/*
  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@infradead.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.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

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

#include "em28xx.h"

#define EM28XX_SNAPSHOT_KEY KEY_CAMERA
#define EM28XX_SBUTTON_QUERY_INTERVAL 500
#define EM28XX_R0C_USBSUSP_SNAPSHOT 0x20

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 i2cdprintk(fmt, arg...) \
        if (ir_debug) { \
                printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
        }

#define dprintk(fmt, arg...) \
        if (ir_debug) { \
                printk(KERN_DEBUG "%s/ir: " fmt, ir->name , ## arg); \
        }

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

struct em28xx_ir_poll_result {
        unsigned int toggle_bit:1;
        unsigned int read_count:7;
        u8 rc_address;
        u8 rc_data[4]; /* 1 byte on em2860/2880, 4 on em2874 */
};

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

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

        int  (*get_key)(struct em28xx_IR *, struct em28xx_ir_poll_result *);
};

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

static int em28xx_get_key_terratec(struct IR_i2c *ir, u32 *ir_key, u32 *ir_raw)
{
        unsigned char b;

        /* poll IR chip */
        if (1 != i2c_master_recv(ir->c, &b, 1)) {
                i2cdprintk("read error\n");
                return -EIO;
        }

        /* it seems that 0xFE indicates that a button is still hold
           down, while 0xff indicates that no button is hold
           down. 0xfe sequences are sometimes interrupted by 0xFF */

        i2cdprintk("key %02x\n", b);

        if (b == 0xff)
                return 0;

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

        *ir_key = b;
        *ir_raw = b;
        return 1;
}

static int em28xx_get_key_em_haup(struct IR_i2c *ir, u32 *ir_key, u32 *ir_raw)
{
        unsigned char buf[2];
        u16 code;
        int size;

        /* poll IR chip */
        size = i2c_master_recv(ir->c, buf, sizeof(buf));

        if (size != 2)
                return -EIO;

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

        ir->old = buf[1];

        /*
         * 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.
         */
        code =
                 ((buf[0] & 0x01) ? 0x0020 : 0) | /*            0010 0000 */
                 ((buf[0] & 0x02) ? 0x0010 : 0) | /*            0001 0000 */
                 ((buf[0] & 0x04) ? 0x0008 : 0) | /*            0000 1000 */
                 ((buf[0] & 0x08) ? 0x0004 : 0) | /*            0000 0100 */
                 ((buf[0] & 0x10) ? 0x0002 : 0) | /*            0000 0010 */
                 ((buf[0] & 0x20) ? 0x0001 : 0) | /*            0000 0001 */
                 ((buf[1] & 0x08) ? 0x1000 : 0) | /* 0001 0000            */
                 ((buf[1] & 0x10) ? 0x0800 : 0) | /* 0000 1000            */
                 ((buf[1] & 0x20) ? 0x0400 : 0) | /* 0000 0100            */
                 ((buf[1] & 0x40) ? 0x0200 : 0) | /* 0000 0010            */
                 ((buf[1] & 0x80) ? 0x0100 : 0);  /* 0000 0001            */

        i2cdprintk("ir hauppauge (em2840): code=0x%02x (rcv=0x%02x%02x)\n",
                        code, buf[1], buf[0]);

        /* return key */
        *ir_key = code;
        *ir_raw = code;
        return 1;
}

static int em28xx_get_key_pinnacle_usb_grey(struct IR_i2c *ir, u32 *ir_key,
                                     u32 *ir_raw)
{
        unsigned char buf[3];

        /* poll IR chip */

        if (3 != i2c_master_recv(ir->c, buf, 3)) {
                i2cdprintk("read error\n");
                return -EIO;
        }

        i2cdprintk("key %02x\n", buf[2]&0x3f);
        if (buf[0] != 0x00)
                return 0;

        *ir_key = buf[2]&0x3f;
        *ir_raw = buf[2]&0x3f;

        return 1;
}

static int em28xx_get_key_winfast_usbii_deluxe(struct IR_i2c *ir, u32 *ir_key,
                                        u32 *ir_raw)
{
        unsigned char subaddr, keydetect, key;

        struct i2c_msg msg[] = { { .addr = ir->c->addr, .flags = 0, .buf = &subaddr, .len = 1},

                                { .addr = ir->c->addr, .flags = I2C_M_RD, .buf = &keydetect, .len = 1} };

        subaddr = 0x10;
        if (2 != i2c_transfer(ir->c->adapter, msg, 2)) {
                i2cdprintk("read error\n");
                return -EIO;
        }
        if (keydetect == 0x00)
                return 0;

        subaddr = 0x00;
        msg[1].buf = &key;
        if (2 != i2c_transfer(ir->c->adapter, msg, 2)) {
                i2cdprintk("read error\n");
        return -EIO;
        }
        if (key == 0x00)
                return 0;

        *ir_key = key;
        *ir_raw = 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 (Reg 0x46) */
        poll_result->rc_address = msg[1];

        /* Remote Control Data (Reg 0x47) */
        poll_result->rc_data[0] = msg[2];

        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) */
        poll_result->rc_address = msg[1];

        /* Remote Control Data (Reg 0x53-55) */
        poll_result->rc_data[0] = msg[2];
        poll_result->rc_data[1] = msg[3];
        poll_result->rc_data[2] = msg[4];

        return 0;
}

/**********************************************************
 Polling code for em28xx
 **********************************************************/

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%02x%02x\n", __func__,
                        poll_result.toggle_bit, poll_result.read_count,
                        poll_result.rc_address, poll_result.rc_data[0]);
                if (ir->full_code)
                        rc_keydown(ir->rc,
                                   poll_result.rc_address << 8 |
                                   poll_result.rc_data[0],
                                   poll_result.toggle_bit);
                else
                        rc_keydown(ir->rc,
                                   poll_result.rc_data[0],
                                   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);

        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 em28xx_ir_change_protocol(struct rc_dev *rc_dev, u64 rc_type)
{
        int rc = 0;
        struct em28xx_IR *ir = rc_dev->priv;
        struct em28xx *dev = ir->dev;
        u8 ir_config = EM2874_IR_RC5;

        /* Adjust xclk based o IR table for RC5/NEC tables */

        if (rc_type == RC_TYPE_RC5) {
                dev->board.xclk |= EM28XX_XCLK_IR_RC5_MODE;
                ir->full_code = 1;
        } else if (rc_type == RC_TYPE_NEC) {
                dev->board.xclk &= ~EM28XX_XCLK_IR_RC5_MODE;
                ir_config = EM2874_IR_NEC;
                ir->full_code = 1;
        } else if (rc_type != RC_TYPE_UNKNOWN)
                rc = -EINVAL;

        em28xx_write_reg_bits(dev, EM28XX_R0F_XCLK, dev->board.xclk,
                              EM28XX_XCLK_IR_RC5_MODE);

        /* Setup the proper handler based on the chip */
        switch (dev->chip_id) {
        case CHIP_ID_EM2860:
        case CHIP_ID_EM2883:
                ir->get_key = default_polling_getkey;
                break;
        case CHIP_ID_EM2884:
        case CHIP_ID_EM2874:
        case CHIP_ID_EM28174:
                ir->get_key = em2874_polling_getkey;
                em28xx_write_regs(dev, EM2874_R50_IR_CONFIG, &ir_config, 1);
                break;
        default:
                printk("Unrecognized em28xx chip id 0x%02x: IR not supported\n",
                        dev->chip_id);
                rc = -EINVAL;
        }

        return rc;
}

static void em28xx_register_i2c_ir(struct em28xx *dev)
{
        /* 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. */
        struct i2c_board_info info;
        const unsigned short addr_list[] = {
                 0x1f, 0x30, 0x47, I2C_CLIENT_END
        };

        memset(&info, 0, sizeof(struct i2c_board_info));
        memset(&dev->init_data, 0, sizeof(dev->init_data));
        strlcpy(info.type, "ir_video", I2C_NAME_SIZE);

        /* detect & configure */
        switch (dev->model) {
        case EM2800_BOARD_TERRATEC_CINERGY_200:
        case EM2820_BOARD_TERRATEC_CINERGY_250:
                dev->init_data.ir_codes = RC_MAP_EM_TERRATEC;
                dev->init_data.get_key = em28xx_get_key_terratec;
                dev->init_data.name = "i2c IR (EM28XX Terratec)";
                break;
        case EM2820_BOARD_PINNACLE_USB_2:
                dev->init_data.ir_codes = RC_MAP_PINNACLE_GREY;
                dev->init_data.get_key = em28xx_get_key_pinnacle_usb_grey;
                dev->init_data.name = "i2c IR (EM28XX Pinnacle PCTV)";
                break;
        case EM2820_BOARD_HAUPPAUGE_WINTV_USB_2:
                dev->init_data.ir_codes = RC_MAP_HAUPPAUGE;
                dev->init_data.get_key = em28xx_get_key_em_haup;
                dev->init_data.name = "i2c IR (EM2840 Hauppauge)";
                break;
        case EM2820_BOARD_LEADTEK_WINFAST_USBII_DELUXE:
                dev->init_data.ir_codes = RC_MAP_WINFAST_USBII_DELUXE;
                dev->init_data.get_key = em28xx_get_key_winfast_usbii_deluxe;
                dev->init_data.name = "i2c IR (EM2820 Winfast TV USBII Deluxe)";
                break;
        }

        if (dev->init_data.name)
                info.platform_data = &dev->init_data;
        i2c_new_probed_device(&dev->i2c_adap, &info, addr_list, NULL);
}

/**********************************************************
 Handle Webcam snapshot button
 **********************************************************/

static void em28xx_query_sbutton(struct work_struct *work)
{
        /* Poll the register and see if the button is depressed */
        struct em28xx *dev =
                container_of(work, struct em28xx, sbutton_query_work.work);
        int ret;

        ret = em28xx_read_reg(dev, EM28XX_R0C_USBSUSP);

        if (ret & EM28XX_R0C_USBSUSP_SNAPSHOT) {
                u8 cleared;
                /* Button is depressed, clear the register */
                cleared = ((u8) ret) & ~EM28XX_R0C_USBSUSP_SNAPSHOT;
                em28xx_write_regs(dev, EM28XX_R0C_USBSUSP, &cleared, 1);

                /* Not emulate the keypress */
                input_report_key(dev->sbutton_input_dev, EM28XX_SNAPSHOT_KEY,
                                 1);
                /* Now unpress the key */
                input_report_key(dev->sbutton_input_dev, EM28XX_SNAPSHOT_KEY,
                                 0);
        }

        /* Schedule next poll */
        schedule_delayed_work(&dev->sbutton_query_work,
                              msecs_to_jiffies(EM28XX_SBUTTON_QUERY_INTERVAL));
}

static void em28xx_register_snapshot_button(struct em28xx *dev)
{
        struct input_dev *input_dev;
        int err;

        em28xx_info("Registering snapshot button...\n");
        input_dev = input_allocate_device();
        if (!input_dev) {
                em28xx_errdev("input_allocate_device failed\n");
                return;
        }

        usb_make_path(dev->udev, dev->snapshot_button_path,
                      sizeof(dev->snapshot_button_path));
        strlcat(dev->snapshot_button_path, "/sbutton",
                sizeof(dev->snapshot_button_path));
        INIT_DELAYED_WORK(&dev->sbutton_query_work, em28xx_query_sbutton);

        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;
        input_dev->id.bustype = BUS_USB;
        input_dev->id.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
        input_dev->id.product = le16_to_cpu(dev->udev->descriptor.idProduct);
        input_dev->id.version = 1;
        input_dev->dev.parent = &dev->udev->dev;

        err = input_register_device(input_dev);
        if (err) {
                em28xx_errdev("input_register_device failed\n");
                input_free_device(input_dev);
                return;
        }

        dev->sbutton_input_dev = input_dev;
        schedule_delayed_work(&dev->sbutton_query_work,
                              msecs_to_jiffies(EM28XX_SBUTTON_QUERY_INTERVAL));
        return;

}

static void em28xx_deregister_snapshot_button(struct em28xx *dev)
{
        if (dev->sbutton_input_dev != NULL) {
                em28xx_info("Deregistering snapshot button\n");
                cancel_delayed_work_sync(&dev->sbutton_query_work);
                input_unregister_device(dev->sbutton_input_dev);
                dev->sbutton_input_dev = NULL;
        }
        return;
}

static int em28xx_ir_init(struct em28xx *dev)
{
        struct em28xx_IR *ir;
        struct rc_dev *rc;
        int err = -ENOMEM;

        if (dev->board.ir_codes == NULL) {
                /* No remote control support */
                em28xx_warn("Remote control support is not available for "
                                "this card.\n");
                return 0;
        }

        ir = kzalloc(sizeof(*ir), GFP_KERNEL);
        rc = rc_allocate_device();
        if (!ir || !rc)
                goto err_out_free;

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

        /*
         * em2874 supports more protocols. For now, let's just announce
         * the two protocols that were already tested
         */
        rc->allowed_protos = RC_TYPE_RC5 | RC_TYPE_NEC;
        rc->priv = ir;
        rc->change_protocol = em28xx_ir_change_protocol;
        rc->open = em28xx_ir_start;
        rc->close = em28xx_ir_stop;

        /* By default, keep protocol field untouched */
        err = em28xx_ir_change_protocol(rc, RC_TYPE_UNKNOWN);
        if (err)
                goto err_out_free;

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

        /* init input device */
        snprintf(ir->name, sizeof(ir->name), "em28xx IR (%s)",
                                                dev->name);

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

        rc->input_name = ir->name;
        rc->input_phys = ir->phys;
        rc->input_id.bustype = BUS_USB;
        rc->input_id.version = 1;
        rc->input_id.vendor = le16_to_cpu(dev->udev->descriptor.idVendor);
        rc->input_id.product = le16_to_cpu(dev->udev->descriptor.idProduct);
        rc->dev.parent = &dev->udev->dev;
        rc->map_name = dev->board.ir_codes;
        rc->driver_name = MODULE_NAME;

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

        em28xx_register_i2c_ir(dev);

#if defined(CONFIG_MODULES) && defined(MODULE)
        if (dev->board.has_ir_i2c)
                request_module("ir-kbd-i2c");
#endif
        if (dev->board.has_snapshot_button)
                em28xx_register_snapshot_button(dev);

        return 0;

 err_out_stop:
        dev->ir = NULL;
 err_out_free:
        rc_free_device(rc);
        kfree(ir);
        return err;
}

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

        em28xx_deregister_snapshot_button(dev);

        /* skip detach on non attached boards */
        if (!ir)
                return 0;

        if (ir->rc)
                rc_unregister_device(ir->rc);

        /* done */
        kfree(ir);
        dev->ir = NULL;
        return 0;
}

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

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");
MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
MODULE_DESCRIPTION("Em28xx Input driver");

module_init(em28xx_rc_register);
module_exit(em28xx_rc_unregister);