1 /*
2  * fireworks_transaction.c - a part of driver for Fireworks based devices
3  *
4  * Copyright (c) 2013-2014 Takashi Sakamoto
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 /*
10  * Fireworks have its own transaction. The transaction can be delivered by AV/C
11  * Vendor Specific command frame or usual asynchronous transaction. At least,
12  * Windows driver and firmware version 5.5 or later don't use AV/C command.
13  *
14  * Transaction substance:
15  *  At first, 6 data exist. Following to the data, parameters for each command
16  *  exist. All of the parameters are 32 bit aligned to big endian.
17  *   data[0]:	Length of transaction substance
18  *   data[1]:	Transaction version
19  *   data[2]:	Sequence number. This is incremented by the device
20  *   data[3]:	Transaction category
21  *   data[4]:	Transaction command
22  *   data[5]:	Return value in response.
23  *   data[6-]:	Parameters
24  *
25  * Transaction address:
26  *  command:	0xecc000000000
27  *  response:	0xecc080000000 (default)
28  *
29  * I note that the address for response can be changed by command. But this
30  * module uses the default address.
31  */
32 #include "./fireworks.h"
33 
34 #define MEMORY_SPACE_EFW_COMMAND	0xecc000000000ULL
35 #define MEMORY_SPACE_EFW_RESPONSE	0xecc080000000ULL
36 
37 #define ERROR_RETRIES 3
38 #define ERROR_DELAY_MS 5
39 #define EFC_TIMEOUT_MS 125
40 
41 static DEFINE_SPINLOCK(instances_lock);
42 static struct snd_efw *instances[SNDRV_CARDS] = SNDRV_DEFAULT_PTR;
43 
44 static DEFINE_SPINLOCK(transaction_queues_lock);
45 static LIST_HEAD(transaction_queues);
46 
47 enum transaction_queue_state {
48 	STATE_PENDING,
49 	STATE_BUS_RESET,
50 	STATE_COMPLETE
51 };
52 
53 struct transaction_queue {
54 	struct list_head list;
55 	struct fw_unit *unit;
56 	void *buf;
57 	unsigned int size;
58 	u32 seqnum;
59 	enum transaction_queue_state state;
60 	wait_queue_head_t wait;
61 };
62 
63 int snd_efw_transaction_cmd(struct fw_unit *unit,
64 			    const void *cmd, unsigned int size)
65 {
66 	return snd_fw_transaction(unit, TCODE_WRITE_BLOCK_REQUEST,
67 				  MEMORY_SPACE_EFW_COMMAND,
68 				  (void *)cmd, size, 0);
69 }
70 
71 int snd_efw_transaction_run(struct fw_unit *unit,
72 			    const void *cmd, unsigned int cmd_size,
73 			    void *resp, unsigned int resp_size)
74 {
75 	struct transaction_queue t;
76 	unsigned int tries;
77 	int ret;
78 
79 	t.unit = unit;
80 	t.buf = resp;
81 	t.size = resp_size;
82 	t.seqnum = be32_to_cpu(((struct snd_efw_transaction *)cmd)->seqnum) + 1;
83 	t.state = STATE_PENDING;
84 	init_waitqueue_head(&t.wait);
85 
86 	spin_lock_irq(&transaction_queues_lock);
87 	list_add_tail(&t.list, &transaction_queues);
88 	spin_unlock_irq(&transaction_queues_lock);
89 
90 	tries = 0;
91 	do {
92 		ret = snd_efw_transaction_cmd(t.unit, (void *)cmd, cmd_size);
93 		if (ret < 0)
94 			break;
95 
96 		wait_event_timeout(t.wait, t.state != STATE_PENDING,
97 				   msecs_to_jiffies(EFC_TIMEOUT_MS));
98 
99 		if (t.state == STATE_COMPLETE) {
100 			ret = t.size;
101 			break;
102 		} else if (t.state == STATE_BUS_RESET) {
103 			msleep(ERROR_DELAY_MS);
104 		} else if (++tries >= ERROR_RETRIES) {
105 			dev_err(&t.unit->device, "EFW transaction timed out\n");
106 			ret = -EIO;
107 			break;
108 		}
109 	} while (1);
110 
111 	spin_lock_irq(&transaction_queues_lock);
112 	list_del(&t.list);
113 	spin_unlock_irq(&transaction_queues_lock);
114 
115 	return ret;
116 }
117 
118 static void
119 copy_resp_to_buf(struct snd_efw *efw, void *data, size_t length, int *rcode)
120 {
121 	size_t capacity, till_end;
122 	struct snd_efw_transaction *t;
123 
124 	spin_lock_irq(&efw->lock);
125 
126 	t = (struct snd_efw_transaction *)data;
127 	length = min_t(size_t, be32_to_cpu(t->length) * sizeof(u32), length);
128 
129 	if (efw->push_ptr < efw->pull_ptr)
130 		capacity = (unsigned int)(efw->pull_ptr - efw->push_ptr);
131 	else
132 		capacity = snd_efw_resp_buf_size -
133 			   (unsigned int)(efw->push_ptr - efw->pull_ptr);
134 
135 	/* confirm enough space for this response */
136 	if (capacity < length) {
137 		*rcode = RCODE_CONFLICT_ERROR;
138 		goto end;
139 	}
140 
141 	/* copy to ring buffer */
142 	while (length > 0) {
143 		till_end = snd_efw_resp_buf_size -
144 			   (unsigned int)(efw->push_ptr - efw->resp_buf);
145 		till_end = min_t(unsigned int, length, till_end);
146 
147 		memcpy(efw->push_ptr, data, till_end);
148 
149 		efw->push_ptr += till_end;
150 		if (efw->push_ptr >= efw->resp_buf + snd_efw_resp_buf_size)
151 			efw->push_ptr -= snd_efw_resp_buf_size;
152 
153 		length -= till_end;
154 		data += till_end;
155 	}
156 
157 	/* for hwdep */
158 	efw->resp_queues++;
159 	wake_up(&efw->hwdep_wait);
160 
161 	*rcode = RCODE_COMPLETE;
162 end:
163 	spin_unlock_irq(&efw->lock);
164 }
165 
166 static void
167 handle_resp_for_user(struct fw_card *card, int generation, int source,
168 		     void *data, size_t length, int *rcode)
169 {
170 	struct fw_device *device;
171 	struct snd_efw *efw;
172 	unsigned int i;
173 
174 	spin_lock_irq(&instances_lock);
175 
176 	for (i = 0; i < SNDRV_CARDS; i++) {
177 		efw = instances[i];
178 		if (efw == NULL)
179 			continue;
180 		device = fw_parent_device(efw->unit);
181 		if ((device->card != card) ||
182 		    (device->generation != generation))
183 			continue;
184 		smp_rmb();	/* node id vs. generation */
185 		if (device->node_id != source)
186 			continue;
187 
188 		break;
189 	}
190 	if (i == SNDRV_CARDS)
191 		goto end;
192 
193 	copy_resp_to_buf(efw, data, length, rcode);
194 end:
195 	spin_unlock_irq(&instances_lock);
196 }
197 
198 static void
199 handle_resp_for_kernel(struct fw_card *card, int generation, int source,
200 		       void *data, size_t length, int *rcode, u32 seqnum)
201 {
202 	struct fw_device *device;
203 	struct transaction_queue *t;
204 	unsigned long flags;
205 
206 	spin_lock_irqsave(&transaction_queues_lock, flags);
207 	list_for_each_entry(t, &transaction_queues, list) {
208 		device = fw_parent_device(t->unit);
209 		if ((device->card != card) ||
210 		    (device->generation != generation))
211 			continue;
212 		smp_rmb();	/* node_id vs. generation */
213 		if (device->node_id != source)
214 			continue;
215 
216 		if ((t->state == STATE_PENDING) && (t->seqnum == seqnum)) {
217 			t->state = STATE_COMPLETE;
218 			t->size = min_t(unsigned int, length, t->size);
219 			memcpy(t->buf, data, t->size);
220 			wake_up(&t->wait);
221 			*rcode = RCODE_COMPLETE;
222 		}
223 	}
224 	spin_unlock_irqrestore(&transaction_queues_lock, flags);
225 }
226 
227 static void
228 efw_response(struct fw_card *card, struct fw_request *request,
229 	     int tcode, int destination, int source,
230 	     int generation, unsigned long long offset,
231 	     void *data, size_t length, void *callback_data)
232 {
233 	int rcode, dummy;
234 	u32 seqnum;
235 
236 	rcode = RCODE_TYPE_ERROR;
237 	if (length < sizeof(struct snd_efw_transaction)) {
238 		rcode = RCODE_DATA_ERROR;
239 		goto end;
240 	} else if (offset != MEMORY_SPACE_EFW_RESPONSE) {
241 		rcode = RCODE_ADDRESS_ERROR;
242 		goto end;
243 	}
244 
245 	seqnum = be32_to_cpu(((struct snd_efw_transaction *)data)->seqnum);
246 	if (seqnum > SND_EFW_TRANSACTION_USER_SEQNUM_MAX + 1) {
247 		handle_resp_for_kernel(card, generation, source,
248 				       data, length, &rcode, seqnum);
249 		if (snd_efw_resp_buf_debug)
250 			handle_resp_for_user(card, generation, source,
251 					     data, length, &dummy);
252 	} else {
253 		handle_resp_for_user(card, generation, source,
254 				     data, length, &rcode);
255 	}
256 end:
257 	fw_send_response(card, request, rcode);
258 }
259 
260 void snd_efw_transaction_add_instance(struct snd_efw *efw)
261 {
262 	unsigned int i;
263 
264 	spin_lock_irq(&instances_lock);
265 
266 	for (i = 0; i < SNDRV_CARDS; i++) {
267 		if (instances[i] != NULL)
268 			continue;
269 		instances[i] = efw;
270 		break;
271 	}
272 
273 	spin_unlock_irq(&instances_lock);
274 }
275 
276 void snd_efw_transaction_remove_instance(struct snd_efw *efw)
277 {
278 	unsigned int i;
279 
280 	spin_lock_irq(&instances_lock);
281 
282 	for (i = 0; i < SNDRV_CARDS; i++) {
283 		if (instances[i] != efw)
284 			continue;
285 		instances[i] = NULL;
286 	}
287 
288 	spin_unlock_irq(&instances_lock);
289 }
290 
291 void snd_efw_transaction_bus_reset(struct fw_unit *unit)
292 {
293 	struct transaction_queue *t;
294 
295 	spin_lock_irq(&transaction_queues_lock);
296 	list_for_each_entry(t, &transaction_queues, list) {
297 		if ((t->unit == unit) &&
298 		    (t->state == STATE_PENDING)) {
299 			t->state = STATE_BUS_RESET;
300 			wake_up(&t->wait);
301 		}
302 	}
303 	spin_unlock_irq(&transaction_queues_lock);
304 }
305 
306 static struct fw_address_handler resp_register_handler = {
307 	.length = SND_EFW_RESPONSE_MAXIMUM_BYTES,
308 	.address_callback = efw_response
309 };
310 
311 int snd_efw_transaction_register(void)
312 {
313 	static const struct fw_address_region resp_register_region = {
314 		.start	= MEMORY_SPACE_EFW_RESPONSE,
315 		.end	= MEMORY_SPACE_EFW_RESPONSE +
316 			  SND_EFW_RESPONSE_MAXIMUM_BYTES
317 	};
318 	return fw_core_add_address_handler(&resp_register_handler,
319 					   &resp_register_region);
320 }
321 
322 void snd_efw_transaction_unregister(void)
323 {
324 	WARN_ON(!list_empty(&transaction_queues));
325 	fw_core_remove_address_handler(&resp_register_handler);
326 }
327