cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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cypress_firmware.c (3148B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*  cypress_firmware.c is part of the DVB USB library.
      3 *
      4 * Copyright (C) 2004-6 Patrick Boettcher (patrick.boettcher@posteo.de)
      5 * see dvb-usb-init.c for copyright information.
      6 *
      7 * This file contains functions for downloading the firmware to Cypress FX 1
      8 * and 2 based devices.
      9 *
     10 */
     11
     12#include <linux/module.h>
     13#include <linux/slab.h>
     14#include <linux/usb.h>
     15#include <linux/firmware.h>
     16#include "cypress_firmware.h"
     17
     18struct usb_cypress_controller {
     19	u8 id;
     20	const char *name;	/* name of the usb controller */
     21	u16 cs_reg;		/* needs to be restarted,
     22				 * when the firmware has been downloaded */
     23};
     24
     25static const struct usb_cypress_controller cypress[] = {
     26	{ .id = CYPRESS_AN2135, .name = "Cypress AN2135", .cs_reg = 0x7f92 },
     27	{ .id = CYPRESS_AN2235, .name = "Cypress AN2235", .cs_reg = 0x7f92 },
     28	{ .id = CYPRESS_FX2,    .name = "Cypress FX2",    .cs_reg = 0xe600 },
     29};
     30
     31/*
     32 * load a firmware packet to the device
     33 */
     34static int usb_cypress_writemem(struct usb_device *udev, u16 addr, u8 *data,
     35		u8 len)
     36{
     37	return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
     38			0xa0, USB_TYPE_VENDOR, addr, 0x00, data, len, 5000);
     39}
     40
     41static int cypress_get_hexline(const struct firmware *fw,
     42				struct hexline *hx, int *pos)
     43{
     44	u8 *b = (u8 *) &fw->data[*pos];
     45	int data_offs = 4;
     46
     47	if (*pos >= fw->size)
     48		return 0;
     49
     50	memset(hx, 0, sizeof(struct hexline));
     51	hx->len = b[0];
     52
     53	if ((*pos + hx->len + 4) >= fw->size)
     54		return -EINVAL;
     55
     56	hx->addr = b[1] | (b[2] << 8);
     57	hx->type = b[3];
     58
     59	if (hx->type == 0x04) {
     60		/* b[4] and b[5] are the Extended linear address record data
     61		 * field */
     62		hx->addr |= (b[4] << 24) | (b[5] << 16);
     63	}
     64
     65	memcpy(hx->data, &b[data_offs], hx->len);
     66	hx->chk = b[hx->len + data_offs];
     67	*pos += hx->len + 5;
     68
     69	return *pos;
     70}
     71
     72int cypress_load_firmware(struct usb_device *udev,
     73		const struct firmware *fw, int type)
     74{
     75	struct hexline *hx;
     76	int ret, pos = 0;
     77
     78	hx = kmalloc(sizeof(*hx), GFP_KERNEL);
     79	if (!hx)
     80		return -ENOMEM;
     81
     82	/* stop the CPU */
     83	hx->data[0] = 1;
     84	ret = usb_cypress_writemem(udev, cypress[type].cs_reg, hx->data, 1);
     85	if (ret != 1) {
     86		dev_err(&udev->dev, "%s: CPU stop failed=%d\n",
     87				KBUILD_MODNAME, ret);
     88		ret = -EIO;
     89		goto err_kfree;
     90	}
     91
     92	/* write firmware to memory */
     93	for (;;) {
     94		ret = cypress_get_hexline(fw, hx, &pos);
     95		if (ret < 0)
     96			goto err_kfree;
     97		else if (ret == 0)
     98			break;
     99
    100		ret = usb_cypress_writemem(udev, hx->addr, hx->data, hx->len);
    101		if (ret < 0) {
    102			goto err_kfree;
    103		} else if (ret != hx->len) {
    104			dev_err(&udev->dev,
    105					"%s: error while transferring firmware (transferred size=%d, block size=%d)\n",
    106					KBUILD_MODNAME, ret, hx->len);
    107			ret = -EIO;
    108			goto err_kfree;
    109		}
    110	}
    111
    112	/* start the CPU */
    113	hx->data[0] = 0;
    114	ret = usb_cypress_writemem(udev, cypress[type].cs_reg, hx->data, 1);
    115	if (ret != 1) {
    116		dev_err(&udev->dev, "%s: CPU start failed=%d\n",
    117				KBUILD_MODNAME, ret);
    118		ret = -EIO;
    119		goto err_kfree;
    120	}
    121
    122	ret = 0;
    123err_kfree:
    124	kfree(hx);
    125	return ret;
    126}
    127EXPORT_SYMBOL(cypress_load_firmware);
    128
    129MODULE_AUTHOR("Antti Palosaari <crope@iki.fi>");
    130MODULE_DESCRIPTION("Cypress firmware download");
    131MODULE_LICENSE("GPL");