GNU Linux-libre 4.19.211-gnu1
[releases.git] / net / caif / cfutill.c
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
24 static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
25 static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
26
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 - 1, "util1");
37         return &util->layer;
38 }
39
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
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 }