/*
   * 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/errno.h>
  #include <linux/slab.h>

  #include <linux/module.h>

  #include <net/caif/caif_layer.h>
  #include <net/caif/cfsrvl.h>
  #include <net/caif/cfpkt.h>
  
  #define SRVL_CTRL_PKT_SIZE 1
  #define SRVL_FLOW_OFF 0x81
  #define SRVL_FLOW_ON  0x80
  #define SRVL_SET_PIN  0x82
  #define SRVL_CTRL_PKT_SIZE 1
  
  #define container_obj(layr) container_of(layr, struct cfsrvl, layer)
  
  static void cfservl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
  				int phyid)
  {
  	struct cfsrvl *service = container_obj(layr);

  	if (layr->up == NULL || layr->up->ctrlcmd == NULL)
  		return;

  	switch (ctrl) {
  	case CAIF_CTRLCMD_INIT_RSP:
  		service->open = true;
  		layr->up->ctrlcmd(layr->up, ctrl, phyid);
  		break;
  	case CAIF_CTRLCMD_DEINIT_RSP:
  	case CAIF_CTRLCMD_INIT_FAIL_RSP:
  		service->open = false;
  		layr->up->ctrlcmd(layr->up, ctrl, phyid);
  		break;
  	case _CAIF_CTRLCMD_PHYIF_FLOW_OFF_IND:
  		if (phyid != service->dev_info.id)
  			break;
  		if (service->modem_flow_on)
  			layr->up->ctrlcmd(layr->up,
  					  CAIF_CTRLCMD_FLOW_OFF_IND, phyid);
  		service->phy_flow_on = false;
  		break;
  	case _CAIF_CTRLCMD_PHYIF_FLOW_ON_IND:
  		if (phyid != service->dev_info.id)
  			return;
  		if (service->modem_flow_on) {
  			layr->up->ctrlcmd(layr->up,
  					   CAIF_CTRLCMD_FLOW_ON_IND,
  					   phyid);
  		}
  		service->phy_flow_on = true;
  		break;
  	case CAIF_CTRLCMD_FLOW_OFF_IND:
  		if (service->phy_flow_on) {
  			layr->up->ctrlcmd(layr->up,
  					  CAIF_CTRLCMD_FLOW_OFF_IND, phyid);
  		}
  		service->modem_flow_on = false;
  		break;
  	case CAIF_CTRLCMD_FLOW_ON_IND:
  		if (service->phy_flow_on) {
  			layr->up->ctrlcmd(layr->up,
  					  CAIF_CTRLCMD_FLOW_ON_IND, phyid);
  		}
  		service->modem_flow_on = true;
  		break;
  	case _CAIF_CTRLCMD_PHYIF_DOWN_IND:
  		/* In case interface is down, let's fake a remove shutdown */
  		layr->up->ctrlcmd(layr->up,
  				CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, phyid);
  		break;
  	case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
  		layr->up->ctrlcmd(layr->up, ctrl, phyid);
  		break;
  	default:

  		pr_warn("Unexpected ctrl in cfsrvl (%d)
  ", ctrl);

  		/* We have both modem and phy flow on, send flow on */
  		layr->up->ctrlcmd(layr->up, ctrl, phyid);
  		service->phy_flow_on = true;
  		break;
  	}
  }
  
  static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
  {
  	struct cfsrvl *service = container_obj(layr);

  	caif_assert(layr != NULL);
  	caif_assert(layr->dn != NULL);
  	caif_assert(layr->dn->transmit != NULL);

  
  	if (!service->supports_flowctrl)
  		return 0;

  	switch (ctrl) {
  	case CAIF_MODEMCMD_FLOW_ON_REQ:
  		{
  			struct cfpkt *pkt;
  			struct caif_payload_info *info;
  			u8 flow_on = SRVL_FLOW_ON;
  			pkt = cfpkt_create(SRVL_CTRL_PKT_SIZE);

  			if (!pkt)

  				return -ENOMEM;

  
  			if (cfpkt_add_head(pkt, &flow_on, 1) < 0) {

  				pr_err("Packet is erroneous!
  ");

  				cfpkt_destroy(pkt);
  				return -EPROTO;
  			}
  			info = cfpkt_info(pkt);
  			info->channel_id = service->layer.id;
  			info->hdr_len = 1;
  			info->dev_info = &service->dev_info;
  			return layr->dn->transmit(layr->dn, pkt);
  		}
  	case CAIF_MODEMCMD_FLOW_OFF_REQ:
  		{
  			struct cfpkt *pkt;
  			struct caif_payload_info *info;
  			u8 flow_off = SRVL_FLOW_OFF;
  			pkt = cfpkt_create(SRVL_CTRL_PKT_SIZE);

  			if (!pkt)

  				return -ENOMEM;

  			if (cfpkt_add_head(pkt, &flow_off, 1) < 0) {

  				pr_err("Packet is erroneous!
  ");

  				cfpkt_destroy(pkt);
  				return -EPROTO;
  			}
  			info = cfpkt_info(pkt);
  			info->channel_id = service->layer.id;
  			info->hdr_len = 1;
  			info->dev_info = &service->dev_info;
  			return layr->dn->transmit(layr->dn, pkt);
  		}
  	default:
  	  break;
  	}
  	return -EINVAL;
  }

  static void cfsrvl_release(struct cflayer *layer)

  {

  	struct cfsrvl *service = container_of(layer, struct cfsrvl, layer);

  	kfree(service);
  }

  void cfsrvl_init(struct cfsrvl *service,

  			u8 channel_id,
  			struct dev_info *dev_info,
  			bool supports_flowctrl
  			)

  {
  	caif_assert(offsetof(struct cfsrvl, layer) == 0);
  	service->open = false;
  	service->modem_flow_on = true;
  	service->phy_flow_on = true;
  	service->layer.id = channel_id;
  	service->layer.ctrlcmd = cfservl_ctrlcmd;
  	service->layer.modemcmd = cfservl_modemcmd;
  	service->dev_info = *dev_info;

  	service->supports_flowctrl = supports_flowctrl;

  	service->release = cfsrvl_release;

  }

  bool cfsrvl_ready(struct cfsrvl *service, int *err)
  {
  	if (service->open && service->modem_flow_on && service->phy_flow_on)
  		return true;
  	if (!service->open) {
  		*err = -ENOTCONN;
  		return false;
  	}
  	caif_assert(!(service->modem_flow_on && service->phy_flow_on));
  	*err = -EAGAIN;
  	return false;
  }

  u8 cfsrvl_getphyid(struct cflayer *layer)
  {
  	struct cfsrvl *servl = container_obj(layer);
  	return servl->dev_info.id;
  }
  
  bool cfsrvl_phyid_match(struct cflayer *layer, int phyid)
  {
  	struct cfsrvl *servl = container_obj(layer);
  	return servl->dev_info.id == phyid;
  }

  
  void caif_free_client(struct cflayer *adap_layer)
  {
  	struct cfsrvl *servl;
  	if (adap_layer == NULL || adap_layer->dn == NULL)
  		return;
  	servl = container_obj(adap_layer->dn);
  	servl->release(&servl->layer);
  }
  EXPORT_SYMBOL(caif_free_client);
  
  void caif_client_register_refcnt(struct cflayer *adapt_layer,
  					void (*hold)(struct cflayer *lyr),
  					void (*put)(struct cflayer *lyr))
  {
  	struct cfsrvl *service;
  	service = container_of(adapt_layer->dn, struct cfsrvl, layer);
  
  	WARN_ON(adapt_layer == NULL || adapt_layer->dn == NULL);
  	service->hold = hold;
  	service->put = put;
  }
  EXPORT_SYMBOL(caif_client_register_refcnt);