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         unsigned int irq;
  94
  95         adbs = find_compatible_devices("adb", "chrp,adb0");
  96         if (adbs == 0)
  97                 return -ENXIO;
  98
  99         if (of_address_to_resource(adbs, 0, &r))
 100                 return -ENXIO;
 101         adb = ioremap(r.start, sizeof(struct adb_regs));
 102
 103         out_8(&adb->ctrl.r, 0);
 104         out_8(&adb->intr.r, 0);
 105         out_8(&adb->error.r, 0);
 106         out_8(&adb->active_hi.r, 0xff); /* for now, set all devices active */
 107         out_8(&adb->active_lo.r, 0xff);
 108         out_8(&adb->autopoll.r, APE);
 109
 110         irq = irq_of_parse_and_map(adbs, 0);
 111         if (request_irq(irq, macio_adb_interrupt, 0, "ADB", (void *)0)) {
 112                 printk(KERN_ERR "ADB: can't get irq %d\n", irq);
 113                 return -EAGAIN;
 114         }
 115         out_8(&adb->intr_enb.r, DFB | TAG);
 116
 117         printk("adb: mac-io driver 1.0 for unified ADB\n");
 118
 119         return 0;
 120 }
 121
 122 static int macio_adb_autopoll(int devs)
 123 {
 124         unsigned long flags;
 125
 126         spin_lock_irqsave(&macio_lock, flags);
 127         out_8(&adb->active_hi.r, devs >> 8);
 128         out_8(&adb->active_lo.r, devs);
 129         out_8(&adb->autopoll.r, devs? APE: 0);
 130         spin_unlock_irqrestore(&macio_lock, flags);
 131         return 0;
 132 }
 133
 134 static int macio_adb_reset_bus(void)
 135 {
 136         unsigned long flags;
 137         int timeout = 1000000;
 138
 139         /* Hrm... we may want to not lock interrupts for so
 140          * long ... oh well, who uses that chip anyway ? :)
 141          * That function will be seldomly used during boot
 142          * on rare machines, so...
 143          */
 144         spin_lock_irqsave(&macio_lock, flags);
 145         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | ADB_RST);
 146         while ((in_8(&adb->ctrl.r) & ADB_RST) != 0) {
 147                 if (--timeout == 0) {
 148                         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) & ~ADB_RST);
 149                         return -1;
 150                 }
 151         }
 152         spin_unlock_irqrestore(&macio_lock, flags);
 153         return 0;
 154 }
 155
 156 /* Send an ADB command */
 157 static int macio_send_request(struct adb_request *req, int sync)
 158 {
 159         unsigned long flags;
 160         int i;
 161
 162         if (req->data[0] != ADB_PACKET)
 163                 return -EINVAL;
 164
 165         for (i = 0; i < req->nbytes - 1; ++i)
 166                 req->data[i] = req->data[i+1];
 167         --req->nbytes;
 168
 169         req->next = NULL;
 170         req->sent = 0;
 171         req->complete = 0;
 172         req->reply_len = 0;
 173
 174         spin_lock_irqsave(&macio_lock, flags);
 175         if (current_req != 0) {
 176                 last_req->next = req;
 177                 last_req = req;
 178         } else {
 179                 current_req = last_req = req;
 180                 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 181         }
 182         spin_unlock_irqrestore(&macio_lock, flags);
 183
 184         if (sync) {
 185                 while (!req->complete)
 186                         macio_adb_poll();
 187         }
 188
 189         return 0;
 190 }
 191
 192 static irqreturn_t macio_adb_interrupt(int irq, void *arg,
 193                                        struct pt_regs *regs)
 194 {
 195         int i, n, err;
 196         struct adb_request *req = NULL;
 197         unsigned char ibuf[16];
 198         int ibuf_len = 0;
 199         int complete = 0;
 200         int autopoll = 0;
 201         int handled = 0;
 202
 203         spin_lock(&macio_lock);
 204         if (in_8(&adb->intr.r) & TAG) {
 205                 handled = 1;
 206                 if ((req = current_req) != 0) {
 207                         /* put the current request in */
 208                         for (i = 0; i < req->nbytes; ++i)
 209                                 out_8(&adb->data[i].r, req->data[i]);
 210                         out_8(&adb->dcount.r, req->nbytes & HMB);
 211                         req->sent = 1;
 212                         if (req->reply_expected) {
 213                                 out_8(&adb->ctrl.r, DTB + CRE);
 214                         } else {
 215                                 out_8(&adb->ctrl.r, DTB);
 216                                 current_req = req->next;
 217                                 complete = 1;
 218                                 if (current_req)
 219                                         out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 220                         }
 221                 }
 222                 out_8(&adb->intr.r, 0);
 223         }
 224
 225         if (in_8(&adb->intr.r) & DFB) {
 226                 handled = 1;
 227                 err = in_8(&adb->error.r);
 228                 if (current_req && current_req->sent) {
 229                         /* this is the response to a command */
 230                         req = current_req;
 231                         if (err == 0) {
 232                                 req->reply_len = in_8(&adb->dcount.r) & HMB;
 233                                 for (i = 0; i < req->reply_len; ++i)
 234                                         req->reply[i] = in_8(&adb->data[i].r);
 235                         }
 236                         current_req = req->next;
 237                         complete = 1;
 238                         if (current_req)
 239                                 out_8(&adb->ctrl.r, in_8(&adb->ctrl.r) | TAR);
 240                 } else if (err == 0) {
 241                         /* autopoll data */
 242                         n = in_8(&adb->dcount.r) & HMB;
 243                         for (i = 0; i < n; ++i)
 244                                 ibuf[i] = in_8(&adb->data[i].r);
 245                         ibuf_len = n;
 246                         autopoll = (in_8(&adb->dcount.r) & APD) != 0;
 247                 }
 248                 out_8(&adb->error.r, 0);
 249                 out_8(&adb->intr.r, 0);
 250         }
 251         spin_unlock(&macio_lock);
 252         if (complete && req) {
 253             void (*done)(struct adb_request *) = req->done;
 254             mb();
 255             req->complete = 1;
 256             /* Here, we assume that if the request has a done member, the
 257              * struct request will survive to setting req->complete to 1
 258              */
 259             if (done)
 260                 (*done)(req);
 261         }
 262         if (ibuf_len)
 263                 adb_input(ibuf, ibuf_len, regs, autopoll);
 264
 265         return IRQ_RETVAL(handled);
 266 }
 267
 268 static void macio_adb_poll(void)
 269 {
 270         unsigned long flags;
 271
 272         local_irq_save(flags);
 273         if (in_8(&adb->intr.r) != 0)
 274                 macio_adb_interrupt(0, NULL, NULL);
 275         local_irq_restore(flags);
 276 }