text: // 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(sizeof(*hx), GFP_KERNEL);
  	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");
  