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
27struct rsi_hci_adapter {
28	void *priv;
29	struct rsi_proto_ops *proto_ops;
30	struct hci_dev *hdev;
31};
32
33static int rsi_hci_open(struct hci_dev *hdev)
34{
35	return 0;
36}
37
38static int rsi_hci_close(struct hci_dev *hdev)
39{
40	return 0;
41}
42
43static int rsi_hci_flush(struct hci_dev *hdev)
44{
45	return 0;
46}
47
48static 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
89static 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
109static 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->dev_type = HCI_PRIMARY;
138	hdev->open = rsi_hci_open;
139	hdev->close = rsi_hci_close;
140	hdev->flush = rsi_hci_flush;
141	hdev->send = rsi_hci_send_pkt;
142
143	err = hci_register_dev(hdev);
144	if (err < 0) {
145		BT_ERR("HCI registration failed with errcode %d", err);
146		hci_free_dev(hdev);
147		goto err;
148	}
149
150	return 0;
151err:
152	h_adapter->hdev = NULL;
153	kfree(h_adapter);
154	return -EINVAL;
155}
156
157static void rsi_hci_detach(void *priv)
158{
159	struct rsi_hci_adapter *h_adapter = priv;
160	struct hci_dev *hdev;
161
162	if (!h_adapter)
163		return;
164
165	hdev = h_adapter->hdev;
166	if (hdev) {
167		hci_unregister_dev(hdev);
168		hci_free_dev(hdev);
169		h_adapter->hdev = NULL;
170	}
171
172	kfree(h_adapter);
173}
174
175const struct rsi_mod_ops rsi_bt_ops = {
176	.attach	= rsi_hci_attach,
177	.detach	= rsi_hci_detach,
178	.recv_pkt = rsi_hci_recv_pkt,
179};
180EXPORT_SYMBOL(rsi_bt_ops);
181
182static int rsi_91x_bt_module_init(void)
183{
184	return 0;
185}
186
187static void rsi_91x_bt_module_exit(void)
188{
189	return;
190}
191
192module_init(rsi_91x_bt_module_init);
193module_exit(rsi_91x_bt_module_exit);
194MODULE_AUTHOR("Redpine Signals Inc");
195MODULE_DESCRIPTION("RSI BT driver");
196MODULE_LICENSE("Dual BSD/GPL");
197