xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision 0c6dfa75)
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 	struct list_head link;
107 };
108 
109 struct amdtp_stream;
110 typedef void (*amdtp_stream_process_ctx_payloads_t)(struct amdtp_stream *s,
111 						    const struct pkt_desc *desc,
112 						    unsigned int count,
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 *packet_descs;
129 	struct list_head packet_descs_list;
130 	struct pkt_desc *packet_descs_cursor;
131 	int tag;
132 	union {
133 		struct {
134 			unsigned int ctx_header_size;
135 
136 			// limit for payload of iso packet.
137 			unsigned int max_ctx_payload_length;
138 
139 			// For quirks of CIP headers.
140 			// Fixed interval of dbc between previos/current
141 			// packets.
142 			unsigned int dbc_interval;
143 
144 			// The device starts multiplexing events to the packet.
145 			bool event_starts;
146 
147 			struct {
148 				struct seq_desc *descs;
149 				unsigned int size;
150 				unsigned int pos;
151 			} cache;
152 		} tx;
153 		struct {
154 			// To generate CIP header.
155 			unsigned int fdf;
156 
157 			// To generate constant hardware IRQ.
158 			unsigned int event_count;
159 
160 			// To calculate CIP data blocks and tstamp.
161 			struct {
162 				struct seq_desc *descs;
163 				unsigned int size;
164 				unsigned int pos;
165 			} seq;
166 
167 			unsigned int data_block_state;
168 			unsigned int syt_offset_state;
169 			unsigned int last_syt_offset;
170 
171 			struct amdtp_stream *replay_target;
172 			unsigned int cache_pos;
173 		} rx;
174 	} ctx_data;
175 
176 	/* For CIP headers. */
177 	unsigned int source_node_id_field;
178 	unsigned int data_block_quadlets;
179 	unsigned int data_block_counter;
180 	unsigned int sph;
181 	unsigned int fmt;
182 
183 	// Internal flags.
184 	unsigned int transfer_delay;
185 	enum cip_sfc sfc;
186 	unsigned int syt_interval;
187 
188 	/* For a PCM substream processing. */
189 	struct snd_pcm_substream *pcm;
190 	snd_pcm_uframes_t pcm_buffer_pointer;
191 	unsigned int pcm_period_pointer;
192 	unsigned int pcm_frame_multiplier;
193 
194 	// To start processing content of packets at the same cycle in several contexts for
195 	// each direction.
196 	bool ready_processing;
197 	wait_queue_head_t ready_wait;
198 	unsigned int next_cycle;
199 
200 	/* For backends to process data blocks. */
201 	void *protocol;
202 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
203 
204 	// For domain.
205 	int channel;
206 	int speed;
207 	struct list_head list;
208 	struct amdtp_domain *domain;
209 };
210 
211 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
212 		      enum amdtp_stream_direction dir, unsigned int flags,
213 		      unsigned int fmt,
214 		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
215 		      unsigned int protocol_size);
216 void amdtp_stream_destroy(struct amdtp_stream *s);
217 
218 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
219 				unsigned int data_block_quadlets, unsigned int pcm_frame_multiplier);
220 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
221 
222 void amdtp_stream_update(struct amdtp_stream *s);
223 
224 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
225 					struct snd_pcm_runtime *runtime);
226 
227 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
228 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
229 
230 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
231 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
232 
233 /**
234  * amdtp_stream_running - check stream is running or not
235  * @s: the AMDTP stream
236  *
237  * If this function returns true, the stream is running.
238  */
239 static inline bool amdtp_stream_running(struct amdtp_stream *s)
240 {
241 	return !IS_ERR(s->context);
242 }
243 
244 /**
245  * amdtp_streaming_error - check for streaming error
246  * @s: the AMDTP stream
247  *
248  * If this function returns true, the stream's packet queue has stopped due to
249  * an asynchronous error.
250  */
251 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
252 {
253 	return s->packet_index < 0;
254 }
255 
256 /**
257  * amdtp_stream_pcm_running - check PCM substream is running or not
258  * @s: the AMDTP stream
259  *
260  * If this function returns true, PCM substream in the AMDTP stream is running.
261  */
262 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
263 {
264 	return !!s->pcm;
265 }
266 
267 /**
268  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
269  * @s: the AMDTP stream
270  * @pcm: the PCM device to be started, or %NULL to stop the current device
271  *
272  * Call this function on a running isochronous stream to enable the actual
273  * transmission of PCM data.  This function should be called from the PCM
274  * device's .trigger callback.
275  */
276 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
277 					    struct snd_pcm_substream *pcm)
278 {
279 	WRITE_ONCE(s->pcm, pcm);
280 }
281 
282 /**
283  * amdtp_stream_next_packet_desc - retrieve next descriptor for amdtp packet.
284  * @s: the AMDTP stream
285  * @desc: the descriptor of packet
286  *
287  * This macro computes next descriptor so that the list of descriptors behaves circular queue.
288  */
289 #define amdtp_stream_next_packet_desc(s, desc) \
290 	list_next_entry_circular(desc, &s->packet_descs_list, link)
291 
292 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
293 {
294 	return sfc & 1;
295 }
296 
297 struct seq_desc {
298 	unsigned int syt_offset;
299 	unsigned int data_blocks;
300 };
301 
302 struct amdtp_domain {
303 	struct list_head streams;
304 
305 	unsigned int events_per_period;
306 	unsigned int events_per_buffer;
307 
308 	struct amdtp_stream *irq_target;
309 
310 	struct {
311 		unsigned int tx_init_skip;
312 		unsigned int tx_start;
313 		unsigned int rx_start;
314 	} processing_cycle;
315 
316 	struct {
317 		bool enable:1;
318 		bool on_the_fly:1;
319 	} replay;
320 };
321 
322 int amdtp_domain_init(struct amdtp_domain *d);
323 void amdtp_domain_destroy(struct amdtp_domain *d);
324 
325 int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
326 			    int channel, int speed);
327 
328 int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, bool replay_seq,
329 		       bool replay_on_the_fly);
330 void amdtp_domain_stop(struct amdtp_domain *d);
331 
332 static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
333 						unsigned int events_per_period,
334 						unsigned int events_per_buffer)
335 {
336 	d->events_per_period = events_per_period;
337 	d->events_per_buffer = events_per_buffer;
338 
339 	return 0;
340 }
341 
342 unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
343 					      struct amdtp_stream *s);
344 int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
345 
346 /**
347  * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
348  * @d: the AMDTP domain
349  * @timeout_ms: msec till timeout
350  *
351  * If this function return false, the AMDTP domain should be stopped.
352  */
353 static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
354 {
355 	struct amdtp_stream *s;
356 
357 	list_for_each_entry(s, &d->streams, list) {
358 		unsigned int j = msecs_to_jiffies(timeout_ms);
359 
360 		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
361 			return false;
362 	}
363 
364 	return true;
365 }
366 
367 #endif
368