/*
   * Copyright (C) ST-Ericsson AB 2010
   * Author:	Sjur Brendeland/sjur.brandeland@stericsson.com
   * License terms: GNU General Public License (GPL) version 2
   */

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

  #include <linux/kernel.h>
  #include <linux/types.h>
  #include <linux/slab.h>
  #include <linux/errno.h>
  #include <net/caif/caif_layer.h>
  #include <net/caif/cfsrvl.h>
  #include <net/caif/cfpkt.h>
  
  #define container_obj(layr) ((struct cfsrvl *) layr)
  #define UTIL_PAYLOAD  0x00
  #define UTIL_CMD_BIT  0x80
  #define UTIL_REMOTE_SHUTDOWN 0x82
  #define UTIL_FLOW_OFF 0x81
  #define UTIL_FLOW_ON  0x80

  static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
  static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
  
  struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
  {

  	struct cfsrvl *util = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  	if (!util)

  		return NULL;

  	caif_assert(offsetof(struct cfsrvl, layer) == 0);

  	cfsrvl_init(util, channel_id, dev_info, true);

  	util->layer.receive = cfutill_receive;
  	util->layer.transmit = cfutill_transmit;
  	snprintf(util->layer.name, CAIF_LAYER_NAME_SZ - 1, "util1");
  	return &util->layer;
  }
  
  static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
  {
  	u8 cmd = -1;
  	struct cfsrvl *service = container_obj(layr);
  	caif_assert(layr != NULL);
  	caif_assert(layr->up != NULL);
  	caif_assert(layr->up->receive != NULL);
  	caif_assert(layr->up->ctrlcmd != NULL);
  	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {

  		pr_err("Packet is erroneous!
  ");

  		cfpkt_destroy(pkt);
  		return -EPROTO;
  	}
  
  	switch (cmd) {
  	case UTIL_PAYLOAD:
  		return layr->up->receive(layr->up, pkt);
  	case UTIL_FLOW_OFF:
  		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  		cfpkt_destroy(pkt);
  		return 0;
  	case UTIL_FLOW_ON:
  		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  		cfpkt_destroy(pkt);
  		return 0;
  	case UTIL_REMOTE_SHUTDOWN:	/* Remote Shutdown Request */

  		pr_err("REMOTE SHUTDOWN REQUEST RECEIVED
  ");

  		layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
  		service->open = false;
  		cfpkt_destroy(pkt);
  		return 0;
  	default:
  		cfpkt_destroy(pkt);

  		pr_warn("Unknown service control %d (0x%x)
  ", cmd, cmd);

  		return -EPROTO;
  	}
  }
  
  static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
  {
  	u8 zero = 0;
  	struct caif_payload_info *info;
  	int ret;
  	struct cfsrvl *service = container_obj(layr);
  	caif_assert(layr != NULL);
  	caif_assert(layr->dn != NULL);
  	caif_assert(layr->dn->transmit != NULL);
  	if (!cfsrvl_ready(service, &ret))
  		return ret;

  	cfpkt_add_head(pkt, &zero, 1);
  	/* Add info for MUX-layer to route the packet out. */
  	info = cfpkt_info(pkt);
  	info->channel_id = service->layer.id;
  	/*
  	 * To optimize alignment, we add up the size of CAIF header before
  	 * payload.
  	 */
  	info->hdr_len = 1;
  	info->dev_info = &service->dev_info;

  	return layr->dn->transmit(layr->dn, pkt);

  }