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#include "hw/qdev-properties.h"
  29
  30#define TYPE_GPIO_MR_MUX "gpio-mr-mux"
  31
  32#define GPIO_MR_MUX(obj) \
  33     OBJECT_CHECK(GpioMrMux, (obj), TYPE_GPIO_MR_MUX)
  34
  35#ifndef MR_MUX_DEBUG
  36#define MR_MUX_DEBUG 0
  37#endif
  38
  39#define MAX_NR_GPIOS (4)
  40#define MAX_REGIONS (1 << MAX_NR_GPIOS)
  41
  42typedef struct GpioMrMux {
  43    SysBusDevice parent_obj;
  44    MemoryRegion iomem;
  45
  46    MemoryRegion *mr[MAX_REGIONS];
  47    MemoryRegion mr_alias[MAX_REGIONS];
  48
  49    struct {
  50        uint64_t mr_size;
  51    } cfg;
  52
  53    uint32_t state;
  54} GpioMrMux;
  55
  56static void update_regions(GpioMrMux *s)
  57{
  58    int i;
  59
  60    for (i = 0; i < MAX_REGIONS; i++) {
  61        bool enabled = s->state == i;
  62        memory_region_set_enabled(&s->mr_alias[i], enabled);
  63    }
  64}
  65
  66static void input_handler(void *opaque, int nr, int level)
  67{
  68    GpioMrMux *s = GPIO_MR_MUX(opaque);
  69
  70    s->state = deposit32(s->state, nr, 1, level);
  71    update_regions(s);
  72}
  73
  74static void gpio_mr_mux_realize(DeviceState *dev, Error **errp)
  75{
  76    GpioMrMux *s = GPIO_MR_MUX(dev);
  77    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
  78    int i;
  79
  80    memory_region_init(&s->iomem, OBJECT(dev),
  81                       TYPE_GPIO_MR_MUX, s->cfg.mr_size);
  82    sysbus_init_mmio(sbd, &s->iomem);
  83
  84    for (i = 0; i < MAX_REGIONS; i++) {
  85        if (s->mr[i]) {
  86            char *name = g_strdup_printf("mr-alias%d", i);
  87
  88            /* Create aliases because we can't modify the orginal MRs */
  89            memory_region_init_alias(&s->mr_alias[i], OBJECT(s),
  90                    name, s->mr[i], 0, memory_region_size(s->mr[i]));
  91            memory_region_add_subregion_overlap(&s->iomem, 0,
  92                                                &s->mr_alias[i], 0);
  93            g_free(name);
  94        }
  95    }
  96}
  97
  98static void gpio_mr_mux_init(Object *obj)
  99{
 100    GpioMrMux *s = GPIO_MR_MUX(obj);
 101    int i;
 102
 103    qdev_init_gpio_in(DEVICE(obj), input_handler, MAX_NR_GPIOS);
 104
 105    for (i = 0; i < MAX_REGIONS; i++) {
 106            char *name = g_strdup_printf("mr%d", i);
 107
 108            object_property_add_link(obj, name, TYPE_MEMORY_REGION,
 109                             (Object **)&s->mr[i],
 110                             qdev_prop_allow_set_link_before_realize,
 111                             OBJ_PROP_LINK_STRONG);
 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    device_class_set_props(dc, 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