xref: /openbmc/linux/drivers/macintosh/adb-iop.c (revision 827634ad)
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 
32 extern void iop_ism_irq(int, void *);
33 
34 static struct adb_request *current_req;
35 static struct adb_request *last_req;
36 #if 0
37 static unsigned char reply_buff[16];
38 static unsigned char *reply_ptr;
39 #endif
40 
41 static enum adb_iop_state {
42     idle,
43     sending,
44     awaiting_reply
45 } adb_iop_state;
46 
47 static void adb_iop_start(void);
48 static int adb_iop_probe(void);
49 static int adb_iop_init(void);
50 static int adb_iop_send_request(struct adb_request *, int);
51 static int adb_iop_write(struct adb_request *);
52 static int adb_iop_autopoll(int);
53 static void adb_iop_poll(void);
54 static int adb_iop_reset_bus(void);
55 
56 struct 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 
66 static 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 
80 static 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 
102 static 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 
161 static 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 
204 int adb_iop_probe(void)
205 {
206 	if (!iop_ism_present) return -ENODEV;
207 	return 0;
208 }
209 
210 int 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 
217 int 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 
230 static 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 
259 int adb_iop_autopoll(int devs)
260 {
261 	/* TODO: how do we enable/disable autopoll? */
262 	return 0;
263 }
264 
265 void adb_iop_poll(void)
266 {
267 	if (adb_iop_state == idle) adb_iop_start();
268 	iop_ism_irq(0, (void *) ADB_IOP);
269 }
270 
271 int 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