/*
   * Copyright (C) ST-Ericsson AB 2010

   * Author:	Sjur Brendeland

   * License terms: GNU General Public License (GPL) version 2
   */

  #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

  #include <linux/stddef.h>
  #include <linux/spinlock.h>
  #include <linux/slab.h>

  #include <linux/pkt_sched.h>

  #include <net/caif/caif_layer.h>
  #include <net/caif/cfpkt.h>
  #include <net/caif/cfctrl.h>
  
  #define container_obj(layr) container_of(layr, struct cfctrl, serv.layer)
  #define UTILITY_NAME_LENGTH 16
  #define CFPKT_CTRL_PKT_LEN 20

  #ifdef CAIF_NO_LOOP
  static int handle_loop(struct cfctrl *ctrl,

  		       int cmd, struct cfpkt *pkt){

  	return -1;

  }
  #else
  static int handle_loop(struct cfctrl *ctrl,

  		       int cmd, struct cfpkt *pkt);

  #endif
  static int cfctrl_recv(struct cflayer *layr, struct cfpkt *pkt);
  static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
  			   int phyid);
  
  
  struct cflayer *cfctrl_create(void)
  {

  	struct dev_info dev_info;

  	struct cfctrl *this =

  		kzalloc(sizeof(struct cfctrl), GFP_ATOMIC);
  	if (!this)

  		return NULL;

  	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);

  	memset(&dev_info, 0, sizeof(dev_info));
  	dev_info.id = 0xff;

  	cfsrvl_init(&this->serv, 0, &dev_info, false);

  	atomic_set(&this->req_seq_no, 1);
  	atomic_set(&this->rsp_seq_no, 1);

  	this->serv.layer.receive = cfctrl_recv;
  	sprintf(this->serv.layer.name, "ctrl");
  	this->serv.layer.ctrlcmd = cfctrl_ctrlcmd;

  #ifndef CAIF_NO_LOOP

  	spin_lock_init(&this->loop_linkid_lock);

  	this->loop_linkid = 1;
  #endif

  	spin_lock_init(&this->info_list_lock);
  	INIT_LIST_HEAD(&this->list);

  	return &this->serv.layer;
  }

  void cfctrl_remove(struct cflayer *layer)
  {
  	struct cfctrl_request_info *p, *tmp;
  	struct cfctrl *ctrl = container_obj(layer);
  
  	spin_lock_bh(&ctrl->info_list_lock);
  	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
  		list_del(&p->list);
  		kfree(p);
  	}
  	spin_unlock_bh(&ctrl->info_list_lock);
  	kfree(layer);
  }

  static bool param_eq(const struct cfctrl_link_param *p1,

  		     const struct cfctrl_link_param *p2)

  {
  	bool eq =
  	    p1->linktype == p2->linktype &&
  	    p1->priority == p2->priority &&
  	    p1->phyid == p2->phyid &&
  	    p1->endpoint == p2->endpoint && p1->chtype == p2->chtype;
  
  	if (!eq)
  		return false;
  
  	switch (p1->linktype) {
  	case CFCTRL_SRV_VEI:
  		return true;
  	case CFCTRL_SRV_DATAGRAM:
  		return p1->u.datagram.connid == p2->u.datagram.connid;
  	case CFCTRL_SRV_RFM:
  		return
  		    p1->u.rfm.connid == p2->u.rfm.connid &&
  		    strcmp(p1->u.rfm.volume, p2->u.rfm.volume) == 0;
  	case CFCTRL_SRV_UTIL:
  		return
  		    p1->u.utility.fifosize_kb == p2->u.utility.fifosize_kb
  		    && p1->u.utility.fifosize_bufs ==
  		    p2->u.utility.fifosize_bufs
  		    && strcmp(p1->u.utility.name, p2->u.utility.name) == 0
  		    && p1->u.utility.paramlen == p2->u.utility.paramlen
  		    && memcmp(p1->u.utility.params, p2->u.utility.params,
  			      p1->u.utility.paramlen) == 0;
  
  	case CFCTRL_SRV_VIDEO:
  		return p1->u.video.connid == p2->u.video.connid;
  	case CFCTRL_SRV_DBG:
  		return true;
  	case CFCTRL_SRV_DECM:
  		return false;
  	default:
  		return false;
  	}
  	return false;
  }

  static bool cfctrl_req_eq(const struct cfctrl_request_info *r1,
  			  const struct cfctrl_request_info *r2)

  {
  	if (r1->cmd != r2->cmd)
  		return false;
  	if (r1->cmd == CFCTRL_CMD_LINK_SETUP)
  		return param_eq(&r1->param, &r2->param);
  	else
  		return r1->channel_id == r2->channel_id;
  }
  
  /* Insert request at the end */

  static void cfctrl_insert_req(struct cfctrl *ctrl,

  			      struct cfctrl_request_info *req)
  {

  	spin_lock_bh(&ctrl->info_list_lock);

  	atomic_inc(&ctrl->req_seq_no);
  	req->sequence_no = atomic_read(&ctrl->req_seq_no);

  	list_add_tail(&req->list, &ctrl->list);

  	spin_unlock_bh(&ctrl->info_list_lock);

  }

  /* Compare and remove request */

  static struct cfctrl_request_info *cfctrl_remove_req(struct cfctrl *ctrl,
  						struct cfctrl_request_info *req)

  {

  	struct cfctrl_request_info *p, *tmp, *first;

  	first = list_first_entry(&ctrl->list, struct cfctrl_request_info, list);

  	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
  		if (cfctrl_req_eq(req, p)) {
  			if (p != first)

  				pr_warn("Requests are not received in order
  ");

  			atomic_set(&ctrl->rsp_seq_no,

  					 p->sequence_no);
  			list_del(&p->list);
  			goto out;

  		}

  	}

  	p = NULL;
  out:

  	return p;

  }
  
  struct cfctrl_rsp *cfctrl_get_respfuncs(struct cflayer *layer)
  {
  	struct cfctrl *this = container_obj(layer);
  	return &this->res;
  }

  static void init_info(struct caif_payload_info *info, struct cfctrl *cfctrl)
  {
  	info->hdr_len = 0;
  	info->channel_id = cfctrl->serv.layer.id;
  	info->dev_info = &cfctrl->serv.dev_info;
  }
  
  void cfctrl_enum_req(struct cflayer *layer, u8 physlinkid)
  {

  	struct cfpkt *pkt;

  	struct cfctrl *cfctrl = container_obj(layer);

  	struct cflayer *dn = cfctrl->serv.layer.dn;

  	if (!dn) {
  		pr_debug("not able to send enum request
  ");
  		return;
  	}

  	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
  	if (!pkt)
  		return;

  	caif_assert(offsetof(struct cfctrl, serv.layer) == 0);
  	init_info(cfpkt_info(pkt), cfctrl);
  	cfpkt_info(pkt)->dev_info->id = physlinkid;
  	cfctrl->serv.dev_info.id = physlinkid;
  	cfpkt_addbdy(pkt, CFCTRL_CMD_ENUM);
  	cfpkt_addbdy(pkt, physlinkid);

  	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);

  	dn->transmit(dn, pkt);

  }

  int cfctrl_linkup_request(struct cflayer *layer,

  			  struct cfctrl_link_param *param,
  			  struct cflayer *user_layer)

  {
  	struct cfctrl *cfctrl = container_obj(layer);
  	u32 tmp32;
  	u16 tmp16;
  	u8 tmp8;
  	struct cfctrl_request_info *req;
  	int ret;
  	char utility_name[16];

  	struct cfpkt *pkt;

  	struct cflayer *dn = cfctrl->serv.layer.dn;
  
  	if (!dn) {
  		pr_debug("not able to send linkup request
  ");
  		return -ENODEV;
  	}

  
  	if (cfctrl_cancel_req(layer, user_layer) > 0) {
  		/* Slight Paranoia, check if already connecting */
  		pr_err("Duplicate connect request for same client
  ");
  		WARN_ON(1);
  		return -EALREADY;
  	}
  
  	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);

  	if (!pkt)

  		return -ENOMEM;

  	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_SETUP);

  	cfpkt_addbdy(pkt, (param->chtype << 4) | param->linktype);
  	cfpkt_addbdy(pkt, (param->priority << 3) | param->phyid);

  	cfpkt_addbdy(pkt, param->endpoint & 0x03);
  
  	switch (param->linktype) {
  	case CFCTRL_SRV_VEI:
  		break;
  	case CFCTRL_SRV_VIDEO:
  		cfpkt_addbdy(pkt, (u8) param->u.video.connid);
  		break;
  	case CFCTRL_SRV_DBG:
  		break;
  	case CFCTRL_SRV_DATAGRAM:
  		tmp32 = cpu_to_le32(param->u.datagram.connid);
  		cfpkt_add_body(pkt, &tmp32, 4);
  		break;
  	case CFCTRL_SRV_RFM:
  		/* Construct a frame, convert DatagramConnectionID to network
  		 * format long and copy it out...
  		 */
  		tmp32 = cpu_to_le32(param->u.rfm.connid);
  		cfpkt_add_body(pkt, &tmp32, 4);
  		/* Add volume name, including zero termination... */
  		cfpkt_add_body(pkt, param->u.rfm.volume,
  			       strlen(param->u.rfm.volume) + 1);
  		break;
  	case CFCTRL_SRV_UTIL:
  		tmp16 = cpu_to_le16(param->u.utility.fifosize_kb);
  		cfpkt_add_body(pkt, &tmp16, 2);
  		tmp16 = cpu_to_le16(param->u.utility.fifosize_bufs);
  		cfpkt_add_body(pkt, &tmp16, 2);
  		memset(utility_name, 0, sizeof(utility_name));
  		strncpy(utility_name, param->u.utility.name,
  			UTILITY_NAME_LENGTH - 1);
  		cfpkt_add_body(pkt, utility_name, UTILITY_NAME_LENGTH);
  		tmp8 = param->u.utility.paramlen;
  		cfpkt_add_body(pkt, &tmp8, 1);
  		cfpkt_add_body(pkt, param->u.utility.params,
  			       param->u.utility.paramlen);
  		break;
  	default:

  		pr_warn("Request setup of bad link type = %d
  ",
  			param->linktype);

  		return -EINVAL;

  	}

  	req = kzalloc(sizeof(*req), GFP_KERNEL);

  	if (!req)

  		return -ENOMEM;

  	req->client_layer = user_layer;
  	req->cmd = CFCTRL_CMD_LINK_SETUP;
  	req->param = *param;
  	cfctrl_insert_req(cfctrl, req);
  	init_info(cfpkt_info(pkt), cfctrl);

  	/*
  	 * NOTE:Always send linkup and linkdown request on the same
  	 *	device as the payload. Otherwise old queued up payload
  	 *	might arrive with the newly allocated channel ID.
  	 */

  	cfpkt_info(pkt)->dev_info->id = param->phyid;

  	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);

  	ret =

  	    dn->transmit(dn, pkt);

  	if (ret < 0) {

  		int count;
  
  		count = cfctrl_cancel_req(&cfctrl->serv.layer,
  						user_layer);

  		if (count != 1) {

  			pr_err("Could not remove request (%d)", count);
  			return -ENODEV;

  		}

  	}

  	return 0;

  }
  
  int cfctrl_linkdown_req(struct cflayer *layer, u8 channelid,

  			struct cflayer *client)

  {
  	int ret;

  	struct cfpkt *pkt;

  	struct cfctrl *cfctrl = container_obj(layer);

  	struct cflayer *dn = cfctrl->serv.layer.dn;

  	if (!dn) {
  		pr_debug("not able to send link-down request
  ");
  		return -ENODEV;
  	}

  	pkt = cfpkt_create(CFPKT_CTRL_PKT_LEN);
  	if (!pkt)
  		return -ENOMEM;

  	cfpkt_addbdy(pkt, CFCTRL_CMD_LINK_DESTROY);
  	cfpkt_addbdy(pkt, channelid);
  	init_info(cfpkt_info(pkt), cfctrl);

  	cfpkt_set_prio(pkt, TC_PRIO_CONTROL);

  	ret =

  	    dn->transmit(dn, pkt);

  #ifndef CAIF_NO_LOOP
  	cfctrl->loop_linkused[channelid] = 0;
  #endif

  	return ret;
  }

  int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)

  {

  	struct cfctrl_request_info *p, *tmp;

  	struct cfctrl *ctrl = container_obj(layr);

  	int found = 0;
  	spin_lock_bh(&ctrl->info_list_lock);

  
  	list_for_each_entry_safe(p, tmp, &ctrl->list, list) {
  		if (p->client_layer == adap_layer) {

  			list_del(&p->list);
  			kfree(p);

  			found++;

  		}

  	}

  	spin_unlock_bh(&ctrl->info_list_lock);
  	return found;

  }

  static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
  {
  	u8 cmdrsp;
  	u8 cmd;
  	int ret = -1;
  	u16 tmp16;
  	u8 len;
  	u8 param[255];
  	u8 linkid;
  	struct cfctrl *cfctrl = container_obj(layer);
  	struct cfctrl_request_info rsp, *req;
  
  
  	cfpkt_extr_head(pkt, &cmdrsp, 1);
  	cmd = cmdrsp & CFCTRL_CMD_MASK;
  	if (cmd != CFCTRL_CMD_LINK_ERR

  	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
  		&& CFCTRL_ERR_BIT != (CFCTRL_ERR_BIT & cmdrsp)) {

  		if (handle_loop(cfctrl, cmd, pkt) != 0)

  			cmdrsp |= CFCTRL_ERR_BIT;

  	}
  
  	switch (cmd) {
  	case CFCTRL_CMD_LINK_SETUP:
  		{
  			enum cfctrl_srv serv;
  			enum cfctrl_srv servtype;
  			u8 endpoint;
  			u8 physlinkid;
  			u8 prio;
  			u8 tmp;
  			u32 tmp32;
  			u8 *cp;
  			int i;
  			struct cfctrl_link_param linkparam;
  			memset(&linkparam, 0, sizeof(linkparam));
  
  			cfpkt_extr_head(pkt, &tmp, 1);
  
  			serv = tmp & CFCTRL_SRV_MASK;
  			linkparam.linktype = serv;
  
  			servtype = tmp >> 4;
  			linkparam.chtype = servtype;
  
  			cfpkt_extr_head(pkt, &tmp, 1);
  			physlinkid = tmp & 0x07;
  			prio = tmp >> 3;
  
  			linkparam.priority = prio;
  			linkparam.phyid = physlinkid;
  			cfpkt_extr_head(pkt, &endpoint, 1);
  			linkparam.endpoint = endpoint & 0x03;
  
  			switch (serv) {
  			case CFCTRL_SRV_VEI:
  			case CFCTRL_SRV_DBG:

  				if (CFCTRL_ERR_BIT & cmdrsp)
  					break;

  				/* Link ID */
  				cfpkt_extr_head(pkt, &linkid, 1);
  				break;
  			case CFCTRL_SRV_VIDEO:
  				cfpkt_extr_head(pkt, &tmp, 1);
  				linkparam.u.video.connid = tmp;

  				if (CFCTRL_ERR_BIT & cmdrsp)
  					break;

  				/* Link ID */
  				cfpkt_extr_head(pkt, &linkid, 1);
  				break;
  
  			case CFCTRL_SRV_DATAGRAM:
  				cfpkt_extr_head(pkt, &tmp32, 4);
  				linkparam.u.datagram.connid =
  				    le32_to_cpu(tmp32);

  				if (CFCTRL_ERR_BIT & cmdrsp)
  					break;

  				/* Link ID */
  				cfpkt_extr_head(pkt, &linkid, 1);
  				break;
  			case CFCTRL_SRV_RFM:
  				/* Construct a frame, convert
  				 * DatagramConnectionID
  				 * to network format long and copy it out...
  				 */
  				cfpkt_extr_head(pkt, &tmp32, 4);
  				linkparam.u.rfm.connid =
  				  le32_to_cpu(tmp32);
  				cp = (u8 *) linkparam.u.rfm.volume;
  				for (cfpkt_extr_head(pkt, &tmp, 1);
  				     cfpkt_more(pkt) && tmp != '\0';
  				     cfpkt_extr_head(pkt, &tmp, 1))
  					*cp++ = tmp;
  				*cp = '\0';

  				if (CFCTRL_ERR_BIT & cmdrsp)
  					break;

  				/* Link ID */
  				cfpkt_extr_head(pkt, &linkid, 1);
  
  				break;
  			case CFCTRL_SRV_UTIL:
  				/* Construct a frame, convert
  				 * DatagramConnectionID
  				 * to network format long and copy it out...
  				 */
  				/* Fifosize KB */
  				cfpkt_extr_head(pkt, &tmp16, 2);
  				linkparam.u.utility.fifosize_kb =
  				    le16_to_cpu(tmp16);
  				/* Fifosize bufs */
  				cfpkt_extr_head(pkt, &tmp16, 2);
  				linkparam.u.utility.fifosize_bufs =
  				    le16_to_cpu(tmp16);
  				/* name */
  				cp = (u8 *) linkparam.u.utility.name;
  				caif_assert(sizeof(linkparam.u.utility.name)
  					     >= UTILITY_NAME_LENGTH);
  				for (i = 0;
  				     i < UTILITY_NAME_LENGTH
  				     && cfpkt_more(pkt); i++) {
  					cfpkt_extr_head(pkt, &tmp, 1);
  					*cp++ = tmp;
  				}
  				/* Length */
  				cfpkt_extr_head(pkt, &len, 1);
  				linkparam.u.utility.paramlen = len;
  				/* Param Data */
  				cp = linkparam.u.utility.params;
  				while (cfpkt_more(pkt) && len--) {
  					cfpkt_extr_head(pkt, &tmp, 1);
  					*cp++ = tmp;
  				}

  				if (CFCTRL_ERR_BIT & cmdrsp)
  					break;

  				/* Link ID */
  				cfpkt_extr_head(pkt, &linkid, 1);
  				/* Length */
  				cfpkt_extr_head(pkt, &len, 1);
  				/* Param Data */
  				cfpkt_extr_head(pkt, &param, len);
  				break;
  			default:

  				pr_warn("Request setup, invalid type (%d)
  ",

  					serv);

  				goto error;
  			}
  
  			rsp.cmd = cmd;
  			rsp.param = linkparam;

  			spin_lock_bh(&cfctrl->info_list_lock);

  			req = cfctrl_remove_req(cfctrl, &rsp);
  
  			if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
  				cfpkt_erroneous(pkt)) {

  				pr_err("Invalid O/E bit or parse error "
  						"on CAIF control channel
  ");

  				cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
  						       0,
  						       req ? req->client_layer
  						       : NULL);
  			} else {
  				cfctrl->res.linksetup_rsp(cfctrl->serv.
  							  layer.up, linkid,
  							  serv, physlinkid,
  							  req ? req->
  							  client_layer : NULL);
  			}

  			kfree(req);

  
  			spin_unlock_bh(&cfctrl->info_list_lock);

  		}
  		break;
  	case CFCTRL_CMD_LINK_DESTROY:
  		cfpkt_extr_head(pkt, &linkid, 1);

  		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);

  		break;
  	case CFCTRL_CMD_LINK_ERR:

  		pr_err("Frame Error Indication received
  ");

  		cfctrl->res.linkerror_ind();
  		break;
  	case CFCTRL_CMD_ENUM:
  		cfctrl->res.enum_rsp();
  		break;
  	case CFCTRL_CMD_SLEEP:
  		cfctrl->res.sleep_rsp();
  		break;
  	case CFCTRL_CMD_WAKE:
  		cfctrl->res.wake_rsp();
  		break;
  	case CFCTRL_CMD_LINK_RECONF:
  		cfctrl->res.restart_rsp();
  		break;
  	case CFCTRL_CMD_RADIO_SET:
  		cfctrl->res.radioset_rsp();
  		break;
  	default:

  		pr_err("Unrecognized Control Frame
  ");

  		goto error;

  	}
  	ret = 0;
  error:
  	cfpkt_destroy(pkt);
  	return ret;
  }
  
  static void cfctrl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,

  			   int phyid)

  {
  	struct cfctrl *this = container_obj(layr);
  	switch (ctrl) {
  	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
  	case CAIF_CTRLCMD_FLOW_OFF_IND:

  		spin_lock_bh(&this->info_list_lock);

  		if (!list_empty(&this->list))

  			pr_debug("Received flow off in control layer
  ");

  		spin_unlock_bh(&this->info_list_lock);

  		break;

  	case _CAIF_CTRLCMD_PHYIF_DOWN_IND: {
  		struct cfctrl_request_info *p, *tmp;
  
  		/* Find all connect request and report failure */
  		spin_lock_bh(&this->info_list_lock);
  		list_for_each_entry_safe(p, tmp, &this->list, list) {
  			if (p->param.phyid == phyid) {
  				list_del(&p->list);
  				p->client_layer->ctrlcmd(p->client_layer,
  						CAIF_CTRLCMD_INIT_FAIL_RSP,
  						phyid);
  				kfree(p);
  			}
  		}
  		spin_unlock_bh(&this->info_list_lock);
  		break;
  	}

  	default:
  		break;
  	}
  }
  
  #ifndef CAIF_NO_LOOP
  static int handle_loop(struct cfctrl *ctrl, int cmd, struct cfpkt *pkt)
  {
  	static int last_linkid;

  	static int dec;

  	u8 linkid, linktype, tmp;
  	switch (cmd) {
  	case CFCTRL_CMD_LINK_SETUP:

  		spin_lock_bh(&ctrl->loop_linkid_lock);
  		if (!dec) {

  			for (linkid = last_linkid + 1; linkid < 254; linkid++)

  				if (!ctrl->loop_linkused[linkid])
  					goto found;
  		}
  		dec = 1;

  		for (linkid = last_linkid - 1; linkid > 1; linkid--)

  			if (!ctrl->loop_linkused[linkid])
  				goto found;

  		spin_unlock_bh(&ctrl->loop_linkid_lock);

  		return -1;

  found:

  		if (linkid < 10)
  			dec = 0;

  		if (!ctrl->loop_linkused[linkid])
  			ctrl->loop_linkused[linkid] = 1;
  
  		last_linkid = linkid;
  
  		cfpkt_add_trail(pkt, &linkid, 1);

  		spin_unlock_bh(&ctrl->loop_linkid_lock);

  		cfpkt_peek_head(pkt, &linktype, 1);
  		if (linktype ==  CFCTRL_SRV_UTIL) {
  			tmp = 0x01;
  			cfpkt_add_trail(pkt, &tmp, 1);
  			cfpkt_add_trail(pkt, &tmp, 1);
  		}
  		break;
  
  	case CFCTRL_CMD_LINK_DESTROY:

  		spin_lock_bh(&ctrl->loop_linkid_lock);

  		cfpkt_peek_head(pkt, &linkid, 1);
  		ctrl->loop_linkused[linkid] = 0;

  		spin_unlock_bh(&ctrl->loop_linkid_lock);

  		break;
  	default:
  		break;
  	}

  	return 0;

  }
  #endif