drivers/macintosh/adb-iop.c

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