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#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
   8
   9#include <linux/kernel.h>
  10#include <linux/types.h>
  11#include <linux/slab.h>
  12#include <linux/errno.h>
  13#include <net/caif/caif_layer.h>
  14#include <net/caif/cfsrvl.h>
  15#include <net/caif/cfpkt.h>
  16
  17#define container_obj(layr) ((struct cfsrvl *) layr)
  18#define UTIL_PAYLOAD  0x00
  19#define UTIL_CMD_BIT  0x80
  20#define UTIL_REMOTE_SHUTDOWN 0x82
  21#define UTIL_FLOW_OFF 0x81
  22#define UTIL_FLOW_ON  0x80
  23#define UTIL_CTRL_PKT_SIZE 1
  24static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
  25static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
  26
  27struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
  28{
  29        struct cfsrvl *util = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  30        if (!util) {
  31                pr_warn("Out of memory\n");
  32                return NULL;
  33        }
  34        caif_assert(offsetof(struct cfsrvl, layer) == 0);
  35        memset(util, 0, sizeof(struct cfsrvl));
  36        cfsrvl_init(util, channel_id, dev_info, true);
  37        util->layer.receive = cfutill_receive;
  38        util->layer.transmit = cfutill_transmit;
  39        snprintf(util->layer.name, CAIF_LAYER_NAME_SZ - 1, "util1");
  40        return &util->layer;
  41}
  42
  43static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
  44{
  45        u8 cmd = -1;
  46        struct cfsrvl *service = container_obj(layr);
  47        caif_assert(layr != NULL);
  48        caif_assert(layr->up != NULL);
  49        caif_assert(layr->up->receive != NULL);
  50        caif_assert(layr->up->ctrlcmd != NULL);
  51        if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
  52                pr_err("Packet is erroneous!\n");
  53                cfpkt_destroy(pkt);
  54                return -EPROTO;
  55        }
  56
  57        switch (cmd) {
  58        case UTIL_PAYLOAD:
  59                return layr->up->receive(layr->up, pkt);
  60        case UTIL_FLOW_OFF:
  61                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  62                cfpkt_destroy(pkt);
  63                return 0;
  64        case UTIL_FLOW_ON:
  65                layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  66                cfpkt_destroy(pkt);
  67                return 0;
  68        case UTIL_REMOTE_SHUTDOWN:      /* Remote Shutdown Request */
  69                pr_err("REMOTE SHUTDOWN REQUEST RECEIVED\n");
  70                layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
  71                service->open = false;
  72                cfpkt_destroy(pkt);
  73                return 0;
  74        default:
  75                cfpkt_destroy(pkt);
  76                pr_warn("Unknown service control %d (0x%x)\n", 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        cfpkt_add_head(pkt, &zero, 1);
  94        /* Add info for MUX-layer to route the packet out. */
  95        info = cfpkt_info(pkt);
  96        info->channel_id = service->layer.id;
  97        /*
  98         * To optimize alignment, we add up the size of CAIF header before
  99         * payload.
 100         */
 101        info->hdr_len = 1;
 102        info->dev_info = &service->dev_info;
 103        ret = layr->dn->transmit(layr->dn, pkt);
 104        if (ret < 0) {
 105                u32 tmp32;
 106                cfpkt_extr_head(pkt, &tmp32, 4);
 107        }
 108        return ret;
 109}
 110