drivers/macintosh/macio-adb.c

   1 /*
   2  * Driver for the ADB controller in the Mac I/O (Hydra) chip.
   3  */
   4 #include <stdarg.h>
   5 #include <linux/types.h>
   6 #include <linux/errno.h>
   7 #include <linux/kernel.h>
   8 #include <linux/delay.h>
   9 #include <linux/sched.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/interrupt.h>
  12 #include <asm/prom.h>
  13 #include <linux/adb.h>
  14 #include <asm/io.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/hydra.h>
  17 #include <asm/irq.h>
  18 #include <asm/system.h>
  19 #include <linux/init.h>
  20 #include <linux/ioport.h>
  21
  22 struct preg {
  23         unsigned char r;
  24         char pad[15];
  25 };
  26
  27 struct adb_regs {
  28         struct preg intr;
  29         struct preg data[9];
  30         struct preg intr_enb;
  31         struct preg dcount;
  32         struct preg error;
  33         struct preg ctrl;
  34         struct preg autopoll;
  35         struct preg active_hi;
  36         struct preg active_lo;
  37         struct preg test;
  38 };
  39
  40 /* Bits in intr and intr_enb registers */
  41 #define DFB     1               /* data from bus */
  42 #define TAG     2               /* transfer access grant */
  43
  44 /* Bits in dcount register */
  45 #define HMB     0x0f            /* how many bytes */
  46 #define APD     0x10            /* auto-poll data */
  47
  48 /* Bits in error register */
  49 #define NRE     1               /* no response error */
  50 #define DLE     2               /* data lost error */
  51
  52 /* Bits in ctrl register */
  53 #define TAR     1               /* transfer access request */
  54 #define DTB     2               /* data to bus */
  55 #define CRE     4               /* command response expected */
  56 #define ADB_RST 8               /* ADB reset */
  57
  58 /* Bits in autopoll register */
  59 #define APE     1               /* autopoll enable */
  60
  61 static volatile struct adb_regs __iomem *adb;
  62 static struct adb_request *current_req, *last_req;
  63 static DEFINE_SPINLOCK(macio_lock);
  64
  65 static int macio_probe(void);
  66 static int macio_init(void);
  67 static irqreturn_t macio_adb_interrupt(int irq, void *arg, struct pt_regs *regs);
  68 static int macio_send_request(struct adb_request *req, int sync);
  69 static int macio_adb_autopoll(int devs);
  70 static void macio_adb_poll(void);
  71 static int macio_adb_reset_bus(void);
  72
  73 struct adb_driver macio_adb_driver = {
  74         "MACIO",
  75         macio_probe,
  76         macio_init,
  77         macio_send_request,
  78         /*macio_write,*/
  79         macio_adb_autopoll,
  80         macio_adb_poll,
  81         macio_adb_reset_bus
  82 };
  83
  84 int macio_probe(void)
  85 {
  86         return find_compatible_devices("adb", "chrp,adb0")? 0: -ENODEV;
  87 }
  88
  89 int macio_init(void)
  90 {
  91         struct device_node *adbs;
  92         struct resource r;
  93
  94         adbs = find_compatible_devices("adb", "chrp,adb0");
  95         if (adbs == 0)
  96                 return -ENXIO;
  97
  98 #if 0
  99         { int i = 0;
 100
 101         printk("macio_adb_init: node = %p, addrs =", adbs->node);
 102         while(!of_address_to_resource(adbs, i, &r))
 103                 printk(" %x(%x)", r.start, r.end - r.start);
 104         printk(", intrs =");
 105         for (i = 0; i < adbs->n_intrs; ++i)
 106                 printk(" %x", adbs->intrs[i].line);
 107         printk("\n"); }
 108 #endif
 109         if (of_address_to_resource(adbs, 0, &r))
 110                 return -ENXIO;
 111         adb = ioremap(r.start, sizeof(struct adb_regs));
 112
 113         out_8(&adb->ctrl.r, 0);
 114         out_8(&adb->intr.r, 0);
 115         out_8(&adb->error.r, 0);
 116         out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */
 117         out_8(&adb->active_lo.r, 0xff);
 118         out_8(&adb->autopoll.r, APE);
 119
 120         if (request_irq(adbs->intrs[0].line, macio_adb_interrupt,
 121                         0, "ADB", (void *)0)) {
 122                 printk(KERN_ERR "ADB: can't get irq %d\n",
 123                        adbs->intrs[0].line);
 124                 return -EAGAIN;
 125         }
 126         out_8(&adb->intr_enb.r, DFB | TAG);
 127
 128         printk("adb: mac-io driver 1.0 for unified ADB\n");
 129
 130         return 0;
 131 }
 132
 133 static int macio_adb_autopoll(int devs)
 134 {
 135         unsigned long flags;
 136
 137         spin_lock_irqsave(&macio_lock, flags);
 138         out_8(&adb->active_hi.r, devs >> 8);
 139         out_8(&adb->active_lo.r, devs);
 140         out_8(&adb->autopoll.r, devs? APE: 0);
 141         spin_unlock_irqrestore(&macio_lock, flags);
 142         return 0;
 143 }
 144
 145 static int macio_adb_reset_bus(void)
 146 {
 147         unsigned long flags;
 148         int timeout = 1000000;
 149
 150         /* Hrm... we may want to not lock interrupts for so
 151          * long ... oh well, who uses that chip anyway ? :)
 152          * That function will be seldomly used during boot
 153          * on rare machines, so...
 154          */
 155         spin_lock_irqsave(&macio_lock, flags);
 156         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);
 157         while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
 158                 if (--timeout == 0) {
 159                         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
 160                         return -1;
 161                 }
 162         }
 163         spin_unlock_irqrestore(&macio_lock, flags);
 164         return 0;
 165 }
 166
 167 /* Send an ADB command */
 168 static int macio_send_request(struct adb_request *req, int sync)
 169 {
 170         unsigned long flags;
 171         int i;
 172
 173         if (req->data[0] != ADB_PACKET)
 174                 return -EINVAL;
 175
 176         for (i = 0; i < req->nbytes - 1; ++i)
 177                 req->data[i] = req->data[i+1];
 178         --req->nbytes;
 179
 180         req->next = NULL;
 181         req->sent = 0;
 182         req->complete = 0;
 183         req->reply_len = 0;
 184
 185         spin_lock_irqsave(&macio_lock, flags);
 186         if (current_req != 0) {
 187                 last_req->next = req;
 188                 last_req = req;
 189         } else {
 190                 current_req = last_req = req;
 191                 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 192         }
 193         spin_unlock_irqrestore(&macio_lock, flags);
 194
 195         if (sync) {
 196                 while (!req->complete)
 197                         macio_adb_poll();
 198         }
 199
 200         return 0;
 201 }
 202
 203 static irqreturn_t macio_adb_interrupt(int irq, void *arg,
 204                                        struct pt_regs *regs)
 205 {
 206         int i, n, err;
 207         struct adb_request *req = NULL;
 208         unsigned char ibuf[16];
 209         int ibuf_len = 0;
 210         int complete = 0;
 211         int autopoll = 0;
 212         int handled = 0;
 213
 214         spin_lock(&macio_lock);
 215         if (in_8(&adb->intr.r) & TAG) {
 216                 handled = 1;
 217                 if ((req = current_req) != 0) {
 218                         /* put the current request in */
 219                         for (i = 0; i < req->nbytes; ++i)
 220                                 out_8(&adb->data[i].r, req->data[i]);
 221                         out_8(&adb->dcount.r, req->nbytes & HMB);
 222                         req->sent = 1;
 223                         if (req->reply_expected) {
 224                                 out_8(&adb->ctrl.r, DTB + CRE);
 225                         } else {
 226                                 out_8(&adb->ctrl.r, DTB);
 227                                 current_req = req->next;
 228                                 complete = 1;
 229                                 if (current_req)
 230                                         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 231                         }
 232                 }
 233                 out_8(&adb->intr.r, 0);
 234         }
 235
 236         if (in_8(&adb->intr.r) & DFB) {
 237                 handled = 1;
 238                 err = in_8(&adb->error.r);
 239                 if (current_req && current_req->sent) {
 240                         /* this is the response to a command */
 241                         req = current_req;
 242                         if (err == 0) {
 243                                 req->reply_len = in_8(&adb->dcount.r) & HMB;
 244                                 for (i = 0; i < req->reply_len; ++i)
 245                                         req->reply[i] = in_8(&adb->data[i].r);
 246                         }
 247                         current_req = req->next;
 248                         complete = 1;
 249                         if (current_req)
 250                                 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 251                 } else if (err == 0) {
 252                         /* autopoll data */
 253                         n = in_8(&adb->dcount.r) & HMB;
 254                         for (i = 0; i < n; ++i)
 255                                 ibuf[i] = in_8(&adb->data[i].r);
 256                         ibuf_len = n;
 257                         autopoll = (in_8(&adb->dcount.r) & APD) != 0;
 258                 }
 259                 out_8(&adb->error.r, 0);
 260                 out_8(&adb->intr.r, 0);
 261         }
 262         spin_unlock(&macio_lock);
 263         if (complete && req) {
 264             void (*done)(struct adb_request *) = req->done;
 265             mb();
 266             req->complete = 1;
 267             /* Here, we assume that if the request has a done member, the
 268              * struct request will survive to setting req->complete to 1
 269              */
 270             if (done)
 271                 (*done)(req);
 272         }
 273         if (ibuf_len)
 274                 adb_input(ibuf, ibuf_len, regs, autopoll);
 275
 276         return IRQ_RETVAL(handled);
 277 }
 278
 279 static void macio_adb_poll(void)
 280 {
 281         unsigned long flags;
 282
 283         local_irq_save(flags);
 284         if (in_8(&adb->intr.r) != 0)
 285                 macio_adb_interrupt(0, NULL, NULL);
 286         local_irq_restore(flags);
 287 }