1 /*
2  * amdtp-ff.c - a part of driver for RME Fireface series
3  *
4  * Copyright (c) 2015-2017 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 "ff.h"
11 
12 struct amdtp_ff {
13 	unsigned int pcm_channels;
14 };
15 
16 int amdtp_ff_set_parameters(struct amdtp_stream *s, unsigned int rate,
17 			    unsigned int pcm_channels)
18 {
19 	struct amdtp_ff *p = s->protocol;
20 	unsigned int data_channels;
21 
22 	if (amdtp_stream_running(s))
23 		return -EBUSY;
24 
25 	p->pcm_channels = pcm_channels;
26 	data_channels = pcm_channels;
27 
28 	return amdtp_stream_set_parameters(s, rate, data_channels);
29 }
30 
31 static void write_pcm_s32(struct amdtp_stream *s,
32 			  struct snd_pcm_substream *pcm,
33 			  __le32 *buffer, unsigned int frames)
34 {
35 	struct amdtp_ff *p = s->protocol;
36 	struct snd_pcm_runtime *runtime = pcm->runtime;
37 	unsigned int channels, remaining_frames, i, c;
38 	const u32 *src;
39 
40 	channels = p->pcm_channels;
41 	src = (void *)runtime->dma_area +
42 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
43 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
44 
45 	for (i = 0; i < frames; ++i) {
46 		for (c = 0; c < channels; ++c) {
47 			buffer[c] = cpu_to_le32(*src);
48 			src++;
49 		}
50 		buffer += s->data_block_quadlets;
51 		if (--remaining_frames == 0)
52 			src = (void *)runtime->dma_area;
53 	}
54 }
55 
56 static void read_pcm_s32(struct amdtp_stream *s,
57 			 struct snd_pcm_substream *pcm,
58 			 __le32 *buffer, unsigned int frames)
59 {
60 	struct amdtp_ff *p = s->protocol;
61 	struct snd_pcm_runtime *runtime = pcm->runtime;
62 	unsigned int channels, remaining_frames, i, c;
63 	u32 *dst;
64 
65 	channels = p->pcm_channels;
66 	dst  = (void *)runtime->dma_area +
67 			frames_to_bytes(runtime, s->pcm_buffer_pointer);
68 	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
69 
70 	for (i = 0; i < frames; ++i) {
71 		for (c = 0; c < channels; ++c) {
72 			*dst = le32_to_cpu(buffer[c]) & 0xffffff00;
73 			dst++;
74 		}
75 		buffer += s->data_block_quadlets;
76 		if (--remaining_frames == 0)
77 			dst = (void *)runtime->dma_area;
78 	}
79 }
80 
81 static void write_pcm_silence(struct amdtp_stream *s,
82 			      __le32 *buffer, unsigned int frames)
83 {
84 	struct amdtp_ff *p = s->protocol;
85 	unsigned int i, c, channels = p->pcm_channels;
86 
87 	for (i = 0; i < frames; ++i) {
88 		for (c = 0; c < channels; ++c)
89 			buffer[c] = cpu_to_le32(0x00000000);
90 		buffer += s->data_block_quadlets;
91 	}
92 }
93 
94 int amdtp_ff_add_pcm_hw_constraints(struct amdtp_stream *s,
95 				    struct snd_pcm_runtime *runtime)
96 {
97 	int err;
98 
99 	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
100 	if (err < 0)
101 		return err;
102 
103 	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
104 }
105 
106 static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
107 					   __be32 *buffer,
108 					   unsigned int data_blocks,
109 					   unsigned int *syt)
110 {
111 	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
112 	unsigned int pcm_frames;
113 
114 	if (pcm) {
115 		write_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
116 		pcm_frames = data_blocks;
117 	} else {
118 		write_pcm_silence(s, (__le32 *)buffer, data_blocks);
119 		pcm_frames = 0;
120 	}
121 
122 	return pcm_frames;
123 }
124 
125 static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
126 					   __be32 *buffer,
127 					   unsigned int data_blocks,
128 					   unsigned int *syt)
129 {
130 	struct snd_pcm_substream *pcm = READ_ONCE(s->pcm);
131 	unsigned int pcm_frames;
132 
133 	if (pcm) {
134 		read_pcm_s32(s, pcm, (__le32 *)buffer, data_blocks);
135 		pcm_frames = data_blocks;
136 	} else {
137 		pcm_frames = 0;
138 	}
139 
140 	return pcm_frames;
141 }
142 
143 int amdtp_ff_init(struct amdtp_stream *s, struct fw_unit *unit,
144 		  enum amdtp_stream_direction dir)
145 {
146 	amdtp_stream_process_data_blocks_t process_data_blocks;
147 
148 	if (dir == AMDTP_IN_STREAM)
149 		process_data_blocks = process_tx_data_blocks;
150 	else
151 		process_data_blocks = process_rx_data_blocks;
152 
153 	return amdtp_stream_init(s, unit, dir, CIP_NO_HEADER, 0,
154 				 process_data_blocks, sizeof(struct amdtp_ff));
155 }
156