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1/*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland
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/cfpkt.h>
14#include <net/caif/cfserl.h>
15
16#define container_obj(layr) ((struct cfserl *) layr)
17
18#define CFSERL_STX 0x02
19#define SERIAL_MINIUM_PACKET_SIZE 4
20#define SERIAL_MAX_FRAMESIZE 4096
21struct cfserl {
22 struct cflayer layer;
23 struct cfpkt *incomplete_frm;
24 /* Protects parallel processing of incoming packets */
25 spinlock_t sync;
26 bool usestx;
27};
28
29static int cfserl_receive(struct cflayer *layr, struct cfpkt *pkt);
30static int cfserl_transmit(struct cflayer *layr, struct cfpkt *pkt);
31static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
32 int phyid);
33
34struct cflayer *cfserl_create(int instance, bool use_stx)
35{
36 struct cfserl *this = kzalloc(sizeof(struct cfserl), GFP_ATOMIC);
37 if (!this)
38 return NULL;
39 caif_assert(offsetof(struct cfserl, layer) == 0);
40 this->layer.receive = cfserl_receive;
41 this->layer.transmit = cfserl_transmit;
42 this->layer.ctrlcmd = cfserl_ctrlcmd;
43 this->usestx = use_stx;
44 spin_lock_init(&this->sync);
45 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
46 return &this->layer;
47}
48
49static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
50{
51 struct cfserl *layr = container_obj(l);
52 u16 pkt_len;
53 struct cfpkt *pkt = NULL;
54 struct cfpkt *tail_pkt = NULL;
55 u8 tmp8;
56 u16 tmp;
57 u8 stx = CFSERL_STX;
58 int ret;
59 u16 expectlen = 0;
60
61 caif_assert(newpkt != NULL);
62 spin_lock(&layr->sync);
63
64 if (layr->incomplete_frm != NULL) {
65 layr->incomplete_frm =
66 cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
67 pkt = layr->incomplete_frm;
68 if (pkt == NULL) {
69 spin_unlock(&layr->sync);
70 return -ENOMEM;
71 }
72 } else {
73 pkt = newpkt;
74 }
75 layr->incomplete_frm = NULL;
76
77 do {
78 /* Search for STX at start of pkt if STX is used */
79 if (layr->usestx) {
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);
85 }
86 if (!cfpkt_more(pkt)) {
87 cfpkt_destroy(pkt);
88 layr->incomplete_frm = NULL;
89 spin_unlock(&layr->sync);
90 return -EPROTO;
91 }
92 }
93 }
94
95 pkt_len = cfpkt_getlen(pkt);
96
97 /*
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.
101 */
102
103 if (pkt_len < 2) {
104 if (layr->usestx)
105 cfpkt_add_head(pkt, &stx, 1);
106 layr->incomplete_frm = pkt;
107 spin_unlock(&layr->sync);
108 return 0;
109 }
110
111 /*
112 * Find length of frame.
113 * expectlen is the length we need for a full frame.
114 */
115 cfpkt_peek_head(pkt, &tmp, 2);
116 expectlen = le16_to_cpu(tmp) + 2;
117 /*
118 * Frame error handling
119 */
120 if (expectlen < SERIAL_MINIUM_PACKET_SIZE
121 || expectlen > SERIAL_MAX_FRAMESIZE) {
122 if (!layr->usestx) {
123 if (pkt != NULL)
124 cfpkt_destroy(pkt);
125 layr->incomplete_frm = NULL;
126 expectlen = 0;
127 spin_unlock(&layr->sync);
128 return -EPROTO;
129 }
130 continue;
131 }
132
133 if (pkt_len < expectlen) {
134 /* Too little received data */
135 if (layr->usestx)
136 cfpkt_add_head(pkt, &stx, 1);
137 layr->incomplete_frm = pkt;
138 spin_unlock(&layr->sync);
139 return 0;
140 }
141
142 /*
143 * Enough data for at least one frame.
144 * Split the frame, if too long
145 */
146 if (pkt_len > expectlen)
147 tail_pkt = cfpkt_split(pkt, expectlen);
148 else
149 tail_pkt = NULL;
150
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) {
156 if (layr->usestx) {
157 if (tail_pkt != NULL)
158 pkt = cfpkt_append(pkt, tail_pkt, 0);
159 /* Start search for next STX if frame failed */
160 continue;
161 } else {
162 cfpkt_destroy(pkt);
163 pkt = NULL;
164 }
165 }
166
167 pkt = tail_pkt;
168
169 } while (pkt != NULL);
170
171 spin_unlock(&layr->sync);
172 return 0;
173}
174
175static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
176{
177 struct cfserl *layr = container_obj(layer);
178 u8 tmp8 = CFSERL_STX;
179 if (layr->usestx)
180 cfpkt_add_head(newpkt, &tmp8, 1);
181 return layer->dn->transmit(layer->dn, newpkt);
182}
183
184static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
185 int phyid)
186{
187 layr->up->ctrlcmd(layr->up, ctrl, phyid);
188}
1/*
2 * Copyright (C) ST-Ericsson AB 2010
3 * Author: Sjur Brendeland
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/cfpkt.h>
14#include <net/caif/cfserl.h>
15
16#define container_obj(layr) ((struct cfserl *) layr)
17
18#define CFSERL_STX 0x02
19#define SERIAL_MINIUM_PACKET_SIZE 4
20#define SERIAL_MAX_FRAMESIZE 4096
21struct cfserl {
22 struct cflayer layer;
23 struct cfpkt *incomplete_frm;
24 /* Protects parallel processing of incoming packets */
25 spinlock_t sync;
26 bool usestx;
27};
28
29static int cfserl_receive(struct cflayer *layr, struct cfpkt *pkt);
30static int cfserl_transmit(struct cflayer *layr, struct cfpkt *pkt);
31static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
32 int phyid);
33
34struct cflayer *cfserl_create(int instance, bool use_stx)
35{
36 struct cfserl *this = kzalloc(sizeof(struct cfserl), GFP_ATOMIC);
37 if (!this)
38 return NULL;
39 caif_assert(offsetof(struct cfserl, layer) == 0);
40 this->layer.receive = cfserl_receive;
41 this->layer.transmit = cfserl_transmit;
42 this->layer.ctrlcmd = cfserl_ctrlcmd;
43 this->usestx = use_stx;
44 spin_lock_init(&this->sync);
45 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
46 return &this->layer;
47}
48
49static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
50{
51 struct cfserl *layr = container_obj(l);
52 u16 pkt_len;
53 struct cfpkt *pkt = NULL;
54 struct cfpkt *tail_pkt = NULL;
55 u8 tmp8;
56 u16 tmp;
57 u8 stx = CFSERL_STX;
58 int ret;
59 u16 expectlen = 0;
60
61 caif_assert(newpkt != NULL);
62 spin_lock(&layr->sync);
63
64 if (layr->incomplete_frm != NULL) {
65 layr->incomplete_frm =
66 cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
67 pkt = layr->incomplete_frm;
68 if (pkt == NULL) {
69 spin_unlock(&layr->sync);
70 return -ENOMEM;
71 }
72 } else {
73 pkt = newpkt;
74 }
75 layr->incomplete_frm = NULL;
76
77 do {
78 /* Search for STX at start of pkt if STX is used */
79 if (layr->usestx) {
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);
85 }
86 if (!cfpkt_more(pkt)) {
87 cfpkt_destroy(pkt);
88 layr->incomplete_frm = NULL;
89 spin_unlock(&layr->sync);
90 return -EPROTO;
91 }
92 }
93 }
94
95 pkt_len = cfpkt_getlen(pkt);
96
97 /*
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.
101 */
102
103 if (pkt_len < 2) {
104 if (layr->usestx)
105 cfpkt_add_head(pkt, &stx, 1);
106 layr->incomplete_frm = pkt;
107 spin_unlock(&layr->sync);
108 return 0;
109 }
110
111 /*
112 * Find length of frame.
113 * expectlen is the length we need for a full frame.
114 */
115 cfpkt_peek_head(pkt, &tmp, 2);
116 expectlen = le16_to_cpu(tmp) + 2;
117 /*
118 * Frame error handling
119 */
120 if (expectlen < SERIAL_MINIUM_PACKET_SIZE
121 || expectlen > SERIAL_MAX_FRAMESIZE) {
122 if (!layr->usestx) {
123 if (pkt != NULL)
124 cfpkt_destroy(pkt);
125 layr->incomplete_frm = NULL;
126 expectlen = 0;
127 spin_unlock(&layr->sync);
128 return -EPROTO;
129 }
130 continue;
131 }
132
133 if (pkt_len < expectlen) {
134 /* Too little received data */
135 if (layr->usestx)
136 cfpkt_add_head(pkt, &stx, 1);
137 layr->incomplete_frm = pkt;
138 spin_unlock(&layr->sync);
139 return 0;
140 }
141
142 /*
143 * Enough data for at least one frame.
144 * Split the frame, if too long
145 */
146 if (pkt_len > expectlen)
147 tail_pkt = cfpkt_split(pkt, expectlen);
148 else
149 tail_pkt = NULL;
150
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) {
156 if (layr->usestx) {
157 if (tail_pkt != NULL)
158 pkt = cfpkt_append(pkt, tail_pkt, 0);
159 /* Start search for next STX if frame failed */
160 continue;
161 } else {
162 cfpkt_destroy(pkt);
163 pkt = NULL;
164 }
165 }
166
167 pkt = tail_pkt;
168
169 } while (pkt != NULL);
170
171 spin_unlock(&layr->sync);
172 return 0;
173}
174
175static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
176{
177 struct cfserl *layr = container_obj(layer);
178 u8 tmp8 = CFSERL_STX;
179 if (layr->usestx)
180 cfpkt_add_head(newpkt, &tmp8, 1);
181 return layer->dn->transmit(layer->dn, newpkt);
182}
183
184static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
185 int phyid)
186{
187 layr->up->ctrlcmd(layr->up, ctrl, phyid);
188}