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/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         uint 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         uint 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 }