caif: Bugfix not all services uses flow-ctrl.
[linux-2.6.git] / net / caif / cfdgml.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/spinlock.h>
9 #include <linux/slab.h>
10 #include <net/caif/caif_layer.h>
11 #include <net/caif/cfsrvl.h>
12 #include <net/caif/cfpkt.h>
13
14 #define container_obj(layr) ((struct cfsrvl *) layr)
15
16 #define DGM_CMD_BIT  0x80
17 #define DGM_FLOW_OFF 0x81
18 #define DGM_FLOW_ON  0x80
19 #define DGM_CTRL_PKT_SIZE 1
20
21 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
22 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
23
24 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
25 {
26         struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
27         if (!dgm) {
28                 pr_warning("CAIF: %s(): Out of memory\n", __func__);
29                 return NULL;
30         }
31         caif_assert(offsetof(struct cfsrvl, layer) == 0);
32         memset(dgm, 0, sizeof(struct cfsrvl));
33         cfsrvl_init(dgm, channel_id, dev_info, true);
34         dgm->layer.receive = cfdgml_receive;
35         dgm->layer.transmit = cfdgml_transmit;
36         snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
37         dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
38         return &dgm->layer;
39 }
40
41 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
42 {
43         u8 cmd = -1;
44         u8 dgmhdr[3];
45         int ret;
46         caif_assert(layr->up != NULL);
47         caif_assert(layr->receive != NULL);
48         caif_assert(layr->ctrlcmd != NULL);
49
50         if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
51                 pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
52                 cfpkt_destroy(pkt);
53                 return -EPROTO;
54         }
55
56         if ((cmd & DGM_CMD_BIT) == 0) {
57                 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
58                         pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
59                         cfpkt_destroy(pkt);
60                         return -EPROTO;
61                 }
62                 ret = layr->up->receive(layr->up, pkt);
63                 return ret;
64         }
65
66         switch (cmd) {
67         case DGM_FLOW_OFF:      /* FLOW OFF */
68                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
69                 cfpkt_destroy(pkt);
70                 return 0;
71         case DGM_FLOW_ON:       /* FLOW ON */
72                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
73                 cfpkt_destroy(pkt);
74                 return 0;
75         default:
76                 cfpkt_destroy(pkt);
77                 pr_info("CAIF: %s(): Unknown datagram control %d (0x%x)\n",
78                         __func__, cmd, cmd);
79                 return -EPROTO;
80         }
81 }
82
83 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
84 {
85         u32 zero = 0;
86         struct caif_payload_info *info;
87         struct cfsrvl *service = container_obj(layr);
88         int ret;
89         if (!cfsrvl_ready(service, &ret))
90                 return ret;
91
92         cfpkt_add_head(pkt, &zero, 4);
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         /* To optimize alignment, we add up the size of CAIF header
98          * before payload.
99          */
100         info->hdr_len = 4;
101         info->dev_info = &service->dev_info;
102         ret = layr->dn->transmit(layr->dn, pkt);
103         if (ret < 0) {
104                 u32 tmp32;
105                 cfpkt_extr_head(pkt, &tmp32, 4);
106         }
107         return ret;
108 }