cfveil.c

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/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:  Sjur Brendeland/[email protected]
 * License terms: GNU General Public License (GPL) version 2
 */

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

#include <linux/stddef.h>
#include <linux/slab.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cfpkt.h>

#define VEI_PAYLOAD  0x00
#define VEI_CMD_BIT  0x80
#define VEI_FLOW_OFF 0x81
#define VEI_FLOW_ON  0x80
#define VEI_SET_PIN  0x82

#define container_obj(layr) container_of(layr, struct cfsrvl, layer)

static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);

struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
{
    struct cfsrvl *vei = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
    if (!vei)
        return NULL;
    caif_assert(offsetof(struct cfsrvl, layer) == 0);
    cfsrvl_init(vei, channel_id, dev_info, true);
    vei->layer.receive = cfvei_receive;
    vei->layer.transmit = cfvei_transmit;
    snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ - 1, "vei%d", channel_id);
    return &vei->layer;
}

static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
{
    u8 cmd;
    int ret;
    caif_assert(layr->up != NULL);
    caif_assert(layr->receive != NULL);
    caif_assert(layr->ctrlcmd != NULL);


    if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
        pr_err("Packet is erroneous!\n");
        cfpkt_destroy(pkt);
        return -EPROTO;
    }
    switch (cmd) {
    case VEI_PAYLOAD:
        ret = layr->up->receive(layr->up, pkt);
        return ret;
    case VEI_FLOW_OFF:
        layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
        cfpkt_destroy(pkt);
        return 0;
    case VEI_FLOW_ON:
        layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
        cfpkt_destroy(pkt);
        return 0;
    case VEI_SET_PIN:   /* SET RS232 PIN */
        cfpkt_destroy(pkt);
        return 0;
    default:        /* SET RS232 PIN */
        pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
        cfpkt_destroy(pkt);
        return -EPROTO;
    }
}

static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
    u8 tmp = 0;
    struct caif_payload_info *info;
    int ret;
    struct cfsrvl *service = container_obj(layr);
    if (!cfsrvl_ready(service, &ret))
        goto err;
    caif_assert(layr->dn != NULL);
    caif_assert(layr->dn->transmit != NULL);

    if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
        pr_err("Packet is erroneous!\n");
        ret = -EPROTO;
        goto err;
    }

    /* Add info-> for MUX-layer to route the packet out. */
    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);
err:
    cfpkt_destroy(pkt);
    return ret;
}