linux/arch/mips/sgi-ip22/ip22-gio.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2#include <linux/export.h>
   3#include <linux/kernel.h>
   4#include <linux/init.h>
   5#include <linux/slab.h>
   6
   7#include <asm/addrspace.h>
   8#include <asm/paccess.h>
   9#include <asm/gio_device.h>
  10#include <asm/sgi/gio.h>
  11#include <asm/sgi/hpc3.h>
  12#include <asm/sgi/mc.h>
  13#include <asm/sgi/ip22.h>
  14
  15static struct bus_type gio_bus_type;
  16
  17static struct {
  18        const char *name;
  19        __u8       id;
  20} gio_name_table[] = {
  21        { .name = "SGI Impact", .id = 0x10 },
  22        { .name = "Phobos G160", .id = 0x35 },
  23        { .name = "Phobos G130", .id = 0x36 },
  24        { .name = "Phobos G100", .id = 0x37 },
  25        { .name = "Set Engineering GFE", .id = 0x38 },
  26        /* fake IDs */
  27        { .name = "SGI Newport", .id = 0x7e },
  28        { .name = "SGI GR2/GR3", .id = 0x7f },
  29};
  30
  31static void gio_bus_release(struct device *dev)
  32{
  33        kfree(dev);
  34}
  35
  36static struct device gio_bus = {
  37        .init_name = "gio",
  38        .release = &gio_bus_release,
  39};
  40
  41/**
  42 * gio_match_device - Tell if an of_device structure has a matching
  43 * gio_match structure
  44 * @ids: array of of device match structures to search in
  45 * @dev: the of device structure to match against
  46 *
  47 * Used by a driver to check whether an of_device present in the
  48 * system is in its list of supported devices.
  49 */
  50static const struct gio_device_id *
  51gio_match_device(const struct gio_device_id *match,
  52                 const struct gio_device *dev)
  53{
  54        const struct gio_device_id *ids;
  55
  56        for (ids = match; ids->id != 0xff; ids++)
  57                if (ids->id == dev->id.id)
  58                        return ids;
  59
  60        return NULL;
  61}
  62
  63struct gio_device *gio_dev_get(struct gio_device *dev)
  64{
  65        struct device *tmp;
  66
  67        if (!dev)
  68                return NULL;
  69        tmp = get_device(&dev->dev);
  70        if (tmp)
  71                return to_gio_device(tmp);
  72        else
  73                return NULL;
  74}
  75EXPORT_SYMBOL_GPL(gio_dev_get);
  76
  77void gio_dev_put(struct gio_device *dev)
  78{
  79        if (dev)
  80                put_device(&dev->dev);
  81}
  82EXPORT_SYMBOL_GPL(gio_dev_put);
  83
  84/**
  85 * gio_release_dev - free an gio device structure when all users of it are finished.
  86 * @dev: device that's been disconnected
  87 *
  88 * Will be called only by the device core when all users of this gio device are
  89 * done.
  90 */
  91void gio_release_dev(struct device *dev)
  92{
  93        struct gio_device *giodev;
  94
  95        giodev = to_gio_device(dev);
  96        kfree(giodev);
  97}
  98EXPORT_SYMBOL_GPL(gio_release_dev);
  99
 100int gio_device_register(struct gio_device *giodev)
 101{
 102        giodev->dev.bus = &gio_bus_type;
 103        giodev->dev.parent = &gio_bus;
 104        return device_register(&giodev->dev);
 105}
 106EXPORT_SYMBOL_GPL(gio_device_register);
 107
 108void gio_device_unregister(struct gio_device *giodev)
 109{
 110        device_unregister(&giodev->dev);
 111}
 112EXPORT_SYMBOL_GPL(gio_device_unregister);
 113
 114static int gio_bus_match(struct device *dev, struct device_driver *drv)
 115{
 116        struct gio_device *gio_dev = to_gio_device(dev);
 117        struct gio_driver *gio_drv = to_gio_driver(drv);
 118
 119        return gio_match_device(gio_drv->id_table, gio_dev) != NULL;
 120}
 121
 122static int gio_device_probe(struct device *dev)
 123{
 124        int error = -ENODEV;
 125        struct gio_driver *drv;
 126        struct gio_device *gio_dev;
 127        const struct gio_device_id *match;
 128
 129        drv = to_gio_driver(dev->driver);
 130        gio_dev = to_gio_device(dev);
 131
 132        if (!drv->probe)
 133                return error;
 134
 135        gio_dev_get(gio_dev);
 136
 137        match = gio_match_device(drv->id_table, gio_dev);
 138        if (match)
 139                error = drv->probe(gio_dev, match);
 140        if (error)
 141                gio_dev_put(gio_dev);
 142
 143        return error;
 144}
 145
 146static void gio_device_remove(struct device *dev)
 147{
 148        struct gio_device *gio_dev = to_gio_device(dev);
 149        struct gio_driver *drv = to_gio_driver(dev->driver);
 150
 151        if (dev->driver && drv->remove)
 152                drv->remove(gio_dev);
 153}
 154
 155static void gio_device_shutdown(struct device *dev)
 156{
 157        struct gio_device *gio_dev = to_gio_device(dev);
 158        struct gio_driver *drv = to_gio_driver(dev->driver);
 159
 160        if (dev->driver && drv->shutdown)
 161                drv->shutdown(gio_dev);
 162}
 163
 164static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
 165                             char *buf)
 166{
 167        struct gio_device *gio_dev = to_gio_device(dev);
 168        int len = snprintf(buf, PAGE_SIZE, "gio:%x\n", gio_dev->id.id);
 169
 170        return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
 171}
 172static DEVICE_ATTR_RO(modalias);
 173
 174static ssize_t name_show(struct device *dev,
 175                         struct device_attribute *attr, char *buf)
 176{
 177        struct gio_device *giodev;
 178
 179        giodev = to_gio_device(dev);
 180        return sprintf(buf, "%s", giodev->name);
 181}
 182static DEVICE_ATTR_RO(name);
 183
 184static ssize_t id_show(struct device *dev,
 185                       struct device_attribute *attr, char *buf)
 186{
 187        struct gio_device *giodev;
 188
 189        giodev = to_gio_device(dev);
 190        return sprintf(buf, "%x", giodev->id.id);
 191}
 192static DEVICE_ATTR_RO(id);
 193
 194static struct attribute *gio_dev_attrs[] = {
 195        &dev_attr_modalias.attr,
 196        &dev_attr_name.attr,
 197        &dev_attr_id.attr,
 198        NULL,
 199};
 200ATTRIBUTE_GROUPS(gio_dev);
 201
 202static int gio_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 203{
 204        struct gio_device *gio_dev = to_gio_device(dev);
 205
 206        add_uevent_var(env, "MODALIAS=gio:%x", gio_dev->id.id);
 207        return 0;
 208}
 209
 210int gio_register_driver(struct gio_driver *drv)
 211{
 212        /* initialize common driver fields */
 213        if (!drv->driver.name)
 214                drv->driver.name = drv->name;
 215        if (!drv->driver.owner)
 216                drv->driver.owner = drv->owner;
 217        drv->driver.bus = &gio_bus_type;
 218
 219        /* register with core */
 220        return driver_register(&drv->driver);
 221}
 222EXPORT_SYMBOL_GPL(gio_register_driver);
 223
 224void gio_unregister_driver(struct gio_driver *drv)
 225{
 226        driver_unregister(&drv->driver);
 227}
 228EXPORT_SYMBOL_GPL(gio_unregister_driver);
 229
 230void gio_set_master(struct gio_device *dev)
 231{
 232        u32 tmp = sgimc->giopar;
 233
 234        switch (dev->slotno) {
 235        case 0:
 236                tmp |= SGIMC_GIOPAR_MASTERGFX;
 237                break;
 238        case 1:
 239                tmp |= SGIMC_GIOPAR_MASTEREXP0;
 240                break;
 241        case 2:
 242                tmp |= SGIMC_GIOPAR_MASTEREXP1;
 243                break;
 244        }
 245        sgimc->giopar = tmp;
 246}
 247EXPORT_SYMBOL_GPL(gio_set_master);
 248
 249void ip22_gio_set_64bit(int slotno)
 250{
 251        u32 tmp = sgimc->giopar;
 252
 253        switch (slotno) {
 254        case 0:
 255                tmp |= SGIMC_GIOPAR_GFX64;
 256                break;
 257        case 1:
 258                tmp |= SGIMC_GIOPAR_EXP064;
 259                break;
 260        case 2:
 261                tmp |= SGIMC_GIOPAR_EXP164;
 262                break;
 263        }
 264        sgimc->giopar = tmp;
 265}
 266
 267static int ip22_gio_id(unsigned long addr, u32 *res)
 268{
 269        u8 tmp8;
 270        u8 tmp16;
 271        u32 tmp32;
 272        u8 *ptr8;
 273        u16 *ptr16;
 274        u32 *ptr32;
 275
 276        ptr32 = (void *)CKSEG1ADDR(addr);
 277        if (!get_dbe(tmp32, ptr32)) {
 278                /*
 279                 * We got no DBE, but this doesn't mean anything.
 280                 * If GIO is pipelined (which can't be disabled
 281                 * for GFX slot) we don't get a DBE, but we see
 282                 * the transfer size as data. So we do an 8bit
 283                 * and a 16bit access and check whether the common
 284                 * data matches
 285                 */
 286                ptr8 = (void *)CKSEG1ADDR(addr + 3);
 287                if (get_dbe(tmp8, ptr8)) {
 288                        /*
 289                         * 32bit access worked, but 8bit doesn't
 290                         * so we don't see phantom reads on
 291                         * a pipelined bus, but a real card which
 292                         * doesn't support 8 bit reads
 293                         */
 294                        *res = tmp32;
 295                        return 1;
 296                }
 297                ptr16 = (void *)CKSEG1ADDR(addr + 2);
 298                get_dbe(tmp16, ptr16);
 299                if (tmp8 == (tmp16 & 0xff) &&
 300                    tmp8 == (tmp32 & 0xff) &&
 301                    tmp16 == (tmp32 & 0xffff)) {
 302                        *res = tmp32;
 303                        return 1;
 304                }
 305        }
 306        return 0; /* nothing here */
 307}
 308
 309#define HQ2_MYSTERY_OFFS       0x6A07C
 310#define NEWPORT_USTATUS_OFFS   0xF133C
 311
 312static int ip22_is_gr2(unsigned long addr)
 313{
 314        u32 tmp;
 315        u32 *ptr;
 316
 317        /* HQ2 only allows 32bit accesses */
 318        ptr = (void *)CKSEG1ADDR(addr + HQ2_MYSTERY_OFFS);
 319        if (!get_dbe(tmp, ptr)) {
 320                if (tmp == 0xdeadbeef)
 321                        return 1;
 322        }
 323        return 0;
 324}
 325
 326
 327static void ip22_check_gio(int slotno, unsigned long addr, int irq)
 328{
 329        const char *name = "Unknown";
 330        struct gio_device *gio_dev;
 331        u32 tmp;
 332        __u8 id;
 333        int i;
 334
 335        /* first look for GR2/GR3 by checking mystery register */
 336        if (ip22_is_gr2(addr))
 337                tmp = 0x7f;
 338        else {
 339                if (!ip22_gio_id(addr, &tmp)) {
 340                        /*
 341                         * no GIO signature at start address of slot
 342                         * since Newport doesn't have one, we check if
 343                         * user status register is readable
 344                         */
 345                        if (ip22_gio_id(addr + NEWPORT_USTATUS_OFFS, &tmp))
 346                                tmp = 0x7e;
 347                        else
 348                                tmp = 0;
 349                }
 350        }
 351        if (tmp) {
 352                id = GIO_ID(tmp);
 353                if (tmp & GIO_32BIT_ID) {
 354                        if (tmp & GIO_64BIT_IFACE)
 355                                ip22_gio_set_64bit(slotno);
 356                }
 357                for (i = 0; i < ARRAY_SIZE(gio_name_table); i++) {
 358                        if (id == gio_name_table[i].id) {
 359                                name = gio_name_table[i].name;
 360                                break;
 361                        }
 362                }
 363                printk(KERN_INFO "GIO: slot %d : %s (id %x)\n",
 364                       slotno, name, id);
 365                gio_dev = kzalloc(sizeof *gio_dev, GFP_KERNEL);
 366                gio_dev->name = name;
 367                gio_dev->slotno = slotno;
 368                gio_dev->id.id = id;
 369                gio_dev->resource.start = addr;
 370                gio_dev->resource.end = addr + 0x3fffff;
 371                gio_dev->resource.flags = IORESOURCE_MEM;
 372                gio_dev->irq = irq;
 373                dev_set_name(&gio_dev->dev, "%d", slotno);
 374                gio_device_register(gio_dev);
 375        } else
 376                printk(KERN_INFO "GIO: slot %d : Empty\n", slotno);
 377}
 378
 379static struct bus_type gio_bus_type = {
 380        .name      = "gio",
 381        .dev_groups = gio_dev_groups,
 382        .match     = gio_bus_match,
 383        .probe     = gio_device_probe,
 384        .remove    = gio_device_remove,
 385        .shutdown  = gio_device_shutdown,
 386        .uevent    = gio_device_uevent,
 387};
 388
 389static struct resource gio_bus_resource = {
 390        .start = GIO_SLOT_GFX_BASE,
 391        .end   = GIO_SLOT_GFX_BASE + 0x9fffff,
 392        .name  = "GIO Bus",
 393        .flags = IORESOURCE_MEM,
 394};
 395
 396int __init ip22_gio_init(void)
 397{
 398        unsigned int pbdma __maybe_unused;
 399        int ret;
 400
 401        ret = device_register(&gio_bus);
 402        if (ret) {
 403                put_device(&gio_bus);
 404                return ret;
 405        }
 406
 407        ret = bus_register(&gio_bus_type);
 408        if (!ret) {
 409                request_resource(&iomem_resource, &gio_bus_resource);
 410                printk(KERN_INFO "GIO: Probing bus...\n");
 411
 412                if (ip22_is_fullhouse()) {
 413                        /* Indigo2 */
 414                        ip22_check_gio(0, GIO_SLOT_GFX_BASE, SGI_GIO_1_IRQ);
 415                        ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIO_1_IRQ);
 416                } else {
 417                        /* Indy/Challenge S */
 418                        if (get_dbe(pbdma, (unsigned int *)&hpc3c1->pbdma[1]))
 419                                ip22_check_gio(0, GIO_SLOT_GFX_BASE,
 420                                               SGI_GIO_0_IRQ);
 421                        ip22_check_gio(1, GIO_SLOT_EXP0_BASE, SGI_GIOEXP0_IRQ);
 422                        ip22_check_gio(2, GIO_SLOT_EXP1_BASE, SGI_GIOEXP1_IRQ);
 423                }
 424        } else
 425                device_unregister(&gio_bus);
 426
 427        return ret;
 428}
 429
 430subsys_initcall(ip22_gio_init);
 431