xref: /linux/include/sound/rawmidi.h (revision 2c8d2a510c15c003749e43ac2b8e1bc79a7a00d6)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef __SOUND_RAWMIDI_H
3 #define __SOUND_RAWMIDI_H
4 
5 /*
6  *  Abstract layer for MIDI v1.0 stream
7  *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
8  */
9 
10 #include <sound/asound.h>
11 #include <linux/interrupt.h>
12 #include <linux/spinlock.h>
13 #include <linux/wait.h>
14 #include <linux/mutex.h>
15 #include <linux/workqueue.h>
16 #include <linux/device.h>
17 
18 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
19 #include <sound/seq_device.h>
20 #endif
21 #include <sound/info.h>
22 
23 /*
24  *  Raw MIDI interface
25  */
26 
27 #define SNDRV_RAWMIDI_DEVICES		8
28 
29 #define SNDRV_RAWMIDI_LFLG_OUTPUT	(1<<0)
30 #define SNDRV_RAWMIDI_LFLG_INPUT	(1<<1)
31 #define SNDRV_RAWMIDI_LFLG_OPEN		(3<<0)
32 #define SNDRV_RAWMIDI_LFLG_APPEND	(1<<2)
33 
34 struct snd_rawmidi;
35 struct snd_rawmidi_substream;
36 struct snd_seq_port_info;
37 struct pid;
38 
39 struct snd_rawmidi_ops {
40 	int (*open) (struct snd_rawmidi_substream * substream);
41 	int (*close) (struct snd_rawmidi_substream * substream);
42 	void (*trigger) (struct snd_rawmidi_substream * substream, int up);
43 	void (*drain) (struct snd_rawmidi_substream * substream);
44 };
45 
46 struct snd_rawmidi_global_ops {
47 	int (*dev_register) (struct snd_rawmidi * rmidi);
48 	int (*dev_unregister) (struct snd_rawmidi * rmidi);
49 	void (*get_port_info)(struct snd_rawmidi *rmidi, int number,
50 			      struct snd_seq_port_info *info);
51 	long (*ioctl)(struct snd_rawmidi *rmidi, unsigned int cmd,
52 		      void __user *argp);
53 	void (*proc_read)(struct snd_info_entry *entry,
54 			  struct snd_info_buffer *buf);
55 };
56 
57 struct snd_rawmidi_runtime {
58 	struct snd_rawmidi_substream *substream;
59 	unsigned int drain: 1,	/* drain stage */
60 		     oss: 1;	/* OSS compatible mode */
61 	/* midi stream buffer */
62 	unsigned char *buffer;	/* buffer for MIDI data */
63 	size_t buffer_size;	/* size of buffer */
64 	size_t appl_ptr;	/* application pointer */
65 	size_t hw_ptr;		/* hardware pointer */
66 	size_t avail_min;	/* min avail for wakeup */
67 	size_t avail;		/* max used buffer for wakeup */
68 	size_t xruns;		/* over/underruns counter */
69 	size_t align;		/* alignment (0 = byte stream, 3 = UMP) */
70 	int buffer_ref;		/* buffer reference count */
71 	/* misc */
72 	wait_queue_head_t sleep;
73 	/* event handler (new bytes, input only) */
74 	void (*event)(struct snd_rawmidi_substream *substream);
75 	/* defers calls to event [input] or ops->trigger [output] */
76 	struct work_struct event_work;
77 	/* private data */
78 	void *private_data;
79 	void (*private_free)(struct snd_rawmidi_substream *substream);
80 };
81 
82 struct snd_rawmidi_substream {
83 	struct list_head list;		/* list of all substream for given stream */
84 	int stream;			/* direction */
85 	int number;			/* substream number */
86 	bool opened;			/* open flag */
87 	bool append;			/* append flag (merge more streams) */
88 	bool active_sensing;		/* send active sensing when close */
89 	unsigned int framing;		/* whether to frame input data */
90 	unsigned int clock_type;	/* clock source to use for input framing */
91 	int use_count;			/* use counter (for output) */
92 	bool inactive;			/* inactive substream (for UMP legacy) */
93 	size_t bytes;
94 	spinlock_t lock;
95 	struct snd_rawmidi *rmidi;
96 	struct snd_rawmidi_str *pstr;
97 	char name[32];
98 	struct snd_rawmidi_runtime *runtime;
99 	struct pid *pid;
100 	/* hardware layer */
101 	const struct snd_rawmidi_ops *ops;
102 };
103 
104 struct snd_rawmidi_file {
105 	struct snd_rawmidi *rmidi;
106 	struct snd_rawmidi_substream *input;
107 	struct snd_rawmidi_substream *output;
108 	unsigned int user_pversion;	/* supported protocol version */
109 };
110 
111 struct snd_rawmidi_str {
112 	unsigned int substream_count;
113 	unsigned int substream_opened;
114 	struct list_head substreams;
115 };
116 
117 struct snd_rawmidi {
118 	struct snd_card *card;
119 	struct list_head list;
120 	unsigned int device;		/* device number */
121 	unsigned int info_flags;	/* SNDRV_RAWMIDI_INFO_XXXX */
122 	unsigned int tied_device;
123 	char id[64];
124 	char name[80];
125 
126 #ifdef CONFIG_SND_OSSEMUL
127 	int ossreg;
128 #endif
129 
130 	const struct snd_rawmidi_global_ops *ops;
131 
132 	struct snd_rawmidi_str streams[2];
133 
134 	void *private_data;
135 	void (*private_free) (struct snd_rawmidi *rmidi);
136 
137 	struct mutex open_mutex;
138 	wait_queue_head_t open_wait;
139 
140 	struct device *dev;
141 
142 	struct snd_info_entry *proc_entry;
143 
144 #if IS_ENABLED(CONFIG_SND_SEQUENCER)
145 	struct snd_seq_device *seq_dev;
146 #endif
147 };
148 
149 /* main rawmidi functions */
150 
151 int snd_rawmidi_new(struct snd_card *card, char *id, int device,
152 		    int output_count, int input_count,
153 		    struct snd_rawmidi **rmidi);
154 void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
155 			 const struct snd_rawmidi_ops *ops);
156 
157 /* internal */
158 int snd_rawmidi_init(struct snd_rawmidi *rmidi,
159 		     struct snd_card *card, char *id, int device,
160 		     int output_count, int input_count,
161 		     unsigned int info_flags);
162 int snd_rawmidi_free(struct snd_rawmidi *rmidi);
163 
164 /* callbacks */
165 
166 int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
167 			const unsigned char *buffer, int count);
168 int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream);
169 int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
170 			      unsigned char *buffer, int count);
171 int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count);
172 int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
173 			 unsigned char *buffer, int count);
174 int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream);
175 
176 /* main midi functions */
177 
178 int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info);
179 int snd_rawmidi_kernel_open(struct snd_rawmidi *rmidi, int subdevice,
180 			    int mode, struct snd_rawmidi_file *rfile);
181 int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile);
182 int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
183 			      struct snd_rawmidi_params *params);
184 int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
185 			     struct snd_rawmidi_params *params);
186 int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream);
187 int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream);
188 int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream);
189 long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
190 			     unsigned char *buf, long count);
191 long snd_rawmidi_kernel_write(struct snd_rawmidi_substream *substream,
192 			      const unsigned char *buf, long count);
193 
194 /* set up the tied devices */
195 static inline void snd_rawmidi_tie_devices(struct snd_rawmidi *r1,
196 					   struct snd_rawmidi *r2)
197 {
198 	/* tied_device field keeps the device+1 (so that 0 being unknown) */
199 	r1->tied_device = r2->device + 1;
200 	r2->tied_device = r1->device + 1;
201 }
202 
203 #endif /* __SOUND_RAWMIDI_H */
204