/*
   *  Texas Instrument's NFC Driver For Shared Transport.
   *
   *  NFC Driver acts as interface between NCI core and
   *  TI Shared Transport Layer.
   *
   *  Copyright (C) 2011 Texas Instruments, Inc.
   *
   *  Written by Ilan Elias <ilane@ti.com>
   *
   *  Acknowledgements:
   *  This file is based on btwilink.c, which was written
   *  by Raja Mani and Pavan Savoy.
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms 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/platform_device.h>
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/firmware.h>
  #include <linux/nfc.h>
  #include <net/nfc/nci.h>
  #include <net/nfc/nci_core.h>
  #include <linux/ti_wilink_st.h>
  
  #define NFCWILINK_CHNL			12
  #define NFCWILINK_OPCODE		7
  #define NFCWILINK_MAX_FRAME_SIZE	300
  #define NFCWILINK_HDR_LEN		4
  #define NFCWILINK_OFFSET_LEN_IN_HDR	1
  #define NFCWILINK_LEN_SIZE		2
  #define NFCWILINK_REGISTER_TIMEOUT	8000	/* 8 sec */
  #define NFCWILINK_CMD_TIMEOUT		5000	/* 5 sec */
  
  #define BTS_FILE_NAME_MAX_SIZE		40
  #define BTS_FILE_HDR_MAGIC		0x42535442
  #define BTS_FILE_CMD_MAX_LEN		0xff
  #define BTS_FILE_ACTION_TYPE_SEND_CMD	1
  
  #define NCI_VS_NFCC_INFO_CMD_GID	0x2f
  #define NCI_VS_NFCC_INFO_CMD_OID	0x12
  #define NCI_VS_NFCC_INFO_RSP_GID	0x4f
  #define NCI_VS_NFCC_INFO_RSP_OID	0x12
  
  struct nfcwilink_hdr {
  	__u8 chnl;
  	__u8 opcode;
  	__le16 len;
  } __packed;
  
  struct nci_vs_nfcc_info_cmd {
  	__u8 gid;
  	__u8 oid;
  	__u8 plen;
  } __packed;
  
  struct nci_vs_nfcc_info_rsp {
  	__u8 gid;
  	__u8 oid;
  	__u8 plen;
  	__u8 status;
  	__u8 hw_id;
  	__u8 sw_ver_x;
  	__u8 sw_ver_z;
  	__u8 patch_id;
  } __packed;
  
  struct bts_file_hdr {
  	__le32 magic;
  	__le32 ver;
  	__u8 rfu[24];
  	__u8 actions[0];
  } __packed;
  
  struct bts_file_action {
  	__le16 type;
  	__le16 len;
  	__u8 data[0];
  } __packed;
  
  struct nfcwilink {
  	struct platform_device		*pdev;
  	struct nci_dev			*ndev;
  	unsigned long			flags;
  
  	char				st_register_cb_status;
  	long				(*st_write) (struct sk_buff *);
  
  	struct completion		completed;
  
  	struct nci_vs_nfcc_info_rsp	nfcc_info;
  };
  
  /* NFCWILINK driver flags */
  enum {
  	NFCWILINK_RUNNING,
  	NFCWILINK_FW_DOWNLOAD,
  };
  
  static int nfcwilink_send(struct nci_dev *ndev, struct sk_buff *skb);
  
  static inline struct sk_buff *nfcwilink_skb_alloc(unsigned int len, gfp_t how)
  {
  	struct sk_buff *skb;
  
  	skb = alloc_skb(len + NFCWILINK_HDR_LEN, how);
  	if (skb)
  		skb_reserve(skb, NFCWILINK_HDR_LEN);
  
  	return skb;
  }
  
  static void nfcwilink_fw_download_receive(struct nfcwilink *drv,
  						struct sk_buff *skb)
  {
  	struct nci_vs_nfcc_info_rsp *rsp = (void *)skb->data;
  
  	/* Detect NCI_VS_NFCC_INFO_RSP and store the result */
  	if ((skb->len > 3) && (rsp->gid == NCI_VS_NFCC_INFO_RSP_GID) &&
  		(rsp->oid == NCI_VS_NFCC_INFO_RSP_OID)) {
  		memcpy(&drv->nfcc_info, rsp,
  			sizeof(struct nci_vs_nfcc_info_rsp));
  	}
  
  	kfree_skb(skb);
  
  	complete(&drv->completed);
  }
  
  static int nfcwilink_get_bts_file_name(struct nfcwilink *drv, char *file_name)
  {
  	struct nci_vs_nfcc_info_cmd *cmd;
  	struct sk_buff *skb;
  	unsigned long comp_ret;
  	int rc;
  
  	skb = nfcwilink_skb_alloc(sizeof(struct nci_vs_nfcc_info_cmd),
  					GFP_KERNEL);
  	if (!skb) {
  		nfc_err(&drv->pdev->dev,
  			"no memory for nci_vs_nfcc_info_cmd
  ");
  		return -ENOMEM;
  	}
  
  	cmd = (struct nci_vs_nfcc_info_cmd *)
  			skb_put(skb, sizeof(struct nci_vs_nfcc_info_cmd));
  	cmd->gid = NCI_VS_NFCC_INFO_CMD_GID;
  	cmd->oid = NCI_VS_NFCC_INFO_CMD_OID;
  	cmd->plen = 0;
  
  	drv->nfcc_info.plen = 0;
  
  	rc = nfcwilink_send(drv->ndev, skb);
  	if (rc)
  		return rc;
  
  	comp_ret = wait_for_completion_timeout(&drv->completed,
  				msecs_to_jiffies(NFCWILINK_CMD_TIMEOUT));
  	dev_dbg(&drv->pdev->dev, "wait_for_completion_timeout returned %ld
  ",
  		comp_ret);
  	if (comp_ret == 0) {
  		nfc_err(&drv->pdev->dev,
  			"timeout on wait_for_completion_timeout
  ");
  		return -ETIMEDOUT;
  	}
  
  	dev_dbg(&drv->pdev->dev, "nci_vs_nfcc_info_rsp: plen %d, status %d
  ",
  		drv->nfcc_info.plen, drv->nfcc_info.status);
  
  	if ((drv->nfcc_info.plen != 5) || (drv->nfcc_info.status != 0)) {
  		nfc_err(&drv->pdev->dev, "invalid nci_vs_nfcc_info_rsp
  ");
  		return -EINVAL;
  	}
  
  	snprintf(file_name, BTS_FILE_NAME_MAX_SIZE,
  			"TINfcInit_%d.%d.%d.%d.bts",
  			drv->nfcc_info.hw_id,
  			drv->nfcc_info.sw_ver_x,
  			drv->nfcc_info.sw_ver_z,
  			drv->nfcc_info.patch_id);
  
  	nfc_info(&drv->pdev->dev, "nfcwilink FW file name: %s
  ", file_name);
  
  	return 0;
  }
  
  static int nfcwilink_send_bts_cmd(struct nfcwilink *drv, __u8 *data, int len)
  {
  	struct nfcwilink_hdr *hdr = (struct nfcwilink_hdr *)data;
  	struct sk_buff *skb;
  	unsigned long comp_ret;
  	int rc;
  
  	/* verify valid cmd for the NFC channel */
  	if ((len <= sizeof(struct nfcwilink_hdr)) ||
  		(len > BTS_FILE_CMD_MAX_LEN) ||
  		(hdr->chnl != NFCWILINK_CHNL) ||
  		(hdr->opcode != NFCWILINK_OPCODE)) {
  		nfc_err(&drv->pdev->dev,
  			"ignoring invalid bts cmd, len %d, chnl %d, opcode %d
  ",
  			len, hdr->chnl, hdr->opcode);
  		return 0;
  	}
  
  	/* remove the ST header */
  	len -= sizeof(struct nfcwilink_hdr);
  	data += sizeof(struct nfcwilink_hdr);
  
  	skb = nfcwilink_skb_alloc(len, GFP_KERNEL);
  	if (!skb) {
  		nfc_err(&drv->pdev->dev, "no memory for bts cmd
  ");
  		return -ENOMEM;
  	}
  
  	memcpy(skb_put(skb, len), data, len);
  
  	rc = nfcwilink_send(drv->ndev, skb);
  	if (rc)
  		return rc;
  
  	comp_ret = wait_for_completion_timeout(&drv->completed,
  				msecs_to_jiffies(NFCWILINK_CMD_TIMEOUT));
  	dev_dbg(&drv->pdev->dev, "wait_for_completion_timeout returned %ld
  ",
  		comp_ret);
  	if (comp_ret == 0) {
  		nfc_err(&drv->pdev->dev,
  			"timeout on wait_for_completion_timeout
  ");
  		return -ETIMEDOUT;
  	}
  
  	return 0;
  }
  
  static int nfcwilink_download_fw(struct nfcwilink *drv)
  {
  	unsigned char file_name[BTS_FILE_NAME_MAX_SIZE];
  	const struct firmware *fw;
  	__u16 action_type, action_len;
  	__u8 *ptr;
  	int len, rc;
  
  	set_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags);
  
  	rc = nfcwilink_get_bts_file_name(drv, file_name);
  	if (rc)
  		goto exit;
  
  	rc = request_firmware(&fw, file_name, &drv->pdev->dev);
  	if (rc) {
  		nfc_err(&drv->pdev->dev, "request_firmware failed %d
  ", rc);
  
  		/* if the file is not found, don't exit with failure */
  		if (rc == -ENOENT)
  			rc = 0;
  
  		goto exit;
  	}
  
  	len = fw->size;
  	ptr = (__u8 *)fw->data;
  
  	if ((len == 0) || (ptr == NULL)) {
  		dev_dbg(&drv->pdev->dev,
  			"request_firmware returned size %d
  ", len);
  		goto release_fw;
  	}
  
  	if (__le32_to_cpu(((struct bts_file_hdr *)ptr)->magic) !=
  			BTS_FILE_HDR_MAGIC) {
  		nfc_err(&drv->pdev->dev, "wrong bts magic number
  ");
  		rc = -EINVAL;
  		goto release_fw;
  	}
  
  	/* remove the BTS header */
  	len -= sizeof(struct bts_file_hdr);
  	ptr += sizeof(struct bts_file_hdr);
  
  	while (len > 0) {
  		action_type =
  			__le16_to_cpu(((struct bts_file_action *)ptr)->type);
  		action_len =
  			__le16_to_cpu(((struct bts_file_action *)ptr)->len);
  
  		dev_dbg(&drv->pdev->dev, "bts_file_action type %d, len %d
  ",
  			action_type, action_len);
  
  		switch (action_type) {
  		case BTS_FILE_ACTION_TYPE_SEND_CMD:
  			rc = nfcwilink_send_bts_cmd(drv,
  					((struct bts_file_action *)ptr)->data,
  					action_len);
  			if (rc)
  				goto release_fw;
  			break;
  		}
  
  		/* advance to the next action */
  		len -= (sizeof(struct bts_file_action) + action_len);
  		ptr += (sizeof(struct bts_file_action) + action_len);
  	}
  
  release_fw:
  	release_firmware(fw);
  
  exit:
  	clear_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags);
  	return rc;
  }
  
  /* Called by ST when registration is complete */
  static void nfcwilink_register_complete(void *priv_data, char data)
  {
  	struct nfcwilink *drv = priv_data;
  
  	/* store ST registration status */
  	drv->st_register_cb_status = data;
  
  	/* complete the wait in nfc_st_open() */
  	complete(&drv->completed);
  }
  
  /* Called by ST when receive data is available */
  static long nfcwilink_receive(void *priv_data, struct sk_buff *skb)
  {
  	struct nfcwilink *drv = priv_data;
  	int rc;
  
  	if (!skb)
  		return -EFAULT;
  
  	if (!drv) {
  		kfree_skb(skb);
  		return -EFAULT;
  	}
  
  	dev_dbg(&drv->pdev->dev, "receive entry, len %d
  ", skb->len);
  
  	/* strip the ST header
  	(apart for the chnl byte, which is not received in the hdr) */
  	skb_pull(skb, (NFCWILINK_HDR_LEN-1));
  
  	if (test_bit(NFCWILINK_FW_DOWNLOAD, &drv->flags)) {
  		nfcwilink_fw_download_receive(drv, skb);
  		return 0;
  	}
  
  	/* Forward skb to NCI core layer */
  	rc = nci_recv_frame(drv->ndev, skb);
  	if (rc < 0) {
  		nfc_err(&drv->pdev->dev, "nci_recv_frame failed %d
  ", rc);
  		return rc;
  	}
  
  	return 0;
  }
  
  /* protocol structure registered with ST */
  static struct st_proto_s nfcwilink_proto = {
  	.chnl_id = NFCWILINK_CHNL,
  	.max_frame_size = NFCWILINK_MAX_FRAME_SIZE,
  	.hdr_len = (NFCWILINK_HDR_LEN-1),	/* not including chnl byte */
  	.offset_len_in_hdr = NFCWILINK_OFFSET_LEN_IN_HDR,
  	.len_size = NFCWILINK_LEN_SIZE,
  	.reserve = 0,
  	.recv = nfcwilink_receive,
  	.reg_complete_cb = nfcwilink_register_complete,
  	.write = NULL,
  };
  
  static int nfcwilink_open(struct nci_dev *ndev)
  {
  	struct nfcwilink *drv = nci_get_drvdata(ndev);
  	unsigned long comp_ret;
  	int rc;
  
  	if (test_and_set_bit(NFCWILINK_RUNNING, &drv->flags)) {
  		rc = -EBUSY;
  		goto exit;
  	}
  
  	nfcwilink_proto.priv_data = drv;
  
  	init_completion(&drv->completed);
  	drv->st_register_cb_status = -EINPROGRESS;
  
  	rc = st_register(&nfcwilink_proto);
  	if (rc < 0) {
  		if (rc == -EINPROGRESS) {
  			comp_ret = wait_for_completion_timeout(
  			&drv->completed,
  			msecs_to_jiffies(NFCWILINK_REGISTER_TIMEOUT));
  
  			dev_dbg(&drv->pdev->dev,
  				"wait_for_completion_timeout returned %ld
  ",
  				comp_ret);
  
  			if (comp_ret == 0) {
  				/* timeout */
  				rc = -ETIMEDOUT;
  				goto clear_exit;
  			} else if (drv->st_register_cb_status != 0) {
  				rc = drv->st_register_cb_status;
  				nfc_err(&drv->pdev->dev,
  					"st_register_cb failed %d
  ", rc);
  				goto clear_exit;
  			}
  		} else {
  			nfc_err(&drv->pdev->dev, "st_register failed %d
  ", rc);
  			goto clear_exit;
  		}
  	}
  
  	/* st_register MUST fill the write callback */
  	BUG_ON(nfcwilink_proto.write == NULL);
  	drv->st_write = nfcwilink_proto.write;
  
  	if (nfcwilink_download_fw(drv)) {
  		nfc_err(&drv->pdev->dev, "nfcwilink_download_fw failed %d
  ",
  			rc);
  		/* open should succeed, even if the FW download failed */
  	}
  
  	goto exit;
  
  clear_exit:
  	clear_bit(NFCWILINK_RUNNING, &drv->flags);
  
  exit:
  	return rc;
  }
  
  static int nfcwilink_close(struct nci_dev *ndev)
  {
  	struct nfcwilink *drv = nci_get_drvdata(ndev);
  	int rc;
  
  	if (!test_and_clear_bit(NFCWILINK_RUNNING, &drv->flags))
  		return 0;
  
  	rc = st_unregister(&nfcwilink_proto);
  	if (rc)
  		nfc_err(&drv->pdev->dev, "st_unregister failed %d
  ", rc);
  
  	drv->st_write = NULL;
  
  	return rc;
  }
  
  static int nfcwilink_send(struct nci_dev *ndev, struct sk_buff *skb)
  {
  	struct nfcwilink *drv = nci_get_drvdata(ndev);
  	struct nfcwilink_hdr hdr = {NFCWILINK_CHNL, NFCWILINK_OPCODE, 0x0000};
  	long len;
  
  	dev_dbg(&drv->pdev->dev, "send entry, len %d
  ", skb->len);
  
  	if (!test_bit(NFCWILINK_RUNNING, &drv->flags)) {
  		kfree_skb(skb);
  		return -EINVAL;
  	}
  
  	/* add the ST hdr to the start of the buffer */
  	hdr.len = cpu_to_le16(skb->len);
  	memcpy(skb_push(skb, NFCWILINK_HDR_LEN), &hdr, NFCWILINK_HDR_LEN);
  
  	/* Insert skb to shared transport layer's transmit queue.
  	 * Freeing skb memory is taken care in shared transport layer,
  	 * so don't free skb memory here.
  	 */
  	len = drv->st_write(skb);
  	if (len < 0) {
  		kfree_skb(skb);
  		nfc_err(&drv->pdev->dev, "st_write failed %ld
  ", len);
  		return -EFAULT;
  	}
  
  	return 0;
  }
  
  static struct nci_ops nfcwilink_ops = {
  	.open = nfcwilink_open,
  	.close = nfcwilink_close,
  	.send = nfcwilink_send,
  };
  
  static int nfcwilink_probe(struct platform_device *pdev)
  {
  	static struct nfcwilink *drv;
  	int rc;
  	__u32 protocols;
  
  	drv = devm_kzalloc(&pdev->dev, sizeof(struct nfcwilink), GFP_KERNEL);
  	if (!drv) {
  		rc = -ENOMEM;
  		goto exit;
  	}
  
  	drv->pdev = pdev;
  
  	protocols = NFC_PROTO_JEWEL_MASK
  		| NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
  		| NFC_PROTO_ISO14443_MASK
  		| NFC_PROTO_ISO14443_B_MASK
  		| NFC_PROTO_NFC_DEP_MASK;
  
  	drv->ndev = nci_allocate_device(&nfcwilink_ops,
  					protocols,
  					NFCWILINK_HDR_LEN,
  					0);
  	if (!drv->ndev) {
  		nfc_err(&pdev->dev, "nci_allocate_device failed
  ");
  		rc = -ENOMEM;
  		goto exit;
  	}
  
  	nci_set_parent_dev(drv->ndev, &pdev->dev);
  	nci_set_drvdata(drv->ndev, drv);
  
  	rc = nci_register_device(drv->ndev);
  	if (rc < 0) {
  		nfc_err(&pdev->dev, "nci_register_device failed %d
  ", rc);
  		goto free_dev_exit;
  	}
  
  	dev_set_drvdata(&pdev->dev, drv);
  
  	goto exit;
  
  free_dev_exit:
  	nci_free_device(drv->ndev);
  
  exit:
  	return rc;
  }
  
  static int nfcwilink_remove(struct platform_device *pdev)
  {
  	struct nfcwilink *drv = dev_get_drvdata(&pdev->dev);
  	struct nci_dev *ndev;
  
  	if (!drv)
  		return -EFAULT;
  
  	ndev = drv->ndev;
  
  	nci_unregister_device(ndev);
  	nci_free_device(ndev);
  
  	return 0;
  }
  
  static struct platform_driver nfcwilink_driver = {
  	.probe = nfcwilink_probe,
  	.remove = nfcwilink_remove,
  	.driver = {
  		.name = "nfcwilink",
  		.owner = THIS_MODULE,
  	},
  };
  
  module_platform_driver(nfcwilink_driver);
  
  /* ------ Module Info ------ */
  
  MODULE_AUTHOR("Ilan Elias <ilane@ti.com>");
  MODULE_DESCRIPTION("NFC Driver for TI Shared Transport");
  MODULE_LICENSE("GPL");