net/caif/cfveil.c

   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/stddef.h>
  10 #include <linux/slab.h>
  11 #include <net/caif/caif_layer.h>
  12 #include <net/caif/cfsrvl.h>
  13 #include <net/caif/cfpkt.h>
  14
  15 #define VEI_PAYLOAD  0x00
  16 #define VEI_CMD_BIT  0x80
  17 #define VEI_FLOW_OFF 0x81
  18 #define VEI_FLOW_ON  0x80
  19 #define VEI_SET_PIN  0x82
  20 #define VEI_CTRL_PKT_SIZE 1
  21 #define container_obj(layr) container_of(layr, struct cfsrvl, layer)
  22
  23 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
  24 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);
  25
  26 struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
  27 {
  28         struct cfsrvl *vei = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  29         if (!vei) {
  30                 pr_warn("Out of memory\n");
  31                 return NULL;
  32         }
  33         caif_assert(offsetof(struct cfsrvl, layer) == 0);
  34         memset(vei, 0, sizeof(struct cfsrvl));
  35         cfsrvl_init(vei, channel_id, dev_info, true);
  36         vei->layer.receive = cfvei_receive;
  37         vei->layer.transmit = cfvei_transmit;
  38         snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ - 1, "vei%d", channel_id);
  39         return &vei->layer;
  40 }
  41
  42 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
  43 {
  44         u8 cmd;
  45         int ret;
  46         caif_assert(layr->up != NULL);
  47         caif_assert(layr->receive != NULL);
  48         caif_assert(layr->ctrlcmd != NULL);
  49
  50
  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         switch (cmd) {
  57         case VEI_PAYLOAD:
  58                 ret = layr->up->receive(layr->up, pkt);
  59                 return ret;
  60         case VEI_FLOW_OFF:
  61                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  62                 cfpkt_destroy(pkt);
  63                 return 0;
  64         case VEI_FLOW_ON:
  65                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  66                 cfpkt_destroy(pkt);
  67                 return 0;
  68         case VEI_SET_PIN:       /* SET RS232 PIN */
  69                 cfpkt_destroy(pkt);
  70                 return 0;
  71         default:                /* SET RS232 PIN */
  72                 pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
  73                 cfpkt_destroy(pkt);
  74                 return -EPROTO;
  75         }
  76 }
  77
  78 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
  79 {
  80         u8 tmp = 0;
  81         struct caif_payload_info *info;
  82         int ret;
  83         struct cfsrvl *service = container_obj(layr);
  84         if (!cfsrvl_ready(service, &ret))
  85                 return ret;
  86         caif_assert(layr->dn != NULL);
  87         caif_assert(layr->dn->transmit != NULL);
  88
  89         if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
  90                 pr_err("Packet is erroneous!\n");
  91                 return -EPROTO;
  92         }
  93
  94         /* Add info-> for MUX-layer to route the packet out. */
  95         info = cfpkt_info(pkt);
  96         info->channel_id = service->layer.id;
  97         info->hdr_len = 1;
  98         info->dev_info = &service->dev_info;
  99         ret = layr->dn->transmit(layr->dn, pkt);
 100         if (ret < 0)
 101                 cfpkt_extr_head(pkt, &tmp, 1);
 102         return ret;
 103 }