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/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
24static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
25static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
26
27struct 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 - 1, "util1");
37	return &util->layer;
38}
39
40static 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
78static 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