Net: caif: Makefile: Remove deprecated items
[linux-2.6.git] / net / caif / cffrml.c
1 /*
2  * CAIF Framing Layer.
3  *
4  * Copyright (C) ST-Ericsson AB 2010
5  * Author:      Sjur Brendeland/sjur.brandeland@stericsson.com
6  * License terms: GNU General Public License (GPL) version 2
7  */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
10
11 #include <linux/stddef.h>
12 #include <linux/spinlock.h>
13 #include <linux/slab.h>
14 #include <linux/crc-ccitt.h>
15 #include <net/caif/caif_layer.h>
16 #include <net/caif/cfpkt.h>
17 #include <net/caif/cffrml.h>
18
19 #define container_obj(layr) container_of(layr, struct cffrml, layer)
20
21 struct cffrml {
22         struct cflayer layer;
23         bool dofcs;             /* !< FCS active */
24 };
25
26 static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt);
27 static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt);
28 static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
29                                 int phyid);
30
31 static u32 cffrml_rcv_error;
32 static u32 cffrml_rcv_checsum_error;
33 struct cflayer *cffrml_create(u16 phyid, bool use_fcs)
34 {
35         struct cffrml *this = kmalloc(sizeof(struct cffrml), GFP_ATOMIC);
36         if (!this) {
37                 pr_warn("Out of memory\n");
38                 return NULL;
39         }
40         caif_assert(offsetof(struct cffrml, layer) == 0);
41
42         memset(this, 0, sizeof(struct cflayer));
43         this->layer.receive = cffrml_receive;
44         this->layer.transmit = cffrml_transmit;
45         this->layer.ctrlcmd = cffrml_ctrlcmd;
46         snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "frm%d", phyid);
47         this->dofcs = use_fcs;
48         this->layer.id = phyid;
49         return (struct cflayer *) this;
50 }
51
52 void cffrml_set_uplayer(struct cflayer *this, struct cflayer *up)
53 {
54         this->up = up;
55 }
56
57 void cffrml_set_dnlayer(struct cflayer *this, struct cflayer *dn)
58 {
59         this->dn = dn;
60 }
61
62 static u16 cffrml_checksum(u16 chks, void *buf, u16 len)
63 {
64         /* FIXME: FCS should be moved to glue in order to use OS-Specific
65          * solutions
66          */
67         return crc_ccitt(chks, buf, len);
68 }
69
70 static int cffrml_receive(struct cflayer *layr, struct cfpkt *pkt)
71 {
72         u16 tmp;
73         u16 len;
74         u16 hdrchks;
75         u16 pktchks;
76         struct cffrml *this;
77         this = container_obj(layr);
78
79         cfpkt_extr_head(pkt, &tmp, 2);
80         len = le16_to_cpu(tmp);
81
82         /* Subtract for FCS on length if FCS is not used. */
83         if (!this->dofcs)
84                 len -= 2;
85
86         if (cfpkt_setlen(pkt, len) < 0) {
87                 ++cffrml_rcv_error;
88                 pr_err("Framing length error (%d)\n", len);
89                 cfpkt_destroy(pkt);
90                 return -EPROTO;
91         }
92         /*
93          * Don't do extract if FCS is false, rather do setlen - then we don't
94          * get a cache-miss.
95          */
96         if (this->dofcs) {
97                 cfpkt_extr_trail(pkt, &tmp, 2);
98                 hdrchks = le16_to_cpu(tmp);
99                 pktchks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
100                 if (pktchks != hdrchks) {
101                         cfpkt_add_trail(pkt, &tmp, 2);
102                         ++cffrml_rcv_error;
103                         ++cffrml_rcv_checsum_error;
104                         pr_info("Frame checksum error (0x%x != 0x%x)\n",
105                                 hdrchks, pktchks);
106                         return -EILSEQ;
107                 }
108         }
109         if (cfpkt_erroneous(pkt)) {
110                 ++cffrml_rcv_error;
111                 pr_err("Packet is erroneous!\n");
112                 cfpkt_destroy(pkt);
113                 return -EPROTO;
114         }
115         return layr->up->receive(layr->up, pkt);
116 }
117
118 static int cffrml_transmit(struct cflayer *layr, struct cfpkt *pkt)
119 {
120         int tmp;
121         u16 chks;
122         u16 len;
123         int ret;
124         struct cffrml *this = container_obj(layr);
125         if (this->dofcs) {
126                 chks = cfpkt_iterate(pkt, cffrml_checksum, 0xffff);
127                 tmp = cpu_to_le16(chks);
128                 cfpkt_add_trail(pkt, &tmp, 2);
129         } else {
130                 cfpkt_pad_trail(pkt, 2);
131         }
132         len = cfpkt_getlen(pkt);
133         tmp = cpu_to_le16(len);
134         cfpkt_add_head(pkt, &tmp, 2);
135         cfpkt_info(pkt)->hdr_len += 2;
136         if (cfpkt_erroneous(pkt)) {
137                 pr_err("Packet is erroneous!\n");
138                 return -EPROTO;
139         }
140         ret = layr->dn->transmit(layr->dn, pkt);
141         if (ret < 0) {
142                 /* Remove header on faulty packet. */
143                 cfpkt_extr_head(pkt, &tmp, 2);
144         }
145         return ret;
146 }
147
148 static void cffrml_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
149                                         int phyid)
150 {
151         if (layr->up->ctrlcmd)
152                 layr->up->ctrlcmd(layr->up, ctrl, layr->id);
153 }