1 /*
2  * amdtp-tascam.c - a part of driver for TASCAM FireWire series
3  *
4  * Copyright (c) 2015 Takashi Sakamoto
5  *
6  * Licensed under the terms of the GNU General Public License, version 2.
7  */
8 
9 #include <sound/pcm.h>
10 #include "tascam.h"
11 
12 #define AMDTP_FMT_TSCM_TX	0x1e
13 #define AMDTP_FMT_TSCM_RX	0x3e
14 
15 struct amdtp_tscm {
16 	unsigned int pcm_channels;
17 };
18 
19 int amdtp_tscm_set_parameters(struct amdtp_stream *s, unsigned int rate)
20 {
21 	struct amdtp_tscm *p = s->protocol;
22 	unsigned int data_channels;
23 
24 	if (amdtp_stream_running(s))
25 		return -EBUSY;
26 
27 	data_channels = p->pcm_channels;
28 
29 	/* Packets in in-stream have extra 2 data channels. */
30 	if (s->direction == AMDTP_IN_STREAM)
31 		data_channels += 2;
32 
33 	return amdtp_stream_set_parameters(s, rate, data_channels);
34 }
35 
36 static void write_pcm_s32(struct amdtp_stream *s,
37 			  struct snd_pcm_substream *pcm,
38 			  __be32 *buffer, unsigned int frames)
39 {
40 	struct amdtp_tscm *p = s->protocol;
41 	struct snd_pcm_runtime *runtime = pcm->runtime;
42 	unsigned int channels, remaining_frames, i, c;
43 	const u32 *src;
44 
45 	channels = p->pcm_channels;
46 	src = (void *)runtime->dma_area +
47 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
48 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
49 
50 	for (i = 0; i < frames; ++i) {
51 		for (c = 0; c < channels; ++c) {
52 			buffer[c] = cpu_to_be32(*src);
53 			src++;
54 		}
55 		buffer += s->data_block_quadlets;
56 		if (--remaining_frames == 0)
57 			src = (void *)runtime->dma_area;
58 	}
59 }
60 
61 static void read_pcm_s32(struct amdtp_stream *s,
62 			 struct snd_pcm_substream *pcm,
63 			 __be32 *buffer, unsigned int frames)
64 {
65 	struct amdtp_tscm *p = s->protocol;
66 	struct snd_pcm_runtime *runtime = pcm->runtime;
67 	unsigned int channels, remaining_frames, i, c;
68 	u32 *dst;
69 
70 	channels = p->pcm_channels;
71 	dst  = (void *)runtime->dma_area +
72 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
73 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
74 
75 	/* The first data channel is for event counter. */
76 	buffer += 1;
77 
78 	for (i = 0; i < frames; ++i) {
79 		for (c = 0; c < channels; ++c) {
80 			*dst = be32_to_cpu(buffer[c]);
81 			dst++;
82 		}
83 		buffer += s->data_block_quadlets;
84 		if (--remaining_frames == 0)
85 			dst = (void *)runtime->dma_area;
86 	}
87 }
88 
89 static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
90 			      unsigned int data_blocks)
91 {
92 	struct amdtp_tscm *p = s->protocol;
93 	unsigned int channels, i, c;
94 
95 	channels = p->pcm_channels;
96 
97 	for (i = 0; i < data_blocks; ++i) {
98 		for (c = 0; c < channels; ++c)
99 			buffer[c] = 0x00000000;
100 		buffer += s->data_block_quadlets;
101 	}
102 }
103 
104 int amdtp_tscm_add_pcm_hw_constraints(struct amdtp_stream *s,
105 				      struct snd_pcm_runtime *runtime)
106 {
107 	int err;
108 
109 	/*
110 	 * Our implementation allows this protocol to deliver 24 bit sample in
111 	 * 32bit data channel.
112 	 */
113 	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
114 	if (err < 0)
115 		return err;
116 
117 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
118 }
119 
120 static void read_status_messages(struct amdtp_stream *s,
121 				 __be32 *buffer, unsigned int data_blocks)
122 {
123 	struct snd_tscm *tscm = container_of(s, struct snd_tscm, tx_stream);
124 	bool used = READ_ONCE(tscm->hwdep->used);
125 	int i;
126 
127 	for (i = 0; i < data_blocks; i++) {
128 		unsigned int index;
129 		__be32 before;
130 		__be32 after;
131 
132 		index = be32_to_cpu(buffer[0]) % SNDRV_FIREWIRE_TASCAM_STATE_COUNT;
133 		before = tscm->state[index];
134 		after = buffer[s->data_block_quadlets - 1];
135 
136 		if (used && index > 4 && index < 16) {
137 			__be32 mask;
138 
139 			if (index == 5)
140 				mask = cpu_to_be32(~0x0000ffff);
141 			else if (index == 6)
142 				mask = cpu_to_be32(~0x0000ffff);
143 			else if (index == 8)
144 				mask = cpu_to_be32(~0x000f0f00);
145 			else
146 				mask = cpu_to_be32(~0x00000000);
147 
148 			if ((before ^ after) & mask) {
149 				struct snd_firewire_tascam_change *entry =
150 						&tscm->queue[tscm->push_pos];
151 
152 				spin_lock_irq(&tscm->lock);
153 				entry->index = index;
154 				entry->before = before;
155 				entry->after = after;
156 				if (++tscm->push_pos >= SND_TSCM_QUEUE_COUNT)
157 					tscm->push_pos = 0;
158 				spin_unlock_irq(&tscm->lock);
159 
160 				wake_up(&tscm->hwdep_wait);
161 			}
162 		}
163 
164 		tscm->state[index] = after;
165 		buffer += s->data_block_quadlets;
166 	}
167 }
168 
169 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
170 					   __be32 *buffer,
171 					   unsigned int data_blocks,
172 					   unsigned int *syt)
173 {
174 	struct snd_pcm_substream *pcm;
175 
176 	pcm = READ_ONCE(s->pcm);
177 	if (data_blocks > 0 && pcm)
178 		read_pcm_s32(s, pcm, buffer, data_blocks);
179 
180 	read_status_messages(s, buffer, data_blocks);
181 
182 	return data_blocks;
183 }
184 
185 static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
186 					   __be32 *buffer,
187 					   unsigned int data_blocks,
188 					   unsigned int *syt)
189 {
190 	struct snd_pcm_substream *pcm;
191 
192 	/* This field is not used. */
193 	*syt = 0x0000;
194 
195 	pcm = READ_ONCE(s->pcm);
196 	if (pcm)
197 		write_pcm_s32(s, pcm, buffer, data_blocks);
198 	else
199 		write_pcm_silence(s, buffer, data_blocks);
200 
201 	return data_blocks;
202 }
203 
204 int amdtp_tscm_init(struct amdtp_stream *s, struct fw_unit *unit,
205 		    enum amdtp_stream_direction dir, unsigned int pcm_channels)
206 {
207 	amdtp_stream_process_data_blocks_t process_data_blocks;
208 	struct amdtp_tscm *p;
209 	unsigned int fmt;
210 	int err;
211 
212 	if (dir == AMDTP_IN_STREAM) {
213 		fmt = AMDTP_FMT_TSCM_TX;
214 		process_data_blocks = process_tx_data_blocks;
215 	} else {
216 		fmt = AMDTP_FMT_TSCM_RX;
217 		process_data_blocks = process_rx_data_blocks;
218 	}
219 
220 	err = amdtp_stream_init(s, unit, dir,
221 				CIP_NONBLOCKING | CIP_SKIP_DBC_ZERO_CHECK, fmt,
222 				process_data_blocks, sizeof(struct amdtp_tscm));
223 	if (err < 0)
224 		return 0;
225 
226 	/* Use fixed value for FDF field. */
227 	s->fdf = 0x00;
228 
229 	/* This protocol uses fixed number of data channels for PCM samples. */
230 	p = s->protocol;
231 	p->pcm_channels = pcm_channels;
232 
233 	return 0;
234 }
235