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 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 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 } 105