net/caif/cfveil.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) ST-Ericsson AB 2010
   4  * Author:      Sjur Brendeland
   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
  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 = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
  29         if (!vei)
  30                 return NULL;
  31         caif_assert(offsetof(struct cfsrvl, layer) == 0);
  32         cfsrvl_init(vei, channel_id, dev_info, true);
  33         vei->layer.receive = cfvei_receive;
  34         vei->layer.transmit = cfvei_transmit;
  35         snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ, "vei%d", channel_id);
  36         return &vei->layer;
  37 }
  38
  39 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
  40 {
  41         u8 cmd;
  42         int ret;
  43         caif_assert(layr->up != NULL);
  44         caif_assert(layr->receive != NULL);
  45         caif_assert(layr->ctrlcmd != NULL);
  46
  47
  48         if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
  49                 pr_err("Packet is erroneous!\n");
  50                 cfpkt_destroy(pkt);
  51                 return -EPROTO;
  52         }
  53         switch (cmd) {
  54         case VEI_PAYLOAD:
  55                 ret = layr->up->receive(layr->up, pkt);
  56                 return ret;
  57         case VEI_FLOW_OFF:
  58                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
  59                 cfpkt_destroy(pkt);
  60                 return 0;
  61         case VEI_FLOW_ON:
  62                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
  63                 cfpkt_destroy(pkt);
  64                 return 0;
  65         case VEI_SET_PIN:       /* SET RS232 PIN */
  66                 cfpkt_destroy(pkt);
  67                 return 0;
  68         default:                /* SET RS232 PIN */
  69                 pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
  70                 cfpkt_destroy(pkt);
  71                 return -EPROTO;
  72         }
  73 }
  74
  75 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
  76 {
  77         u8 tmp = 0;
  78         struct caif_payload_info *info;
  79         int ret;
  80         struct cfsrvl *service = container_obj(layr);
  81         if (!cfsrvl_ready(service, &ret))
  82                 goto err;
  83         caif_assert(layr->dn != NULL);
  84         caif_assert(layr->dn->transmit != NULL);
  85
  86         if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
  87                 pr_err("Packet is erroneous!\n");
  88                 ret = -EPROTO;
  89                 goto err;
  90         }
  91
  92         /* Add info-> for MUX-layer to route the packet out. */
  93         info = cfpkt_info(pkt);
  94         info->channel_id = service->layer.id;
  95         info->hdr_len = 1;
  96         info->dev_info = &service->dev_info;
  97         return layr->dn->transmit(layr->dn, pkt);
  98 err:
  99         cfpkt_destroy(pkt);
 100         return ret;
 101 }