drivers/macintosh/adb-iop.c

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