xref: /linux/sound/firewire/motu/motu-transaction.c (revision 05a54fa773284d1a7923cdfdd8f0c8dabb98bd26)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * motu-transaction.c - a part of driver for MOTU FireWire series
4  *
5  * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
6  */
7 
8 
9 #include "motu.h"
10 
11 #define SND_MOTU_ADDR_BASE	0xfffff0000000ULL
12 #define ASYNC_ADDR_HI  0x0b04
13 #define ASYNC_ADDR_LO  0x0b08
14 
15 int snd_motu_transaction_read(struct snd_motu *motu, u32 offset, __be32 *reg,
16 			      size_t size)
17 {
18 	int tcode;
19 
20 	if (size % sizeof(__be32) > 0 || size <= 0)
21 		return -EINVAL;
22 	if (size == sizeof(__be32))
23 		tcode = TCODE_READ_QUADLET_REQUEST;
24 	else
25 		tcode = TCODE_READ_BLOCK_REQUEST;
26 
27 	return snd_fw_transaction(motu->unit, tcode,
28 				  SND_MOTU_ADDR_BASE + offset, reg, size, 0);
29 }
30 
31 int snd_motu_transaction_write(struct snd_motu *motu, u32 offset, __be32 *reg,
32 			       size_t size)
33 {
34 	int tcode;
35 
36 	if (size % sizeof(__be32) > 0 || size <= 0)
37 		return -EINVAL;
38 	if (size == sizeof(__be32))
39 		tcode = TCODE_WRITE_QUADLET_REQUEST;
40 	else
41 		tcode = TCODE_WRITE_BLOCK_REQUEST;
42 
43 	return snd_fw_transaction(motu->unit, tcode,
44 				  SND_MOTU_ADDR_BASE + offset, reg, size, 0);
45 }
46 
47 static void handle_message(struct fw_card *card, struct fw_request *request,
48 			   int tcode, int destination, int source,
49 			   int generation, unsigned long long offset,
50 			   void *data, size_t length, void *callback_data)
51 {
52 	struct snd_motu *motu = callback_data;
53 	__be32 *buf = (__be32 *)data;
54 
55 	if (tcode != TCODE_WRITE_QUADLET_REQUEST) {
56 		fw_send_response(card, request, RCODE_COMPLETE);
57 		return;
58 	}
59 
60 	if (offset != motu->async_handler.offset || length != 4) {
61 		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
62 		return;
63 	}
64 
65 	scoped_guard(spinlock_irqsave, &motu->lock) {
66 		motu->msg = be32_to_cpu(*buf);
67 	}
68 
69 	fw_send_response(card, request, RCODE_COMPLETE);
70 
71 	wake_up(&motu->hwdep_wait);
72 }
73 
74 int snd_motu_transaction_reregister(struct snd_motu *motu)
75 {
76 	struct fw_device *device = fw_parent_device(motu->unit);
77 	__be32 data;
78 	int err;
79 
80 	if (motu->async_handler.callback_data == NULL)
81 		return -EINVAL;
82 
83 	/* Register messaging address. Block transaction is not allowed. */
84 	data = cpu_to_be32((device->card->node_id << 16) |
85 			   (motu->async_handler.offset >> 32));
86 	err = snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data,
87 					 sizeof(data));
88 	if (err < 0)
89 		return err;
90 
91 	data = cpu_to_be32(motu->async_handler.offset);
92 	return snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data,
93 					  sizeof(data));
94 }
95 
96 int snd_motu_transaction_register(struct snd_motu *motu)
97 {
98 	static const struct fw_address_region resp_register_region = {
99 		.start	= 0xffffe0000000ull,
100 		.end	= 0xffffe000ffffull,
101 	};
102 	int err;
103 
104 	/* Perhaps, 4 byte messages are transferred. */
105 	motu->async_handler.length = 4;
106 	motu->async_handler.address_callback = handle_message;
107 	motu->async_handler.callback_data = motu;
108 
109 	err = fw_core_add_address_handler(&motu->async_handler,
110 					  &resp_register_region);
111 	if (err < 0)
112 		return err;
113 
114 	err = snd_motu_transaction_reregister(motu);
115 	if (err < 0) {
116 		fw_core_remove_address_handler(&motu->async_handler);
117 		motu->async_handler.address_callback = NULL;
118 	}
119 
120 	return err;
121 }
122 
123 void snd_motu_transaction_unregister(struct snd_motu *motu)
124 {
125 	__be32 data;
126 
127 	if (motu->async_handler.address_callback != NULL)
128 		fw_core_remove_address_handler(&motu->async_handler);
129 	motu->async_handler.address_callback = NULL;
130 
131 	/* Unregister the address. */
132 	data = cpu_to_be32(0x00000000);
133 	snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data, sizeof(data));
134 	snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data, sizeof(data));
135 }
136