1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Author: Sjur Brendeland/sjur.brandeland@stericsson.com 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/stddef.h> 10 #include <linux/spinlock.h> 11 #include <linux/slab.h> 12 #include <net/caif/caif_layer.h> 13 #include <net/caif/cfsrvl.h> 14 #include <net/caif/cfpkt.h> 15 16 #define container_obj(layr) ((struct cfsrvl *) layr) 17 18 #define DGM_CMD_BIT 0x80 19 #define DGM_FLOW_OFF 0x81 20 #define DGM_FLOW_ON 0x80 21 #define DGM_MTU 1500 22 23 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt); 24 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt); 25 26 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info) 27 { 28 struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC); 29 if (!dgm) { 30 pr_warn("Out of memory\n"); 31 return NULL; 32 } 33 caif_assert(offsetof(struct cfsrvl, layer) == 0); 34 memset(dgm, 0, sizeof(struct cfsrvl)); 35 cfsrvl_init(dgm, channel_id, dev_info, true); 36 dgm->layer.receive = cfdgml_receive; 37 dgm->layer.transmit = cfdgml_transmit; 38 snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id); 39 dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0'; 40 return &dgm->layer; 41 } 42 43 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt) 44 { 45 u8 cmd = -1; 46 u8 dgmhdr[3]; 47 int ret; 48 caif_assert(layr->up != NULL); 49 caif_assert(layr->receive != NULL); 50 caif_assert(layr->ctrlcmd != NULL); 51 52 if (cfpkt_extr_head(pkt, &cmd, 1) < 0) { 53 pr_err("Packet is erroneous!\n"); 54 cfpkt_destroy(pkt); 55 return -EPROTO; 56 } 57 58 if ((cmd & DGM_CMD_BIT) == 0) { 59 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) { 60 pr_err("Packet is erroneous!\n"); 61 cfpkt_destroy(pkt); 62 return -EPROTO; 63 } 64 ret = layr->up->receive(layr->up, pkt); 65 return ret; 66 } 67 68 switch (cmd) { 69 case DGM_FLOW_OFF: /* FLOW OFF */ 70 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0); 71 cfpkt_destroy(pkt); 72 return 0; 73 case DGM_FLOW_ON: /* FLOW ON */ 74 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0); 75 cfpkt_destroy(pkt); 76 return 0; 77 default: 78 cfpkt_destroy(pkt); 79 pr_info("Unknown datagram control %d (0x%x)\n", cmd, cmd); 80 return -EPROTO; 81 } 82 } 83 84 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt) 85 { 86 u32 zero = 0; 87 struct caif_payload_info *info; 88 struct cfsrvl *service = container_obj(layr); 89 int ret; 90 if (!cfsrvl_ready(service, &ret)) 91 return ret; 92 93 /* STE Modem cannot handle more than 1500 bytes datagrams */ 94 if (cfpkt_getlen(pkt) > DGM_MTU) 95 return -EMSGSIZE; 96 97 cfpkt_add_head(pkt, &zero, 4); 98 99 /* Add info for MUX-layer to route the packet out. */ 100 info = cfpkt_info(pkt); 101 info->channel_id = service->layer.id; 102 /* To optimize alignment, we add up the size of CAIF header 103 * before payload. 104 */ 105 info->hdr_len = 4; 106 info->dev_info = &service->dev_info; 107 ret = layr->dn->transmit(layr->dn, pkt); 108 if (ret < 0) { 109 u32 tmp32; 110 cfpkt_extr_head(pkt, &tmp32, 4); 111 } 112 return ret; 113 } 114