xref: /openbmc/linux/net/caif/cfveil.c (revision e4c0d0e2)
1 /*
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
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 = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
29 	if (!vei) {
30 		pr_warn("Out of memory\n");
31 		return NULL;
32 	}
33 	caif_assert(offsetof(struct cfsrvl, layer) == 0);
34 	memset(vei, 0, sizeof(struct cfsrvl));
35 	cfsrvl_init(vei, channel_id, dev_info, true);
36 	vei->layer.receive = cfvei_receive;
37 	vei->layer.transmit = cfvei_transmit;
38 	snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ - 1, "vei%d", channel_id);
39 	return &vei->layer;
40 }
41 
42 static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
43 {
44 	u8 cmd;
45 	int ret;
46 	caif_assert(layr->up != NULL);
47 	caif_assert(layr->receive != NULL);
48 	caif_assert(layr->ctrlcmd != NULL);
49 
50 
51 	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
52 		pr_err("Packet is erroneous!\n");
53 		cfpkt_destroy(pkt);
54 		return -EPROTO;
55 	}
56 	switch (cmd) {
57 	case VEI_PAYLOAD:
58 		ret = layr->up->receive(layr->up, pkt);
59 		return ret;
60 	case VEI_FLOW_OFF:
61 		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
62 		cfpkt_destroy(pkt);
63 		return 0;
64 	case VEI_FLOW_ON:
65 		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
66 		cfpkt_destroy(pkt);
67 		return 0;
68 	case VEI_SET_PIN:	/* SET RS232 PIN */
69 		cfpkt_destroy(pkt);
70 		return 0;
71 	default:		/* SET RS232 PIN */
72 		pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
73 		cfpkt_destroy(pkt);
74 		return -EPROTO;
75 	}
76 }
77 
78 static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
79 {
80 	u8 tmp = 0;
81 	struct caif_payload_info *info;
82 	int ret;
83 	struct cfsrvl *service = container_obj(layr);
84 	if (!cfsrvl_ready(service, &ret))
85 		goto err;
86 	caif_assert(layr->dn != NULL);
87 	caif_assert(layr->dn->transmit != NULL);
88 
89 	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
90 		pr_err("Packet is erroneous!\n");
91 		ret = -EPROTO;
92 		goto err;
93 	}
94 
95 	/* Add info-> for MUX-layer to route the packet out. */
96 	info = cfpkt_info(pkt);
97 	info->channel_id = service->layer.id;
98 	info->hdr_len = 1;
99 	info->dev_info = &service->dev_info;
100 	return layr->dn->transmit(layr->dn, pkt);
101 err:
102 	cfpkt_destroy(pkt);
103 	return ret;
104 }
105