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 #include <linux/stddef.h>
   8 #include <linux/slab.h>
   9 #include <net/caif/caif_layer.h>
  10 #include <net/caif/cfsrvl.h>
  11 #include <net/caif/cfpkt.h>
  12
  13 #define VEI_PAYLOAD  0x00
  14 #define VEI_CMD_BIT  0x80
  15 #define VEI_FLOW_OFF 0x81
  16 #define VEI_FLOW_ON  0x80
  17 #define VEI_SET_PIN  0x82
  18 #define VEI_CTRL_PKT_SIZE 1
  19 #define container_obj(layr) container_of(layr, struct cfsrvl, layer)
  20
  21 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
  22 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);
  23
  24 struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
  25 {
  26         struct cfsrvl *vei = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  27         if (!vei) {
  28                 pr_warning("CAIF: %s(): Out of memory\n", __func__);
  29                 return NULL;
  30         }
  31         caif_assert(offsetof(struct cfsrvl, layer) == 0);
  32         memset(vei, 0, sizeof(struct cfsrvl));
  33         cfsrvl_init(vei, channel_id, dev_info);
  34         vei->layer.receive = cfvei_receive;
  35         vei->layer.transmit = cfvei_transmit;
  36         snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ - 1, "vei%d", channel_id);
  37         return &vei->layer;
  38 }
  39
  40 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
  41 {
  42         u8 cmd;
  43         int ret;
  44         caif_assert(layr->up != NULL);
  45         caif_assert(layr->receive != NULL);
  46         caif_assert(layr->ctrlcmd != NULL);
  47
  48
  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         switch (cmd) {
  55         case VEI_PAYLOAD:
  56                 ret = layr->up->receive(layr->up, pkt);
  57                 return ret;
  58         case VEI_FLOW_OFF:
  59                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  60                 cfpkt_destroy(pkt);
  61                 return 0;
  62         case VEI_FLOW_ON:
  63                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  64                 cfpkt_destroy(pkt);
  65                 return 0;
  66         case VEI_SET_PIN:       /* SET RS232 PIN */
  67                 cfpkt_destroy(pkt);
  68                 return 0;
  69         default:                /* SET RS232 PIN */
  70                 pr_warning("CAIF: %s():Unknown VEI control packet %d (0x%x)!\n",
  71                            __func__, cmd, cmd);
  72                 cfpkt_destroy(pkt);
  73                 return -EPROTO;
  74         }
  75 }
  76
  77 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
  78 {
  79         u8 tmp = 0;
  80         struct caif_payload_info *info;
  81         int ret;
  82         struct cfsrvl *service = container_obj(layr);
  83         if (!cfsrvl_ready(service, &ret))
  84                 return ret;
  85         caif_assert(layr->dn != NULL);
  86         caif_assert(layr->dn->transmit != NULL);
  87         if (cfpkt_getlen(pkt) > CAIF_MAX_PAYLOAD_SIZE) {
  88                 pr_warning("CAIF: %s(): Packet too large - size=%d\n",
  89                            __func__, cfpkt_getlen(pkt));
  90                 return -EOVERFLOW;
  91         }
  92
  93         if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
  94                 pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
  95                 return -EPROTO;
  96         }
  97
  98         /* Add info-> for MUX-layer to route the packet out. */
  99         info = cfpkt_info(pkt);
 100         info->channel_id = service->layer.id;
 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                 cfpkt_extr_head(pkt, &tmp, 1);
 106         return ret;
 107 }