xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision 2ae1beb3)
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  * @CIP_DBC_IS_PAYLOAD_QUADLETS: Available for incoming packet, and only effective with
41  *	CIP_DBC_IS_END_EVENT flag. The value of dbc field is the number of accumulated quadlets
42  *	in CIP payload, instead of the number of accumulated data blocks.
43  */
44 enum cip_flags {
45 	CIP_NONBLOCKING		= 0x00,
46 	CIP_BLOCKING		= 0x01,
47 	CIP_EMPTY_WITH_TAG0	= 0x02,
48 	CIP_DBC_IS_END_EVENT	= 0x04,
49 	CIP_WRONG_DBS		= 0x08,
50 	CIP_SKIP_DBC_ZERO_CHECK	= 0x10,
51 	CIP_EMPTY_HAS_WRONG_DBC	= 0x20,
52 	CIP_JUMBO_PAYLOAD	= 0x40,
53 	CIP_HEADER_WITHOUT_EOH	= 0x80,
54 	CIP_NO_HEADER		= 0x100,
55 	CIP_UNALIGHED_DBC	= 0x200,
56 	CIP_UNAWARE_SYT		= 0x400,
57 	CIP_DBC_IS_PAYLOAD_QUADLETS = 0x800,
58 };
59 
60 /**
61  * enum cip_sfc - supported Sampling Frequency Codes (SFCs)
62  * @CIP_SFC_32000:   32,000 data blocks
63  * @CIP_SFC_44100:   44,100 data blocks
64  * @CIP_SFC_48000:   48,000 data blocks
65  * @CIP_SFC_88200:   88,200 data blocks
66  * @CIP_SFC_96000:   96,000 data blocks
67  * @CIP_SFC_176400: 176,400 data blocks
68  * @CIP_SFC_192000: 192,000 data blocks
69  * @CIP_SFC_COUNT: the number of supported SFCs
70  *
71  * These values are used to show nominal Sampling Frequency Code in
72  * Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
73  * this code means the number of events per second. Actually the code
74  * represents the number of data blocks transferred per second in an AMDTP
75  * stream.
76  *
77  * In IEC 61883-6:2005, some extensions were added to support more types of
78  * data such as 'One Bit LInear Audio', therefore the meaning of SFC became
79  * different depending on the types.
80  *
81  * Currently our implementation is compatible with IEC 61883-6:2002.
82  */
83 enum cip_sfc {
84 	CIP_SFC_32000  = 0,
85 	CIP_SFC_44100  = 1,
86 	CIP_SFC_48000  = 2,
87 	CIP_SFC_88200  = 3,
88 	CIP_SFC_96000  = 4,
89 	CIP_SFC_176400 = 5,
90 	CIP_SFC_192000 = 6,
91 	CIP_SFC_COUNT
92 };
93 
94 struct fw_unit;
95 struct fw_iso_context;
96 struct snd_pcm_substream;
97 struct snd_pcm_runtime;
98 
99 enum amdtp_stream_direction {
100 	AMDTP_OUT_STREAM = 0,
101 	AMDTP_IN_STREAM
102 };
103 
104 struct pkt_desc {
105 	u32 cycle;
106 	u32 syt;
107 	unsigned int data_blocks;
108 	unsigned int data_block_counter;
109 	__be32 *ctx_payload;
110 	struct list_head link;
111 };
112 
113 struct amdtp_stream;
114 typedef void (*amdtp_stream_process_ctx_payloads_t)(struct amdtp_stream *s,
115 						    const struct pkt_desc *desc,
116 						    unsigned int count,
117 						    struct snd_pcm_substream *pcm);
118 
119 struct amdtp_domain;
120 struct amdtp_stream {
121 	struct fw_unit *unit;
122 	// The combination of cip_flags enumeration-constants.
123 	unsigned int flags;
124 	enum amdtp_stream_direction direction;
125 	struct mutex mutex;
126 
127 	/* For packet processing. */
128 	struct fw_iso_context *context;
129 	struct iso_packets_buffer buffer;
130 	unsigned int queue_size;
131 	int packet_index;
132 	struct pkt_desc *packet_descs;
133 	struct list_head packet_descs_list;
134 	struct pkt_desc *packet_descs_cursor;
135 	int tag;
136 	union {
137 		struct {
138 			unsigned int ctx_header_size;
139 
140 			// limit for payload of iso packet.
141 			unsigned int max_ctx_payload_length;
142 
143 			// For quirks of CIP headers.
144 			// Fixed interval of dbc between previos/current
145 			// packets.
146 			unsigned int dbc_interval;
147 
148 			// The device starts multiplexing events to the packet.
149 			bool event_starts;
150 
151 			struct {
152 				struct seq_desc *descs;
153 				unsigned int size;
154 				unsigned int pos;
155 			} cache;
156 		} tx;
157 		struct {
158 			// To generate CIP header.
159 			unsigned int fdf;
160 
161 			// To generate constant hardware IRQ.
162 			unsigned int event_count;
163 
164 			// To calculate CIP data blocks and tstamp.
165 			struct {
166 				struct seq_desc *descs;
167 				unsigned int size;
168 				unsigned int pos;
169 			} seq;
170 
171 			unsigned int data_block_state;
172 			unsigned int syt_offset_state;
173 			unsigned int last_syt_offset;
174 
175 			struct amdtp_stream *replay_target;
176 			unsigned int cache_pos;
177 		} rx;
178 	} ctx_data;
179 
180 	/* For CIP headers. */
181 	unsigned int source_node_id_field;
182 	unsigned int data_block_quadlets;
183 	unsigned int data_block_counter;
184 	unsigned int sph;
185 	unsigned int fmt;
186 
187 	// Internal flags.
188 	unsigned int transfer_delay;
189 	enum cip_sfc sfc;
190 	unsigned int syt_interval;
191 
192 	/* For a PCM substream processing. */
193 	struct snd_pcm_substream *pcm;
194 	struct work_struct period_work;
195 	snd_pcm_uframes_t pcm_buffer_pointer;
196 	unsigned int pcm_period_pointer;
197 	unsigned int pcm_frame_multiplier;
198 
199 	// To start processing content of packets at the same cycle in several contexts for
200 	// each direction.
201 	bool ready_processing;
202 	wait_queue_head_t ready_wait;
203 	unsigned int next_cycle;
204 
205 	/* For backends to process data blocks. */
206 	void *protocol;
207 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
208 
209 	// For domain.
210 	int channel;
211 	int speed;
212 	struct list_head list;
213 	struct amdtp_domain *domain;
214 };
215 
216 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
217 		      enum amdtp_stream_direction dir, unsigned int flags,
218 		      unsigned int fmt,
219 		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
220 		      unsigned int protocol_size);
221 void amdtp_stream_destroy(struct amdtp_stream *s);
222 
223 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
224 				unsigned int data_block_quadlets, unsigned int pcm_frame_multiplier);
225 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
226 
227 void amdtp_stream_update(struct amdtp_stream *s);
228 
229 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
230 					struct snd_pcm_runtime *runtime);
231 
232 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
233 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
234 
235 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
236 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
237 
238 /**
239  * amdtp_stream_running - check stream is running or not
240  * @s: the AMDTP stream
241  *
242  * If this function returns true, the stream is running.
243  */
244 static inline bool amdtp_stream_running(struct amdtp_stream *s)
245 {
246 	return !IS_ERR(s->context);
247 }
248 
249 /**
250  * amdtp_streaming_error - check for streaming error
251  * @s: the AMDTP stream
252  *
253  * If this function returns true, the stream's packet queue has stopped due to
254  * an asynchronous error.
255  */
256 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
257 {
258 	return s->packet_index < 0;
259 }
260 
261 /**
262  * amdtp_stream_pcm_running - check PCM substream is running or not
263  * @s: the AMDTP stream
264  *
265  * If this function returns true, PCM substream in the AMDTP stream is running.
266  */
267 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
268 {
269 	return !!s->pcm;
270 }
271 
272 /**
273  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
274  * @s: the AMDTP stream
275  * @pcm: the PCM device to be started, or %NULL to stop the current device
276  *
277  * Call this function on a running isochronous stream to enable the actual
278  * transmission of PCM data.  This function should be called from the PCM
279  * device's .trigger callback.
280  */
281 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
282 					    struct snd_pcm_substream *pcm)
283 {
284 	WRITE_ONCE(s->pcm, pcm);
285 }
286 
287 /**
288  * amdtp_stream_next_packet_desc - retrieve next descriptor for amdtp packet.
289  * @s: the AMDTP stream
290  * @desc: the descriptor of packet
291  *
292  * This macro computes next descriptor so that the list of descriptors behaves circular queue.
293  */
294 #define amdtp_stream_next_packet_desc(s, desc) \
295 	list_next_entry_circular(desc, &s->packet_descs_list, link)
296 
297 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
298 {
299 	return sfc & 1;
300 }
301 
302 struct seq_desc {
303 	unsigned int syt_offset;
304 	unsigned int data_blocks;
305 };
306 
307 struct amdtp_domain {
308 	struct list_head streams;
309 
310 	unsigned int events_per_period;
311 	unsigned int events_per_buffer;
312 
313 	struct amdtp_stream *irq_target;
314 
315 	struct {
316 		unsigned int tx_init_skip;
317 		unsigned int tx_start;
318 		unsigned int rx_start;
319 	} processing_cycle;
320 
321 	struct {
322 		bool enable:1;
323 		bool on_the_fly:1;
324 	} replay;
325 };
326 
327 int amdtp_domain_init(struct amdtp_domain *d);
328 void amdtp_domain_destroy(struct amdtp_domain *d);
329 
330 int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
331 			    int channel, int speed);
332 
333 int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, bool replay_seq,
334 		       bool replay_on_the_fly);
335 void amdtp_domain_stop(struct amdtp_domain *d);
336 
337 static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
338 						unsigned int events_per_period,
339 						unsigned int events_per_buffer)
340 {
341 	d->events_per_period = events_per_period;
342 	d->events_per_buffer = events_per_buffer;
343 
344 	return 0;
345 }
346 
347 unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
348 					      struct amdtp_stream *s);
349 int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
350 
351 /**
352  * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
353  * @d: the AMDTP domain
354  * @timeout_ms: msec till timeout
355  *
356  * If this function return false, the AMDTP domain should be stopped.
357  */
358 static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
359 {
360 	struct amdtp_stream *s;
361 
362 	list_for_each_entry(s, &d->streams, list) {
363 		unsigned int j = msecs_to_jiffies(timeout_ms);
364 
365 		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
366 			return false;
367 	}
368 
369 	return true;
370 }
371 
372 #endif
373