LXR qemu/hw/misc/gpio-mr-mux.c

   1/*
   2 * QEMU model of a gpio based memory region muxer
   3 *
   4 * Copyright (c) 2017 Xilinx Inc.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a copy
   7 * of this software and associated documentation files (the "Software"), to deal
   8 * in the Software without restriction, including without limitation the rights
   9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 * copies of the Software, and to permit persons to whom the Software is
  11 * furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in
  14 * all copies or substantial portions of the Software.
  15 *
  16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22 * THE SOFTWARE.
  23 */
  24#include "qemu/osdep.h"
  25#include "hw/sysbus.h"
  26#include "qemu/log.h"
  27#include "qapi/error.h"
  28
  29#define TYPE_GPIO_MR_MUX "gpio-mr-mux"
  30
  31#define GPIO_MR_MUX(obj) \
  32     OBJECT_CHECK(GpioMrMux, (obj), TYPE_GPIO_MR_MUX)
  33
  34#ifndef MR_MUX_DEBUG
  35#define MR_MUX_DEBUG 0
  36#endif
  37
  38#define MAX_NR_GPIOS (4)
  39#define MAX_REGIONS (1 << MAX_NR_GPIOS)
  40
  41typedef struct GpioMrMux {
  42    SysBusDevice parent_obj;
  43    MemoryRegion iomem;
  44
  45    MemoryRegion *mr[MAX_REGIONS];
  46    MemoryRegion mr_alias[MAX_REGIONS];
  47
  48    struct {
  49        uint64_t mr_size;
  50    } cfg;
  51
  52    uint32_t state;
  53} GpioMrMux;
  54
  55static void update_regions(GpioMrMux *s)
  56{
  57    int i;
  58
  59    for (i = 0; i < MAX_REGIONS; i++) {
  60        bool enabled = s->state == i;
  61        memory_region_set_enabled(&s->mr_alias[i], enabled);
  62    }
  63}
  64
  65static void input_handler(void *opaque, int nr, int level)
  66{
  67    GpioMrMux *s = GPIO_MR_MUX(opaque);
  68
  69    s->state = deposit32(s->state, nr, 1, level);
  70    update_regions(s);
  71}
  72
  73static void gpio_mr_mux_realize(DeviceState *dev, Error **errp)
  74{
  75    GpioMrMux *s = GPIO_MR_MUX(dev);
  76    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
  77    int i;
  78
  79    memory_region_init(&s->iomem, OBJECT(dev),
  80                       TYPE_GPIO_MR_MUX, s->cfg.mr_size);
  81    sysbus_init_mmio(sbd, &s->iomem);
  82
  83    for (i = 0; i < MAX_REGIONS; i++) {
  84        if (s->mr[i]) {
  85            char *name = g_strdup_printf("mr-alias%d", i);
  86
  87            /* Create aliases because we can't modify the orginal MRs */
  88            memory_region_init_alias(&s->mr_alias[i], OBJECT(s),
  89                    name, s->mr[i], 0, memory_region_size(s->mr[i]));
  90            memory_region_add_subregion_overlap(&s->iomem, 0,
  91                                                &s->mr_alias[i], 0);
  92            g_free(name);
  93        }
  94    }
  95}
  96
  97static void gpio_mr_mux_init(Object *obj)
  98{
  99    GpioMrMux *s = GPIO_MR_MUX(obj);
 100    int i;
 101
 102    qdev_init_gpio_in(DEVICE(obj), input_handler, MAX_NR_GPIOS);
 103
 104    for (i = 0; i < MAX_REGIONS; i++) {
 105            char *name = g_strdup_printf("mr%d", i);
 106
 107            object_property_add_link(obj, name, TYPE_MEMORY_REGION,
 108                    (Object **)&s->mr[i],
 109                    qdev_prop_allow_set_link_before_realize,
 110                    OBJ_PROP_LINK_UNREF_ON_RELEASE,
 111                    &error_abort);
 112            g_free(name);
 113    }
 114}
 115
 116static Property gpio_mr_mux_properties[] = {
 117    DEFINE_PROP_UINT64("mr-size", GpioMrMux, cfg.mr_size, UINT64_MAX),
 118    DEFINE_PROP_END_OF_LIST(),
 119};
 120
 121static void gpio_mr_mux_class_init(ObjectClass *klass, void *data)
 122{
 123    DeviceClass *dc = DEVICE_CLASS(klass);
 124
 125    dc->realize = gpio_mr_mux_realize;
 126    dc->props = gpio_mr_mux_properties;
 127}
 128
 129static const TypeInfo gpio_mr_mux_info = {
 130    .name          = TYPE_GPIO_MR_MUX,
 131    .parent        = TYPE_SYS_BUS_DEVICE,
 132    .instance_size = sizeof(GpioMrMux),
 133    .class_init    = gpio_mr_mux_class_init,
 134    .instance_init = gpio_mr_mux_init,
 135};
 136
 137static void gpio_mr_mux_register_types(void)
 138{
 139    type_register_static(&gpio_mr_mux_info);
 140}
 141
 142type_init(gpio_mr_mux_register_types)
 143