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
15int 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
31int 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
47static 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	unsigned long flags;
55
56	if (tcode != TCODE_WRITE_QUADLET_REQUEST) {
57		fw_send_response(card, request, RCODE_COMPLETE);
58		return;
59	}
60
61	if (offset != motu->async_handler.offset || length != 4) {
62		fw_send_response(card, request, RCODE_ADDRESS_ERROR);
63		return;
64	}
65
66	spin_lock_irqsave(&motu->lock, flags);
67	motu->msg = be32_to_cpu(*buf);
68	spin_unlock_irqrestore(&motu->lock, flags);
69
70	fw_send_response(card, request, RCODE_COMPLETE);
71
72	wake_up(&motu->hwdep_wait);
73}
74
75int snd_motu_transaction_reregister(struct snd_motu *motu)
76{
77	struct fw_device *device = fw_parent_device(motu->unit);
78	__be32 data;
79	int err;
80
81	if (motu->async_handler.callback_data == NULL)
82		return -EINVAL;
83
84	/* Register messaging address. Block transaction is not allowed. */
85	data = cpu_to_be32((device->card->node_id << 16) |
86			   (motu->async_handler.offset >> 32));
87	err = snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data,
88					 sizeof(data));
89	if (err < 0)
90		return err;
91
92	data = cpu_to_be32(motu->async_handler.offset);
93	return snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data,
94					  sizeof(data));
95}
96
97int snd_motu_transaction_register(struct snd_motu *motu)
98{
99	static const struct fw_address_region resp_register_region = {
100		.start	= 0xffffe0000000ull,
101		.end	= 0xffffe000ffffull,
102	};
103	int err;
104
105	/* Perhaps, 4 byte messages are transferred. */
106	motu->async_handler.length = 4;
107	motu->async_handler.address_callback = handle_message;
108	motu->async_handler.callback_data = motu;
109
110	err = fw_core_add_address_handler(&motu->async_handler,
111					  &resp_register_region);
112	if (err < 0)
113		return err;
114
115	err = snd_motu_transaction_reregister(motu);
116	if (err < 0) {
117		fw_core_remove_address_handler(&motu->async_handler);
118		motu->async_handler.address_callback = NULL;
119	}
120
121	return err;
122}
123
124void snd_motu_transaction_unregister(struct snd_motu *motu)
125{
126	__be32 data;
127
128	if (motu->async_handler.address_callback != NULL)
129		fw_core_remove_address_handler(&motu->async_handler);
130	motu->async_handler.address_callback = NULL;
131
132	/* Unregister the address. */
133	data = cpu_to_be32(0x00000000);
134	snd_motu_transaction_write(motu, ASYNC_ADDR_HI, &data, sizeof(data));
135	snd_motu_transaction_write(motu, ASYNC_ADDR_LO, &data, sizeof(data));
136}
137