xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision 63705da3)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
3 #define SOUND_FIREWIRE_AMDTP_H_INCLUDED
4 
5 #include <linux/err.h>
6 #include <linux/interrupt.h>
7 #include <linux/mutex.h>
8 #include <linux/sched.h>
9 #include <sound/asound.h>
10 #include "packets-buffer.h"
11 
12 /**
13  * enum cip_flags - describes details of the streaming protocol
14  * @CIP_NONBLOCKING: In non-blocking mode, each packet contains
15  *	sample_rate/8000 samples, with rounding up or down to adjust
16  *	for clock skew and left-over fractional samples.  This should
17  *	be used if supported by the device.
18  * @CIP_BLOCKING: In blocking mode, each packet contains either zero or
19  *	SYT_INTERVAL samples, with these two types alternating so that
20  *	the overall sample rate comes out right.
21  * @CIP_EMPTY_WITH_TAG0: Only for in-stream. Empty in-packets have TAG0.
22  * @CIP_DBC_IS_END_EVENT: The value of dbc in an packet corresponds to the end
23  * of event in the packet. Out of IEC 61883.
24  * @CIP_WRONG_DBS: Only for in-stream. The value of dbs is wrong in in-packets.
25  *	The value of data_block_quadlets is used instead of reported value.
26  * @CIP_SKIP_DBC_ZERO_CHECK: Only for in-stream.  Packets with zero in dbc is
27  *	skipped for detecting discontinuity.
28  * @CIP_EMPTY_HAS_WRONG_DBC: Only for in-stream. The value of dbc in empty
29  *	packet is wrong but the others are correct.
30  * @CIP_JUMBO_PAYLOAD: Only for in-stream. The number of data blocks in an
31  *	packet is larger than IEC 61883-6 defines. Current implementation
32  *	allows 5 times as large as IEC 61883-6 defines.
33  * @CIP_HEADER_WITHOUT_EOH: Only for in-stream. CIP Header doesn't include
34  *	valid EOH.
35  * @CIP_NO_HEADERS: a lack of headers in packets
36  * @CIP_UNALIGHED_DBC: Only for in-stream. The value of dbc is not alighed to
37  *	the value of current SYT_INTERVAL; e.g. initial value is not zero.
38  * @CIP_UNAWARE_SYT: For outgoing packet, the value in SYT field of CIP is 0xffff.
39  *	For incoming packet, the value in SYT field of CIP is not handled.
40  */
41 enum cip_flags {
42 	CIP_NONBLOCKING		= 0x00,
43 	CIP_BLOCKING		= 0x01,
44 	CIP_EMPTY_WITH_TAG0	= 0x02,
45 	CIP_DBC_IS_END_EVENT	= 0x04,
46 	CIP_WRONG_DBS		= 0x08,
47 	CIP_SKIP_DBC_ZERO_CHECK	= 0x10,
48 	CIP_EMPTY_HAS_WRONG_DBC	= 0x20,
49 	CIP_JUMBO_PAYLOAD	= 0x40,
50 	CIP_HEADER_WITHOUT_EOH	= 0x80,
51 	CIP_NO_HEADER		= 0x100,
52 	CIP_UNALIGHED_DBC	= 0x200,
53 	CIP_UNAWARE_SYT		= 0x400,
54 };
55 
56 /**
57  * enum cip_sfc - supported Sampling Frequency Codes (SFCs)
58  * @CIP_SFC_32000:   32,000 data blocks
59  * @CIP_SFC_44100:   44,100 data blocks
60  * @CIP_SFC_48000:   48,000 data blocks
61  * @CIP_SFC_88200:   88,200 data blocks
62  * @CIP_SFC_96000:   96,000 data blocks
63  * @CIP_SFC_176400: 176,400 data blocks
64  * @CIP_SFC_192000: 192,000 data blocks
65  * @CIP_SFC_COUNT: the number of supported SFCs
66  *
67  * These values are used to show nominal Sampling Frequency Code in
68  * Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
69  * this code means the number of events per second. Actually the code
70  * represents the number of data blocks transferred per second in an AMDTP
71  * stream.
72  *
73  * In IEC 61883-6:2005, some extensions were added to support more types of
74  * data such as 'One Bit LInear Audio', therefore the meaning of SFC became
75  * different depending on the types.
76  *
77  * Currently our implementation is compatible with IEC 61883-6:2002.
78  */
79 enum cip_sfc {
80 	CIP_SFC_32000  = 0,
81 	CIP_SFC_44100  = 1,
82 	CIP_SFC_48000  = 2,
83 	CIP_SFC_88200  = 3,
84 	CIP_SFC_96000  = 4,
85 	CIP_SFC_176400 = 5,
86 	CIP_SFC_192000 = 6,
87 	CIP_SFC_COUNT
88 };
89 
90 struct fw_unit;
91 struct fw_iso_context;
92 struct snd_pcm_substream;
93 struct snd_pcm_runtime;
94 
95 enum amdtp_stream_direction {
96 	AMDTP_OUT_STREAM = 0,
97 	AMDTP_IN_STREAM
98 };
99 
100 struct pkt_desc {
101 	u32 cycle;
102 	u32 syt;
103 	unsigned int data_blocks;
104 	unsigned int data_block_counter;
105 	__be32 *ctx_payload;
106 };
107 
108 struct amdtp_stream;
109 typedef unsigned int (*amdtp_stream_process_ctx_payloads_t)(
110 						struct amdtp_stream *s,
111 						const struct pkt_desc *desc,
112 						unsigned int packets,
113 						struct snd_pcm_substream *pcm);
114 
115 struct amdtp_domain;
116 struct amdtp_stream {
117 	struct fw_unit *unit;
118 	// The combination of cip_flags enumeration-constants.
119 	unsigned int flags;
120 	enum amdtp_stream_direction direction;
121 	struct mutex mutex;
122 
123 	/* For packet processing. */
124 	struct fw_iso_context *context;
125 	struct iso_packets_buffer buffer;
126 	unsigned int queue_size;
127 	int packet_index;
128 	struct pkt_desc *pkt_descs;
129 	int tag;
130 	union {
131 		struct {
132 			unsigned int ctx_header_size;
133 
134 			// limit for payload of iso packet.
135 			unsigned int max_ctx_payload_length;
136 
137 			// For quirks of CIP headers.
138 			// Fixed interval of dbc between previos/current
139 			// packets.
140 			unsigned int dbc_interval;
141 
142 			// The device starts multiplexing events to the packet.
143 			bool event_starts;
144 
145 			struct {
146 				struct seq_desc *descs;
147 				unsigned int size;
148 				unsigned int tail;
149 			} cache;
150 		} tx;
151 		struct {
152 			// To generate CIP header.
153 			unsigned int fdf;
154 
155 			// To generate constant hardware IRQ.
156 			unsigned int event_count;
157 
158 			// To calculate CIP data blocks and tstamp.
159 			struct {
160 				struct seq_desc *descs;
161 				unsigned int size;
162 				unsigned int tail;
163 				unsigned int head;
164 			} seq;
165 
166 			unsigned int data_block_state;
167 			unsigned int syt_offset_state;
168 			unsigned int last_syt_offset;
169 
170 			struct amdtp_stream *replay_target;
171 			unsigned int cache_head;
172 		} rx;
173 	} ctx_data;
174 
175 	/* For CIP headers. */
176 	unsigned int source_node_id_field;
177 	unsigned int data_block_quadlets;
178 	unsigned int data_block_counter;
179 	unsigned int sph;
180 	unsigned int fmt;
181 
182 	// Internal flags.
183 	unsigned int transfer_delay;
184 	enum cip_sfc sfc;
185 	unsigned int syt_interval;
186 
187 	/* For a PCM substream processing. */
188 	struct snd_pcm_substream *pcm;
189 	snd_pcm_uframes_t pcm_buffer_pointer;
190 	unsigned int pcm_period_pointer;
191 
192 	// To start processing content of packets at the same cycle in several contexts for
193 	// each direction.
194 	bool ready_processing;
195 	wait_queue_head_t ready_wait;
196 	unsigned int next_cycle;
197 
198 	/* For backends to process data blocks. */
199 	void *protocol;
200 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
201 
202 	// For domain.
203 	int channel;
204 	int speed;
205 	struct list_head list;
206 	struct amdtp_domain *domain;
207 };
208 
209 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
210 		      enum amdtp_stream_direction dir, unsigned int flags,
211 		      unsigned int fmt,
212 		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
213 		      unsigned int protocol_size);
214 void amdtp_stream_destroy(struct amdtp_stream *s);
215 
216 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
217 				unsigned int data_block_quadlets);
218 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
219 
220 void amdtp_stream_update(struct amdtp_stream *s);
221 
222 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
223 					struct snd_pcm_runtime *runtime);
224 
225 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
226 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
227 
228 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
229 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
230 
231 /**
232  * amdtp_stream_running - check stream is running or not
233  * @s: the AMDTP stream
234  *
235  * If this function returns true, the stream is running.
236  */
237 static inline bool amdtp_stream_running(struct amdtp_stream *s)
238 {
239 	return !IS_ERR(s->context);
240 }
241 
242 /**
243  * amdtp_streaming_error - check for streaming error
244  * @s: the AMDTP stream
245  *
246  * If this function returns true, the stream's packet queue has stopped due to
247  * an asynchronous error.
248  */
249 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
250 {
251 	return s->packet_index < 0;
252 }
253 
254 /**
255  * amdtp_stream_pcm_running - check PCM substream is running or not
256  * @s: the AMDTP stream
257  *
258  * If this function returns true, PCM substream in the AMDTP stream is running.
259  */
260 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
261 {
262 	return !!s->pcm;
263 }
264 
265 /**
266  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
267  * @s: the AMDTP stream
268  * @pcm: the PCM device to be started, or %NULL to stop the current device
269  *
270  * Call this function on a running isochronous stream to enable the actual
271  * transmission of PCM data.  This function should be called from the PCM
272  * device's .trigger callback.
273  */
274 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
275 					    struct snd_pcm_substream *pcm)
276 {
277 	WRITE_ONCE(s->pcm, pcm);
278 }
279 
280 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
281 {
282 	return sfc & 1;
283 }
284 
285 struct seq_desc {
286 	unsigned int syt_offset;
287 	unsigned int data_blocks;
288 };
289 
290 struct amdtp_domain {
291 	struct list_head streams;
292 
293 	unsigned int events_per_period;
294 	unsigned int events_per_buffer;
295 
296 	struct amdtp_stream *irq_target;
297 
298 	struct {
299 		unsigned int tx_init_skip;
300 		unsigned int tx_start;
301 		unsigned int rx_start;
302 	} processing_cycle;
303 
304 	struct {
305 		bool enable:1;
306 		bool on_the_fly:1;
307 	} replay;
308 };
309 
310 int amdtp_domain_init(struct amdtp_domain *d);
311 void amdtp_domain_destroy(struct amdtp_domain *d);
312 
313 int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
314 			    int channel, int speed);
315 
316 int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, bool replay_seq,
317 		       bool replay_on_the_fly);
318 void amdtp_domain_stop(struct amdtp_domain *d);
319 
320 static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
321 						unsigned int events_per_period,
322 						unsigned int events_per_buffer)
323 {
324 	d->events_per_period = events_per_period;
325 	d->events_per_buffer = events_per_buffer;
326 
327 	return 0;
328 }
329 
330 unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
331 					      struct amdtp_stream *s);
332 int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
333 
334 /**
335  * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
336  * @d: the AMDTP domain
337  * @timeout_ms: msec till timeout
338  *
339  * If this function return false, the AMDTP domain should be stopped.
340  */
341 static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
342 {
343 	struct amdtp_stream *s;
344 
345 	list_for_each_entry(s, &d->streams, list) {
346 		unsigned int j = msecs_to_jiffies(timeout_ms);
347 
348 		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
349 			return false;
350 	}
351 
352 	return true;
353 }
354 
355 #endif
356