linux/net/caif/cfutill.c
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   1/*
   2 * Copyright (C) ST-Ericsson AB 2010
   3 * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
   4 * License terms: GNU General Public License (GPL) version 2
   5 */
   6
   7#include <linux/kernel.h>
   8#include <linux/types.h>
   9#include <linux/slab.h>
  10#include <linux/errno.h>
  11#include <net/caif/caif_layer.h>
  12#include <net/caif/cfsrvl.h>
  13#include <net/caif/cfpkt.h>
  14
  15#define container_obj(layr) ((struct cfsrvl *) layr)
  16#define UTIL_PAYLOAD  0x00
  17#define UTIL_CMD_BIT  0x80
  18#define UTIL_REMOTE_SHUTDOWN 0x82
  19#define UTIL_FLOW_OFF 0x81
  20#define UTIL_FLOW_ON  0x80
  21#define UTIL_CTRL_PKT_SIZE 1
  22static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
  23static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
  24
  25struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
  26{
  27        struct cfsrvl *util = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  28        if (!util) {
  29                pr_warning("CAIF: %s(): Out of memory\n", __func__);
  30                return NULL;
  31        }
  32        caif_assert(offsetof(struct cfsrvl, layer) == 0);
  33        memset(util, 0, sizeof(struct cfsrvl));
  34        cfsrvl_init(util, channel_id, dev_info);
  35        util->layer.receive = cfutill_receive;
  36        util->layer.transmit = cfutill_transmit;
  37        snprintf(util->layer.name, CAIF_LAYER_NAME_SZ - 1, "util1");
  38        return &util->layer;
  39}
  40
  41static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
  42{
  43        u8 cmd = -1;
  44        struct cfsrvl *service = container_obj(layr);
  45        caif_assert(layr != NULL);
  46        caif_assert(layr->up != NULL);
  47        caif_assert(layr->up->receive != NULL);
  48        caif_assert(layr->up->ctrlcmd != NULL);
  49        if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
  50                pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
  51                cfpkt_destroy(pkt);
  52                return -EPROTO;
  53        }
  54
  55        switch (cmd) {
  56        case UTIL_PAYLOAD:
  57                return layr->up->receive(layr->up, pkt);
  58        case UTIL_FLOW_OFF:
  59                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  60                cfpkt_destroy(pkt);
  61                return 0;
  62        case UTIL_FLOW_ON:
  63                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  64                cfpkt_destroy(pkt);
  65                return 0;
  66        case UTIL_REMOTE_SHUTDOWN:      /* Remote Shutdown Request */
  67                pr_err("CAIF: %s(): REMOTE SHUTDOWN REQUEST RECEIVED\n",
  68                        __func__);
  69                layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
  70                service->open = false;
  71                cfpkt_destroy(pkt);
  72                return 0;
  73        default:
  74                cfpkt_destroy(pkt);
  75                pr_warning("CAIF: %s(): Unknown service control %d (0x%x)\n",
  76                           __func__, cmd, cmd);
  77                return -EPROTO;
  78        }
  79}
  80
  81static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
  82{
  83        u8 zero = 0;
  84        struct caif_payload_info *info;
  85        int ret;
  86        struct cfsrvl *service = container_obj(layr);
  87        caif_assert(layr != NULL);
  88        caif_assert(layr->dn != NULL);
  89        caif_assert(layr->dn->transmit != NULL);
  90        if (!cfsrvl_ready(service, &ret))
  91                return ret;
  92
  93        if (cfpkt_getlen(pkt) > CAIF_MAX_PAYLOAD_SIZE) {
  94                pr_err("CAIF: %s(): packet too large size=%d\n",
  95                        __func__, cfpkt_getlen(pkt));
  96                return -EOVERFLOW;
  97        }
  98
  99        cfpkt_add_head(pkt, &zero, 1);
 100        /* Add info for MUX-layer to route the packet out. */
 101        info = cfpkt_info(pkt);
 102        info->channel_id = service->layer.id;
 103        /*
 104         * To optimize alignment, we add up the size of CAIF header before
 105         * payload.
 106         */
 107        info->hdr_len = 1;
 108        info->dev_info = &service->dev_info;
 109        ret = layr->dn->transmit(layr->dn, pkt);
 110        if (ret < 0) {
 111                u32 tmp32;
 112                cfpkt_extr_head(pkt, &tmp32, 4);
 113        }
 114        return ret;
 115}
 116