xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision 877013bc)
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 		} tx;
145 		struct {
146 			// To generate CIP header.
147 			unsigned int fdf;
148 
149 			// To generate constant hardware IRQ.
150 			unsigned int event_count;
151 
152 			// To calculate CIP data blocks and tstamp.
153 			struct {
154 				struct seq_desc *descs;
155 				unsigned int size;
156 				unsigned int tail;
157 				unsigned int head;
158 			} seq;
159 
160 			unsigned int data_block_state;
161 			unsigned int syt_offset_state;
162 			unsigned int last_syt_offset;
163 		} rx;
164 	} ctx_data;
165 
166 	/* For CIP headers. */
167 	unsigned int source_node_id_field;
168 	unsigned int data_block_quadlets;
169 	unsigned int data_block_counter;
170 	unsigned int sph;
171 	unsigned int fmt;
172 
173 	// Internal flags.
174 	unsigned int transfer_delay;
175 	enum cip_sfc sfc;
176 	unsigned int syt_interval;
177 
178 	/* For a PCM substream processing. */
179 	struct snd_pcm_substream *pcm;
180 	struct work_struct period_work;
181 	snd_pcm_uframes_t pcm_buffer_pointer;
182 	unsigned int pcm_period_pointer;
183 
184 	// To start processing content of packets at the same cycle in several contexts for
185 	// each direction.
186 	bool ready_processing;
187 	wait_queue_head_t ready_wait;
188 	unsigned int next_cycle;
189 
190 	/* For backends to process data blocks. */
191 	void *protocol;
192 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
193 
194 	// For domain.
195 	int channel;
196 	int speed;
197 	struct list_head list;
198 	struct amdtp_domain *domain;
199 };
200 
201 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
202 		      enum amdtp_stream_direction dir, unsigned int flags,
203 		      unsigned int fmt,
204 		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
205 		      unsigned int protocol_size);
206 void amdtp_stream_destroy(struct amdtp_stream *s);
207 
208 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
209 				unsigned int data_block_quadlets);
210 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
211 
212 void amdtp_stream_update(struct amdtp_stream *s);
213 
214 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
215 					struct snd_pcm_runtime *runtime);
216 
217 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
218 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
219 
220 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
221 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
222 
223 /**
224  * amdtp_stream_running - check stream is running or not
225  * @s: the AMDTP stream
226  *
227  * If this function returns true, the stream is running.
228  */
229 static inline bool amdtp_stream_running(struct amdtp_stream *s)
230 {
231 	return !IS_ERR(s->context);
232 }
233 
234 /**
235  * amdtp_streaming_error - check for streaming error
236  * @s: the AMDTP stream
237  *
238  * If this function returns true, the stream's packet queue has stopped due to
239  * an asynchronous error.
240  */
241 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
242 {
243 	return s->packet_index < 0;
244 }
245 
246 /**
247  * amdtp_stream_pcm_running - check PCM substream is running or not
248  * @s: the AMDTP stream
249  *
250  * If this function returns true, PCM substream in the AMDTP stream is running.
251  */
252 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
253 {
254 	return !!s->pcm;
255 }
256 
257 /**
258  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
259  * @s: the AMDTP stream
260  * @pcm: the PCM device to be started, or %NULL to stop the current device
261  *
262  * Call this function on a running isochronous stream to enable the actual
263  * transmission of PCM data.  This function should be called from the PCM
264  * device's .trigger callback.
265  */
266 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
267 					    struct snd_pcm_substream *pcm)
268 {
269 	WRITE_ONCE(s->pcm, pcm);
270 }
271 
272 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
273 {
274 	return sfc & 1;
275 }
276 
277 struct seq_desc {
278 	unsigned int syt_offset;
279 	unsigned int data_blocks;
280 };
281 
282 struct amdtp_domain {
283 	struct list_head streams;
284 
285 	unsigned int events_per_period;
286 	unsigned int events_per_buffer;
287 
288 	struct amdtp_stream *irq_target;
289 
290 	struct {
291 		unsigned int tx_init_skip;
292 		unsigned int tx_start;
293 		unsigned int rx_start;
294 	} processing_cycle;
295 };
296 
297 int amdtp_domain_init(struct amdtp_domain *d);
298 void amdtp_domain_destroy(struct amdtp_domain *d);
299 
300 int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
301 			    int channel, int speed);
302 
303 int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles);
304 void amdtp_domain_stop(struct amdtp_domain *d);
305 
306 static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
307 						unsigned int events_per_period,
308 						unsigned int events_per_buffer)
309 {
310 	d->events_per_period = events_per_period;
311 	d->events_per_buffer = events_per_buffer;
312 
313 	return 0;
314 }
315 
316 unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
317 					      struct amdtp_stream *s);
318 int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
319 
320 /**
321  * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
322  * @d: the AMDTP domain
323  * @timeout_ms: msec till timeout
324  *
325  * If this function return false, the AMDTP domain should be stopped.
326  */
327 static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
328 {
329 	struct amdtp_stream *s;
330 
331 	list_for_each_entry(s, &d->streams, list) {
332 		unsigned int j = msecs_to_jiffies(timeout_ms);
333 
334 		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
335 			return false;
336 	}
337 
338 	return true;
339 }
340 
341 #endif
342