xref: /linux/net/caif/cfrfml.c (revision 36239c6704b71da7fb8e2a9429e159a84d0c5a3e)
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 #include <linux/stddef.h>
8 #include <linux/spinlock.h>
9 #include <linux/slab.h>
10 #include <net/caif/caif_layer.h>
11 #include <net/caif/cfsrvl.h>
12 #include <net/caif/cfpkt.h>
13 
14 #define container_obj(layr) container_of(layr, struct cfsrvl, layer)
15 
16 #define RFM_SEGMENTATION_BIT 0x01
17 #define RFM_PAYLOAD  0x00
18 #define RFM_CMD_BIT  0x80
19 #define RFM_FLOW_OFF 0x81
20 #define RFM_FLOW_ON  0x80
21 #define RFM_SET_PIN  0x82
22 #define RFM_CTRL_PKT_SIZE 1
23 
24 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt);
25 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt);
26 static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl);
27 
28 struct cflayer *cfrfml_create(u8 channel_id, struct dev_info *dev_info)
29 {
30 	struct cfsrvl *rfm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
31 	if (!rfm) {
32 		pr_warning("CAIF: %s(): Out of memory\n", __func__);
33 		return NULL;
34 	}
35 	caif_assert(offsetof(struct cfsrvl, layer) == 0);
36 	memset(rfm, 0, sizeof(struct cfsrvl));
37 	cfsrvl_init(rfm, channel_id, dev_info);
38 	rfm->layer.modemcmd = cfservl_modemcmd;
39 	rfm->layer.receive = cfrfml_receive;
40 	rfm->layer.transmit = cfrfml_transmit;
41 	snprintf(rfm->layer.name, CAIF_LAYER_NAME_SZ, "rfm%d", channel_id);
42 	return &rfm->layer;
43 }
44 
45 static int cfservl_modemcmd(struct cflayer *layr, enum caif_modemcmd ctrl)
46 {
47        return -EPROTO;
48 }
49 
50 static int cfrfml_receive(struct cflayer *layr, struct cfpkt *pkt)
51 {
52 	u8 tmp;
53 	bool segmented;
54 	int ret;
55 	caif_assert(layr->up != NULL);
56 	caif_assert(layr->receive != NULL);
57 
58 	/*
59 	 * RFM is taking care of segmentation and stripping of
60 	 * segmentation bit.
61 	 */
62 	if (cfpkt_extr_head(pkt, &tmp, 1) < 0) {
63 		pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
64 		cfpkt_destroy(pkt);
65 		return -EPROTO;
66 	}
67 	segmented = tmp & RFM_SEGMENTATION_BIT;
68 	caif_assert(!segmented);
69 
70 	ret = layr->up->receive(layr->up, pkt);
71 	return ret;
72 }
73 
74 static int cfrfml_transmit(struct cflayer *layr, struct cfpkt *pkt)
75 {
76 	u8 tmp = 0;
77 	int ret;
78 	struct cfsrvl *service = container_obj(layr);
79 
80 	caif_assert(layr->dn != NULL);
81 	caif_assert(layr->dn->transmit != NULL);
82 
83 	if (!cfsrvl_ready(service, &ret))
84 		return ret;
85 
86 	if (cfpkt_getlen(pkt) > CAIF_MAX_PAYLOAD_SIZE) {
87 		pr_err("CAIF: %s():Packet too large - size=%d\n",
88 			__func__, cfpkt_getlen(pkt));
89 		return -EOVERFLOW;
90 	}
91 	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
92 		pr_err("CAIF: %s(): Packet is erroneous!\n", __func__);
93 		return -EPROTO;
94 	}
95 
96 	/* Add info for MUX-layer to route the packet out. */
97 	cfpkt_info(pkt)->channel_id = service->layer.id;
98 	/*
99 	 * To optimize alignment, we add up the size of CAIF header before
100 	 * payload.
101 	 */
102 	cfpkt_info(pkt)->hdr_len = 1;
103 	cfpkt_info(pkt)->dev_info = &service->dev_info;
104 	ret = layr->dn->transmit(layr->dn, pkt);
105 	if (ret < 0)
106 		cfpkt_extr_head(pkt, &tmp, 1);
107 	return ret;
108 }
109