1/*
2 * I/O Processor (IOP) ADB Driver
3 * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
4 * Based on via-cuda.c by Paul Mackerras.
5 *
6 * 1999-07-01 (jmt) - First implementation for new driver architecture.
7 *
8 * 1999-07-31 (jmt) - First working version.
9 *
10 * TODO:
11 *
12 * o Implement SRQ handling.
13 */
14
15#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/mm.h>
18#include <linux/delay.h>
19#include <linux/init.h>
20#include <linux/proc_fs.h>
21
22#include <asm/macintosh.h>
23#include <asm/macints.h>
24#include <asm/mac_iop.h>
25#include <asm/mac_oss.h>
26#include <asm/adb_iop.h>
27
28#include <linux/adb.h>
29
30/*#define DEBUG_ADB_IOP*/
31
32extern void iop_ism_irq(int, void *);
33
34static struct adb_request *current_req;
35static struct adb_request *last_req;
36#if 0
37static unsigned char reply_buff[16];
38static unsigned char *reply_ptr;
39#endif
40
41static enum adb_iop_state {
42    idle,
43    sending,
44    awaiting_reply
45} adb_iop_state;
46
47static void adb_iop_start(void);
48static int adb_iop_probe(void);
49static int adb_iop_init(void);
50static int adb_iop_send_request(struct adb_request *, int);
51static int adb_iop_write(struct adb_request *);
52static int adb_iop_autopoll(int);
53static void adb_iop_poll(void);
54static int adb_iop_reset_bus(void);
55
56struct adb_driver adb_iop_driver = {
57	"ISM IOP",
58	adb_iop_probe,
59	adb_iop_init,
60	adb_iop_send_request,
61	adb_iop_autopoll,
62	adb_iop_poll,
63	adb_iop_reset_bus
64};
65
66static void adb_iop_end_req(struct adb_request *req, int state)
67{
68	req->complete = 1;
69	current_req = req->next;
70	if (req->done) (*req->done)(req);
71	adb_iop_state = state;
72}
73
74/*
75 * Completion routine for ADB commands sent to the IOP.
76 *
77 * This will be called when a packet has been successfully sent.
78 */
79
80static void adb_iop_complete(struct iop_msg *msg)
81{
82	struct adb_request *req;
83	unsigned long flags;
84
85	local_irq_save(flags);
86
87	req = current_req;
88	if ((adb_iop_state == sending) && req && req->reply_expected) {
89		adb_iop_state = awaiting_reply;
90	}
91
92	local_irq_restore(flags);
93}
94
95/*
96 * Listen for ADB messages from the IOP.
97 *
98 * This will be called when unsolicited messages (usually replies to TALK
99 * commands or autopoll packets) are received.
100 */
101
102static void adb_iop_listen(struct iop_msg *msg)
103{
104	struct adb_iopmsg *amsg = (struct adb_iopmsg *) msg->message;
105	struct adb_request *req;
106	unsigned long flags;
107#ifdef DEBUG_ADB_IOP
108	int i;
109#endif
110
111	local_irq_save(flags);
112
113	req = current_req;
114
115#ifdef DEBUG_ADB_IOP
116	printk("adb_iop_listen %p: rcvd packet, %d bytes: %02X %02X", req,
117		(uint) amsg->count + 2, (uint) amsg->flags, (uint) amsg->cmd);
118	for (i = 0; i < amsg->count; i++)
119		printk(" %02X", (uint) amsg->data[i]);
120	printk("\n");
121#endif
122
123	/* Handle a timeout. Timeout packets seem to occur even after */
124	/* we've gotten a valid reply to a TALK, so I'm assuming that */
125	/* a "timeout" is actually more like an "end-of-data" signal. */
126	/* We need to send back a timeout packet to the IOP to shut   */
127	/* it up, plus complete the current request, if any.          */
128
129	if (amsg->flags & ADB_IOP_TIMEOUT) {
130		msg->reply[0] = ADB_IOP_TIMEOUT | ADB_IOP_AUTOPOLL;
131		msg->reply[1] = 0;
132		msg->reply[2] = 0;
133		if (req && (adb_iop_state != idle)) {
134			adb_iop_end_req(req, idle);
135		}
136	} else {
137		/* TODO: is it possible for more than one chunk of data  */
138		/*       to arrive before the timeout? If so we need to */
139		/*       use reply_ptr here like the other drivers do.  */
140		if ((adb_iop_state == awaiting_reply) &&
141		    (amsg->flags & ADB_IOP_EXPLICIT)) {
142			req->reply_len = amsg->count + 1;
143			memcpy(req->reply, &amsg->cmd, req->reply_len);
144		} else {
145			adb_input(&amsg->cmd, amsg->count + 1,
146				  amsg->flags & ADB_IOP_AUTOPOLL);
147		}
148		memcpy(msg->reply, msg->message, IOP_MSG_LEN);
149	}
150	iop_complete_message(msg);
151	local_irq_restore(flags);
152}
153
154/*
155 * Start sending an ADB packet, IOP style
156 *
157 * There isn't much to do other than hand the packet over to the IOP
158 * after encapsulating it in an adb_iopmsg.
159 */
160
161static void adb_iop_start(void)
162{
163	unsigned long flags;
164	struct adb_request *req;
165	struct adb_iopmsg amsg;
166#ifdef DEBUG_ADB_IOP
167	int i;
168#endif
169
170	/* get the packet to send */
171	req = current_req;
172	if (!req) return;
173
174	local_irq_save(flags);
175
176#ifdef DEBUG_ADB_IOP
177	printk("adb_iop_start %p: sending packet, %d bytes:", req, req->nbytes);
178	for (i = 0 ; i < req->nbytes ; i++)
179		printk(" %02X", (uint) req->data[i]);
180	printk("\n");
181#endif
182
183	/* The IOP takes MacII-style packets, so */
184	/* strip the initial ADB_PACKET byte.    */
185
186	amsg.flags = ADB_IOP_EXPLICIT;
187	amsg.count = req->nbytes - 2;
188
189	/* amsg.data immediately follows amsg.cmd, effectively making */
190	/* amsg.cmd a pointer to the beginning of a full ADB packet.  */
191	memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);
192
193	req->sent = 1;
194	adb_iop_state = sending;
195	local_irq_restore(flags);
196
197	/* Now send it. The IOP manager will call adb_iop_complete */
198	/* when the packet has been sent.                          */
199
200	iop_send_message(ADB_IOP, ADB_CHAN, req,
201			 sizeof(amsg), (__u8 *) &amsg, adb_iop_complete);
202}
203
204int adb_iop_probe(void)
205{
206	if (!iop_ism_present) return -ENODEV;
207	return 0;
208}
209
210int adb_iop_init(void)
211{
212	printk("adb: IOP ISM driver v0.4 for Unified ADB.\n");
213	iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
214	return 0;
215}
216
217int adb_iop_send_request(struct adb_request *req, int sync)
218{
219	int err;
220
221	err = adb_iop_write(req);
222	if (err) return err;
223
224	if (sync) {
225		while (!req->complete) adb_iop_poll();
226	}
227	return 0;
228}
229
230static int adb_iop_write(struct adb_request *req)
231{
232	unsigned long flags;
233
234	if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
235		req->complete = 1;
236		return -EINVAL;
237	}
238
239	local_irq_save(flags);
240
241	req->next = NULL;
242	req->sent = 0;
243	req->complete = 0;
244	req->reply_len = 0;
245
246	if (current_req != 0) {
247		last_req->next = req;
248		last_req = req;
249	} else {
250		current_req = req;
251		last_req = req;
252	}
253
254	local_irq_restore(flags);
255	if (adb_iop_state == idle) adb_iop_start();
256	return 0;
257}
258
259int adb_iop_autopoll(int devs)
260{
261	/* TODO: how do we enable/disable autopoll? */
262	return 0;
263}
264
265void adb_iop_poll(void)
266{
267	if (adb_iop_state == idle) adb_iop_start();
268	iop_ism_irq(0, (void *) ADB_IOP);
269}
270
271int adb_iop_reset_bus(void)
272{
273	struct adb_request req = {
274		.reply_expected = 0,
275		.nbytes = 2,
276		.data = { ADB_PACKET, 0 },
277	};
278
279	adb_iop_write(&req);
280	while (!req.complete) {
281		adb_iop_poll();
282		schedule();
283	}
284
285	return 0;
286}
287