xref: /openbmc/linux/net/caif/cfutill.c (revision af873fce)
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