/*
 * lirc_igorplugusb - USB remote support for LIRC
 *
 * Supports the standard homebrew IgorPlugUSB receiver with Igor's firmware.
 * See http://www.cesko.host.sk/IgorPlugUSB/IgorPlug-USB%20(AVR)_eng.htm
 *
 * The device can only record bursts of up to 36 pulses/spaces.
 * Works fine with RC5. Longer commands lead to device buffer overrun.
 * (Maybe a better firmware or a microcontroller with more ram can help?)
 *
 * Version 0.1  [beta status]
 *
 * Copyright (C) 2004 Jan M. Hochstein
 *      <hochstein@algo.informatik.tu-darmstadt.de>
 *
 * This driver was derived from:
 *   Paul Miller <pmiller9@users.sourceforge.net>
 *      "lirc_atiusb" module
 *   Vladimir Dergachev <volodya@minspring.com>'s 2002
 *      "USB ATI Remote support" (input device)
 *   Adrian Dewhurst <sailor-lk@sailorfrag.net>'s 2002
 *      "USB StreamZap remote driver" (LIRC)
 *   Artur Lipowski <alipowski@kki.net.pl>'s 2002
 *      "lirc_dev" and "lirc_gpio" LIRC modules
 */

/*
 * 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/kernel.h>
#include <linux/kmod.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/usb.h>
#include <linux/time.h>

#include <media/lirc.h>
#include <media/lirc_dev.h>


/* module identification */
#define DRIVER_VERSION          "0.2"
#define DRIVER_AUTHOR           \
        "Jan M. Hochstein <hochstein@algo.informatik.tu-darmstadt.de>"
#define DRIVER_DESC             "Igorplug USB remote driver for LIRC"
#define DRIVER_NAME             "lirc_igorplugusb"

/* One mode2 pulse/space has 4 bytes. */
#define CODE_LENGTH          sizeof(int)

/* Igor's firmware cannot record bursts longer than 36. */
#define DEVICE_BUFLEN      36

/*
 * Header at the beginning of the device's buffer:
 *      unsigned char data_length
 *      unsigned char data_start    (!=0 means ring-buffer overrun)
 *      unsigned char counter       (incremented by each burst)
 */
#define DEVICE_HEADERLEN        3

/* This is for the gap */
#define ADDITIONAL_LIRC_BYTES   2

/* times to poll per second */
#define SAMPLE_RATE          100
static int sample_rate = SAMPLE_RATE;


/**** Igor's USB Request Codes */

#define SET_INFRABUFFER_EMPTY   1
/**
 * Params: none
 * Answer: empty
 */

#define GET_INFRACODE      2
/**
 * Params:
 *   wValue: offset to begin reading infra buffer
 *
 * Answer: infra data
 */

#define SET_DATAPORT_DIRECTION  3
/**
 * Params:
 *   wValue: (byte) 1 bit for each data port pin (0=in, 1=out)
 *
 * Answer: empty
 */

#define GET_DATAPORT_DIRECTION  4
/**
 * Params: none
 *
 * Answer: (byte) 1 bit for each data port pin (0=in, 1=out)
 */

#define SET_OUT_DATAPORT        5
/**
 * Params:
 *   wValue: byte to write to output data port
 *
 * Answer: empty
 */

#define GET_OUT_DATAPORT        6
/**
 * Params: none
 *
 * Answer: least significant 3 bits read from output data port
 */

#define GET_IN_DATAPORT  7
/**
 * Params: none
 *
 * Answer: least significant 3 bits read from input data port
 */

#define READ_EEPROM          8
/**
 * Params:
 *   wValue: offset to begin reading EEPROM
 *
 * Answer: EEPROM bytes
 */

#define WRITE_EEPROM        9
/**
 * Params:
 *   wValue: offset to EEPROM byte
 *   wIndex: byte to write
 *
 * Answer: empty
 */

#define SEND_RS232            10
/**
 * Params:
 *   wValue: byte to send
 *
 * Answer: empty
 */

#define RECV_RS232            11
/**
 * Params: none
 *
 * Answer: byte received
 */

#define SET_RS232_BAUD    12
/**
 * Params:
 *   wValue: byte to write to UART bit rate register (UBRR)
 *
 * Answer: empty
 */

#define GET_RS232_BAUD    13
/**
 * Params: none
 *
 * Answer: byte read from UART bit rate register (UBRR)
 */


/* data structure for each usb remote */
struct igorplug {

        /* usb */
        struct usb_device *usbdev;
        int devnum;

        unsigned char *buf_in;
        unsigned int len_in;
        int in_space;
        struct timeval last_time;

        dma_addr_t dma_in;

        /* lirc */
        struct lirc_driver *d;

        /* handle sending (init strings) */
        int send_flags;
};

static int unregister_from_lirc(struct igorplug *ir)
{
        struct lirc_driver *d;
        int devnum;

        if (!ir) {
                dev_err(&ir->usbdev->dev,
                        "%s: called with NULL device struct!\n", __func__);
                return -EINVAL;
        }

        devnum = ir->devnum;
        d = ir->d;

        if (!d) {
                dev_err(&ir->usbdev->dev,
                        "%s: called with NULL lirc driver struct!\n", __func__);
                return -EINVAL;
        }

        dev_dbg(&ir->usbdev->dev, "calling lirc_unregister_driver\n");
        lirc_unregister_driver(d->minor);

        return devnum;
}

static int set_use_inc(void *data)
{
        struct igorplug *ir = data;

        if (!ir) {
                printk(DRIVER_NAME "[?]: set_use_inc called with no context\n");
                return -EIO;
        }

        dev_dbg(&ir->usbdev->dev, "set use inc\n");

        if (!ir->usbdev)
                return -ENODEV;

        return 0;
}

static void set_use_dec(void *data)
{
        struct igorplug *ir = data;

        if (!ir) {
                printk(DRIVER_NAME "[?]: set_use_dec called with no context\n");
                return;
        }

        dev_dbg(&ir->usbdev->dev, "set use dec\n");
}

static void send_fragment(struct igorplug *ir, struct lirc_buffer *buf,
                           int i, int max)
{
        int code;

        /* MODE2: pulse/space (PULSE_BIT) in 1us units */
        while (i < max) {
                /* 1 Igor-tick = 85.333333 us */
                code = (unsigned int)ir->buf_in[i] * 85 +
                        (unsigned int)ir->buf_in[i] / 3;
                ir->last_time.tv_usec += code;
                if (ir->in_space)
                        code |= PULSE_BIT;
                lirc_buffer_write(buf, (unsigned char *)&code);
                /* 1 chunk = CODE_LENGTH bytes */
                ir->in_space ^= 1;
                ++i;
        }
}

/**
 * Called in user context.
 * return 0 if data was added to the buffer and
 * -ENODATA if none was available. This should add some number of bits
 * evenly divisible by code_length to the buffer
 */
static int igorplugusb_remote_poll(void *data, struct lirc_buffer *buf)
{
        int ret;
        struct igorplug *ir = (struct igorplug *)data;

        if (!ir || !ir->usbdev)  /* Has the device been removed? */
                return -ENODEV;

        memset(ir->buf_in, 0, ir->len_in);

        ret = usb_control_msg(ir->usbdev, usb_rcvctrlpipe(ir->usbdev, 0),
                              GET_INFRACODE, USB_TYPE_VENDOR | USB_DIR_IN,
                              0/* offset */, /*unused*/0,
                              ir->buf_in, ir->len_in,
                              /*timeout*/HZ * USB_CTRL_GET_TIMEOUT);
        if (ret > 0) {
                int code, timediff;
                struct timeval now;

                /* ACK packet has 1 byte --> ignore */
                if (ret < DEVICE_HEADERLEN)
                        return -ENODATA;

                dev_dbg(&ir->usbdev->dev, "Got %d bytes. Header: %*ph\n",
                        ret, 3, ir->buf_in);

                do_gettimeofday(&now);
                timediff = now.tv_sec - ir->last_time.tv_sec;
                if (timediff + 1 > PULSE_MASK / 1000000)
                        timediff = PULSE_MASK;
                else {
                        timediff *= 1000000;
                        timediff += now.tv_usec - ir->last_time.tv_usec;
                }
                ir->last_time.tv_sec = now.tv_sec;
                ir->last_time.tv_usec = now.tv_usec;

                /* create leading gap  */
                code = timediff;
                lirc_buffer_write(buf, (unsigned char *)&code);
                ir->in_space = 1;   /* next comes a pulse */

                if (ir->buf_in[2] == 0)
                        send_fragment(ir, buf, DEVICE_HEADERLEN, ret);
                else {
                        dev_warn(&ir->usbdev->dev,
                                 "[%d]: Device buffer overrun.\n", ir->devnum);
                        /* HHHNNNNNNNNNNNOOOOOOOO H = header
                              <---[2]--->         N = newer
                           <---------ret--------> O = older */
                        ir->buf_in[2] %= ret - DEVICE_HEADERLEN; /* sanitize */
                        /* keep even-ness to not desync pulse/pause */
                        send_fragment(ir, buf, DEVICE_HEADERLEN +
                                      ir->buf_in[2] - (ir->buf_in[2] & 1), ret);
                        send_fragment(ir, buf, DEVICE_HEADERLEN,
                                      DEVICE_HEADERLEN + ir->buf_in[2]);
                }

                ret = usb_control_msg(
                      ir->usbdev, usb_rcvctrlpipe(ir->usbdev, 0),
                      SET_INFRABUFFER_EMPTY, USB_TYPE_VENDOR|USB_DIR_IN,
                      /*unused*/0, /*unused*/0,
                      /*dummy*/ir->buf_in, /*dummy*/ir->len_in,
                      /*timeout*/HZ * USB_CTRL_GET_TIMEOUT);
                if (ret < 0)
                        printk(DRIVER_NAME "[%d]: SET_INFRABUFFER_EMPTY: error %d\n",
                               ir->devnum, ret);
                return 0;
        } else if (ret < 0)
                printk(DRIVER_NAME "[%d]: GET_INFRACODE: error %d\n",
                        ir->devnum, ret);

        return -ENODATA;
}

static int igorplugusb_remote_probe(struct usb_interface *intf,
                                    const struct usb_device_id *id)
{
        struct usb_device *dev;
        struct usb_host_interface *idesc = NULL;
        struct usb_endpoint_descriptor *ep;
        struct igorplug *ir = NULL;
        struct lirc_driver *driver = NULL;
        int devnum, pipe, maxp;
        char buf[63], name[128] = "";
        int ret;

        dev_dbg(&intf->dev, "%s: usb probe called.\n", __func__);

        dev = interface_to_usbdev(intf);

        idesc = intf->cur_altsetting;

        if (idesc->desc.bNumEndpoints != 1)
                return -ENODEV;

        ep = &idesc->endpoint->desc;
        if (((ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
            != USB_DIR_IN)
            || (ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
            != USB_ENDPOINT_XFER_CONTROL)
                return -ENODEV;

        pipe = usb_rcvctrlpipe(dev, ep->bEndpointAddress);
        devnum = dev->devnum;
        maxp = usb_maxpacket(dev, pipe, usb_pipeout(pipe));

        dev_dbg(&intf->dev, "%s: bytes_in_key=%zu maxp=%d\n",
                __func__, CODE_LENGTH, maxp);

        ir = devm_kzalloc(&intf->dev, sizeof(*ir), GFP_KERNEL);
        if (!ir)
                return -ENOMEM;

        driver = devm_kzalloc(&intf->dev, sizeof(*driver), GFP_KERNEL);
        if (!driver)
                return -ENOMEM;

        ir->buf_in = usb_alloc_coherent(dev, DEVICE_BUFLEN + DEVICE_HEADERLEN,
                                        GFP_ATOMIC, &ir->dma_in);
        if (!ir->buf_in)
                return -ENOMEM;

        strcpy(driver->name, DRIVER_NAME " ");
        driver->minor = -1;
        driver->code_length = CODE_LENGTH * 8; /* in bits */
        driver->features = LIRC_CAN_REC_MODE2;
        driver->data = ir;
        driver->chunk_size = CODE_LENGTH;
        driver->buffer_size = DEVICE_BUFLEN + ADDITIONAL_LIRC_BYTES;
        driver->set_use_inc = &set_use_inc;
        driver->set_use_dec = &set_use_dec;
        driver->sample_rate = sample_rate;    /* per second */
        driver->add_to_buf = &igorplugusb_remote_poll;
        driver->dev = &intf->dev;
        driver->owner = THIS_MODULE;

        ret = lirc_register_driver(driver);
        if (ret < 0) {
                usb_free_coherent(dev, DEVICE_BUFLEN + DEVICE_HEADERLEN,
                        ir->buf_in, ir->dma_in);
                return ret;
        }

        driver->minor = ret;
        ir->d = driver;
        ir->devnum = devnum;
        ir->usbdev = dev;
        ir->len_in = DEVICE_BUFLEN + DEVICE_HEADERLEN;
        ir->in_space = 1; /* First mode2 event is a space. */
        do_gettimeofday(&ir->last_time);

        if (dev->descriptor.iManufacturer
            && usb_string(dev, dev->descriptor.iManufacturer,
                          buf, sizeof(buf)) > 0)
                strlcpy(name, buf, sizeof(name));
        if (dev->descriptor.iProduct
            && usb_string(dev, dev->descriptor.iProduct, buf, sizeof(buf)) > 0)
                snprintf(name + strlen(name), sizeof(name) - strlen(name),
                         " %s", buf);
        printk(DRIVER_NAME "[%d]: %s on usb%d:%d\n", devnum, name,
               dev->bus->busnum, devnum);

        /* clear device buffer */
        ret = usb_control_msg(ir->usbdev, usb_rcvctrlpipe(ir->usbdev, 0),
                SET_INFRABUFFER_EMPTY, USB_TYPE_VENDOR|USB_DIR_IN,
                /*unused*/0, /*unused*/0,
                /*dummy*/ir->buf_in, /*dummy*/ir->len_in,
                /*timeout*/HZ * USB_CTRL_GET_TIMEOUT);
        if (ret < 0)
                printk(DRIVER_NAME "[%d]: SET_INFRABUFFER_EMPTY: error %d\n",
                        devnum, ret);

        usb_set_intfdata(intf, ir);
        return 0;
}

static void igorplugusb_remote_disconnect(struct usb_interface *intf)
{
        struct usb_device *usbdev = interface_to_usbdev(intf);
        struct igorplug *ir = usb_get_intfdata(intf);
        struct device *dev = &intf->dev;
        int devnum;

        usb_set_intfdata(intf, NULL);

        if (!ir || !ir->d)
                return;

        ir->usbdev = NULL;

        usb_free_coherent(usbdev, ir->len_in, ir->buf_in, ir->dma_in);

        devnum = unregister_from_lirc(ir);

        dev_info(dev, DRIVER_NAME "[%d]: %s done\n", devnum, __func__);
}

static struct usb_device_id igorplugusb_remote_id_table[] = {
        /* Igor Plug USB (Atmel's Manufact. ID) */
        { USB_DEVICE(0x03eb, 0x0002) },
        /* Fit PC2 Infrared Adapter */
        { USB_DEVICE(0x03eb, 0x21fe) },

        /* Terminating entry */
        { }
};

static struct usb_driver igorplugusb_remote_driver = {
        .name =         DRIVER_NAME,
        .probe =        igorplugusb_remote_probe,
        .disconnect =   igorplugusb_remote_disconnect,
        .id_table =     igorplugusb_remote_id_table
};

module_usb_driver(igorplugusb_remote_driver);

#include <linux/vermagic.h>
MODULE_INFO(vermagic, VERMAGIC_STRING);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(usb, igorplugusb_remote_id_table);

module_param(sample_rate, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(sample_rate, "Sampling rate in Hz (default: 100)");