1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * fireworks_transaction.c - a part of driver for Fireworks based devices
4  *
5  * Copyright (c) 2013-2014 Takashi Sakamoto
6  */
7 
8 /*
9  * Fireworks have its own transaction. The transaction can be delivered by AV/C
10  * Vendor Specific command frame or usual asynchronous transaction. At least,
11  * Windows driver and firmware version 5.5 or later don't use AV/C command.
12  *
13  * Transaction substance:
14  *  At first, 6 data exist. Following to the data, parameters for each command
15  *  exist. All of the parameters are 32 bit aligned to big endian.
16  *   data[0]:	Length of transaction substance
17  *   data[1]:	Transaction version
18  *   data[2]:	Sequence number. This is incremented by the device
19  *   data[3]:	Transaction category
20  *   data[4]:	Transaction command
21  *   data[5]:	Return value in response.
22  *   data[6-]:	Parameters
23  *
24  * Transaction address:
25  *  command:	0xecc000000000
26  *  response:	0xecc080000000 (default)
27  *
28  * I note that the address for response can be changed by command. But this
29  * module uses the default address.
30  */
31 #include "./fireworks.h"
32 
33 #define MEMORY_SPACE_EFW_COMMAND	0xecc000000000ULL
34 #define MEMORY_SPACE_EFW_RESPONSE	0xecc080000000ULL
35 
36 #define ERROR_RETRIES 3
37 #define ERROR_DELAY_MS 5
38 #define EFC_TIMEOUT_MS 125
39 
40 static DEFINE_SPINLOCK(instances_lock);
41 static struct snd_efw *instances[SNDRV_CARDS] = SNDRV_DEFAULT_PTR;
42 
43 static DEFINE_SPINLOCK(transaction_queues_lock);
44 static LIST_HEAD(transaction_queues);
45 
46 enum transaction_queue_state {
47 	STATE_PENDING,
48 	STATE_BUS_RESET,
49 	STATE_COMPLETE
50 };
51 
52 struct transaction_queue {
53 	struct list_head list;
54 	struct fw_unit *unit;
55 	void *buf;
56 	unsigned int size;
57 	u32 seqnum;
58 	enum transaction_queue_state state;
59 	wait_queue_head_t wait;
60 };
61 
62 int snd_efw_transaction_cmd(struct fw_unit *unit,
63 			    const void *cmd, unsigned int size)
64 {
65 	return snd_fw_transaction(unit, TCODE_WRITE_BLOCK_REQUEST,
66 				  MEMORY_SPACE_EFW_COMMAND,
67 				  (void *)cmd, size, 0);
68 }
69 
70 int snd_efw_transaction_run(struct fw_unit *unit,
71 			    const void *cmd, unsigned int cmd_size,
72 			    void *resp, unsigned int resp_size)
73 {
74 	struct transaction_queue t;
75 	unsigned int tries;
76 	int ret;
77 
78 	t.unit = unit;
79 	t.buf = resp;
80 	t.size = resp_size;
81 	t.seqnum = be32_to_cpu(((struct snd_efw_transaction *)cmd)->seqnum) + 1;
82 	t.state = STATE_PENDING;
83 	init_waitqueue_head(&t.wait);
84 
85 	spin_lock_irq(&transaction_queues_lock);
86 	list_add_tail(&t.list, &transaction_queues);
87 	spin_unlock_irq(&transaction_queues_lock);
88 
89 	tries = 0;
90 	do {
91 		ret = snd_efw_transaction_cmd(t.unit, (void *)cmd, cmd_size);
92 		if (ret < 0)
93 			break;
94 
95 		wait_event_timeout(t.wait, t.state != STATE_PENDING,
96 				   msecs_to_jiffies(EFC_TIMEOUT_MS));
97 
98 		if (t.state == STATE_COMPLETE) {
99 			ret = t.size;
100 			break;
101 		} else if (t.state == STATE_BUS_RESET) {
102 			msleep(ERROR_DELAY_MS);
103 		} else if (++tries >= ERROR_RETRIES) {
104 			dev_err(&t.unit->device, "EFW transaction timed out\n");
105 			ret = -EIO;
106 			break;
107 		}
108 	} while (1);
109 
110 	spin_lock_irq(&transaction_queues_lock);
111 	list_del(&t.list);
112 	spin_unlock_irq(&transaction_queues_lock);
113 
114 	return ret;
115 }
116 
117 static void
118 copy_resp_to_buf(struct snd_efw *efw, void *data, size_t length, int *rcode)
119 {
120 	size_t capacity, till_end;
121 	struct snd_efw_transaction *t;
122 
123 	t = (struct snd_efw_transaction *)data;
124 	length = min_t(size_t, be32_to_cpu(t->length) * sizeof(u32), length);
125 
126 	spin_lock_irq(&efw->lock);
127 
128 	if (efw->push_ptr < efw->pull_ptr)
129 		capacity = (unsigned int)(efw->pull_ptr - efw->push_ptr);
130 	else
131 		capacity = snd_efw_resp_buf_size -
132 			   (unsigned int)(efw->push_ptr - efw->pull_ptr);
133 
134 	/* confirm enough space for this response */
135 	if (capacity < length) {
136 		*rcode = RCODE_CONFLICT_ERROR;
137 		goto end;
138 	}
139 
140 	/* copy to ring buffer */
141 	while (length > 0) {
142 		till_end = snd_efw_resp_buf_size -
143 			   (unsigned int)(efw->push_ptr - efw->resp_buf);
144 		till_end = min_t(unsigned int, length, till_end);
145 
146 		memcpy(efw->push_ptr, data, till_end);
147 
148 		efw->push_ptr += till_end;
149 		if (efw->push_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
150 			efw->push_ptr -= snd_efw_resp_buf_size;
151 
152 		length -= till_end;
153 		data += till_end;
154 	}
155 
156 	/* for hwdep */
157 	wake_up(&efw->hwdep_wait);
158 
159 	*rcode = RCODE_COMPLETE;
160 end:
161 	spin_unlock_irq(&efw->lock);
162 }
163 
164 static void
165 handle_resp_for_user(struct fw_card *card, int generation, int source,
166 		     void *data, size_t length, int *rcode)
167 {
168 	struct fw_device *device;
169 	struct snd_efw *efw;
170 	unsigned int i;
171 
172 	spin_lock_irq(&instances_lock);
173 
174 	for (i = 0; i < SNDRV_CARDS; i++) {
175 		efw = instances[i];
176 		if (efw == NULL)
177 			continue;
178 		device = fw_parent_device(efw->unit);
179 		if ((device->card != card) ||
180 		    (device->generation != generation))
181 			continue;
182 		smp_rmb();	/* node id vs. generation */
183 		if (device->node_id != source)
184 			continue;
185 
186 		break;
187 	}
188 	if (i == SNDRV_CARDS)
189 		goto end;
190 
191 	copy_resp_to_buf(efw, data, length, rcode);
192 end:
193 	spin_unlock_irq(&instances_lock);
194 }
195 
196 static void
197 handle_resp_for_kernel(struct fw_card *card, int generation, int source,
198 		       void *data, size_t length, int *rcode, u32 seqnum)
199 {
200 	struct fw_device *device;
201 	struct transaction_queue *t;
202 	unsigned long flags;
203 
204 	spin_lock_irqsave(&transaction_queues_lock, flags);
205 	list_for_each_entry(t, &transaction_queues, list) {
206 		device = fw_parent_device(t->unit);
207 		if ((device->card != card) ||
208 		    (device->generation != generation))
209 			continue;
210 		smp_rmb();	/* node_id vs. generation */
211 		if (device->node_id != source)
212 			continue;
213 
214 		if ((t->state == STATE_PENDING) && (t->seqnum == seqnum)) {
215 			t->state = STATE_COMPLETE;
216 			t->size = min_t(unsigned int, length, t->size);
217 			memcpy(t->buf, data, t->size);
218 			wake_up(&t->wait);
219 			*rcode = RCODE_COMPLETE;
220 		}
221 	}
222 	spin_unlock_irqrestore(&transaction_queues_lock, flags);
223 }
224 
225 static void
226 efw_response(struct fw_card *card, struct fw_request *request,
227 	     int tcode, int destination, int source,
228 	     int generation, unsigned long long offset,
229 	     void *data, size_t length, void *callback_data)
230 {
231 	int rcode, dummy;
232 	u32 seqnum;
233 
234 	rcode = RCODE_TYPE_ERROR;
235 	if (length < sizeof(struct snd_efw_transaction)) {
236 		rcode = RCODE_DATA_ERROR;
237 		goto end;
238 	} else if (offset != MEMORY_SPACE_EFW_RESPONSE) {
239 		rcode = RCODE_ADDRESS_ERROR;
240 		goto end;
241 	}
242 
243 	seqnum = be32_to_cpu(((struct snd_efw_transaction *)data)->seqnum);
244 	if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX + 1) {
245 		handle_resp_for_kernel(card, generation, source,
246 				       data, length, &rcode, seqnum);
247 		if (snd_efw_resp_buf_debug)
248 			handle_resp_for_user(card, generation, source,
249 					     data, length, &dummy);
250 	} else {
251 		handle_resp_for_user(card, generation, source,
252 				     data, length, &rcode);
253 	}
254 end:
255 	fw_send_response(card, request, rcode);
256 }
257 
258 void snd_efw_transaction_add_instance(struct snd_efw *efw)
259 {
260 	unsigned int i;
261 
262 	spin_lock_irq(&instances_lock);
263 
264 	for (i = 0; i < SNDRV_CARDS; i++) {
265 		if (instances[i] != NULL)
266 			continue;
267 		instances[i] = efw;
268 		break;
269 	}
270 
271 	spin_unlock_irq(&instances_lock);
272 }
273 
274 void snd_efw_transaction_remove_instance(struct snd_efw *efw)
275 {
276 	unsigned int i;
277 
278 	spin_lock_irq(&instances_lock);
279 
280 	for (i = 0; i < SNDRV_CARDS; i++) {
281 		if (instances[i] != efw)
282 			continue;
283 		instances[i] = NULL;
284 	}
285 
286 	spin_unlock_irq(&instances_lock);
287 }
288 
289 void snd_efw_transaction_bus_reset(struct fw_unit *unit)
290 {
291 	struct transaction_queue *t;
292 
293 	spin_lock_irq(&transaction_queues_lock);
294 	list_for_each_entry(t, &transaction_queues, list) {
295 		if ((t->unit == unit) &&
296 		    (t->state == STATE_PENDING)) {
297 			t->state = STATE_BUS_RESET;
298 			wake_up(&t->wait);
299 		}
300 	}
301 	spin_unlock_irq(&transaction_queues_lock);
302 }
303 
304 static struct fw_address_handler resp_register_handler = {
305 	.length = SND_EFW_RESPONSE_MAXIMUM_BYTES,
306 	.address_callback = efw_response
307 };
308 
309 int snd_efw_transaction_register(void)
310 {
311 	static const struct fw_address_region resp_register_region = {
312 		.start	= MEMORY_SPACE_EFW_RESPONSE,
313 		.end	= MEMORY_SPACE_EFW_RESPONSE +
314 			  SND_EFW_RESPONSE_MAXIMUM_BYTES
315 	};
316 	return fw_core_add_address_handler(&resp_register_handler,
317 					   &resp_register_region);
318 }
319 
320 void snd_efw_transaction_unregister(void)
321 {
322 	WARN_ON(!list_empty(&transaction_queues));
323 	fw_core_remove_address_handler(&resp_register_handler);
324 }
325