xref: /linux/sound/firewire/tascam/amdtp-tascam.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * amdtp-tascam.c - a part of driver for TASCAM FireWire series
4  *
5  * Copyright (c) 2015 Takashi Sakamoto
6  */
7 
8 #include <sound/pcm.h>
9 #include "tascam.h"
10 
11 #define AMDTP_FMT_TSCM_TX	0x1e
12 #define AMDTP_FMT_TSCM_RX	0x3e
13 
14 struct amdtp_tscm {
15 	unsigned int pcm_channels;
16 };
17 
18 int amdtp_tscm_set_parameters(struct amdtp_stream *s, unsigned int rate)
19 {
20 	struct amdtp_tscm *p = s->protocol;
21 	unsigned int data_channels;
22 
23 	if (amdtp_stream_running(s))
24 		return -EBUSY;
25 
26 	data_channels = p->pcm_channels;
27 
28 	/* Packets in in-stream have extra 2 data channels. */
29 	if (s->direction == AMDTP_IN_STREAM)
30 		data_channels += 2;
31 
32 	return amdtp_stream_set_parameters(s, rate, data_channels);
33 }
34 
35 static void write_pcm_s32(struct amdtp_stream *s,
36 			  struct snd_pcm_substream *pcm,
37 			  __be32 *buffer, unsigned int frames)
38 {
39 	struct amdtp_tscm *p = s->protocol;
40 	struct snd_pcm_runtime *runtime = pcm->runtime;
41 	unsigned int channels, remaining_frames, i, c;
42 	const u32 *src;
43 
44 	channels = p->pcm_channels;
45 	src = (void *)runtime->dma_area +
46 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
47 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
48 
49 	for (i = 0; i < frames; ++i) {
50 		for (c = 0; c < channels; ++c) {
51 			buffer[c] = cpu_to_be32(*src);
52 			src++;
53 		}
54 		buffer += s->data_block_quadlets;
55 		if (--remaining_frames == 0)
56 			src = (void *)runtime->dma_area;
57 	}
58 }
59 
60 static void read_pcm_s32(struct amdtp_stream *s,
61 			 struct snd_pcm_substream *pcm,
62 			 __be32 *buffer, unsigned int frames)
63 {
64 	struct amdtp_tscm *p = s->protocol;
65 	struct snd_pcm_runtime *runtime = pcm->runtime;
66 	unsigned int channels, remaining_frames, i, c;
67 	u32 *dst;
68 
69 	channels = p->pcm_channels;
70 	dst  = (void *)runtime->dma_area +
71 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
72 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
73 
74 	/* The first data channel is for event counter. */
75 	buffer += 1;
76 
77 	for (i = 0; i < frames; ++i) {
78 		for (c = 0; c < channels; ++c) {
79 			*dst = be32_to_cpu(buffer[c]);
80 			dst++;
81 		}
82 		buffer += s->data_block_quadlets;
83 		if (--remaining_frames == 0)
84 			dst = (void *)runtime->dma_area;
85 	}
86 }
87 
88 static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
89 			      unsigned int data_blocks)
90 {
91 	struct amdtp_tscm *p = s->protocol;
92 	unsigned int channels, i, c;
93 
94 	channels = p->pcm_channels;
95 
96 	for (i = 0; i < data_blocks; ++i) {
97 		for (c = 0; c < channels; ++c)
98 			buffer[c] = 0x00000000;
99 		buffer += s->data_block_quadlets;
100 	}
101 }
102 
103 int amdtp_tscm_add_pcm_hw_constraints(struct amdtp_stream *s,
104 				      struct snd_pcm_runtime *runtime)
105 {
106 	int err;
107 
108 	/*
109 	 * Our implementation allows this protocol to deliver 24 bit sample in
110 	 * 32bit data channel.
111 	 */
112 	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
113 	if (err < 0)
114 		return err;
115 
116 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
117 }
118 
119 static void read_status_messages(struct amdtp_stream *s,
120 				 __be32 *buffer, unsigned int data_blocks)
121 {
122 	struct snd_tscm *tscm = container_of(s, struct snd_tscm, tx_stream);
123 	bool used = READ_ONCE(tscm->hwdep->used);
124 	int i;
125 
126 	for (i = 0; i < data_blocks; i++) {
127 		unsigned int index;
128 		__be32 before;
129 		__be32 after;
130 
131 		index = be32_to_cpu(buffer[0]) % SNDRV_FIREWIRE_TASCAM_STATE_COUNT;
132 		before = tscm->state[index];
133 		after = buffer[s->data_block_quadlets - 1];
134 
135 		if (used && index > 4 && index < 16) {
136 			__be32 mask;
137 
138 			if (index == 5)
139 				mask = cpu_to_be32(~0x0000ffff);
140 			else if (index == 6)
141 				mask = cpu_to_be32(~0x0000ffff);
142 			else if (index == 8)
143 				mask = cpu_to_be32(~0x000f0f00);
144 			else
145 				mask = cpu_to_be32(~0x00000000);
146 
147 			if ((before ^ after) & mask) {
148 				struct snd_firewire_tascam_change *entry =
149 						&tscm->queue[tscm->push_pos];
150 
151 				spin_lock_irq(&tscm->lock);
152 				entry->index = index;
153 				entry->before = before;
154 				entry->after = after;
155 				if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
156 					tscm->push_pos = 0;
157 				spin_unlock_irq(&tscm->lock);
158 
159 				wake_up(&tscm->hwdep_wait);
160 			}
161 		}
162 
163 		tscm->state[index] = after;
164 		buffer += s->data_block_quadlets;
165 	}
166 }
167 
168 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
169 					   __be32 *buffer,
170 					   unsigned int data_blocks,
171 					   unsigned int *syt)
172 {
173 	struct snd_pcm_substream *pcm;
174 
175 	pcm = READ_ONCE(s->pcm);
176 	if (data_blocks > 0 && pcm)
177 		read_pcm_s32(s, pcm, buffer, data_blocks);
178 
179 	read_status_messages(s, buffer, data_blocks);
180 
181 	return data_blocks;
182 }
183 
184 static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
185 					   __be32 *buffer,
186 					   unsigned int data_blocks,
187 					   unsigned int *syt)
188 {
189 	struct snd_pcm_substream *pcm;
190 
191 	/* This field is not used. */
192 	*syt = 0x0000;
193 
194 	pcm = READ_ONCE(s->pcm);
195 	if (pcm)
196 		write_pcm_s32(s, pcm, buffer, data_blocks);
197 	else
198 		write_pcm_silence(s, buffer, data_blocks);
199 
200 	return data_blocks;
201 }
202 
203 int amdtp_tscm_init(struct amdtp_stream *s, struct fw_unit *unit,
204 		    enum amdtp_stream_direction dir, unsigned int pcm_channels)
205 {
206 	amdtp_stream_process_data_blocks_t process_data_blocks;
207 	struct amdtp_tscm *p;
208 	unsigned int fmt;
209 	int err;
210 
211 	if (dir == AMDTP_IN_STREAM) {
212 		fmt = AMDTP_FMT_TSCM_TX;
213 		process_data_blocks = process_tx_data_blocks;
214 	} else {
215 		fmt = AMDTP_FMT_TSCM_RX;
216 		process_data_blocks = process_rx_data_blocks;
217 	}
218 
219 	err = amdtp_stream_init(s, unit, dir,
220 				CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
221 				process_data_blocks, sizeof(struct amdtp_tscm));
222 	if (err < 0)
223 		return 0;
224 
225 	/* Use fixed value for FDF field. */
226 	s->ctx_data.rx.fdf = 0x00;
227 
228 	/* This protocol uses fixed number of data channels for PCM samples. */
229 	p = s->protocol;
230 	p->pcm_channels = pcm_channels;
231 
232 	return 0;
233 }
234