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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson AB 2010
4 * Author: Sjur Brendeland
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
34void cfserl_release(struct cflayer *layer)
35{
36 kfree(layer);
37}
38
39struct cflayer *cfserl_create(int instance, bool use_stx)
40{
41 struct cfserl *this = kzalloc(sizeof(struct cfserl), GFP_ATOMIC);
42 if (!this)
43 return NULL;
44 caif_assert(offsetof(struct cfserl, layer) == 0);
45 this->layer.receive = cfserl_receive;
46 this->layer.transmit = cfserl_transmit;
47 this->layer.ctrlcmd = cfserl_ctrlcmd;
48 this->usestx = use_stx;
49 spin_lock_init(&this->sync);
50 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
51 return &this->layer;
52}
53
54static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
55{
56 struct cfserl *layr = container_obj(l);
57 u16 pkt_len;
58 struct cfpkt *pkt = NULL;
59 struct cfpkt *tail_pkt = NULL;
60 u8 tmp8;
61 u16 tmp;
62 u8 stx = CFSERL_STX;
63 int ret;
64 u16 expectlen = 0;
65
66 caif_assert(newpkt != NULL);
67 spin_lock(&layr->sync);
68
69 if (layr->incomplete_frm != NULL) {
70 layr->incomplete_frm =
71 cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
72 pkt = layr->incomplete_frm;
73 if (pkt == NULL) {
74 spin_unlock(&layr->sync);
75 return -ENOMEM;
76 }
77 } else {
78 pkt = newpkt;
79 }
80 layr->incomplete_frm = NULL;
81
82 do {
83 /* Search for STX at start of pkt if STX is used */
84 if (layr->usestx) {
85 cfpkt_extr_head(pkt, &tmp8, 1);
86 if (tmp8 != CFSERL_STX) {
87 while (cfpkt_more(pkt)
88 && tmp8 != CFSERL_STX) {
89 cfpkt_extr_head(pkt, &tmp8, 1);
90 }
91 if (!cfpkt_more(pkt)) {
92 cfpkt_destroy(pkt);
93 layr->incomplete_frm = NULL;
94 spin_unlock(&layr->sync);
95 return -EPROTO;
96 }
97 }
98 }
99
100 pkt_len = cfpkt_getlen(pkt);
101
102 /*
103 * pkt_len is the accumulated length of the packet data
104 * we have received so far.
105 * Exit if frame doesn't hold length.
106 */
107
108 if (pkt_len < 2) {
109 if (layr->usestx)
110 cfpkt_add_head(pkt, &stx, 1);
111 layr->incomplete_frm = pkt;
112 spin_unlock(&layr->sync);
113 return 0;
114 }
115
116 /*
117 * Find length of frame.
118 * expectlen is the length we need for a full frame.
119 */
120 cfpkt_peek_head(pkt, &tmp, 2);
121 expectlen = le16_to_cpu(tmp) + 2;
122 /*
123 * Frame error handling
124 */
125 if (expectlen < SERIAL_MINIUM_PACKET_SIZE
126 || expectlen > SERIAL_MAX_FRAMESIZE) {
127 if (!layr->usestx) {
128 if (pkt != NULL)
129 cfpkt_destroy(pkt);
130 layr->incomplete_frm = NULL;
131 expectlen = 0;
132 spin_unlock(&layr->sync);
133 return -EPROTO;
134 }
135 continue;
136 }
137
138 if (pkt_len < expectlen) {
139 /* Too little received data */
140 if (layr->usestx)
141 cfpkt_add_head(pkt, &stx, 1);
142 layr->incomplete_frm = pkt;
143 spin_unlock(&layr->sync);
144 return 0;
145 }
146
147 /*
148 * Enough data for at least one frame.
149 * Split the frame, if too long
150 */
151 if (pkt_len > expectlen)
152 tail_pkt = cfpkt_split(pkt, expectlen);
153 else
154 tail_pkt = NULL;
155
156 /* Send the first part of packet upwards.*/
157 spin_unlock(&layr->sync);
158 ret = layr->layer.up->receive(layr->layer.up, pkt);
159 spin_lock(&layr->sync);
160 if (ret == -EILSEQ) {
161 if (layr->usestx) {
162 if (tail_pkt != NULL)
163 pkt = cfpkt_append(pkt, tail_pkt, 0);
164 /* Start search for next STX if frame failed */
165 continue;
166 } else {
167 cfpkt_destroy(pkt);
168 pkt = NULL;
169 }
170 }
171
172 pkt = tail_pkt;
173
174 } while (pkt != NULL);
175
176 spin_unlock(&layr->sync);
177 return 0;
178}
179
180static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
181{
182 struct cfserl *layr = container_obj(layer);
183 u8 tmp8 = CFSERL_STX;
184 if (layr->usestx)
185 cfpkt_add_head(newpkt, &tmp8, 1);
186 return layer->dn->transmit(layer->dn, newpkt);
187}
188
189static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
190 int phyid)
191{
192 layr->up->ctrlcmd(layr->up, ctrl, phyid);
193}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson AB 2010
4 * Author: Sjur Brendeland
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
34void cfserl_release(struct cflayer *layer)
35{
36 kfree(layer);
37}
38
39struct cflayer *cfserl_create(int instance, bool use_stx)
40{
41 struct cfserl *this = kzalloc(sizeof(struct cfserl), GFP_ATOMIC);
42 if (!this)
43 return NULL;
44 caif_assert(offsetof(struct cfserl, layer) == 0);
45 this->layer.receive = cfserl_receive;
46 this->layer.transmit = cfserl_transmit;
47 this->layer.ctrlcmd = cfserl_ctrlcmd;
48 this->usestx = use_stx;
49 spin_lock_init(&this->sync);
50 snprintf(this->layer.name, CAIF_LAYER_NAME_SZ, "ser1");
51 return &this->layer;
52}
53
54static int cfserl_receive(struct cflayer *l, struct cfpkt *newpkt)
55{
56 struct cfserl *layr = container_obj(l);
57 u16 pkt_len;
58 struct cfpkt *pkt = NULL;
59 struct cfpkt *tail_pkt = NULL;
60 u8 tmp8;
61 u16 tmp;
62 u8 stx = CFSERL_STX;
63 int ret;
64 u16 expectlen = 0;
65
66 caif_assert(newpkt != NULL);
67 spin_lock(&layr->sync);
68
69 if (layr->incomplete_frm != NULL) {
70 layr->incomplete_frm =
71 cfpkt_append(layr->incomplete_frm, newpkt, expectlen);
72 pkt = layr->incomplete_frm;
73 if (pkt == NULL) {
74 spin_unlock(&layr->sync);
75 return -ENOMEM;
76 }
77 } else {
78 pkt = newpkt;
79 }
80 layr->incomplete_frm = NULL;
81
82 do {
83 /* Search for STX at start of pkt if STX is used */
84 if (layr->usestx) {
85 cfpkt_extr_head(pkt, &tmp8, 1);
86 if (tmp8 != CFSERL_STX) {
87 while (cfpkt_more(pkt)
88 && tmp8 != CFSERL_STX) {
89 cfpkt_extr_head(pkt, &tmp8, 1);
90 }
91 if (!cfpkt_more(pkt)) {
92 cfpkt_destroy(pkt);
93 layr->incomplete_frm = NULL;
94 spin_unlock(&layr->sync);
95 return -EPROTO;
96 }
97 }
98 }
99
100 pkt_len = cfpkt_getlen(pkt);
101
102 /*
103 * pkt_len is the accumulated length of the packet data
104 * we have received so far.
105 * Exit if frame doesn't hold length.
106 */
107
108 if (pkt_len < 2) {
109 if (layr->usestx)
110 cfpkt_add_head(pkt, &stx, 1);
111 layr->incomplete_frm = pkt;
112 spin_unlock(&layr->sync);
113 return 0;
114 }
115
116 /*
117 * Find length of frame.
118 * expectlen is the length we need for a full frame.
119 */
120 cfpkt_peek_head(pkt, &tmp, 2);
121 expectlen = le16_to_cpu(tmp) + 2;
122 /*
123 * Frame error handling
124 */
125 if (expectlen < SERIAL_MINIUM_PACKET_SIZE
126 || expectlen > SERIAL_MAX_FRAMESIZE) {
127 if (!layr->usestx) {
128 if (pkt != NULL)
129 cfpkt_destroy(pkt);
130 layr->incomplete_frm = NULL;
131 spin_unlock(&layr->sync);
132 return -EPROTO;
133 }
134 continue;
135 }
136
137 if (pkt_len < expectlen) {
138 /* Too little received data */
139 if (layr->usestx)
140 cfpkt_add_head(pkt, &stx, 1);
141 layr->incomplete_frm = pkt;
142 spin_unlock(&layr->sync);
143 return 0;
144 }
145
146 /*
147 * Enough data for at least one frame.
148 * Split the frame, if too long
149 */
150 if (pkt_len > expectlen)
151 tail_pkt = cfpkt_split(pkt, expectlen);
152 else
153 tail_pkt = NULL;
154
155 /* Send the first part of packet upwards.*/
156 spin_unlock(&layr->sync);
157 ret = layr->layer.up->receive(layr->layer.up, pkt);
158 spin_lock(&layr->sync);
159 if (ret == -EILSEQ) {
160 if (layr->usestx) {
161 if (tail_pkt != NULL)
162 pkt = cfpkt_append(pkt, tail_pkt, 0);
163 /* Start search for next STX if frame failed */
164 continue;
165 } else {
166 cfpkt_destroy(pkt);
167 pkt = NULL;
168 }
169 }
170
171 pkt = tail_pkt;
172
173 } while (pkt != NULL);
174
175 spin_unlock(&layr->sync);
176 return 0;
177}
178
179static int cfserl_transmit(struct cflayer *layer, struct cfpkt *newpkt)
180{
181 struct cfserl *layr = container_obj(layer);
182 u8 tmp8 = CFSERL_STX;
183 if (layr->usestx)
184 cfpkt_add_head(newpkt, &tmp8, 1);
185 return layer->dn->transmit(layer->dn, newpkt);
186}
187
188static void cfserl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
189 int phyid)
190{
191 layr->up->ctrlcmd(layr->up, ctrl, phyid);
192}