xref: /openbmc/linux/net/caif/cfveil.c (revision a44e4f3a)
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/slab.h>
11 #include <net/caif/caif_layer.h>
12 #include <net/caif/cfsrvl.h>
13 #include <net/caif/cfpkt.h>
14 
15 #define VEI_PAYLOAD  0x00
16 #define VEI_CMD_BIT  0x80
17 #define VEI_FLOW_OFF 0x81
18 #define VEI_FLOW_ON  0x80
19 #define VEI_SET_PIN  0x82
20 
21 #define container_obj(layr) container_of(layr, struct cfsrvl, layer)
22 
23 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
24 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);
25 
26 struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
27 {
28 	struct cfsrvl *vei = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
29 	if (!vei)
30 		return NULL;
31 	caif_assert(offsetof(struct cfsrvl, layer) == 0);
32 	cfsrvl_init(vei, channel_id, dev_info, true);
33 	vei->layer.receive = cfvei_receive;
34 	vei->layer.transmit = cfvei_transmit;
35 	snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ, "vei%d", channel_id);
36 	return &vei->layer;
37 }
38 
39 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
40 {
41 	u8 cmd;
42 	int ret;
43 	caif_assert(layr->up != NULL);
44 	caif_assert(layr->receive != NULL);
45 	caif_assert(layr->ctrlcmd != NULL);
46 
47 
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 	switch (cmd) {
54 	case VEI_PAYLOAD:
55 		ret = layr->up->receive(layr->up, pkt);
56 		return ret;
57 	case VEI_FLOW_OFF:
58 		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
59 		cfpkt_destroy(pkt);
60 		return 0;
61 	case VEI_FLOW_ON:
62 		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
63 		cfpkt_destroy(pkt);
64 		return 0;
65 	case VEI_SET_PIN:	/* SET RS232 PIN */
66 		cfpkt_destroy(pkt);
67 		return 0;
68 	default:		/* SET RS232 PIN */
69 		pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
70 		cfpkt_destroy(pkt);
71 		return -EPROTO;
72 	}
73 }
74 
75 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
76 {
77 	u8 tmp = 0;
78 	struct caif_payload_info *info;
79 	int ret;
80 	struct cfsrvl *service = container_obj(layr);
81 	if (!cfsrvl_ready(service, &ret))
82 		goto err;
83 	caif_assert(layr->dn != NULL);
84 	caif_assert(layr->dn->transmit != NULL);
85 
86 	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
87 		pr_err("Packet is erroneous!\n");
88 		ret = -EPROTO;
89 		goto err;
90 	}
91 
92 	/* Add info-> for MUX-layer to route the packet out. */
93 	info = cfpkt_info(pkt);
94 	info->channel_id = service->layer.id;
95 	info->hdr_len = 1;
96 	info->dev_info = &service->dev_info;
97 	return layr->dn->transmit(layr->dn, pkt);
98 err:
99 	cfpkt_destroy(pkt);
100 	return ret;
101 }
102