// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Linux driver for TerraTec DMX 6Fire USB
 *
 * Device communications
 *
 * Author:      Torsten Schenk <torsten.schenk@zoho.com>
 * Created:     Jan 01, 2011
 * Copyright:   (C) Torsten Schenk
 */

#include "comm.h"
#include "chip.h"
#include "midi.h"

enum {
        COMM_EP = 1,
        COMM_FPGA_EP = 2
};

static void usb6fire_comm_init_urb(struct comm_runtime *rt, struct urb *urb,
                u8 *buffer, void *context, void(*handler)(struct urb *urb))
{
        usb_init_urb(urb);
        urb->transfer_buffer = buffer;
        urb->pipe = usb_sndintpipe(rt->chip->dev, COMM_EP);
        urb->complete = handler;
        urb->context = context;
        urb->interval = 1;
        urb->dev = rt->chip->dev;
}

static void usb6fire_comm_receiver_handler(struct urb *urb)
{
        struct comm_runtime *rt = urb->context;
        struct midi_runtime *midi_rt = rt->chip->midi;

        if (!urb->status) {
                if (rt->receiver_buffer[0] == 0x10) /* midi in event */
                        if (midi_rt)
                                midi_rt->in_received(midi_rt,
                                                rt->receiver_buffer + 2,
                                                rt->receiver_buffer[1]);
        }

        if (!rt->chip->shutdown) {
                urb->status = 0;
                urb->actual_length = 0;
                if (usb_submit_urb(urb, GFP_ATOMIC) < 0)
                        dev_warn(&urb->dev->dev,
                                        "comm data receiver aborted.\n");
        }
}

static void usb6fire_comm_init_buffer(u8 *buffer, u8 id, u8 request,
                u8 reg, u8 vl, u8 vh)
{
        buffer[0] = 0x01;
        buffer[2] = request;
        buffer[3] = id;
        switch (request) {
        case 0x02:
                buffer[1] = 0x05; /* length (starting at buffer[2]) */
                buffer[4] = reg;
                buffer[5] = vl;
                buffer[6] = vh;
                break;

        case 0x12:
                buffer[1] = 0x0b; /* length (starting at buffer[2]) */
                buffer[4] = 0x00;
                buffer[5] = 0x18;
                buffer[6] = 0x05;
                buffer[7] = 0x00;
                buffer[8] = 0x01;
                buffer[9] = 0x00;
                buffer[10] = 0x9e;
                buffer[11] = reg;
                buffer[12] = vl;
                break;

        case 0x20:
        case 0x21:
        case 0x22:
                buffer[1] = 0x04;
                buffer[4] = reg;
                buffer[5] = vl;
                break;
        }
}

static int usb6fire_comm_send_buffer(u8 *buffer, struct usb_device *dev)
{
        int ret;
        int actual_len;

        ret = usb_interrupt_msg(dev, usb_sndintpipe(dev, COMM_EP),
                        buffer, buffer[1] + 2, &actual_len, 1000);
        if (ret < 0)
                return ret;
        else if (actual_len != buffer[1] + 2)
                return -EIO;
        return 0;
}

static int usb6fire_comm_write8(struct comm_runtime *rt, u8 request,
                u8 reg, u8 value)
{
        u8 *buffer;
        int ret;

        /* 13: maximum length of message */
        buffer = kmalloc(13, GFP_KERNEL);
        if (!buffer)
                return -ENOMEM;

        usb6fire_comm_init_buffer(buffer, 0x00, request, reg, value, 0x00);
        ret = usb6fire_comm_send_buffer(buffer, rt->chip->dev);

        kfree(buffer);
        return ret;
}

static int usb6fire_comm_write16(struct comm_runtime *rt, u8 request,
                u8 reg, u8 vl, u8 vh)
{
        u8 *buffer;
        int ret;

        /* 13: maximum length of message */
        buffer = kmalloc(13, GFP_KERNEL);
        if (!buffer)
                return -ENOMEM;

        usb6fire_comm_init_buffer(buffer, 0x00, request, reg, vl, vh);
        ret = usb6fire_comm_send_buffer(buffer, rt->chip->dev);

        kfree(buffer);
        return ret;
}

int usb6fire_comm_init(struct sfire_chip *chip)
{
        struct comm_runtime *rt = kzalloc_obj(struct comm_runtime);
        struct urb *urb;
        int ret;

        if (!rt)
                return -ENOMEM;

        rt->receiver_buffer = kzalloc(COMM_RECEIVER_BUFSIZE, GFP_KERNEL);
        if (!rt->receiver_buffer) {
                kfree(rt);
                return -ENOMEM;
        }

        urb = &rt->receiver;
        rt->serial = 1;
        rt->chip = chip;
        usb_init_urb(urb);
        rt->init_urb = usb6fire_comm_init_urb;
        rt->write8 = usb6fire_comm_write8;
        rt->write16 = usb6fire_comm_write16;

        /* submit an urb that receives communication data from device */
        urb->transfer_buffer = rt->receiver_buffer;
        urb->transfer_buffer_length = COMM_RECEIVER_BUFSIZE;
        urb->pipe = usb_rcvintpipe(chip->dev, COMM_EP);
        urb->dev = chip->dev;
        urb->complete = usb6fire_comm_receiver_handler;
        urb->context = rt;
        urb->interval = 1;
        ret = usb_submit_urb(urb, GFP_KERNEL);
        if (ret < 0) {
                kfree(rt->receiver_buffer);
                kfree(rt);
                dev_err(&chip->dev->dev, "cannot create comm data receiver.");
                return ret;
        }
        chip->comm = rt;
        return 0;
}

void usb6fire_comm_abort(struct sfire_chip *chip)
{
        struct comm_runtime *rt = chip->comm;

        if (rt)
                usb_poison_urb(&rt->receiver);
}

void usb6fire_comm_destroy(struct sfire_chip *chip)
{
        struct comm_runtime *rt = chip->comm;

        kfree(rt->receiver_buffer);
        kfree(rt);
        chip->comm = NULL;
}