hw/gpio/bcm2835_gpio.c

   1 /*
   2  * Raspberry Pi (BCM2835) GPIO Controller
   3  *
   4  * Copyright (c) 2017 Antfield SAS
   5  *
   6  * Authors:
   7  *  Clement Deschamps <clement.deschamps@antfield.fr>
   8  *  Luc Michel <luc.michel@antfield.fr>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "qemu/log.h"
  16 #include "qemu/timer.h"
  17 #include "qapi/error.h"
  18 #include "hw/sysbus.h"
  19 #include "hw/sd/sd.h"
  20 #include "hw/gpio/bcm2835_gpio.h"
  21
  22 #define GPFSEL0   0x00
  23 #define GPFSEL1   0x04
  24 #define GPFSEL2   0x08
  25 #define GPFSEL3   0x0C
  26 #define GPFSEL4   0x10
  27 #define GPFSEL5   0x14
  28 #define GPSET0    0x1C
  29 #define GPSET1    0x20
  30 #define GPCLR0    0x28
  31 #define GPCLR1    0x2C
  32 #define GPLEV0    0x34
  33 #define GPLEV1    0x38
  34 #define GPEDS0    0x40
  35 #define GPEDS1    0x44
  36 #define GPREN0    0x4C
  37 #define GPREN1    0x50
  38 #define GPFEN0    0x58
  39 #define GPFEN1    0x5C
  40 #define GPHEN0    0x64
  41 #define GPHEN1    0x68
  42 #define GPLEN0    0x70
  43 #define GPLEN1    0x74
  44 #define GPAREN0   0x7C
  45 #define GPAREN1   0x80
  46 #define GPAFEN0   0x88
  47 #define GPAFEN1   0x8C
  48 #define GPPUD     0x94
  49 #define GPPUDCLK0 0x98
  50 #define GPPUDCLK1 0x9C
  51
  52 static uint32_t gpfsel_get(BCM2835GpioState *s, uint8_t reg)
  53 {
  54     int i;
  55     uint32_t value = 0;
  56     for (i = 0; i < 10; i++) {
  57         uint32_t index = 10 * reg + i;
  58         if (index < sizeof(s->fsel)) {
  59             value |= (s->fsel[index] & 0x7) << (3 * i);
  60         }
  61     }
  62     return value;
  63 }
  64
  65 static void gpfsel_set(BCM2835GpioState *s, uint8_t reg, uint32_t value)
  66 {
  67     int i;
  68     for (i = 0; i < 10; i++) {
  69         uint32_t index = 10 * reg + i;
  70         if (index < sizeof(s->fsel)) {
  71             int fsel = (value >> (3 * i)) & 0x7;
  72             s->fsel[index] = fsel;
  73         }
  74     }
  75
  76     /* SD controller selection (48-53) */
  77     if (s->sd_fsel != 0
  78             && (s->fsel[48] == 0) /* SD_CLK_R */
  79             && (s->fsel[49] == 0) /* SD_CMD_R */
  80             && (s->fsel[50] == 0) /* SD_DATA0_R */
  81             && (s->fsel[51] == 0) /* SD_DATA1_R */
  82             && (s->fsel[52] == 0) /* SD_DATA2_R */
  83             && (s->fsel[53] == 0) /* SD_DATA3_R */
  84             ) {
  85         /* SDHCI controller selected */
  86         sdbus_reparent_card(s->sdbus_sdhost, s->sdbus_sdhci);
  87         s->sd_fsel = 0;
  88     } else if (s->sd_fsel != 4
  89             && (s->fsel[48] == 4) /* SD_CLK_R */
  90             && (s->fsel[49] == 4) /* SD_CMD_R */
  91             && (s->fsel[50] == 4) /* SD_DATA0_R */
  92             && (s->fsel[51] == 4) /* SD_DATA1_R */
  93             && (s->fsel[52] == 4) /* SD_DATA2_R */
  94             && (s->fsel[53] == 4) /* SD_DATA3_R */
  95             ) {
  96         /* SDHost controller selected */
  97         sdbus_reparent_card(s->sdbus_sdhci, s->sdbus_sdhost);
  98         s->sd_fsel = 4;
  99     }
 100 }
 101
 102 static int gpfsel_is_out(BCM2835GpioState *s, int index)
 103 {
 104     if (index >= 0 && index < 54) {
 105         return s->fsel[index] == 1;
 106     }
 107     return 0;
 108 }
 109
 110 static void gpset(BCM2835GpioState *s,
 111         uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
 112 {
 113     uint32_t changes = val & ~*lev;
 114     uint32_t cur = 1;
 115
 116     int i;
 117     for (i = 0; i < count; i++) {
 118         if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
 119             qemu_set_irq(s->out[start + i], 1);
 120         }
 121         cur <<= 1;
 122     }
 123
 124     *lev |= val;
 125 }
 126
 127 static void gpclr(BCM2835GpioState *s,
 128         uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
 129 {
 130     uint32_t changes = val & *lev;
 131     uint32_t cur = 1;
 132
 133     int i;
 134     for (i = 0; i < count; i++) {
 135         if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
 136             qemu_set_irq(s->out[start + i], 0);
 137         }
 138         cur <<= 1;
 139     }
 140
 141     *lev &= ~val;
 142 }
 143
 144 static uint64_t bcm2835_gpio_read(void *opaque, hwaddr offset,
 145         unsigned size)
 146 {
 147     BCM2835GpioState *s = (BCM2835GpioState *)opaque;
 148
 149     switch (offset) {
 150     case GPFSEL0:
 151     case GPFSEL1:
 152     case GPFSEL2:
 153     case GPFSEL3:
 154     case GPFSEL4:
 155     case GPFSEL5:
 156         return gpfsel_get(s, offset / 4);
 157     case GPSET0:
 158     case GPSET1:
 159         /* Write Only */
 160         return 0;
 161     case GPCLR0:
 162     case GPCLR1:
 163         /* Write Only */
 164         return 0;
 165     case GPLEV0:
 166         return s->lev0;
 167     case GPLEV1:
 168         return s->lev1;
 169     case GPEDS0:
 170     case GPEDS1:
 171     case GPREN0:
 172     case GPREN1:
 173     case GPFEN0:
 174     case GPFEN1:
 175     case GPHEN0:
 176     case GPHEN1:
 177     case GPLEN0:
 178     case GPLEN1:
 179     case GPAREN0:
 180     case GPAREN1:
 181     case GPAFEN0:
 182     case GPAFEN1:
 183     case GPPUD:
 184     case GPPUDCLK0:
 185     case GPPUDCLK1:
 186         /* Not implemented */
 187         return 0;
 188     default:
 189         qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
 190                 __func__, offset);
 191         break;
 192     }
 193
 194     return 0;
 195 }
 196
 197 static void bcm2835_gpio_write(void *opaque, hwaddr offset,
 198         uint64_t value, unsigned size)
 199 {
 200     BCM2835GpioState *s = (BCM2835GpioState *)opaque;
 201
 202     switch (offset) {
 203     case GPFSEL0:
 204     case GPFSEL1:
 205     case GPFSEL2:
 206     case GPFSEL3:
 207     case GPFSEL4:
 208     case GPFSEL5:
 209         gpfsel_set(s, offset / 4, value);
 210         break;
 211     case GPSET0:
 212         gpset(s, value, 0, 32, &s->lev0);
 213         break;
 214     case GPSET1:
 215         gpset(s, value, 32, 22, &s->lev1);
 216         break;
 217     case GPCLR0:
 218         gpclr(s, value, 0, 32, &s->lev0);
 219         break;
 220     case GPCLR1:
 221         gpclr(s, value, 32, 22, &s->lev1);
 222         break;
 223     case GPLEV0:
 224     case GPLEV1:
 225         /* Read Only */
 226         break;
 227     case GPEDS0:
 228     case GPEDS1:
 229     case GPREN0:
 230     case GPREN1:
 231     case GPFEN0:
 232     case GPFEN1:
 233     case GPHEN0:
 234     case GPHEN1:
 235     case GPLEN0:
 236     case GPLEN1:
 237     case GPAREN0:
 238     case GPAREN1:
 239     case GPAFEN0:
 240     case GPAFEN1:
 241     case GPPUD:
 242     case GPPUDCLK0:
 243     case GPPUDCLK1:
 244         /* Not implemented */
 245         break;
 246     default:
 247         goto err_out;
 248     }
 249     return;
 250
 251 err_out:
 252     qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
 253             __func__, offset);
 254 }
 255
 256 static void bcm2835_gpio_reset(DeviceState *dev)
 257 {
 258     BCM2835GpioState *s = BCM2835_GPIO(dev);
 259
 260     int i;
 261     for (i = 0; i < 6; i++) {
 262         gpfsel_set(s, i, 0);
 263     }
 264
 265     s->sd_fsel = 0;
 266
 267     /* SDHCI is selected by default */
 268     sdbus_reparent_card(&s->sdbus, s->sdbus_sdhci);
 269
 270     s->lev0 = 0;
 271     s->lev1 = 0;
 272 }
 273
 274 static const MemoryRegionOps bcm2835_gpio_ops = {
 275     .read = bcm2835_gpio_read,
 276     .write = bcm2835_gpio_write,
 277     .endianness = DEVICE_NATIVE_ENDIAN,
 278 };
 279
 280 static const VMStateDescription vmstate_bcm2835_gpio = {
 281     .name = "bcm2835_gpio",
 282     .version_id = 1,
 283     .minimum_version_id = 1,
 284     .fields = (VMStateField[]) {
 285         VMSTATE_UINT8_ARRAY(fsel, BCM2835GpioState, 54),
 286         VMSTATE_UINT32(lev0, BCM2835GpioState),
 287         VMSTATE_UINT32(lev1, BCM2835GpioState),
 288         VMSTATE_UINT8(sd_fsel, BCM2835GpioState),
 289         VMSTATE_END_OF_LIST()
 290     }
 291 };
 292
 293 static void bcm2835_gpio_init(Object *obj)
 294 {
 295     BCM2835GpioState *s = BCM2835_GPIO(obj);
 296     DeviceState *dev = DEVICE(obj);
 297     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 298
 299     qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
 300                         TYPE_SD_BUS, DEVICE(s), "sd-bus");
 301
 302     memory_region_init_io(&s->iomem, obj,
 303             &bcm2835_gpio_ops, s, "bcm2835_gpio", 0x1000);
 304     sysbus_init_mmio(sbd, &s->iomem);
 305     qdev_init_gpio_out(dev, s->out, 54);
 306 }
 307
 308 static void bcm2835_gpio_realize(DeviceState *dev, Error **errp)
 309 {
 310     BCM2835GpioState *s = BCM2835_GPIO(dev);
 311     Object *obj;
 312     Error *err = NULL;
 313
 314     obj = object_property_get_link(OBJECT(dev), "sdbus-sdhci", &err);
 315     if (obj == NULL) {
 316         error_setg(errp, "%s: required sdhci link not found: %s",
 317                 __func__, error_get_pretty(err));
 318         return;
 319     }
 320     s->sdbus_sdhci = SD_BUS(obj);
 321
 322     obj = object_property_get_link(OBJECT(dev), "sdbus-sdhost", &err);
 323     if (obj == NULL) {
 324         error_setg(errp, "%s: required sdhost link not found: %s",
 325                 __func__, error_get_pretty(err));
 326         return;
 327     }
 328     s->sdbus_sdhost = SD_BUS(obj);
 329 }
 330
 331 static void bcm2835_gpio_class_init(ObjectClass *klass, void *data)
 332 {
 333     DeviceClass *dc = DEVICE_CLASS(klass);
 334
 335     dc->vmsd = &vmstate_bcm2835_gpio;
 336     dc->realize = &bcm2835_gpio_realize;
 337     dc->reset = &bcm2835_gpio_reset;
 338 }
 339
 340 static const TypeInfo bcm2835_gpio_info = {
 341     .name          = TYPE_BCM2835_GPIO,
 342     .parent        = TYPE_SYS_BUS_DEVICE,
 343     .instance_size = sizeof(BCM2835GpioState),
 344     .instance_init = bcm2835_gpio_init,
 345     .class_init    = bcm2835_gpio_class_init,
 346 };
 347
 348 static void bcm2835_gpio_register_types(void)
 349 {
 350     type_register_static(&bcm2835_gpio_info);
 351 }
 352
 353 type_init(bcm2835_gpio_register_types)