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/kernel.h>
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/errno.h>
13 #include <net/caif/caif_layer.h>
14 #include <net/caif/cfsrvl.h>
15 #include <net/caif/cfpkt.h>
16
17 #define container_obj(layr) ((struct cfsrvl *) layr)
18 #define UTIL_PAYLOAD 0x00
19 #define UTIL_CMD_BIT 0x80
20 #define UTIL_REMOTE_SHUTDOWN 0x82
21 #define UTIL_FLOW_OFF 0x81
22 #define UTIL_FLOW_ON 0x80
23
24 static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
25 static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
26
cfutill_create(u8 channel_id,struct dev_info * dev_info)27 struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
28 {
29 struct cfsrvl *util = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
30 if (!util)
31 return NULL;
32 caif_assert(offsetof(struct cfsrvl, layer) == 0);
33 cfsrvl_init(util, channel_id, dev_info, true);
34 util->layer.receive = cfutill_receive;
35 util->layer.transmit = cfutill_transmit;
36 snprintf(util->layer.name, CAIF_LAYER_NAME_SZ, "util1");
37 return &util->layer;
38 }
39
cfutill_receive(struct cflayer * layr,struct cfpkt * pkt)40 static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
41 {
42 u8 cmd = -1;
43 struct cfsrvl *service = container_obj(layr);
44 caif_assert(layr != NULL);
45 caif_assert(layr->up != NULL);
46 caif_assert(layr->up->receive != NULL);
47 caif_assert(layr->up->ctrlcmd != NULL);
48 if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
49 pr_err("Packet is erroneous!\n");
50 cfpkt_destroy(pkt);
51 return -EPROTO;
52 }
53
54 switch (cmd) {
55 case UTIL_PAYLOAD:
56 return layr->up->receive(layr->up, pkt);
57 case UTIL_FLOW_OFF:
58 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
59 cfpkt_destroy(pkt);
60 return 0;
61 case UTIL_FLOW_ON:
62 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
63 cfpkt_destroy(pkt);
64 return 0;
65 case UTIL_REMOTE_SHUTDOWN: /* Remote Shutdown Request */
66 pr_err("REMOTE SHUTDOWN REQUEST RECEIVED\n");
67 layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
68 service->open = false;
69 cfpkt_destroy(pkt);
70 return 0;
71 default:
72 cfpkt_destroy(pkt);
73 pr_warn("Unknown service control %d (0x%x)\n", cmd, cmd);
74 return -EPROTO;
75 }
76 }
77
cfutill_transmit(struct cflayer * layr,struct cfpkt * pkt)78 static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
79 {
80 u8 zero = 0;
81 struct caif_payload_info *info;
82 int ret;
83 struct cfsrvl *service = container_obj(layr);
84 caif_assert(layr != NULL);
85 caif_assert(layr->dn != NULL);
86 caif_assert(layr->dn->transmit != NULL);
87
88 if (!cfsrvl_ready(service, &ret)) {
89 cfpkt_destroy(pkt);
90 return ret;
91 }
92
93 cfpkt_add_head(pkt, &zero, 1);
94 /* Add info for MUX-layer to route the packet out. */
95 info = cfpkt_info(pkt);
96 info->channel_id = service->layer.id;
97 /*
98 * To optimize alignment, we add up the size of CAIF header before
99 * payload.
100 */
101 info->hdr_len = 1;
102 info->dev_info = &service->dev_info;
103 return layr->dn->transmit(layr->dn, pkt);
104 }
105