1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * I/O Processor (IOP) ADB Driver
4 * Written and (C) 1999 by Joshua M. Thompson (funaho@jurai.org)
5 * Based on via-cuda.c by Paul Mackerras.
6 *
7 * 1999-07-01 (jmt) - First implementation for new driver architecture.
8 *
9 * 1999-07-31 (jmt) - First working version.
10 */
11
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/mm.h>
15 #include <linux/delay.h>
16 #include <linux/init.h>
17
18 #include <asm/macintosh.h>
19 #include <asm/macints.h>
20 #include <asm/mac_iop.h>
21 #include <asm/adb_iop.h>
22 #include <linux/unaligned.h>
23
24 #include <linux/adb.h>
25
26 static struct adb_request *current_req;
27 static struct adb_request *last_req;
28 static unsigned int autopoll_devs;
29 static u8 autopoll_addr;
30
31 static enum adb_iop_state {
32 idle,
33 sending,
34 awaiting_reply
35 } adb_iop_state;
36
37 static void adb_iop_start(void);
38 static int adb_iop_probe(void);
39 static int adb_iop_init(void);
40 static int adb_iop_send_request(struct adb_request *, int);
41 static int adb_iop_write(struct adb_request *);
42 static int adb_iop_autopoll(int);
43 static void adb_iop_poll(void);
44 static int adb_iop_reset_bus(void);
45
46 /* ADB command byte structure */
47 #define ADDR_MASK 0xF0
48 #define OP_MASK 0x0C
49 #define TALK 0x0C
50
51 struct adb_driver adb_iop_driver = {
52 .name = "ISM IOP",
53 .probe = adb_iop_probe,
54 .init = adb_iop_init,
55 .send_request = adb_iop_send_request,
56 .autopoll = adb_iop_autopoll,
57 .poll = adb_iop_poll,
58 .reset_bus = adb_iop_reset_bus
59 };
60
adb_iop_done(void)61 static void adb_iop_done(void)
62 {
63 struct adb_request *req = current_req;
64
65 adb_iop_state = idle;
66
67 req->complete = 1;
68 current_req = req->next;
69 if (req->done)
70 (*req->done)(req);
71
72 if (adb_iop_state == idle)
73 adb_iop_start();
74 }
75
76 /*
77 * Completion routine for ADB commands sent to the IOP.
78 *
79 * This will be called when a packet has been successfully sent.
80 */
81
adb_iop_complete(struct iop_msg * msg)82 static void adb_iop_complete(struct iop_msg *msg)
83 {
84 unsigned long flags;
85
86 local_irq_save(flags);
87
88 adb_iop_state = awaiting_reply;
89
90 local_irq_restore(flags);
91 }
92
93 /*
94 * Listen for ADB messages from the IOP.
95 *
96 * This will be called when unsolicited IOP messages are received.
97 * These IOP messages can carry ADB autopoll responses and also occur
98 * after explicit ADB commands.
99 */
100
adb_iop_listen(struct iop_msg * msg)101 static void adb_iop_listen(struct iop_msg *msg)
102 {
103 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
104 u8 addr = (amsg->cmd & ADDR_MASK) >> 4;
105 u8 op = amsg->cmd & OP_MASK;
106 unsigned long flags;
107 bool req_done = false;
108
109 local_irq_save(flags);
110
111 /* Responses to Talk commands may be unsolicited as they are
112 * produced when the IOP polls devices. They are mostly timeouts.
113 */
114 if (op == TALK && ((1 << addr) & autopoll_devs))
115 autopoll_addr = addr;
116
117 switch (amsg->flags & (ADB_IOP_EXPLICIT |
118 ADB_IOP_AUTOPOLL |
119 ADB_IOP_TIMEOUT)) {
120 case ADB_IOP_EXPLICIT:
121 case ADB_IOP_EXPLICIT | ADB_IOP_TIMEOUT:
122 if (adb_iop_state == awaiting_reply) {
123 struct adb_request *req = current_req;
124
125 if (req->reply_expected) {
126 req->reply_len = amsg->count + 1;
127 memcpy(req->reply, &amsg->cmd, req->reply_len);
128 }
129
130 req_done = true;
131 }
132 break;
133 case ADB_IOP_AUTOPOLL:
134 if (((1 << addr) & autopoll_devs) &&
135 amsg->cmd == ADB_READREG(addr, 0))
136 adb_input(&amsg->cmd, amsg->count + 1, 1);
137 break;
138 }
139 msg->reply[0] = autopoll_addr ? ADB_IOP_AUTOPOLL : 0;
140 msg->reply[1] = 0;
141 msg->reply[2] = autopoll_addr ? ADB_READREG(autopoll_addr, 0) : 0;
142 iop_complete_message(msg);
143
144 if (req_done)
145 adb_iop_done();
146
147 local_irq_restore(flags);
148 }
149
150 /*
151 * Start sending an ADB packet, IOP style
152 *
153 * There isn't much to do other than hand the packet over to the IOP
154 * after encapsulating it in an adb_iopmsg.
155 */
156
adb_iop_start(void)157 static void adb_iop_start(void)
158 {
159 struct adb_request *req;
160 struct adb_iopmsg amsg;
161
162 /* get the packet to send */
163 req = current_req;
164 if (!req)
165 return;
166
167 /* The IOP takes MacII-style packets, so strip the initial
168 * ADB_PACKET byte.
169 */
170 amsg.flags = ADB_IOP_EXPLICIT;
171 amsg.count = req->nbytes - 2;
172
173 /* amsg.data immediately follows amsg.cmd, effectively making
174 * &amsg.cmd a pointer to the beginning of a full ADB packet.
175 */
176 memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);
177
178 req->sent = 1;
179 adb_iop_state = sending;
180
181 /* Now send it. The IOP manager will call adb_iop_complete
182 * when the message has been sent.
183 */
184 iop_send_message(ADB_IOP, ADB_CHAN, req, sizeof(amsg), (__u8 *)&amsg,
185 adb_iop_complete);
186 }
187
adb_iop_probe(void)188 static int adb_iop_probe(void)
189 {
190 if (!iop_ism_present)
191 return -ENODEV;
192 return 0;
193 }
194
adb_iop_init(void)195 static int adb_iop_init(void)
196 {
197 pr_info("adb: IOP ISM driver v0.4 for Unified ADB\n");
198 iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
199 return 0;
200 }
201
adb_iop_send_request(struct adb_request * req,int sync)202 static int adb_iop_send_request(struct adb_request *req, int sync)
203 {
204 int err;
205
206 err = adb_iop_write(req);
207 if (err)
208 return err;
209
210 if (sync) {
211 while (!req->complete)
212 adb_iop_poll();
213 }
214 return 0;
215 }
216
adb_iop_write(struct adb_request * req)217 static int adb_iop_write(struct adb_request *req)
218 {
219 unsigned long flags;
220
221 if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
222 req->complete = 1;
223 return -EINVAL;
224 }
225
226 req->next = NULL;
227 req->sent = 0;
228 req->complete = 0;
229 req->reply_len = 0;
230
231 local_irq_save(flags);
232
233 if (current_req) {
234 last_req->next = req;
235 last_req = req;
236 } else {
237 current_req = req;
238 last_req = req;
239 }
240
241 if (adb_iop_state == idle)
242 adb_iop_start();
243
244 local_irq_restore(flags);
245
246 return 0;
247 }
248
adb_iop_set_ap_complete(struct iop_msg * msg)249 static void adb_iop_set_ap_complete(struct iop_msg *msg)
250 {
251 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
252
253 autopoll_devs = get_unaligned_be16(amsg->data);
254 if (autopoll_devs & (1 << autopoll_addr))
255 return;
256 autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;
257 }
258
adb_iop_autopoll(int devs)259 static int adb_iop_autopoll(int devs)
260 {
261 struct adb_iopmsg amsg;
262 unsigned long flags;
263 unsigned int mask = (unsigned int)devs & 0xFFFE;
264
265 local_irq_save(flags);
266
267 amsg.flags = ADB_IOP_SET_AUTOPOLL | (mask ? ADB_IOP_AUTOPOLL : 0);
268 amsg.count = 2;
269 amsg.cmd = 0;
270 put_unaligned_be16(mask, amsg.data);
271
272 iop_send_message(ADB_IOP, ADB_CHAN, NULL, sizeof(amsg), (__u8 *)&amsg,
273 adb_iop_set_ap_complete);
274
275 local_irq_restore(flags);
276
277 return 0;
278 }
279
adb_iop_poll(void)280 static void adb_iop_poll(void)
281 {
282 iop_ism_irq_poll(ADB_IOP);
283 }
284
adb_iop_reset_bus(void)285 static int adb_iop_reset_bus(void)
286 {
287 struct adb_request req;
288
289 /* Command = 0, Address = ignored */
290 adb_request(&req, NULL, ADBREQ_NOSEND, 1, ADB_BUSRESET);
291 adb_iop_send_request(&req, 1);
292
293 /* Don't want any more requests during the Global Reset low time. */
294 mdelay(3);
295
296 return 0;
297 }
298