caif: Use link layer MTU instead of fixed MTU
[linux-2.6.git] / 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, true);
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
88         if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
89                 pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
90                 return -EPROTO;
91         }
92
93         /* Add info-> for MUX-layer to route the packet out. */
94         info = cfpkt_info(pkt);
95         info->channel_id = service->layer.id;
96         info->hdr_len = 1;
97         info->dev_info = &service->dev_info;
98         ret = layr->dn->transmit(layr->dn, pkt);
99         if (ret < 0)
100                 cfpkt_extr_head(pkt, &tmp, 1);
101         return ret;
102 }