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
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/cfpkt.h>
12 #include <net/caif/cfserl.h>
14 #define container_obj(layr) ((struct cfserl *) layr)
16 #define CFSERL_STX 0x02
17 #define CAIF_MINIUM_PACKET_SIZE 4
20 struct cfpkt *incomplete_frm;
21 /* Protects parallel processing of incoming packets */
25 #define STXLEN(layr) (layr->usestx ? 1 : 0)
27 static int cfserl_receive(struct cflayer *layr, struct cfpkt *pkt);
28 static int cfserl_transmit(struct cflayer *layr, struct cfpkt *pkt);
29 static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
32 struct cflayer *cfserl_create(int type, int instance, bool use_stx)
34 struct cfserl *this = kmalloc(sizeof(struct cfserl), GFP_ATOMIC);
36 pr_warning("CAIF: %s(): Out of memory\n", __func__);
39 caif_assert(offsetof(struct cfserl, layer) == 0);
40 memset(this, 0, sizeof(struct cfserl));
41 this->layer.receive = cfserl_receive;
42 this->layer.transmit = cfserl_transmit;
43 this->layer.ctrlcmd = cfserl_ctrlcmd;
44 this->layer.type = type;
45 this->usestx = use_stx;
46 spin_lock_init(&this->sync);
47 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
51 static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
53 struct cfserl *layr = container_obj(l);
55 struct cfpkt *pkt = NULL;
56 struct cfpkt *tail_pkt = NULL;
62 caif_assert(newpkt != NULL);
63 spin_lock(&layr->sync);
65 if (layr->incomplete_frm != NULL) {
67 layr->incomplete_frm =
68 cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
69 pkt = layr->incomplete_frm;
75 layr->incomplete_frm = NULL;
78 /* Search for STX at start of pkt if STX is used */
80 cfpkt_extr_head(pkt, &tmp8, 1);
81 if (tmp8 != CFSERL_STX) {
82 while (cfpkt_more(pkt)
83 && tmp8 != CFSERL_STX) {
84 cfpkt_extr_head(pkt, &tmp8, 1);
86 if (!cfpkt_more(pkt)) {
88 layr->incomplete_frm = NULL;
89 spin_unlock(&layr->sync);
95 pkt_len = cfpkt_getlen(pkt);
98 * pkt_len is the accumulated length of the packet data
99 * we have received so far.
100 * Exit if frame doesn't hold length.
105 cfpkt_add_head(pkt, &stx, 1);
106 layr->incomplete_frm = pkt;
107 spin_unlock(&layr->sync);
112 * Find length of frame.
113 * expectlen is the length we need for a full frame.
115 cfpkt_peek_head(pkt, &tmp, 2);
116 expectlen = le16_to_cpu(tmp) + 2;
118 * Frame error handling
120 if (expectlen < CAIF_MINIUM_PACKET_SIZE
121 || expectlen > CAIF_MAX_FRAMESIZE) {
125 layr->incomplete_frm = NULL;
127 spin_unlock(&layr->sync);
133 if (pkt_len < expectlen) {
134 /* Too little received data */
136 cfpkt_add_head(pkt, &stx, 1);
137 layr->incomplete_frm = pkt;
138 spin_unlock(&layr->sync);
143 * Enough data for at least one frame.
144 * Split the frame, if too long
146 if (pkt_len > expectlen)
147 tail_pkt = cfpkt_split(pkt, expectlen);
151 /* Send the first part of packet upwards.*/
152 spin_unlock(&layr->sync);
153 ret = layr->layer.up->receive(layr->layer.up, pkt);
154 spin_lock(&layr->sync);
155 if (ret == -EILSEQ) {
157 if (tail_pkt != NULL)
158 pkt = cfpkt_append(pkt, tail_pkt, 0);
159 /* Start search for next STX if frame failed */
169 } while (pkt != NULL);
171 spin_unlock(&layr->sync);
175 static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
177 struct cfserl *layr = container_obj(layer);
179 u8 tmp8 = CFSERL_STX;
181 cfpkt_add_head(newpkt, &tmp8, 1);
182 ret = layer->dn->transmit(layer->dn, newpkt);
184 cfpkt_extr_head(newpkt, &tmp8, 1);
189 static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
192 layr->up->ctrlcmd(layr->up, ctrl, phyid);