// SPDX-License-Identifier: GPL-2.0-only
/*  cypress_firmware.c is part of the DVB USB library.
 *
 * Copyright (C) 2004-6 Patrick Boettcher (patrick.boettcher@posteo.de)
 * see dvb-usb-init.c for copyright information.
 *
 * This file contains functions for downloading the firmware to Cypress FX 1
 * and 2 based devices.
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/firmware.h>
#include "cypress_firmware.h"

struct usb_cypress_controller {
        u8 id;
        const char *name;       /* name of the usb controller */
        u16 cs_reg;             /* needs to be restarted,
                                 * when the firmware has been downloaded */
};

static const struct usb_cypress_controller cypress[] = {
        { .id = CYPRESS_AN2135, .name = "Cypress AN2135", .cs_reg = 0x7f92 },
        { .id = CYPRESS_AN2235, .name = "Cypress AN2235", .cs_reg = 0x7f92 },
        { .id = CYPRESS_FX2,    .name = "Cypress FX2",    .cs_reg = 0xe600 },
};

/*
 * load a firmware packet to the device
 */
static int usb_cypress_writemem(struct usb_device *udev, u16 addr, u8 *data,
                u8 len)
{
        return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
                        0xa0, USB_TYPE_VENDOR, addr, 0x00, data, len, 5000);
}

static int cypress_get_hexline(const struct firmware *fw,
                                struct hexline *hx, int *pos)
{
        u8 *b = (u8 *) &fw->data[*pos];
        int data_offs = 4;

        if (*pos >= fw->size)
                return 0;

        memset(hx, 0, sizeof(struct hexline));
        hx->len = b[0];

        if ((*pos + hx->len + 4) >= fw->size)
                return -EINVAL;

        hx->addr = b[1] | (b[2] << 8);
        hx->type = b[3];

        if (hx->type == 0x04) {
                /* b[4] and b[5] are the Extended linear address record data
                 * field */
                hx->addr |= (b[4] << 24) | (b[5] << 16);
        }

        memcpy(hx->data, &b[data_offs], hx->len);
        hx->chk = b[hx->len + data_offs];
        *pos += hx->len + 5;

        return *pos;
}

int cypress_load_firmware(struct usb_device *udev,
                const struct firmware *fw, int type)
{
        struct hexline *hx;
        int ret, pos = 0;

        hx = kmalloc_obj(*hx);
        if (!hx)
                return -ENOMEM;

        /* stop the CPU */
        hx->data[0] = 1;
        ret = usb_cypress_writemem(udev, cypress[type].cs_reg, hx->data, 1);
        if (ret != 1) {
                dev_err(&udev->dev, "%s: CPU stop failed=%d\n",
                                KBUILD_MODNAME, ret);
                ret = -EIO;
                goto err_kfree;
        }

        /* write firmware to memory */
        for (;;) {
                ret = cypress_get_hexline(fw, hx, &pos);
                if (ret < 0)
                        goto err_kfree;
                else if (ret == 0)
                        break;

                ret = usb_cypress_writemem(udev, hx->addr, hx->data, hx->len);
                if (ret < 0) {
                        goto err_kfree;
                } else if (ret != hx->len) {
                        dev_err(&udev->dev,
                                        "%s: error while transferring firmware (transferred size=%d, block size=%d)\n",
                                        KBUILD_MODNAME, ret, hx->len);
                        ret = -EIO;
                        goto err_kfree;
                }
        }

        /* start the CPU */
        hx->data[0] = 0;
        ret = usb_cypress_writemem(udev, cypress[type].cs_reg, hx->data, 1);
        if (ret != 1) {
                dev_err(&udev->dev, "%s: CPU start failed=%d\n",
                                KBUILD_MODNAME, ret);
                ret = -EIO;
                goto err_kfree;
        }

        ret = 0;
err_kfree:
        kfree(hx);
        return ret;
}
EXPORT_SYMBOL(cypress_load_firmware);

MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
MODULE_DESCRIPTION("Cypress firmware download");
MODULE_LICENSE("GPL");