text: /*
   * NCI based driver for Samsung S3FWRN5 NFC chip
   *
   * Copyright (C) 2015 Samsung Electrnoics
   * Robert Baldyga <r.baldyga@samsung.com>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2 or later, as published by the Free Software Foundation.
   *
   * 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/>.
   */
  
  #include <linux/completion.h>
  #include <linux/firmware.h>
  #include <crypto/hash.h>
  #include <crypto/sha.h>
  
  #include "s3fwrn5.h"
  #include "firmware.h"
  
  struct s3fwrn5_fw_version {
  	__u8 major;
  	__u8 build1;
  	__u8 build2;
  	__u8 target;
  };
  
  static int s3fwrn5_fw_send_msg(struct s3fwrn5_fw_info *fw_info,
  	struct sk_buff *msg, struct sk_buff **rsp)
  {
  	struct s3fwrn5_info *info =
  		container_of(fw_info, struct s3fwrn5_info, fw_info);
  	long ret;
  
  	reinit_completion(&fw_info->completion);
  
  	ret = s3fwrn5_write(info, msg);
  	if (ret < 0)
  		return ret;
  
  	ret = wait_for_completion_interruptible_timeout(
  		&fw_info->completion, msecs_to_jiffies(1000));
  	if (ret < 0)
  		return ret;
  	else if (ret == 0)
  		return -ENXIO;
  
  	if (!fw_info->rsp)
  		return -EINVAL;
  
  	*rsp = fw_info->rsp;
  	fw_info->rsp = NULL;
  
  	return 0;
  }
  
  static int s3fwrn5_fw_prep_msg(struct s3fwrn5_fw_info *fw_info,
  	struct sk_buff **msg, u8 type, u8 code, const void *data, u16 len)
  {
  	struct s3fwrn5_fw_header hdr;
  	struct sk_buff *skb;
  
  	hdr.type = type | fw_info->parity;
  	fw_info->parity ^= 0x80;
  	hdr.code = code;
  	hdr.len = len;
  
  	skb = alloc_skb(S3FWRN5_FW_HDR_SIZE + len, GFP_KERNEL);
  	if (!skb)
  		return -ENOMEM;
  
  	skb_put_data(skb, &hdr, S3FWRN5_FW_HDR_SIZE);
  	if (len)
  		skb_put_data(skb, data, len);
  
  	*msg = skb;
  
  	return 0;
  }
  
  static int s3fwrn5_fw_get_bootinfo(struct s3fwrn5_fw_info *fw_info,
  	struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo)
  {
  	struct sk_buff *msg, *rsp = NULL;
  	struct s3fwrn5_fw_header *hdr;
  	int ret;
  
  	/* Send GET_BOOTINFO command */
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
  		S3FWRN5_FW_CMD_GET_BOOTINFO, NULL, 0);
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
  		ret = -EINVAL;
  		goto out;
  	}
  
  	memcpy(bootinfo, rsp->data + S3FWRN5_FW_HDR_SIZE, 10);
  
  out:
  	kfree_skb(rsp);
  	return ret;
  }
  
  static int s3fwrn5_fw_enter_update_mode(struct s3fwrn5_fw_info *fw_info,
  	const void *hash_data, u16 hash_size,
  	const void *sig_data, u16 sig_size)
  {
  	struct s3fwrn5_fw_cmd_enter_updatemode args;
  	struct sk_buff *msg, *rsp = NULL;
  	struct s3fwrn5_fw_header *hdr;
  	int ret;
  
  	/* Send ENTER_UPDATE_MODE command */
  
  	args.hashcode_size = hash_size;
  	args.signature_size = sig_size;
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
  		S3FWRN5_FW_CMD_ENTER_UPDATE_MODE, &args, sizeof(args));
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
  		ret = -EPROTO;
  		goto out;
  	}
  
  	kfree_skb(rsp);
  
  	/* Send hashcode data */
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_DATA, 0,
  		hash_data, hash_size);
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
  		ret = -EPROTO;
  		goto out;
  	}
  
  	kfree_skb(rsp);
  
  	/* Send signature data */
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_DATA, 0,
  		sig_data, sig_size);
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS)
  		ret = -EPROTO;
  
  out:
  	kfree_skb(rsp);
  	return ret;
  }
  
  static int s3fwrn5_fw_update_sector(struct s3fwrn5_fw_info *fw_info,
  	u32 base_addr, const void *data)
  {
  	struct s3fwrn5_fw_cmd_update_sector args;
  	struct sk_buff *msg, *rsp = NULL;
  	struct s3fwrn5_fw_header *hdr;
  	int ret, i;
  
  	/* Send UPDATE_SECTOR command */
  
  	args.base_address = base_addr;
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
  		S3FWRN5_FW_CMD_UPDATE_SECTOR, &args, sizeof(args));
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
  		ret = -EPROTO;
  		goto err;
  	}
  
  	kfree_skb(rsp);
  
  	/* Send data split into 256-byte packets */
  
  	for (i = 0; i < 16; ++i) {
  		ret = s3fwrn5_fw_prep_msg(fw_info, &msg,
  			S3FWRN5_FW_MSG_DATA, 0, data+256*i, 256);
  		if (ret < 0)
  			break;
  
  		ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  		kfree_skb(msg);
  		if (ret < 0)
  			break;
  
  		hdr = (struct s3fwrn5_fw_header *) rsp->data;
  		if (hdr->code != S3FWRN5_FW_RET_SUCCESS) {
  			ret = -EPROTO;
  			goto err;
  		}
  
  		kfree_skb(rsp);
  	}
  
  	return ret;
  
  err:
  	kfree_skb(rsp);
  	return ret;
  }
  
  static int s3fwrn5_fw_complete_update_mode(struct s3fwrn5_fw_info *fw_info)
  {
  	struct sk_buff *msg, *rsp = NULL;
  	struct s3fwrn5_fw_header *hdr;
  	int ret;
  
  	/* Send COMPLETE_UPDATE_MODE command */
  
  	ret = s3fwrn5_fw_prep_msg(fw_info, &msg, S3FWRN5_FW_MSG_CMD,
  		S3FWRN5_FW_CMD_COMPLETE_UPDATE_MODE, NULL, 0);
  	if (ret < 0)
  		return ret;
  
  	ret = s3fwrn5_fw_send_msg(fw_info, msg, &rsp);
  	kfree_skb(msg);
  	if (ret < 0)
  		return ret;
  
  	hdr = (struct s3fwrn5_fw_header *) rsp->data;
  	if (hdr->code != S3FWRN5_FW_RET_SUCCESS)
  		ret = -EPROTO;
  
  	kfree_skb(rsp);
  
  	return ret;
  }
  
  /*
   * Firmware header stucture:
   *
   * 0x00 - 0x0B : Date and time string (w/o NUL termination)
   * 0x10 - 0x13 : Firmware version
   * 0x14 - 0x17 : Signature address
   * 0x18 - 0x1B : Signature size
   * 0x1C - 0x1F : Firmware image address
   * 0x20 - 0x23 : Firmware sectors count
   * 0x24 - 0x27 : Custom signature address
   * 0x28 - 0x2B : Custom signature size
   */
  
  #define S3FWRN5_FW_IMAGE_HEADER_SIZE 44
  
  static int s3fwrn5_fw_request_firmware(struct s3fwrn5_fw_info *fw_info)
  {
  	struct s3fwrn5_fw_image *fw = &fw_info->fw;
  	u32 sig_off;
  	u32 image_off;
  	u32 custom_sig_off;
  	int ret;
  
  	ret = request_firmware(&fw->fw, fw_info->fw_name,
  		&fw_info->ndev->nfc_dev->dev);
  	if (ret < 0)
  		return ret;
  
  	if (fw->fw->size < S3FWRN5_FW_IMAGE_HEADER_SIZE)
  		return -EINVAL;
  
  	memcpy(fw->date, fw->fw->data + 0x00, 12);
  	fw->date[12] = '\0';
  
  	memcpy(&fw->version, fw->fw->data + 0x10, 4);
  
  	memcpy(&sig_off, fw->fw->data + 0x14, 4);
  	fw->sig = fw->fw->data + sig_off;
  	memcpy(&fw->sig_size, fw->fw->data + 0x18, 4);
  
  	memcpy(&image_off, fw->fw->data + 0x1C, 4);
  	fw->image = fw->fw->data + image_off;
  	memcpy(&fw->image_sectors, fw->fw->data + 0x20, 4);
  
  	memcpy(&custom_sig_off, fw->fw->data + 0x24, 4);
  	fw->custom_sig = fw->fw->data + custom_sig_off;
  	memcpy(&fw->custom_sig_size, fw->fw->data + 0x28, 4);
  
  	return 0;
  }
  
  static void s3fwrn5_fw_release_firmware(struct s3fwrn5_fw_info *fw_info)
  {
  	release_firmware(fw_info->fw.fw);
  }
  
  static int s3fwrn5_fw_get_base_addr(
  	struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo, u32 *base_addr)
  {
  	int i;
  	static const struct {
  		u8 version[4];
  		u32 base_addr;
  	} match[] = {
  		{{0x05, 0x00, 0x00, 0x00}, 0x00005000},
  		{{0x05, 0x00, 0x00, 0x01}, 0x00003000},
  		{{0x05, 0x00, 0x00, 0x02}, 0x00003000},
  		{{0x05, 0x00, 0x00, 0x03}, 0x00003000},
  		{{0x05, 0x00, 0x00, 0x05}, 0x00003000}
  	};
  
  	for (i = 0; i < ARRAY_SIZE(match); ++i)
  		if (bootinfo->hw_version[0] == match[i].version[0] &&
  			bootinfo->hw_version[1] == match[i].version[1] &&
  			bootinfo->hw_version[3] == match[i].version[3]) {
  			*base_addr = match[i].base_addr;
  			return 0;
  		}
  
  	return -EINVAL;
  }
  
  static inline bool
  s3fwrn5_fw_is_custom(struct s3fwrn5_fw_cmd_get_bootinfo_rsp *bootinfo)
  {
  	return !!bootinfo->hw_version[2];
  }
  
  int s3fwrn5_fw_setup(struct s3fwrn5_fw_info *fw_info)
  {
  	struct s3fwrn5_fw_cmd_get_bootinfo_rsp bootinfo;
  	int ret;
  
  	/* Get firmware data */
  
  	ret = s3fwrn5_fw_request_firmware(fw_info);
  	if (ret < 0) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Failed to get fw file, ret=%02x\n", ret);
  		return ret;
  	}
  
  	/* Get bootloader info */
  
  	ret = s3fwrn5_fw_get_bootinfo(fw_info, &bootinfo);
  	if (ret < 0) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Failed to get bootinfo, ret=%02x\n", ret);
  		goto err;
  	}
  
  	/* Match hardware version to obtain firmware base address */
  
  	ret = s3fwrn5_fw_get_base_addr(&bootinfo, &fw_info->base_addr);
  	if (ret < 0) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Unknown hardware version\n");
  		goto err;
  	}
  
  	fw_info->sector_size = bootinfo.sector_size;
  
  	fw_info->sig_size = s3fwrn5_fw_is_custom(&bootinfo) ?
  		fw_info->fw.custom_sig_size : fw_info->fw.sig_size;
  	fw_info->sig = s3fwrn5_fw_is_custom(&bootinfo) ?
  		fw_info->fw.custom_sig : fw_info->fw.sig;
  
  	return 0;
  
  err:
  	s3fwrn5_fw_release_firmware(fw_info);
  	return ret;
  }
  
  bool s3fwrn5_fw_check_version(struct s3fwrn5_fw_info *fw_info, u32 version)
  {
  	struct s3fwrn5_fw_version *new = (void *) &fw_info->fw.version;
  	struct s3fwrn5_fw_version *old = (void *) &version;
  
  	if (new->major > old->major)
  		return true;
  	if (new->build1 > old->build1)
  		return true;
  	if (new->build2 > old->build2)
  		return true;
  
  	return false;
  }
  
  int s3fwrn5_fw_download(struct s3fwrn5_fw_info *fw_info)
  {
  	struct s3fwrn5_fw_image *fw = &fw_info->fw;
  	u8 hash_data[SHA1_DIGEST_SIZE];
  	struct crypto_shash *tfm;
  	u32 image_size, off;
  	int ret;
  
  	image_size = fw_info->sector_size * fw->image_sectors;
  
  	/* Compute SHA of firmware data */
  
  	tfm = crypto_alloc_shash("sha1", 0, 0);
  	if (IS_ERR(tfm)) {
  		ret = PTR_ERR(tfm);
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Cannot allocate shash (code=%d)\n", ret);
  		goto out;
  	}
  
  	{
  		SHASH_DESC_ON_STACK(desc, tfm);
  
  		desc->tfm = tfm;
  		desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
  
  		ret = crypto_shash_digest(desc, fw->image, image_size,
  					  hash_data);
  		shash_desc_zero(desc);
  	}
  
  	crypto_free_shash(tfm);
  	if (ret) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Cannot compute hash (code=%d)\n", ret);
  		goto out;
  	}
  
  	/* Firmware update process */
  
  	dev_info(&fw_info->ndev->nfc_dev->dev,
  		"Firmware update: %s\n", fw_info->fw_name);
  
  	ret = s3fwrn5_fw_enter_update_mode(fw_info, hash_data,
  		SHA1_DIGEST_SIZE, fw_info->sig, fw_info->sig_size);
  	if (ret < 0) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Unable to enter update mode\n");
  		goto out;
  	}
  
  	for (off = 0; off < image_size; off += fw_info->sector_size) {
  		ret = s3fwrn5_fw_update_sector(fw_info,
  			fw_info->base_addr + off, fw->image + off);
  		if (ret < 0) {
  			dev_err(&fw_info->ndev->nfc_dev->dev,
  				"Firmware update error (code=%d)\n", ret);
  			goto out;
  		}
  	}
  
  	ret = s3fwrn5_fw_complete_update_mode(fw_info);
  	if (ret < 0) {
  		dev_err(&fw_info->ndev->nfc_dev->dev,
  			"Unable to complete update mode\n");
  		goto out;
  	}
  
  	dev_info(&fw_info->ndev->nfc_dev->dev,
  		"Firmware update: success\n");
  
  out:
  	return ret;
  }
  
  void s3fwrn5_fw_init(struct s3fwrn5_fw_info *fw_info, const char *fw_name)
  {
  	fw_info->parity = 0x00;
  	fw_info->rsp = NULL;
  	fw_info->fw.fw = NULL;
  	strcpy(fw_info->fw_name, fw_name);
  	init_completion(&fw_info->completion);
  }
  
  void s3fwrn5_fw_cleanup(struct s3fwrn5_fw_info *fw_info)
  {
  	s3fwrn5_fw_release_firmware(fw_info);
  }
  
  int s3fwrn5_fw_recv_frame(struct nci_dev *ndev, struct sk_buff *skb)
  {
  	struct s3fwrn5_info *info = nci_get_drvdata(ndev);
  	struct s3fwrn5_fw_info *fw_info = &info->fw_info;
  
  	BUG_ON(fw_info->rsp);
  
  	fw_info->rsp = skb;
  
  	complete(&fw_info->completion);
  
  	return 0;
  }
  