Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
[pandora-kernel.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 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
8
9 #include <linux/stddef.h>
10 #include <linux/spinlock.h>
11 #include <linux/slab.h>
12 #include <net/caif/caif_layer.h>
13 #include <net/caif/cfsrvl.h>
14 #include <net/caif/cfpkt.h>
15
16 #define container_obj(layr) ((struct cfsrvl *) layr)
17
18 #define DGM_CMD_BIT  0x80
19 #define DGM_FLOW_OFF 0x81
20 #define DGM_FLOW_ON  0x80
21 #define DGM_MTU 1500
22
23 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt);
24 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt);
25
26 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info)
27 {
28         struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
29         if (!dgm) {
30                 pr_warn("Out of memory\n");
31                 return NULL;
32         }
33         caif_assert(offsetof(struct cfsrvl, layer) == 0);
34         memset(dgm, 0, sizeof(struct cfsrvl));
35         cfsrvl_init(dgm, channel_id, dev_info, true);
36         dgm->layer.receive = cfdgml_receive;
37         dgm->layer.transmit = cfdgml_transmit;
38         snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id);
39         dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0';
40         return &dgm->layer;
41 }
42
43 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt)
44 {
45         u8 cmd = -1;
46         u8 dgmhdr[3];
47         int ret;
48         caif_assert(layr->up != NULL);
49         caif_assert(layr->receive != NULL);
50         caif_assert(layr->ctrlcmd != NULL);
51
52         if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
53                 pr_err("Packet is erroneous!\n");
54                 cfpkt_destroy(pkt);
55                 return -EPROTO;
56         }
57
58         if ((cmd & DGM_CMD_BIT) == 0) {
59                 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) {
60                         pr_err("Packet is erroneous!\n");
61                         cfpkt_destroy(pkt);
62                         return -EPROTO;
63                 }
64                 ret = layr->up->receive(layr->up, pkt);
65                 return ret;
66         }
67
68         switch (cmd) {
69         case DGM_FLOW_OFF:      /* FLOW OFF */
70                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
71                 cfpkt_destroy(pkt);
72                 return 0;
73         case DGM_FLOW_ON:       /* FLOW ON */
74                 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
75                 cfpkt_destroy(pkt);
76                 return 0;
77         default:
78                 cfpkt_destroy(pkt);
79                 pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd);
80                 return -EPROTO;
81         }
82 }
83
84 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt)
85 {
86         u32 zero = 0;
87         struct caif_payload_info *info;
88         struct cfsrvl *service = container_obj(layr);
89         int ret;
90         if (!cfsrvl_ready(service, &ret))
91                 return ret;
92
93         /* STE Modem cannot handle more than 1500 bytes datagrams */
94         if (cfpkt_getlen(pkt) > DGM_MTU)
95                 return -EMSGSIZE;
96
97         cfpkt_add_head(pkt, &zero, 4);
98
99         /* Add info for MUX-layer to route the packet out. */
100         info = cfpkt_info(pkt);
101         info->channel_id = service->layer.id;
102         /* To optimize alignment, we add up the size of CAIF header
103          * before payload.
104          */
105         info->hdr_len = 4;
106         info->dev_info = &service->dev_info;
107         ret = layr->dn->transmit(layr->dn, pkt);
108         if (ret < 0) {
109                 u32 tmp32;
110                 cfpkt_extr_head(pkt, &tmp32, 4);
111         }
112         return ret;
113 }