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
14struct amdtp_tscm {
15	unsigned int pcm_channels;
16};
17
18int 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
35static void write_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
36			  __be32 *buffer, unsigned int frames,
37			  unsigned int pcm_frames)
38{
39	struct amdtp_tscm *p = s->protocol;
40	unsigned int channels = p->pcm_channels;
41	struct snd_pcm_runtime *runtime = pcm->runtime;
42	unsigned int pcm_buffer_pointer;
43	int remaining_frames;
44	const u32 *src;
45	int i, c;
46
47	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
48	pcm_buffer_pointer %= runtime->buffer_size;
49
50	src = (void *)runtime->dma_area +
51				frames_to_bytes(runtime, pcm_buffer_pointer);
52	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
53
54	for (i = 0; i < frames; ++i) {
55		for (c = 0; c < channels; ++c) {
56			buffer[c] = cpu_to_be32(*src);
57			src++;
58		}
59		buffer += s->data_block_quadlets;
60		if (--remaining_frames == 0)
61			src = (void *)runtime->dma_area;
62	}
63}
64
65static void read_pcm_s32(struct amdtp_stream *s, struct snd_pcm_substream *pcm,
66			 __be32 *buffer, unsigned int frames,
67			 unsigned int pcm_frames)
68{
69	struct amdtp_tscm *p = s->protocol;
70	unsigned int channels = p->pcm_channels;
71	struct snd_pcm_runtime *runtime = pcm->runtime;
72	unsigned int pcm_buffer_pointer;
73	int remaining_frames;
74	u32 *dst;
75	int i, c;
76
77	pcm_buffer_pointer = s->pcm_buffer_pointer + pcm_frames;
78	pcm_buffer_pointer %= runtime->buffer_size;
79
80	dst  = (void *)runtime->dma_area +
81				frames_to_bytes(runtime, pcm_buffer_pointer);
82	remaining_frames = runtime->buffer_size - pcm_buffer_pointer;
83
84	/* The first data channel is for event counter. */
85	buffer += 1;
86
87	for (i = 0; i < frames; ++i) {
88		for (c = 0; c < channels; ++c) {
89			*dst = be32_to_cpu(buffer[c]);
90			dst++;
91		}
92		buffer += s->data_block_quadlets;
93		if (--remaining_frames == 0)
94			dst = (void *)runtime->dma_area;
95	}
96}
97
98static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
99			      unsigned int data_blocks)
100{
101	struct amdtp_tscm *p = s->protocol;
102	unsigned int channels, i, c;
103
104	channels = p->pcm_channels;
105
106	for (i = 0; i < data_blocks; ++i) {
107		for (c = 0; c < channels; ++c)
108			buffer[c] = 0x00000000;
109		buffer += s->data_block_quadlets;
110	}
111}
112
113int amdtp_tscm_add_pcm_hw_constraints(struct amdtp_stream *s,
114				      struct snd_pcm_runtime *runtime)
115{
116	int err;
117
118	/*
119	 * Our implementation allows this protocol to deliver 24 bit sample in
120	 * 32bit data channel.
121	 */
122	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
123	if (err < 0)
124		return err;
125
126	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
127}
128
129static void read_status_messages(struct amdtp_stream *s,
130				 __be32 *buffer, unsigned int data_blocks)
131{
132	struct snd_tscm *tscm = container_of(s, struct snd_tscm, tx_stream);
133	bool used = READ_ONCE(tscm->hwdep->used);
134	int i;
135
136	for (i = 0; i < data_blocks; i++) {
137		unsigned int index;
138		__be32 before;
139		__be32 after;
140
141		index = be32_to_cpu(buffer[0]) % SNDRV_FIREWIRE_TASCAM_STATE_COUNT;
142		before = tscm->state[index];
143		after = buffer[s->data_block_quadlets - 1];
144
145		if (used && index > 4 && index < 16) {
146			__be32 mask;
147
148			if (index == 5)
149				mask = cpu_to_be32(~0x0000ffff);
150			else if (index == 6)
151				mask = cpu_to_be32(~0x0000ffff);
152			else if (index == 8)
153				mask = cpu_to_be32(~0x000f0f00);
154			else
155				mask = cpu_to_be32(~0x00000000);
156
157			if ((before ^ after) & mask) {
158				struct snd_firewire_tascam_change *entry =
159						&tscm->queue[tscm->push_pos];
160				unsigned long flag;
161
162				spin_lock_irqsave(&tscm->lock, flag);
163				entry->index = index;
164				entry->before = before;
165				entry->after = after;
166				if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
167					tscm->push_pos = 0;
168				spin_unlock_irqrestore(&tscm->lock, flag);
169
170				wake_up(&tscm->hwdep_wait);
171			}
172		}
173
174		tscm->state[index] = after;
175		buffer += s->data_block_quadlets;
176	}
177}
178
179static unsigned int process_ir_ctx_payloads(struct amdtp_stream *s,
180					    const struct pkt_desc *descs,
181					    unsigned int packets,
182					    struct snd_pcm_substream *pcm)
183{
184	unsigned int pcm_frames = 0;
185	int i;
186
187	for (i = 0; i < packets; ++i) {
188		const struct pkt_desc *desc = descs + i;
189		__be32 *buf = desc->ctx_payload;
190		unsigned int data_blocks = desc->data_blocks;
191
192		if (pcm) {
193			read_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
194			pcm_frames += data_blocks;
195		}
196
197		read_status_messages(s, buf, data_blocks);
198	}
199
200	return pcm_frames;
201}
202
203static unsigned int process_it_ctx_payloads(struct amdtp_stream *s,
204					    const struct pkt_desc *descs,
205					    unsigned int packets,
206					    struct snd_pcm_substream *pcm)
207{
208	unsigned int pcm_frames = 0;
209	int i;
210
211	for (i = 0; i < packets; ++i) {
212		const struct pkt_desc *desc = descs + i;
213		__be32 *buf = desc->ctx_payload;
214		unsigned int data_blocks = desc->data_blocks;
215
216		if (pcm) {
217			write_pcm_s32(s, pcm, buf, data_blocks, pcm_frames);
218			pcm_frames += data_blocks;
219		} else {
220			write_pcm_silence(s, buf, data_blocks);
221		}
222	}
223
224	return pcm_frames;
225}
226
227int amdtp_tscm_init(struct amdtp_stream *s, struct fw_unit *unit,
228		    enum amdtp_stream_direction dir, unsigned int pcm_channels)
229{
230	amdtp_stream_process_ctx_payloads_t process_ctx_payloads;
231	struct amdtp_tscm *p;
232	unsigned int fmt;
233	int err;
234
235	if (dir == AMDTP_IN_STREAM) {
236		fmt = AMDTP_FMT_TSCM_TX;
237		process_ctx_payloads = process_ir_ctx_payloads;
238	} else {
239		fmt = AMDTP_FMT_TSCM_RX;
240		process_ctx_payloads = process_it_ctx_payloads;
241	}
242
243	err = amdtp_stream_init(s, unit, dir,
244			CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
245			process_ctx_payloads, sizeof(struct amdtp_tscm));
246	if (err < 0)
247		return 0;
248
249	if (dir == AMDTP_OUT_STREAM) {
250		// Use fixed value for FDF field.
251		s->ctx_data.rx.fdf = 0x00;
252		// Not used.
253		s->ctx_data.rx.syt_override = 0x0000;
254	}
255
256	/* This protocol uses fixed number of data channels for PCM samples. */
257	p = s->protocol;
258	p->pcm_channels = pcm_channels;
259
260	return 0;
261}
262