n");

        return 0;

error:
        kfree(ir->i2c_client);
        dev->ir = NULL;
        rc_free_device(rc);
        kfree(ir);
ref_put:
        em28xx_shutdown_buttons(dev);
        return err;
}

static int em28xx_ir_fini(struct em28xx *dev)
{
        struct em28xx_IR *ir = dev->ir;

        if (dev->is_audio_only) {
                /* Shouldn't initialize IR for this interface */
                return 0;
        }

        dev_info(&dev->intf->dev, "Closing input extension\n");

        em28xx_shutdown_buttons(dev);

        /* skip detach on non attached boards */
        if (!ir)
                goto ref_put;

        rc_unregister_device(ir->rc);

        kfree(ir->i2c_client);

        /* done */
        kfree(ir);
        dev->ir = NULL;

ref_put:
        kref_put(&dev->ref, em28xx_free_device);

        return 0;
}

static int em28xx_ir_suspend(struct em28xx *dev)
{
        struct em28xx_IR *ir = dev->ir;

        if (dev->is_audio_only)
                return 0;

        dev_info(&dev->intf->dev, "Suspending input extension\n");
        if (ir)
                cancel_delayed_work_sync(&ir->work);
        cancel_delayed_work_sync(&dev->buttons_query_work);
        /*
         * is canceling delayed work sufficient or does the rc event
         * kthread needs stopping? kthread is stopped in
         * ir_raw_event_unregister()
         */
        return 0;
}

static int em28xx_ir_resume(struct em28xx *dev)
{
        struct em28xx_IR *ir = dev->ir;

        if (dev->is_audio_only)
                return 0;

        dev_info(&dev->intf->dev, "Resuming input extension\n");
        /*
         * if suspend calls ir_raw_event_unregister(), the should call
         * ir_raw_event_register()
         */
        if (ir)
                schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
        if (dev->num_button_polling_addresses)
                schedule_delayed_work(&dev->buttons_query_work,
                                      msecs_to_jiffies(dev->button_polling_interval));
        return 0;
}

static struct em28xx_ops rc_ops = {
        .id   = EM28XX_RC,
        .name = "Em28xx Input Extension",
        .init = em28xx_ir_init,
        .fini = em28xx_ir_fini,
        .suspend = em28xx_ir_suspend,
        .resume = em28xx_ir_resume,
};

static int __init em28xx_rc_register(void)
{
        return em28xx_register_extension(&rc_ops);
}

static void __exit em28xx_rc_unregister(void)
{
        em28xx_unregister_extension(&rc_ops);
}

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Mauro Carvalho Chehab");
MODULE_DESCRIPTION(DRIVER_DESC " - input interface");
MODULE_VERSION(EM28XX_VERSION);

module_init(em28xx_rc_register);
module_exit(em28xx_rc_unregister);