1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Atheros Communication Bluetooth HCIATH3K UART protocol
4  *
5  *  HCIATH3K (HCI Atheros AR300x Protocol) is a Atheros Communication's
6  *  power management protocol extension to H4 to support AR300x Bluetooth Chip.
7  *
8  *  Copyright (c) 2009-2010 Atheros Communications Inc.
9  *
10  *  Acknowledgements:
11  *  This file is based on hci_h4.c, which was written
12  *  by Maxim Krasnyansky and Marcel Holtmann.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/kernel.h>
17 
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/tty.h>
21 #include <linux/errno.h>
22 #include <linux/ioctl.h>
23 #include <linux/skbuff.h>
24 
25 #include <net/bluetooth/bluetooth.h>
26 #include <net/bluetooth/hci_core.h>
27 
28 #include "hci_uart.h"
29 
30 struct ath_struct {
31 	struct hci_uart *hu;
32 	unsigned int cur_sleep;
33 
34 	struct sk_buff *rx_skb;
35 	struct sk_buff_head txq;
36 	struct work_struct ctxtsw;
37 };
38 
39 #define OP_WRITE_TAG	0x01
40 
41 #define INDEX_BDADDR	0x01
42 
43 struct ath_vendor_cmd {
44 	__u8 opcode;
45 	__le16 index;
46 	__u8 len;
47 	__u8 data[251];
48 } __packed;
49 
ath_wakeup_ar3k(struct tty_struct * tty)50 static int ath_wakeup_ar3k(struct tty_struct *tty)
51 {
52 	int status = tty->driver->ops->tiocmget(tty);
53 
54 	if (status & TIOCM_CTS)
55 		return status;
56 
57 	/* Clear RTS first */
58 	tty->driver->ops->tiocmget(tty);
59 	tty->driver->ops->tiocmset(tty, 0x00, TIOCM_RTS);
60 	msleep(20);
61 
62 	/* Set RTS, wake up board */
63 	tty->driver->ops->tiocmget(tty);
64 	tty->driver->ops->tiocmset(tty, TIOCM_RTS, 0x00);
65 	msleep(20);
66 
67 	status = tty->driver->ops->tiocmget(tty);
68 	return status;
69 }
70 
ath_hci_uart_work(struct work_struct * work)71 static void ath_hci_uart_work(struct work_struct *work)
72 {
73 	int status;
74 	struct ath_struct *ath;
75 	struct hci_uart *hu;
76 	struct tty_struct *tty;
77 
78 	ath = container_of(work, struct ath_struct, ctxtsw);
79 
80 	hu = ath->hu;
81 	tty = hu->tty;
82 
83 	/* verify and wake up controller */
84 	if (ath->cur_sleep) {
85 		status = ath_wakeup_ar3k(tty);
86 		if (!(status & TIOCM_CTS))
87 			return;
88 	}
89 
90 	/* Ready to send Data */
91 	clear_bit(HCI_UART_SENDING, &hu->tx_state);
92 	hci_uart_tx_wakeup(hu);
93 }
94 
ath_open(struct hci_uart * hu)95 static int ath_open(struct hci_uart *hu)
96 {
97 	struct ath_struct *ath;
98 
99 	BT_DBG("hu %p", hu);
100 
101 	if (!hci_uart_has_flow_control(hu))
102 		return -EOPNOTSUPP;
103 
104 	ath = kzalloc(sizeof(*ath), GFP_KERNEL);
105 	if (!ath)
106 		return -ENOMEM;
107 
108 	skb_queue_head_init(&ath->txq);
109 
110 	hu->priv = ath;
111 	ath->hu = hu;
112 
113 	INIT_WORK(&ath->ctxtsw, ath_hci_uart_work);
114 
115 	return 0;
116 }
117 
ath_close(struct hci_uart * hu)118 static int ath_close(struct hci_uart *hu)
119 {
120 	struct ath_struct *ath = hu->priv;
121 
122 	BT_DBG("hu %p", hu);
123 
124 	skb_queue_purge(&ath->txq);
125 
126 	kfree_skb(ath->rx_skb);
127 
128 	cancel_work_sync(&ath->ctxtsw);
129 
130 	hu->priv = NULL;
131 	kfree(ath);
132 
133 	return 0;
134 }
135 
ath_flush(struct hci_uart * hu)136 static int ath_flush(struct hci_uart *hu)
137 {
138 	struct ath_struct *ath = hu->priv;
139 
140 	BT_DBG("hu %p", hu);
141 
142 	skb_queue_purge(&ath->txq);
143 
144 	return 0;
145 }
146 
ath_vendor_cmd(struct hci_dev * hdev,uint8_t opcode,uint16_t index,const void * data,size_t dlen)147 static int ath_vendor_cmd(struct hci_dev *hdev, uint8_t opcode, uint16_t index,
148 			  const void *data, size_t dlen)
149 {
150 	struct sk_buff *skb;
151 	struct ath_vendor_cmd cmd;
152 
153 	if (dlen > sizeof(cmd.data))
154 		return -EINVAL;
155 
156 	cmd.opcode = opcode;
157 	cmd.index = cpu_to_le16(index);
158 	cmd.len = dlen;
159 	memcpy(cmd.data, data, dlen);
160 
161 	skb = __hci_cmd_sync(hdev, 0xfc0b, dlen + 4, &cmd, HCI_INIT_TIMEOUT);
162 	if (IS_ERR(skb))
163 		return PTR_ERR(skb);
164 	kfree_skb(skb);
165 
166 	return 0;
167 }
168 
ath_set_bdaddr(struct hci_dev * hdev,const bdaddr_t * bdaddr)169 static int ath_set_bdaddr(struct hci_dev *hdev, const bdaddr_t *bdaddr)
170 {
171 	return ath_vendor_cmd(hdev, OP_WRITE_TAG, INDEX_BDADDR, bdaddr,
172 			      sizeof(*bdaddr));
173 }
174 
ath_setup(struct hci_uart * hu)175 static int ath_setup(struct hci_uart *hu)
176 {
177 	BT_DBG("hu %p", hu);
178 
179 	hu->hdev->set_bdaddr = ath_set_bdaddr;
180 
181 	return 0;
182 }
183 
184 static const struct h4_recv_pkt ath_recv_pkts[] = {
185 	{ H4_RECV_ACL,   .recv = hci_recv_frame },
186 	{ H4_RECV_SCO,   .recv = hci_recv_frame },
187 	{ H4_RECV_EVENT, .recv = hci_recv_frame },
188 };
189 
ath_recv(struct hci_uart * hu,const void * data,int count)190 static int ath_recv(struct hci_uart *hu, const void *data, int count)
191 {
192 	struct ath_struct *ath = hu->priv;
193 
194 	ath->rx_skb = h4_recv_buf(hu->hdev, ath->rx_skb, data, count,
195 				  ath_recv_pkts, ARRAY_SIZE(ath_recv_pkts));
196 	if (IS_ERR(ath->rx_skb)) {
197 		int err = PTR_ERR(ath->rx_skb);
198 		bt_dev_err(hu->hdev, "Frame reassembly failed (%d)", err);
199 		ath->rx_skb = NULL;
200 		return err;
201 	}
202 
203 	return count;
204 }
205 
206 #define HCI_OP_ATH_SLEEP 0xFC04
207 
ath_enqueue(struct hci_uart * hu,struct sk_buff * skb)208 static int ath_enqueue(struct hci_uart *hu, struct sk_buff *skb)
209 {
210 	struct ath_struct *ath = hu->priv;
211 
212 	if (hci_skb_pkt_type(skb) == HCI_SCODATA_PKT) {
213 		kfree_skb(skb);
214 		return 0;
215 	}
216 
217 	/* Update power management enable flag with parameters of
218 	 * HCI sleep enable vendor specific HCI command.
219 	 */
220 	if (hci_skb_pkt_type(skb) == HCI_COMMAND_PKT) {
221 		struct hci_command_hdr *hdr = (void *)skb->data;
222 
223 		if (__le16_to_cpu(hdr->opcode) == HCI_OP_ATH_SLEEP)
224 			ath->cur_sleep = skb->data[HCI_COMMAND_HDR_SIZE];
225 	}
226 
227 	BT_DBG("hu %p skb %p", hu, skb);
228 
229 	/* Prepend skb with frame type */
230 	memcpy(skb_push(skb, 1), &hci_skb_pkt_type(skb), 1);
231 
232 	skb_queue_tail(&ath->txq, skb);
233 	set_bit(HCI_UART_SENDING, &hu->tx_state);
234 
235 	schedule_work(&ath->ctxtsw);
236 
237 	return 0;
238 }
239 
ath_dequeue(struct hci_uart * hu)240 static struct sk_buff *ath_dequeue(struct hci_uart *hu)
241 {
242 	struct ath_struct *ath = hu->priv;
243 
244 	return skb_dequeue(&ath->txq);
245 }
246 
247 static const struct hci_uart_proto athp = {
248 	.id		= HCI_UART_ATH3K,
249 	.name		= "ATH3K",
250 	.manufacturer	= 69,
251 	.open		= ath_open,
252 	.close		= ath_close,
253 	.flush		= ath_flush,
254 	.setup		= ath_setup,
255 	.recv		= ath_recv,
256 	.enqueue	= ath_enqueue,
257 	.dequeue	= ath_dequeue,
258 };
259 
ath_init(void)260 int __init ath_init(void)
261 {
262 	return hci_uart_register_proto(&athp);
263 }
264 
ath_deinit(void)265 int __exit ath_deinit(void)
266 {
267 	return hci_uart_unregister_proto(&athp);
268 }
269