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