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 */
44enum 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 */
83enum 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
94struct fw_unit;
95struct fw_iso_context;
96struct snd_pcm_substream;
97struct snd_pcm_runtime;
98
99enum amdtp_stream_direction {
100	AMDTP_OUT_STREAM = 0,
101	AMDTP_IN_STREAM
102};
103
104struct 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
113struct amdtp_stream;
114typedef 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
119struct amdtp_domain;
120struct 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	snd_pcm_uframes_t pcm_buffer_pointer;
195	unsigned int pcm_period_pointer;
196	unsigned int pcm_frame_multiplier;
197
198	// To start processing content of packets at the same cycle in several contexts for
199	// each direction.
200	bool ready_processing;
201	wait_queue_head_t ready_wait;
202	unsigned int next_cycle;
203
204	/* For backends to process data blocks. */
205	void *protocol;
206	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
207
208	// For domain.
209	int channel;
210	int speed;
211	struct list_head list;
212	struct amdtp_domain *domain;
213};
214
215int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
216		      enum amdtp_stream_direction dir, unsigned int flags,
217		      unsigned int fmt,
218		      amdtp_stream_process_ctx_payloads_t process_ctx_payloads,
219		      unsigned int protocol_size);
220void amdtp_stream_destroy(struct amdtp_stream *s);
221
222int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
223				unsigned int data_block_quadlets, unsigned int pcm_frame_multiplier);
224unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
225
226void amdtp_stream_update(struct amdtp_stream *s);
227
228int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
229					struct snd_pcm_runtime *runtime);
230
231void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
232void amdtp_stream_pcm_abort(struct amdtp_stream *s);
233
234extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
235extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
236
237/**
238 * amdtp_stream_running - check stream is running or not
239 * @s: the AMDTP stream
240 *
241 * If this function returns true, the stream is running.
242 */
243static inline bool amdtp_stream_running(struct amdtp_stream *s)
244{
245	return !IS_ERR(s->context);
246}
247
248/**
249 * amdtp_streaming_error - check for streaming error
250 * @s: the AMDTP stream
251 *
252 * If this function returns true, the stream's packet queue has stopped due to
253 * an asynchronous error.
254 */
255static inline bool amdtp_streaming_error(struct amdtp_stream *s)
256{
257	return s->packet_index < 0;
258}
259
260/**
261 * amdtp_stream_pcm_running - check PCM substream is running or not
262 * @s: the AMDTP stream
263 *
264 * If this function returns true, PCM substream in the AMDTP stream is running.
265 */
266static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
267{
268	return !!s->pcm;
269}
270
271/**
272 * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
273 * @s: the AMDTP stream
274 * @pcm: the PCM device to be started, or %NULL to stop the current device
275 *
276 * Call this function on a running isochronous stream to enable the actual
277 * transmission of PCM data.  This function should be called from the PCM
278 * device's .trigger callback.
279 */
280static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
281					    struct snd_pcm_substream *pcm)
282{
283	WRITE_ONCE(s->pcm, pcm);
284}
285
286/**
287 * amdtp_stream_next_packet_desc - retrieve next descriptor for amdtp packet.
288 * @s: the AMDTP stream
289 * @desc: the descriptor of packet
290 *
291 * This macro computes next descriptor so that the list of descriptors behaves circular queue.
292 */
293#define amdtp_stream_next_packet_desc(s, desc) \
294	list_next_entry_circular(desc, &s->packet_descs_list, link)
295
296static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
297{
298	return sfc & 1;
299}
300
301struct seq_desc {
302	unsigned int syt_offset;
303	unsigned int data_blocks;
304};
305
306struct amdtp_domain {
307	struct list_head streams;
308
309	unsigned int events_per_period;
310	unsigned int events_per_buffer;
311
312	struct amdtp_stream *irq_target;
313
314	struct {
315		unsigned int tx_init_skip;
316		unsigned int tx_start;
317		unsigned int rx_start;
318	} processing_cycle;
319
320	struct {
321		bool enable:1;
322		bool on_the_fly:1;
323	} replay;
324};
325
326int amdtp_domain_init(struct amdtp_domain *d);
327void amdtp_domain_destroy(struct amdtp_domain *d);
328
329int amdtp_domain_add_stream(struct amdtp_domain *d, struct amdtp_stream *s,
330			    int channel, int speed);
331
332int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, bool replay_seq,
333		       bool replay_on_the_fly);
334void amdtp_domain_stop(struct amdtp_domain *d);
335
336static inline int amdtp_domain_set_events_per_period(struct amdtp_domain *d,
337						unsigned int events_per_period,
338						unsigned int events_per_buffer)
339{
340	d->events_per_period = events_per_period;
341	d->events_per_buffer = events_per_buffer;
342
343	return 0;
344}
345
346unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
347					      struct amdtp_stream *s);
348int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s);
349
350/**
351 * amdtp_domain_wait_ready - sleep till being ready to process packets or timeout
352 * @d: the AMDTP domain
353 * @timeout_ms: msec till timeout
354 *
355 * If this function return false, the AMDTP domain should be stopped.
356 */
357static inline bool amdtp_domain_wait_ready(struct amdtp_domain *d, unsigned int timeout_ms)
358{
359	struct amdtp_stream *s;
360
361	list_for_each_entry(s, &d->streams, list) {
362		unsigned int j = msecs_to_jiffies(timeout_ms);
363
364		if (wait_event_interruptible_timeout(s->ready_wait, s->ready_processing, j) <= 0)
365			return false;
366	}
367
368	return true;
369}
370
371#endif
372