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 *, struct pt_regs *);
  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, struct pt_regs *regs)
  82 {
  83         struct adb_request *req;
  84         uint flags;
  85
  86         save_flags(flags);
  87         cli();
  88
  89         req = current_req;
  90         if ((adb_iop_state == sending) && req && req->reply_expected) {
  91                 adb_iop_state = awaiting_reply;
  92         }
  93
  94         restore_flags(flags);
  95 }
  96
  97 /*
  98  * Listen for ADB messages from the IOP.
  99  *
 100  * This will be called when unsolicited messages (usually replies to TALK
 101  * commands or autopoll packets) are received.
 102  */
 103
 104 static void adb_iop_listen(struct iop_msg *msg, struct pt_regs *regs)
 105 {
 106         struct adb_iopmsg *amsg = (struct adb_iopmsg *) msg->message;
 107         struct adb_request *req;
 108         uint flags;
 109
 110         save_flags(flags);
 111         cli();
 112
 113         req = current_req;
 114
 115 #ifdef DEBUG_ADB_IOP
 116         printk("adb_iop_listen: rcvd packet, %d bytes: %02X %02X",
 117                 (uint) amsg->count + 2, (uint) amsg->flags, (uint) amsg->cmd);
 118         i = 0;
 119         while (i < amsg->count) {
 120                 printk(" %02X", (uint) amsg->data[i++]);
 121         }
 122         printk("\n");
 123 #endif
 124
 125         /* Handle a timeout. Timeout packets seem to occur even after */
 126         /* we've gotten a valid reply to a TALK, so I'm assuming that */
 127         /* a "timeout" is actually more like an "end-of-data" signal. */
 128         /* We need to send back a timeout packet to the IOP to shut   */
 129         /* it up, plus complete the current request, if any.          */
 130
 131         if (amsg->flags & ADB_IOP_TIMEOUT) {
 132                 msg->reply[0] = ADB_IOP_TIMEOUT | ADB_IOP_AUTOPOLL;
 133                 msg->reply[1] = 0;
 134                 msg->reply[2] = 0;
 135                 if (req && (adb_iop_state != idle)) {
 136                         adb_iop_end_req(req, idle);
 137                 }
 138         } else {
 139                 /* TODO: is it possible for more tha one chunk of data  */
 140                 /*       to arrive before the timeout? If so we need to */
 141                 /*       use reply_ptr here like the other drivers do.  */
 142                 if ((adb_iop_state == awaiting_reply) &&
 143                     (amsg->flags & ADB_IOP_EXPLICIT)) {
 144                         req->reply_len = amsg->count + 1;
 145                         memcpy(req->reply, &amsg->cmd, req->reply_len);
 146                 } else {
 147                         adb_input(&amsg->cmd, amsg->count + 1, regs,
 148                                   amsg->flags & ADB_IOP_AUTOPOLL);
 149                 }
 150                 memcpy(msg->reply, msg->message, IOP_MSG_LEN);
 151         }
 152         iop_complete_message(msg);
 153         restore_flags(flags);
 154 }
 155
 156 /*
 157  * Start sending an ADB packet, IOP style
 158  *
 159  * There isn't much to do other than hand the packet over to the IOP
 160  * after encapsulating it in an adb_iopmsg.
 161  */
 162
 163 static void adb_iop_start(void)
 164 {
 165         unsigned long flags;
 166         struct adb_request *req;
 167         struct adb_iopmsg amsg;
 168
 169         /* get the packet to send */
 170         req = current_req;
 171         if (!req) return;
 172
 173         save_flags(flags);
 174         cli();
 175
 176 #ifdef DEBUG_ADB_IOP
 177         printk("adb_iop_start: sending packet, %d bytes:", 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         restore_flags(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         save_flags(flags);
 240         cli();
 241
 242         req->next = 0;
 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         restore_flags(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, NULL);
 270 }
 271
 272 int adb_iop_reset_bus(void)
 273 {
 274         struct adb_request req;
 275
 276         req.reply_expected = 0;
 277         req.nbytes = 2;
 278         req.data[0] = ADB_PACKET;
 279         req.data[1] = 0; /* RESET */
 280         adb_iop_write(&req);
 281         while (!req.complete) adb_iop_poll();
 282         return 0;
 283 }