/*
   * Generic driver for NXP NCI NFC chips
   *
   * Copyright (C) 2014  NXP Semiconductors  All rights reserved.
   *
   * Author: Clément Perrochaud <clement.perrochaud@nxp.com>
   *
   * Derived from PN544 device driver:
   * Copyright (C) 2012  Intel Corporation. All rights reserved.
   *
   * 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, 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 <linux/nfc.h>
  #include <linux/unaligned/access_ok.h>
  
  #include "nxp-nci.h"
  
  /* Crypto operations can take up to 30 seconds */
  #define NXP_NCI_FW_ANSWER_TIMEOUT	msecs_to_jiffies(30000)
  
  #define NXP_NCI_FW_CMD_RESET		0xF0
  #define NXP_NCI_FW_CMD_GETVERSION	0xF1
  #define NXP_NCI_FW_CMD_CHECKINTEGRITY	0xE0
  #define NXP_NCI_FW_CMD_WRITE		0xC0
  #define NXP_NCI_FW_CMD_READ		0xA2
  #define NXP_NCI_FW_CMD_GETSESSIONSTATE	0xF2
  #define NXP_NCI_FW_CMD_LOG		0xA7
  #define NXP_NCI_FW_CMD_FORCE		0xD0
  #define NXP_NCI_FW_CMD_GET_DIE_ID	0xF4
  
  #define NXP_NCI_FW_CHUNK_FLAG	0x0400
  
  #define NXP_NCI_FW_RESULT_OK				0x00
  #define NXP_NCI_FW_RESULT_INVALID_ADDR			0x01
  #define NXP_NCI_FW_RESULT_GENERIC_ERROR			0x02
  #define NXP_NCI_FW_RESULT_UNKNOWN_CMD			0x0B
  #define NXP_NCI_FW_RESULT_ABORTED_CMD			0x0C
  #define NXP_NCI_FW_RESULT_PLL_ERROR			0x0D
  #define NXP_NCI_FW_RESULT_ADDR_RANGE_OFL_ERROR		0x1E
  #define NXP_NCI_FW_RESULT_BUFFER_OFL_ERROR		0x1F
  #define NXP_NCI_FW_RESULT_MEM_BSY			0x20
  #define NXP_NCI_FW_RESULT_SIGNATURE_ERROR		0x21
  #define NXP_NCI_FW_RESULT_FIRMWARE_VERSION_ERROR	0x24
  #define NXP_NCI_FW_RESULT_PROTOCOL_ERROR		0x28
  #define NXP_NCI_FW_RESULT_SFWU_DEGRADED			0x2A
  #define NXP_NCI_FW_RESULT_PH_STATUS_FIRST_CHUNK		0x2D
  #define NXP_NCI_FW_RESULT_PH_STATUS_NEXT_CHUNK		0x2E
  #define NXP_NCI_FW_RESULT_PH_STATUS_INTERNAL_ERROR_5	0xC5
  
  void nxp_nci_fw_work_complete(struct nxp_nci_info *info, int result)
  {
  	struct nxp_nci_fw_info *fw_info = &info->fw_info;
  	int r;
  
  	if (info->phy_ops->set_mode) {
  		r = info->phy_ops->set_mode(info->phy_id, NXP_NCI_MODE_COLD);
  		if (r < 0 && result == 0)
  			result = -r;
  	}
  
  	info->mode = NXP_NCI_MODE_COLD;
  
  	if (fw_info->fw) {
  		release_firmware(fw_info->fw);
  		fw_info->fw = NULL;
  	}
  
  	nfc_fw_download_done(info->ndev->nfc_dev, fw_info->name, (u32) -result);
  }
  
  /* crc_ccitt cannot be used since it is computed MSB first and not LSB first */
  static u16 nxp_nci_fw_crc(u8 const *buffer, size_t len)
  {
  	u16 crc = 0xffff;
  
  	while (len--) {
  		crc = ((crc >> 8) | (crc << 8)) ^ *buffer++;
  		crc ^= (crc & 0xff) >> 4;
  		crc ^= (crc & 0xff) << 12;
  		crc ^= (crc & 0xff) << 5;
  	}
  
  	return crc;
  }
  
  static int nxp_nci_fw_send_chunk(struct nxp_nci_info *info)
  {
  	struct nxp_nci_fw_info *fw_info = &info->fw_info;
  	u16 header, crc;
  	struct sk_buff *skb;
  	size_t chunk_len;
  	size_t remaining_len;
  	int r;
  
  	skb = nci_skb_alloc(info->ndev, info->max_payload, GFP_KERNEL);
  	if (!skb) {
  		r = -ENOMEM;
  		goto chunk_exit;
  	}
  
  	chunk_len = info->max_payload - NXP_NCI_FW_HDR_LEN - NXP_NCI_FW_CRC_LEN;
  	remaining_len = fw_info->frame_size - fw_info->written;
  
  	if (remaining_len > chunk_len) {
  		header = NXP_NCI_FW_CHUNK_FLAG;
  	} else {
  		chunk_len = remaining_len;
  		header = 0x0000;
  	}
  
  	header |= chunk_len & NXP_NCI_FW_FRAME_LEN_MASK;
  	put_unaligned_be16(header, skb_put(skb, NXP_NCI_FW_HDR_LEN));
  
  	memcpy(skb_put(skb, chunk_len), fw_info->data + fw_info->written,
  	       chunk_len);
  
  	crc = nxp_nci_fw_crc(skb->data, chunk_len + NXP_NCI_FW_HDR_LEN);
  	put_unaligned_be16(crc, skb_put(skb, NXP_NCI_FW_CRC_LEN));
  
  	r = info->phy_ops->write(info->phy_id, skb);
  	if (r >= 0)
  		r = chunk_len;
  
  	kfree_skb(skb);
  
  chunk_exit:
  	return r;
  }
  
  static int nxp_nci_fw_send(struct nxp_nci_info *info)
  {
  	struct nxp_nci_fw_info *fw_info = &info->fw_info;
  	long completion_rc;
  	int r;
  
  	reinit_completion(&fw_info->cmd_completion);
  
  	if (fw_info->written == 0) {
  		fw_info->frame_size = get_unaligned_be16(fw_info->data) &
  				      NXP_NCI_FW_FRAME_LEN_MASK;
  		fw_info->data += NXP_NCI_FW_HDR_LEN;
  		fw_info->size -= NXP_NCI_FW_HDR_LEN;
  	}
  
  	if (fw_info->frame_size > fw_info->size)
  		return -EMSGSIZE;
  
  	r = nxp_nci_fw_send_chunk(info);
  	if (r < 0)
  		return r;
  
  	fw_info->written += r;
  
  	if (*fw_info->data == NXP_NCI_FW_CMD_RESET) {
  		fw_info->cmd_result = 0;
  		if (fw_info->fw)
  			schedule_work(&fw_info->work);
  	} else {
  		completion_rc = wait_for_completion_interruptible_timeout(
  			&fw_info->cmd_completion, NXP_NCI_FW_ANSWER_TIMEOUT);
  		if (completion_rc == 0)
  			return -ETIMEDOUT;
  	}
  
  	return 0;
  }
  
  void nxp_nci_fw_work(struct work_struct *work)
  {
  	struct nxp_nci_info *info;
  	struct nxp_nci_fw_info *fw_info;
  	int r;
  
  	fw_info = container_of(work, struct nxp_nci_fw_info, work);
  	info = container_of(fw_info, struct nxp_nci_info, fw_info);
  
  	mutex_lock(&info->info_lock);
  
  	r = fw_info->cmd_result;
  	if (r < 0)
  		goto exit_work;
  
  	if (fw_info->written == fw_info->frame_size) {
  		fw_info->data += fw_info->frame_size;
  		fw_info->size -= fw_info->frame_size;
  		fw_info->written = 0;
  	}
  
  	if (fw_info->size > 0)
  		r = nxp_nci_fw_send(info);
  
  exit_work:
  	if (r < 0 || fw_info->size == 0)
  		nxp_nci_fw_work_complete(info, r);
  	mutex_unlock(&info->info_lock);
  }
  
  int nxp_nci_fw_download(struct nci_dev *ndev, const char *firmware_name)
  {
  	struct nxp_nci_info *info = nci_get_drvdata(ndev);
  	struct nxp_nci_fw_info *fw_info = &info->fw_info;
  	int r;
  
  	mutex_lock(&info->info_lock);
  
  	if (!info->phy_ops->set_mode || !info->phy_ops->write) {
  		r = -ENOTSUPP;
  		goto fw_download_exit;
  	}
  
  	if (!firmware_name || firmware_name[0] == '\0') {
  		r = -EINVAL;
  		goto fw_download_exit;
  	}
  
  	strcpy(fw_info->name, firmware_name);
  
  	r = request_firmware(&fw_info->fw, firmware_name,
  			     ndev->nfc_dev->dev.parent);
  	if (r < 0)
  		goto fw_download_exit;
  
  	r = info->phy_ops->set_mode(info->phy_id, NXP_NCI_MODE_FW);
  	if (r < 0) {
  		release_firmware(fw_info->fw);
  		goto fw_download_exit;
  	}
  
  	info->mode = NXP_NCI_MODE_FW;
  
  	fw_info->data = fw_info->fw->data;
  	fw_info->size = fw_info->fw->size;
  	fw_info->written = 0;
  	fw_info->frame_size = 0;
  	fw_info->cmd_result = 0;
  
  	schedule_work(&fw_info->work);
  
  fw_download_exit:
  	mutex_unlock(&info->info_lock);
  	return r;
  }
  
  static int nxp_nci_fw_read_status(u8 stat)
  {
  	switch (stat) {
  	case NXP_NCI_FW_RESULT_OK:
  		return 0;
  	case NXP_NCI_FW_RESULT_INVALID_ADDR:
  		return -EINVAL;
  	case NXP_NCI_FW_RESULT_UNKNOWN_CMD:
  		return -EINVAL;
  	case NXP_NCI_FW_RESULT_ABORTED_CMD:
  		return -EMSGSIZE;
  	case NXP_NCI_FW_RESULT_ADDR_RANGE_OFL_ERROR:
  		return -EADDRNOTAVAIL;
  	case NXP_NCI_FW_RESULT_BUFFER_OFL_ERROR:
  		return -ENOBUFS;
  	case NXP_NCI_FW_RESULT_MEM_BSY:
  		return -ENOKEY;
  	case NXP_NCI_FW_RESULT_SIGNATURE_ERROR:
  		return -EKEYREJECTED;
  	case NXP_NCI_FW_RESULT_FIRMWARE_VERSION_ERROR:
  		return -EALREADY;
  	case NXP_NCI_FW_RESULT_PROTOCOL_ERROR:
  		return -EPROTO;
  	case NXP_NCI_FW_RESULT_SFWU_DEGRADED:
  		return -EHWPOISON;
  	case NXP_NCI_FW_RESULT_PH_STATUS_FIRST_CHUNK:
  		return 0;
  	case NXP_NCI_FW_RESULT_PH_STATUS_NEXT_CHUNK:
  		return 0;
  	case NXP_NCI_FW_RESULT_PH_STATUS_INTERNAL_ERROR_5:
  		return -EINVAL;
  	default:
  		return -EIO;
  	}
  }
  
  static u16 nxp_nci_fw_check_crc(struct sk_buff *skb)
  {
  	u16 crc, frame_crc;
  	size_t len = skb->len - NXP_NCI_FW_CRC_LEN;
  
  	crc = nxp_nci_fw_crc(skb->data, len);
  	frame_crc = get_unaligned_be16(skb->data + len);
  
  	return (crc ^ frame_crc);
  }
  
  void nxp_nci_fw_recv_frame(struct nci_dev *ndev, struct sk_buff *skb)
  {
  	struct nxp_nci_info *info = nci_get_drvdata(ndev);
  	struct nxp_nci_fw_info *fw_info = &info->fw_info;
  
  	complete(&fw_info->cmd_completion);
  
  	if (skb) {
  		if (nxp_nci_fw_check_crc(skb) != 0x00)
  			fw_info->cmd_result = -EBADMSG;
  		else
  			fw_info->cmd_result = nxp_nci_fw_read_status(
  					*skb_pull(skb, NXP_NCI_FW_HDR_LEN));
  		kfree_skb(skb);
  	} else {
  		fw_info->cmd_result = -EIO;
  	}
  
  	if (fw_info->fw)
  		schedule_work(&fw_info->work);
  }
  EXPORT_SYMBOL(nxp_nci_fw_recv_frame);