/* Copyright (c) 2011,2012 Simon Schubert <2@0x2c.org>.
 * Modifications by Jacob Alexander 2014 <haata@kiibohd.com>
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 */

// ----- Local Includes -----

#include "usb.h"
#include "dfu.h"



// ----- Functions -----

void dfu_write_done( enum dfu_status err, struct dfu_ctx *ctx )
{
        ctx->status = err;
        if (ctx->status == DFU_STATUS_OK) {
                switch (ctx->state) {
                case DFU_STATE_dfuDNBUSY:
                        ctx->state = DFU_STATE_dfuDNLOAD_IDLE;
                        break;
                default:
                        break;
                }
        } else {
                ctx->state = DFU_STATE_dfuERROR;
        }
}

static void dfu_dnload_complete( void *buf, ssize_t len, void *cbdata )
{
        struct dfu_ctx *ctx = cbdata;

        if (len > 0)
                ctx->state = DFU_STATE_dfuDNBUSY;
        else
                ctx->state = DFU_STATE_dfuMANIFEST;
        ctx->status = ctx->finish_write(buf, ctx->off, len);
        ctx->off += len;
        ctx->len = len;

        if (ctx->status != DFU_STATUS_async)
                dfu_write_done(ctx->status, ctx);

        usb_handle_control_status(ctx->state == DFU_STATE_dfuERROR);
}

static void dfu_reset_system( void *buf, ssize_t len, void *cbdata )
{
        SOFTWARE_RESET();
}

static int dfu_handle_control( struct usb_ctrl_req_t *req, void *data )
{
        struct dfu_ctx *ctx = data;
        int fail = 1;

        switch ((enum dfu_ctrl_req_code)req->bRequest) {
        case USB_CTRL_REQ_DFU_DNLOAD: {
                void *buf;

                switch (ctx->state) {
                case DFU_STATE_dfuIDLE:
                        ctx->off = 0;
                        break;
                case DFU_STATE_dfuDNLOAD_IDLE:
                        break;
                default:
                        goto err;
                }

                /**
                 * XXX we are not allowed to STALL here, and we need to eat all transferred data.
                 * better not allow setup_write to break the protocol.
                 */
                ctx->status = ctx->setup_write(ctx->off, req->wLength, &buf);
                if (ctx->status != DFU_STATUS_OK) {
                        ctx->state = DFU_STATE_dfuERROR;
                        goto err_have_status;
                }

                if (req->wLength > 0)
                        usb_ep0_rx(buf, req->wLength, dfu_dnload_complete, ctx);
                else
                        dfu_dnload_complete(NULL, 0, ctx);
                goto out_no_status;
        }
        case USB_CTRL_REQ_DFU_GETSTATUS: {
                struct dfu_status_t st;

                st.bState = ctx->state;
                st.bStatus = ctx->status;
                st.bwPollTimeout = 1000; /* XXX */
                /**
                 * If we're in DFU_STATE_dfuMANIFEST, we just finished
                 * the download, and we're just about to send our last
                 * status report.  Once the report has been sent, go
                 * and reset the system to put the new firmware into
                 * effect.
                 */
                usb_ep0_tx_cp(&st, sizeof(st), req->wLength, NULL, NULL);
                if (ctx->state == DFU_STATE_dfuMANIFEST) {
                        usb_handle_control_status_cb(dfu_reset_system);
                        goto out_no_status;
                }
                break;
        }
        case USB_CTRL_REQ_DFU_CLRSTATUS:
                ctx->state = DFU_STATE_dfuIDLE;
                ctx->status = DFU_STATUS_OK;
                break;
        case USB_CTRL_REQ_DFU_GETSTATE: {
                uint8_t st = ctx->state;
                usb_ep0_tx_cp(&st, sizeof(st), req->wLength, NULL, NULL);
                break;
        }
        case USB_CTRL_REQ_DFU_ABORT:
                switch (ctx->state) {
                case DFU_STATE_dfuIDLE:
                case DFU_STATE_dfuDNLOAD_IDLE:
                /* case DFU_STATE_dfuUPLOAD_IDLE: */
                        ctx->state = DFU_STATE_dfuIDLE;
                        break;
                default:
                        goto err;
                }
                break;
        /* case USB_CTRL_REQ_DFU_UPLOAD: */
        default:
                return (0);
        }

        fail = 0;
        goto out;

err:
        ctx->status = DFU_STATUS_errSTALLEDPKT;
err_have_status:
        ctx->state = DFU_STATE_dfuERROR;
out:
        usb_handle_control_status(fail);
out_no_status:
        return (1);
}

void dfu_init( dfu_setup_write_t setup_write, dfu_finish_write_t finish_write, struct dfu_ctx *ctx )
{
        ctx->state = DFU_STATE_dfuIDLE;
        ctx->setup_write = setup_write;
        ctx->finish_write = finish_write;
        usb_attach_function(&dfu_function, &ctx->header);
}

const struct usbd_function dfu_function = {
        .control = dfu_handle_control,
        .interface_count = USB_FUNCTION_DFU_IFACE_COUNT,
};