1 // SPDX-License-Identifier: GPL-2.0
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.
7 * 1999-07-01 (jmt) - First implementation for new driver architecture.
9 * 1999-07-31 (jmt) - First working version.
12 #include <linux/types.h>
13 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/init.h>
18 #include <asm/macintosh.h>
19 #include <asm/macints.h>
20 #include <asm/mac_iop.h>
21 #include <asm/adb_iop.h>
23 #include <linux/adb.h>
25 static struct adb_request *current_req;
26 static struct adb_request *last_req;
27 static unsigned int autopoll_devs;
28 static u8 autopoll_addr;
30 static enum adb_iop_state {
36 static void adb_iop_start(void);
37 static int adb_iop_probe(void);
38 static int adb_iop_init(void);
39 static int adb_iop_send_request(struct adb_request *, int);
40 static int adb_iop_write(struct adb_request *);
41 static int adb_iop_autopoll(int);
42 static void adb_iop_poll(void);
43 static int adb_iop_reset_bus(void);
45 /* ADB command byte structure */
46 #define ADDR_MASK 0xF0
50 struct adb_driver adb_iop_driver = {
52 .probe = adb_iop_probe,
54 .send_request = adb_iop_send_request,
55 .autopoll = adb_iop_autopoll,
57 .reset_bus = adb_iop_reset_bus
60 static void adb_iop_done(void)
62 struct adb_request *req = current_req;
67 current_req = req->next;
71 if (adb_iop_state == idle)
76 * Completion routine for ADB commands sent to the IOP.
78 * This will be called when a packet has been successfully sent.
81 static void adb_iop_complete(struct iop_msg *msg)
85 local_irq_save(flags);
87 adb_iop_state = awaiting_reply;
89 local_irq_restore(flags);
93 * Listen for ADB messages from the IOP.
95 * This will be called when unsolicited IOP messages are received.
96 * These IOP messages can carry ADB autopoll responses and also occur
97 * after explicit ADB commands.
100 static void adb_iop_listen(struct iop_msg *msg)
102 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
103 u8 addr = (amsg->cmd & ADDR_MASK) >> 4;
104 u8 op = amsg->cmd & OP_MASK;
106 bool req_done = false;
108 local_irq_save(flags);
110 /* Responses to Talk commands may be unsolicited as they are
111 * produced when the IOP polls devices. They are mostly timeouts.
113 if (op == TALK && ((1 << addr) & autopoll_devs))
114 autopoll_addr = addr;
116 switch (amsg->flags & (ADB_IOP_EXPLICIT |
119 case ADB_IOP_EXPLICIT:
120 case ADB_IOP_EXPLICIT | ADB_IOP_TIMEOUT:
121 if (adb_iop_state == awaiting_reply) {
122 struct adb_request *req = current_req;
124 if (req->reply_expected) {
125 req->reply_len = amsg->count + 1;
126 memcpy(req->reply, &amsg->cmd, req->reply_len);
132 case ADB_IOP_AUTOPOLL:
133 if (((1 << addr) & autopoll_devs) &&
134 amsg->cmd == ADB_READREG(addr, 0))
135 adb_input(&amsg->cmd, amsg->count + 1, 1);
138 msg->reply[0] = autopoll_addr ? ADB_IOP_AUTOPOLL : 0;
140 msg->reply[2] = autopoll_addr ? ADB_READREG(autopoll_addr, 0) : 0;
141 iop_complete_message(msg);
146 local_irq_restore(flags);
150 * Start sending an ADB packet, IOP style
152 * There isn't much to do other than hand the packet over to the IOP
153 * after encapsulating it in an adb_iopmsg.
156 static void adb_iop_start(void)
158 struct adb_request *req;
159 struct adb_iopmsg amsg;
161 /* get the packet to send */
166 /* The IOP takes MacII-style packets, so strip the initial
169 amsg.flags = ADB_IOP_EXPLICIT;
170 amsg.count = req->nbytes - 2;
172 /* amsg.data immediately follows amsg.cmd, effectively making
173 * &amsg.cmd a pointer to the beginning of a full ADB packet.
175 memcpy(&amsg.cmd, req->data + 1, req->nbytes - 1);
178 adb_iop_state = sending;
180 /* Now send it. The IOP manager will call adb_iop_complete
181 * when the message has been sent.
183 iop_send_message(ADB_IOP, ADB_CHAN, req, sizeof(amsg), (__u8 *)&amsg,
187 static int adb_iop_probe(void)
189 if (!iop_ism_present)
194 static int adb_iop_init(void)
196 pr_info("adb: IOP ISM driver v0.4 for Unified ADB\n");
197 iop_listen(ADB_IOP, ADB_CHAN, adb_iop_listen, "ADB");
201 static int adb_iop_send_request(struct adb_request *req, int sync)
205 err = adb_iop_write(req);
210 while (!req->complete)
216 static int adb_iop_write(struct adb_request *req)
220 if ((req->nbytes < 2) || (req->data[0] != ADB_PACKET)) {
230 local_irq_save(flags);
233 last_req->next = req;
240 if (adb_iop_state == idle)
243 local_irq_restore(flags);
248 static void adb_iop_set_ap_complete(struct iop_msg *msg)
250 struct adb_iopmsg *amsg = (struct adb_iopmsg *)msg->message;
252 autopoll_devs = (amsg->data[1] << 8) | amsg->data[0];
253 if (autopoll_devs & (1 << autopoll_addr))
255 autopoll_addr = autopoll_devs ? (ffs(autopoll_devs) - 1) : 0;
258 static int adb_iop_autopoll(int devs)
260 struct adb_iopmsg amsg;
262 unsigned int mask = (unsigned int)devs & 0xFFFE;
264 local_irq_save(flags);
266 amsg.flags = ADB_IOP_SET_AUTOPOLL | (mask ? ADB_IOP_AUTOPOLL : 0);
269 amsg.data[0] = mask & 0xFF;
270 amsg.data[1] = (mask >> 8) & 0xFF;
272 iop_send_message(ADB_IOP, ADB_CHAN, NULL, sizeof(amsg), (__u8 *)&amsg,
273 adb_iop_set_ap_complete);
275 local_irq_restore(flags);
280 static void adb_iop_poll(void)
282 iop_ism_irq_poll(ADB_IOP);
285 static int adb_iop_reset_bus(void)
287 struct adb_request req;
289 /* Command = 0, Address = ignored */
290 adb_request(&req, NULL, ADBREQ_NOSEND, 1, ADB_BUSRESET);
291 adb_iop_send_request(&req, 1);
293 /* Don't want any more requests during the Global Reset low time. */