xref: /openbmc/linux/sound/firewire/amdtp-stream.h (revision 2169e6da)
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  */
37 enum cip_flags {
38 	CIP_NONBLOCKING		= 0x00,
39 	CIP_BLOCKING		= 0x01,
40 	CIP_EMPTY_WITH_TAG0	= 0x02,
41 	CIP_DBC_IS_END_EVENT	= 0x04,
42 	CIP_WRONG_DBS		= 0x08,
43 	CIP_SKIP_DBC_ZERO_CHECK	= 0x10,
44 	CIP_EMPTY_HAS_WRONG_DBC	= 0x20,
45 	CIP_JUMBO_PAYLOAD	= 0x40,
46 	CIP_HEADER_WITHOUT_EOH	= 0x80,
47 	CIP_NO_HEADER		= 0x100,
48 };
49 
50 /**
51  * enum cip_sfc - supported Sampling Frequency Codes (SFCs)
52  * @CIP_SFC_32000:   32,000 data blocks
53  * @CIP_SFC_44100:   44,100 data blocks
54  * @CIP_SFC_48000:   48,000 data blocks
55  * @CIP_SFC_88200:   88,200 data blocks
56  * @CIP_SFC_96000:   96,000 data blocks
57  * @CIP_SFC_176400: 176,400 data blocks
58  * @CIP_SFC_192000: 192,000 data blocks
59  * @CIP_SFC_COUNT: the number of supported SFCs
60  *
61  * These values are used to show nominal Sampling Frequency Code in
62  * Format Dependent Field (FDF) of AMDTP packet header. In IEC 61883-6:2002,
63  * this code means the number of events per second. Actually the code
64  * represents the number of data blocks transferred per second in an AMDTP
65  * stream.
66  *
67  * In IEC 61883-6:2005, some extensions were added to support more types of
68  * data such as 'One Bit LInear Audio', therefore the meaning of SFC became
69  * different depending on the types.
70  *
71  * Currently our implementation is compatible with IEC 61883-6:2002.
72  */
73 enum cip_sfc {
74 	CIP_SFC_32000  = 0,
75 	CIP_SFC_44100  = 1,
76 	CIP_SFC_48000  = 2,
77 	CIP_SFC_88200  = 3,
78 	CIP_SFC_96000  = 4,
79 	CIP_SFC_176400 = 5,
80 	CIP_SFC_192000 = 6,
81 	CIP_SFC_COUNT
82 };
83 
84 struct fw_unit;
85 struct fw_iso_context;
86 struct snd_pcm_substream;
87 struct snd_pcm_runtime;
88 
89 enum amdtp_stream_direction {
90 	AMDTP_OUT_STREAM = 0,
91 	AMDTP_IN_STREAM
92 };
93 
94 struct amdtp_stream;
95 typedef unsigned int (*amdtp_stream_process_data_blocks_t)(
96 						struct amdtp_stream *s,
97 						__be32 *buffer,
98 						unsigned int data_blocks,
99 						unsigned int *syt);
100 struct amdtp_stream {
101 	struct fw_unit *unit;
102 	enum cip_flags flags;
103 	enum amdtp_stream_direction direction;
104 	struct mutex mutex;
105 
106 	/* For packet processing. */
107 	struct fw_iso_context *context;
108 	struct iso_packets_buffer buffer;
109 	int packet_index;
110 	int tag;
111 	union {
112 		struct {
113 			unsigned int ctx_header_size;
114 
115 			// limit for payload of iso packet.
116 			unsigned int max_ctx_payload_length;
117 
118 			// For quirks of CIP headers.
119 			// Fixed interval of dbc between previos/current
120 			// packets.
121 			unsigned int dbc_interval;
122 			// Indicate the value of dbc field in a first packet.
123 			unsigned int first_dbc;
124 		} tx;
125 		struct {
126 			// To calculate CIP data blocks and tstamp.
127 			unsigned int transfer_delay;
128 			unsigned int data_block_state;
129 			unsigned int last_syt_offset;
130 			unsigned int syt_offset_state;
131 
132 			// To generate CIP header.
133 			unsigned int fdf;
134 		} rx;
135 	} ctx_data;
136 
137 	/* For CIP headers. */
138 	unsigned int source_node_id_field;
139 	unsigned int data_block_quadlets;
140 	unsigned int data_block_counter;
141 	unsigned int sph;
142 	unsigned int fmt;
143 
144 	/* Internal flags. */
145 	enum cip_sfc sfc;
146 	unsigned int syt_interval;
147 
148 	/* For a PCM substream processing. */
149 	struct snd_pcm_substream *pcm;
150 	struct tasklet_struct period_tasklet;
151 	snd_pcm_uframes_t pcm_buffer_pointer;
152 	unsigned int pcm_period_pointer;
153 
154 	/* To wait for first packet. */
155 	bool callbacked;
156 	wait_queue_head_t callback_wait;
157 	u32 start_cycle;
158 
159 	/* For backends to process data blocks. */
160 	void *protocol;
161 	amdtp_stream_process_data_blocks_t process_data_blocks;
162 };
163 
164 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
165 		      enum amdtp_stream_direction dir, enum cip_flags flags,
166 		      unsigned int fmt,
167 		      amdtp_stream_process_data_blocks_t process_data_blocks,
168 		      unsigned int protocol_size);
169 void amdtp_stream_destroy(struct amdtp_stream *s);
170 
171 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
172 				unsigned int data_block_quadlets);
173 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s);
174 
175 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed);
176 void amdtp_stream_update(struct amdtp_stream *s);
177 void amdtp_stream_stop(struct amdtp_stream *s);
178 
179 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
180 					struct snd_pcm_runtime *runtime);
181 
182 void amdtp_stream_pcm_prepare(struct amdtp_stream *s);
183 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s);
184 int amdtp_stream_pcm_ack(struct amdtp_stream *s);
185 void amdtp_stream_pcm_abort(struct amdtp_stream *s);
186 
187 extern const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
188 extern const unsigned int amdtp_rate_table[CIP_SFC_COUNT];
189 
190 /**
191  * amdtp_stream_running - check stream is running or not
192  * @s: the AMDTP stream
193  *
194  * If this function returns true, the stream is running.
195  */
196 static inline bool amdtp_stream_running(struct amdtp_stream *s)
197 {
198 	return !IS_ERR(s->context);
199 }
200 
201 /**
202  * amdtp_streaming_error - check for streaming error
203  * @s: the AMDTP stream
204  *
205  * If this function returns true, the stream's packet queue has stopped due to
206  * an asynchronous error.
207  */
208 static inline bool amdtp_streaming_error(struct amdtp_stream *s)
209 {
210 	return s->packet_index < 0;
211 }
212 
213 /**
214  * amdtp_stream_pcm_running - check PCM substream is running or not
215  * @s: the AMDTP stream
216  *
217  * If this function returns true, PCM substream in the AMDTP stream is running.
218  */
219 static inline bool amdtp_stream_pcm_running(struct amdtp_stream *s)
220 {
221 	return !!s->pcm;
222 }
223 
224 /**
225  * amdtp_stream_pcm_trigger - start/stop playback from a PCM device
226  * @s: the AMDTP stream
227  * @pcm: the PCM device to be started, or %NULL to stop the current device
228  *
229  * Call this function on a running isochronous stream to enable the actual
230  * transmission of PCM data.  This function should be called from the PCM
231  * device's .trigger callback.
232  */
233 static inline void amdtp_stream_pcm_trigger(struct amdtp_stream *s,
234 					    struct snd_pcm_substream *pcm)
235 {
236 	WRITE_ONCE(s->pcm, pcm);
237 }
238 
239 static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
240 {
241 	return sfc & 1;
242 }
243 
244 /**
245  * amdtp_stream_wait_callback - sleep till callbacked or timeout
246  * @s: the AMDTP stream
247  * @timeout: msec till timeout
248  *
249  * If this function return false, the AMDTP stream should be stopped.
250  */
251 static inline bool amdtp_stream_wait_callback(struct amdtp_stream *s,
252 					      unsigned int timeout)
253 {
254 	return wait_event_timeout(s->callback_wait,
255 				  s->callbacked == true,
256 				  msecs_to_jiffies(timeout)) > 0;
257 }
258 
259 #endif
260