aboutsummaryrefslogtreecommitdiff
path: root/drivers/macintosh/adb-iop.c
blob: fca31640e3efdbe3578301254a228ff74f7259b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
// SPDX-License-Identifier: GPL-2.0
/*
 * I/O Processor (IOP) ADB Driver
 * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
 * Based on via-cuda.c by Paul Mackerras.
 *
 * 1999-07-01 (jmt) - First implementation for new driver architecture.
 *
 * 1999-07-31 (jmt) - First working version.
 *
 * TODO:
 *
 * o Implement SRQ handling.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/proc_fs.h>

#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_iop.h>
#include <asm/mac_oss.h>
#include <asm/adb_iop.h>

#include <linux/adb.h>

/*#define DEBUG_ADB_IOP*/

static struct adb_request *current_req;
static struct adb_request *last_req;
#if 0
static unsigned char reply_buff[16];
static unsigned char *reply_ptr;
#endif

static enum adb_iop_state {
	idle,
	sending,
	awaiting_reply
} adb_iop_state;

static void adb_iop_start(void);
static int adb_iop_probe(void);
static int adb_iop_init(void);
static int adb_iop_send_request(struct adb_request *, int);
static int adb_iop_write(struct adb_request *);
static int adb_iop_autopoll(int);
static void adb_iop_poll(void);
static int adb_iop_reset_bus(void);

struct adb_driver adb_iop_driver = {
	.name         = "ISM IOP",
	.probe        = adb_iop_probe,
	.init         = adb_iop_init,
	.send_request = adb_iop_send_request,
	.autopoll     = adb_iop_autopoll,
	.poll         = adb_iop_poll,
	.reset_bus    = adb_iop_reset_bus
};

static void adb_iop_end_req(struct adb_request *req, int state)
{
	req->complete = 1;
	current_req = req->next;
	if (req->done)
		(*req->done)(req);
	adb_iop_state = state;
}

/*
 * Completion routine for ADB commands sent to the IOP.
 *
 * This will be called when a packet has been successfully sent.
 */

static void adb_iop_complete(struct iop_msg *msg)
{
	struct adb_request *req;
	unsigned long flags;

	local_irq_save(flags);

	req = current_req;
	if ((adb_iop_state == sending) && req && req->reply_expected) {
		adb_iop_state = awaiting_reply;
	}

	local_irq_restore(flags);
}

/*
 * Listen for ADB messages from the IOP.
 *
 * This will be called when unsolicited messages (usually replies to TALK
 * commands or autopoll packets) are received.
 */

static void adb_iop_listen(struct iop_msg *msg)
{
	struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
	struct adb_request *req;
	unsigned long flags;
#ifdef DEBUG_ADB_IOP
	int i;
#endif

	local_irq_save(flags);

	req = current_req;

#ifdef DEBUG_ADB_IOP
	printk("adb_iop_listen %p: rcvd packet, %d bytes: %02X %02X", req,
	       (uint)amsg->count + 2, (uint)amsg->flags, (uint)amsg->cmd);
	for (i = 0; i < amsg->count; i++)
		printk(" %02X", (uint)amsg->data[i]);
	printk("\n");
#endif

	/* Handle a timeout. Timeout packets seem to occur even after */
	/* we've gotten a valid reply to a TALK, so I'm assuming that */
	/* a "timeout" is actually more like an "end-of-data" signal. */
	/* We need to send back a timeout packet to the IOP to shut   */
	/* it up, plus complete the current request, if any.          */

	if (amsg->flags & ADB_IOP_TIMEOUT) {
		msg->reply[0] = ADB_IOP_TIMEOUT | ADB_IOP_AUTOPOLL;
		msg->reply[1] = 0;
		msg->reply[2] = 0;
		if (req && (adb_iop_state != idle)) {
			adb_iop_end_req(req, idle);
		}
	} else {
		/* TODO: is it possible for more than one chunk of data  */
		/*       to arrive before the timeout? If so we need to */
		/*       use reply_ptr here like the other drivers do.  */
		if ((adb_iop_state == awaiting_reply) &&
		    (amsg->flags & ADB_IOP_EXPLICIT)) {
			req->reply_len = amsg->count + 1;
			memcpy(req->reply, &amsg->cmd, req->reply_len);
		} else {
			adb_input(&amsg->cmd, amsg->count + 1,
				  amsg->flags & ADB_IOP_AUTOPOLL);
		}
		memcpy(msg->reply, msg->message, IOP_MSG_LEN);
	}
	iop_complete_message(msg);
	local_irq_restore(flags);
}

/*
 * Start sending an ADB packet, IOP style
 *
 * There isn't much to do other than hand the packet over to the IOP
 * after encapsulating it in an adb_iopmsg.
 */

static void adb_iop_start(void)
{
	unsigned long flags;
	struct adb_request *req;
	struct adb_iopmsg amsg;
#ifdef DEBUG_ADB_IOP
	int i;
#endif

	/* get the packet to send */
	req = current_req;
	if (!req)
		return;

	local_irq_save(flags);

#ifdef DEBUG_ADB_IOP
	printk("adb_iop_start %p: sending packet, %d bytes:", req, req->nbytes);
	for (i = 0; i < req->nbytes; i++)
		printk(" %02X", (uint)req->data[i]);
	printk("\n");
#endif

	/* The IOP takes MacII-style packets, so */
	/* strip the initial ADB_PACKET byte.    */

	amsg.flags = ADB_IOP_EXPLICIT;
	amsg.count = req->nbytes - 2;

	/* amsg.data immediately follows amsg.cmd, effectively making */
	/* amsg.cmd a pointer to the beginning of a full ADB packet.  */
	memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);

	req->sent = 1;
	adb_iop_state = sending;
	local_irq_restore(flags);

	/* Now send it. The IOP manager will call adb_iop_complete */
	/* when the packet has been sent.                          */

	iop_send_message(ADB_IOP, ADB_CHAN, req, sizeof(amsg), (__u8 *)&amsg,
			 adb_iop_complete);
}

int adb_iop_probe(void)
{
	if (!iop_ism_present)
		return -ENODEV;
	return 0;
}

int adb_iop_init(void)
{
	pr_info("adb: IOP ISM driver v0.4 for Unified ADB\n");
	iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
	return 0;
}

int adb_iop_send_request(struct adb_request *req, int sync)
{
	int err;

	err = adb_iop_write(req);
	if (err)
		return err;

	if (sync) {
		while (!req->complete)
			adb_iop_poll();
	}
	return 0;
}

static int adb_iop_write(struct adb_request *req)
{
	unsigned long flags;

	if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
		req->complete = 1;
		return -EINVAL;
	}

	local_irq_save(flags);

	req->next = NULL;
	req->sent = 0;
	req->complete = 0;
	req->reply_len = 0;

	if (current_req != 0) {
		last_req->next = req;
		last_req = req;
	} else {
		current_req = req;
		last_req = req;
	}

	local_irq_restore(flags);

	if (adb_iop_state == idle)
		adb_iop_start();
	return 0;
}

int adb_iop_autopoll(int devs)
{
	/* TODO: how do we enable/disable autopoll? */
	return 0;
}

void adb_iop_poll(void)
{
	if (adb_iop_state == idle)
		adb_iop_start();
	iop_ism_irq_poll(ADB_IOP);
}

int adb_iop_reset_bus(void)
{
	struct adb_request req = {
		.reply_expected = 0,
		.nbytes = 2,
		.data = { ADB_PACKET, 0 },
	};

	adb_iop_write(&req);
	while (!req.complete) {
		adb_iop_poll();
		schedule();
	}

	return 0;
}