xref: /linux/drivers/bluetooth/btrsi.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 /*
2  * Copyright (c) 2017 Redpine Signals Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 #include <linux/module.h>
17 #include <linux/kernel.h>
18 #include <net/bluetooth/bluetooth.h>
19 #include <net/bluetooth/hci_core.h>
20 #include <asm/unaligned.h>
21 #include <net/rsi_91x.h>
22 
23 #define RSI_DMA_ALIGN	8
24 #define RSI_FRAME_DESC_SIZE	16
25 #define RSI_HEADROOM_FOR_BT_HAL	(RSI_FRAME_DESC_SIZE + RSI_DMA_ALIGN)
26 
27 struct rsi_hci_adapter {
28 	void *priv;
29 	struct rsi_proto_ops *proto_ops;
30 	struct hci_dev *hdev;
31 };
32 
33 static int rsi_hci_open(struct hci_dev *hdev)
34 {
35 	return 0;
36 }
37 
38 static int rsi_hci_close(struct hci_dev *hdev)
39 {
40 	return 0;
41 }
42 
43 static int rsi_hci_flush(struct hci_dev *hdev)
44 {
45 	return 0;
46 }
47 
48 static int rsi_hci_send_pkt(struct hci_dev *hdev, struct sk_buff *skb)
49 {
50 	struct rsi_hci_adapter *h_adapter = hci_get_drvdata(hdev);
51 	struct sk_buff *new_skb = NULL;
52 
53 	switch (hci_skb_pkt_type(skb)) {
54 	case HCI_COMMAND_PKT:
55 		hdev->stat.cmd_tx++;
56 		break;
57 	case HCI_ACLDATA_PKT:
58 		hdev->stat.acl_tx++;
59 		break;
60 	case HCI_SCODATA_PKT:
61 		hdev->stat.sco_tx++;
62 		break;
63 	}
64 
65 	if (skb_headroom(skb) < RSI_HEADROOM_FOR_BT_HAL) {
66 		/* Insufficient skb headroom - allocate a new skb */
67 		new_skb = skb_realloc_headroom(skb, RSI_HEADROOM_FOR_BT_HAL);
68 		if (unlikely(!new_skb))
69 			return -ENOMEM;
70 		bt_cb(new_skb)->pkt_type = hci_skb_pkt_type(skb);
71 		kfree_skb(skb);
72 		skb = new_skb;
73 		if (!IS_ALIGNED((unsigned long)skb->data, RSI_DMA_ALIGN)) {
74 			u8 *skb_data = skb->data;
75 			int skb_len = skb->len;
76 
77 			skb_push(skb, RSI_DMA_ALIGN);
78 			skb_pull(skb, PTR_ALIGN(skb->data,
79 						RSI_DMA_ALIGN) - skb->data);
80 			memmove(skb->data, skb_data, skb_len);
81 			skb_trim(skb, skb_len);
82 		}
83 	}
84 
85 	return h_adapter->proto_ops->coex_send_pkt(h_adapter->priv, skb,
86 						   RSI_BT_Q);
87 }
88 
89 static int rsi_hci_recv_pkt(void *priv, const u8 *pkt)
90 {
91 	struct rsi_hci_adapter *h_adapter = priv;
92 	struct hci_dev *hdev = h_adapter->hdev;
93 	struct sk_buff *skb;
94 	int pkt_len = get_unaligned_le16(pkt) & 0x0fff;
95 
96 	skb = dev_alloc_skb(pkt_len);
97 	if (!skb)
98 		return -ENOMEM;
99 
100 	memcpy(skb->data, pkt + RSI_FRAME_DESC_SIZE, pkt_len);
101 	skb_put(skb, pkt_len);
102 	h_adapter->hdev->stat.byte_rx += skb->len;
103 
104 	hci_skb_pkt_type(skb) = pkt[14];
105 
106 	return hci_recv_frame(hdev, skb);
107 }
108 
109 static int rsi_hci_attach(void *priv, struct rsi_proto_ops *ops)
110 {
111 	struct rsi_hci_adapter *h_adapter = NULL;
112 	struct hci_dev *hdev;
113 	int err = 0;
114 
115 	h_adapter = kzalloc(sizeof(*h_adapter), GFP_KERNEL);
116 	if (!h_adapter)
117 		return -ENOMEM;
118 
119 	h_adapter->priv = priv;
120 	ops->set_bt_context(priv, h_adapter);
121 	h_adapter->proto_ops = ops;
122 
123 	hdev = hci_alloc_dev();
124 	if (!hdev) {
125 		BT_ERR("Failed to alloc HCI device");
126 		goto err;
127 	}
128 
129 	h_adapter->hdev = hdev;
130 
131 	if (ops->get_host_intf(priv) == RSI_HOST_INTF_SDIO)
132 		hdev->bus = HCI_SDIO;
133 	else
134 		hdev->bus = HCI_USB;
135 
136 	hci_set_drvdata(hdev, h_adapter);
137 	hdev->open = rsi_hci_open;
138 	hdev->close = rsi_hci_close;
139 	hdev->flush = rsi_hci_flush;
140 	hdev->send = rsi_hci_send_pkt;
141 
142 	err = hci_register_dev(hdev);
143 	if (err < 0) {
144 		BT_ERR("HCI registration failed with errcode %d", err);
145 		hci_free_dev(hdev);
146 		goto err;
147 	}
148 
149 	return 0;
150 err:
151 	h_adapter->hdev = NULL;
152 	kfree(h_adapter);
153 	return -EINVAL;
154 }
155 
156 static void rsi_hci_detach(void *priv)
157 {
158 	struct rsi_hci_adapter *h_adapter = priv;
159 	struct hci_dev *hdev;
160 
161 	if (!h_adapter)
162 		return;
163 
164 	hdev = h_adapter->hdev;
165 	if (hdev) {
166 		hci_unregister_dev(hdev);
167 		hci_free_dev(hdev);
168 		h_adapter->hdev = NULL;
169 	}
170 
171 	kfree(h_adapter);
172 }
173 
174 const struct rsi_mod_ops rsi_bt_ops = {
175 	.attach	= rsi_hci_attach,
176 	.detach	= rsi_hci_detach,
177 	.recv_pkt = rsi_hci_recv_pkt,
178 };
179 EXPORT_SYMBOL(rsi_bt_ops);
180 
181 static int rsi_91x_bt_module_init(void)
182 {
183 	return 0;
184 }
185 
186 static void rsi_91x_bt_module_exit(void)
187 {
188 	return;
189 }
190 
191 module_init(rsi_91x_bt_module_init);
192 module_exit(rsi_91x_bt_module_exit);
193 MODULE_AUTHOR("Redpine Signals Inc");
194 MODULE_DESCRIPTION("RSI BT driver");
195 MODULE_LICENSE("Dual BSD/GPL");
196