xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision bdaedca74d6293b6ac643a8ebe8231b52bf1171b)
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  */
39 enum cip_flags {
40 	CIP_NONBLOCKING		= 0x00,
41 	CIP_BLOCKING		= 0x01,
42 	CIP_EMPTY_WITH_TAG0	= 0x02,
43 	CIP_DBC_IS_END_EVENT	= 0x04,
44 	CIP_WRONG_DBS		= 0x08,
45 	CIP_SKIP_DBC_ZERO_CHECK	= 0x10,
46 	CIP_EMPTY_HAS_WRONG_DBC	= 0x20,
47 	CIP_JUMBO_PAYLOAD	= 0x40,
48 	CIP_HEADER_WITHOUT_EOH	= 0x80,
49 	CIP_NO_HEADER		= 0x100,
50 	CIP_UNALIGHED_DBC	= 0x200,
51 };
52 
53 /**
54  * enum cip_sfc - supported Sampling Frequency Codes (SFCs)
55  * @CIP_SFC_32000:   32,000 data blocks
56  * @CIP_SFC_44100:   44,100 data blocks
57  * @CIP_SFC_48000:   48,000 data blocks
58  * @CIP_SFC_88200:   88,200 data blocks
59  * @CIP_SFC_96000:   96,000 data blocks
60  * @CIP_SFC_176400: 176,400 data blocks
61  * @CIP_SFC_192000: 192,000 data blocks
62  * @CIP_SFC_COUNT: the number of supported SFCs
63  *
64  * These values are used to show nominal Sampling Frequency Code in
65  * Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
66  * this code means the number of events per second. Actually the code
67  * represents the number of data blocks transferred per second in an AMDTP
68  * stream.
69  *
70  * In IEC 61883-6:2005, some extensions were added to support more types of
71  * data such as 'One Bit LInear Audio', therefore the meaning of SFC became
72  * different depending on the types.
73  *
74  * Currently our implementation is compatible with IEC 61883-6:2002.
75  */
76 enum cip_sfc {
77 	CIP_SFC_32000  = 0,
78 	CIP_SFC_44100  = 1,
79 	CIP_SFC_48000  = 2,
80 	CIP_SFC_88200  = 3,
81 	CIP_SFC_96000  = 4,
82 	CIP_SFC_176400 = 5,
83 	CIP_SFC_192000 = 6,
84 	CIP_SFC_COUNT
85 };
86 
87 struct fw_unit;
88 struct fw_iso_context;
89 struct snd_pcm_substream;
90 struct snd_pcm_runtime;
91 
92 enum amdtp_stream_direction {
93 	AMDTP_OUT_STREAM = 0,
94 	AMDTP_IN_STREAM
95 };
96 
97 struct pkt_desc {
98 	u32 cycle;
99 	u32 syt;
100 	unsigned int data_blocks;
101 	unsigned int data_block_counter;
102 	__be32 *ctx_payload;
103 };
104 
105 struct amdtp_stream;
106 typedef unsigned int (*amdtp_stream_process_ctx_payloads_t)(
107 						struct amdtp_stream *s,
108 						const struct pkt_desc *desc,
109 						unsigned int packets,
110 						struct snd_pcm_substream *pcm);
111 
112 struct amdtp_domain;
113 struct amdtp_stream {
114 	struct fw_unit *unit;
115 	// The combination of cip_flags enumeration-constants.
116 	unsigned int flags;
117 	enum amdtp_stream_direction direction;
118 	struct mutex mutex;
119 
120 	/* For packet processing. */
121 	struct fw_iso_context *context;
122 	struct iso_packets_buffer buffer;
123 	unsigned int queue_size;
124 	int packet_index;
125 	struct pkt_desc *pkt_descs;
126 	int tag;
127 	union {
128 		struct {
129 			unsigned int ctx_header_size;
130 
131 			// limit for payload of iso packet.
132 			unsigned int max_ctx_payload_length;
133 
134 			// For quirks of CIP headers.
135 			// Fixed interval of dbc between previos/current
136 			// packets.
137 			unsigned int dbc_interval;
138 		} tx;
139 		struct {
140 			// To calculate CIP data blocks and tstamp.
141 			unsigned int transfer_delay;
142 			unsigned int seq_index;
143 
144 			// To generate CIP header.
145 			unsigned int fdf;
146 			int syt_override;
147 
148 			// To generate constant hardware IRQ.
149 			unsigned int event_count;
150 		} rx;
151 	} ctx_data;
152 
153 	/* For CIP headers. */
154 	unsigned int source_node_id_field;
155 	unsigned int data_block_quadlets;
156 	unsigned int data_block_counter;
157 	unsigned int sph;
158 	unsigned int fmt;
159 
160 	/* Internal flags. */
161 	enum cip_sfc sfc;
162 	unsigned int syt_interval;
163 
164 	/* For a PCM substream processing. */
165 	struct snd_pcm_substream *pcm;
166 	struct work_struct period_work;
167 	snd_pcm_uframes_t pcm_buffer_pointer;
168 	unsigned int pcm_period_pointer;
169 
170 	// To start processing content of packets at the same cycle in several contexts for
171 	// each direction.
172 	bool callbacked:1;
173 	bool ready_processing:1;
174 	wait_queue_head_t ready_wait;
175 	unsigned int next_cycle;
176 
177 	/* For backends to process data blocks. */
178 	void *protocol;
179 	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
180 
181 	// For domain.
182 	int channel;
183 	int speed;
184 	struct list_head list;
185 	struct amdtp_domain *domain;
186 };
187 
188 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
189 		      enum amdtp_stream_direction dir, unsigned int flags,
190 		      unsigned int fmt,
191 		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
192 		      unsigned int protocol_size);
193 void amdtp_stream_destroy(struct amdtp_stream *s);
194 
195 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
196 				unsigned int data_block_quadlets);
197 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
198 
199 void amdtp_stream_update(struct amdtp_stream *s);
200 
201 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
202 					struct snd_pcm_runtime *runtime);
203 
204 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
205 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
206 
207 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
208 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
209 
210 /**
211  * amdtp_stream_running - check stream is running or not
212  * @s: the AMDTP stream
213  *
214  * If this function returns true, the stream is running.
215  */
216 static inline bool amdtp_stream_running(struct amdtp_stream *s)
217 {
218 	return !IS_ERR(s->context);
219 }
220 
221 /**
222  * amdtp_streaming_error - check for streaming error
223  * @s: the AMDTP stream
224  *
225  * If this function returns true, the stream's packet queue has stopped due to
226  * an asynchronous error.
227  */
228 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
229 {
230 	return s->packet_index < 0;
231 }
232 
233 /**
234  * amdtp_stream_pcm_running - check PCM substream is running or not
235  * @s: the AMDTP stream
236  *
237  * If this function returns true, PCM substream in the AMDTP stream is running.
238  */
239 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
240 {
241 	return !!s->pcm;
242 }
243 
244 /**
245  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
246  * @s: the AMDTP stream
247  * @pcm: the PCM device to be started, or %NULL to stop the current device
248  *
249  * Call this function on a running isochronous stream to enable the actual
250  * transmission of PCM data.  This function should be called from the PCM
251  * device's .trigger callback.
252  */
253 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
254 					    struct snd_pcm_substream *pcm)
255 {
256 	WRITE_ONCE(s->pcm, pcm);
257 }
258 
259 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
260 {
261 	return sfc & 1;
262 }
263 
264 struct seq_desc {
265 	unsigned int syt_offset;
266 	unsigned int data_blocks;
267 };
268 
269 struct amdtp_domain {
270 	struct list_head streams;
271 
272 	unsigned int events_per_period;
273 	unsigned int events_per_buffer;
274 
275 	struct amdtp_stream *irq_target;
276 
277 	struct {
278 		unsigned int tx_init_skip;
279 		unsigned int tx_start;
280 		unsigned int rx_start;
281 	} processing_cycle;
282 
283 	struct {
284 		struct seq_desc *descs;
285 		unsigned int size;
286 		unsigned int tail;
287 	} seq;
288 
289 	unsigned int data_block_state;
290 	unsigned int syt_offset_state;
291 	unsigned int last_syt_offset;
292 };
293 
294 int amdtp_domain_init(struct amdtp_domain *d);
295 void amdtp_domain_destroy(struct amdtp_domain *d);
296 
297 int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
298 			    int channel, int speed);
299 
300 int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles);
301 void amdtp_domain_stop(struct amdtp_domain *d);
302 
303 static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
304 						unsigned int events_per_period,
305 						unsigned int events_per_buffer)
306 {
307 	d->events_per_period = events_per_period;
308 	d->events_per_buffer = events_per_buffer;
309 
310 	return 0;
311 }
312 
313 unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
314 					      struct amdtp_stream *s);
315 int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
316 
317 /**
318  * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
319  * @d: the AMDTP domain
320  * @timeout_ms: msec till timeout
321  *
322  * If this function return false, the AMDTP domain should be stopped.
323  */
324 static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
325 {
326 	struct amdtp_stream *s;
327 
328 	list_for_each_entry(s, &d->streams, list) {
329 		unsigned int j = msecs_to_jiffies(timeout_ms);
330 
331 		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
332 			return false;
333 	}
334 
335 	return true;
336 }
337 
338 #endif
339