net/caif/cfutill.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) ST-Ericsson AB 2010
0004  * Author:  Sjur Brendeland
0005  */
0006
0007 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
0008
0009 #include <linux/kernel.h>
0010 #include <linux/types.h>
0011 #include <linux/slab.h>
0012 #include <linux/errno.h>
0013 #include <net/caif/caif_layer.h>
0014 #include <net/caif/cfsrvl.h>
0015 #include <net/caif/cfpkt.h>
0016
0017 #define container_obj(layr) ((struct cfsrvl *) layr)
0018 #define UTIL_PAYLOAD  0x00
0019 #define UTIL_CMD_BIT  0x80
0020 #define UTIL_REMOTE_SHUTDOWN 0x82
0021 #define UTIL_FLOW_OFF 0x81
0022 #define UTIL_FLOW_ON  0x80
0023
0024 static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt);
0025 static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt);
0026
0027 struct cflayer *cfutill_create(u8 channel_id, struct dev_info *dev_info)
0028 {
0029     struct cfsrvl *util = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
0030     if (!util)
0031         return NULL;
0032     caif_assert(offsetof(struct cfsrvl, layer) == 0);
0033     cfsrvl_init(util, channel_id, dev_info, true);
0034     util->layer.receive = cfutill_receive;
0035     util->layer.transmit = cfutill_transmit;
0036     snprintf(util->layer.name, CAIF_LAYER_NAME_SZ, "util1");
0037     return &util->layer;
0038 }
0039
0040 static int cfutill_receive(struct cflayer *layr, struct cfpkt *pkt)
0041 {
0042     u8 cmd = -1;
0043     struct cfsrvl *service = container_obj(layr);
0044     caif_assert(layr != NULL);
0045     caif_assert(layr->up != NULL);
0046     caif_assert(layr->up->receive != NULL);
0047     caif_assert(layr->up->ctrlcmd != NULL);
0048     if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
0049         pr_err("Packet is erroneous!\n");
0050         cfpkt_destroy(pkt);
0051         return -EPROTO;
0052     }
0053
0054     switch (cmd) {
0055     case UTIL_PAYLOAD:
0056         return layr->up->receive(layr->up, pkt);
0057     case UTIL_FLOW_OFF:
0058         layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
0059         cfpkt_destroy(pkt);
0060         return 0;
0061     case UTIL_FLOW_ON:
0062         layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
0063         cfpkt_destroy(pkt);
0064         return 0;
0065     case UTIL_REMOTE_SHUTDOWN:  /* Remote Shutdown Request */
0066         pr_err("REMOTE SHUTDOWN REQUEST RECEIVED\n");
0067         layr->ctrlcmd(layr, CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND, 0);
0068         service->open = false;
0069         cfpkt_destroy(pkt);
0070         return 0;
0071     default:
0072         cfpkt_destroy(pkt);
0073         pr_warn("Unknown service control %d (0x%x)\n", cmd, cmd);
0074         return -EPROTO;
0075     }
0076 }
0077
0078 static int cfutill_transmit(struct cflayer *layr, struct cfpkt *pkt)
0079 {
0080     u8 zero = 0;
0081     struct caif_payload_info *info;
0082     int ret;
0083     struct cfsrvl *service = container_obj(layr);
0084     caif_assert(layr != NULL);
0085     caif_assert(layr->dn != NULL);
0086     caif_assert(layr->dn->transmit != NULL);
0087
0088     if (!cfsrvl_ready(service, &ret)) {
0089         cfpkt_destroy(pkt);
0090         return ret;
0091     }
0092
0093     cfpkt_add_head(pkt, &zero, 1);
0094     /* Add info for MUX-layer to route the packet out. */
0095     info = cfpkt_info(pkt);
0096     info->channel_id = service->layer.id;
0097     /*
0098      * To optimize alignment, we add up the size of CAIF header before
0099      * payload.
0100      */
0101     info->hdr_len = 1;
0102     info->dev_info = &service->dev_info;
0103     return layr->dn->transmit(layr->dn, pkt);
0104 }