hw/ssi/ssi.c

   1 /*
   2  * QEMU Synchronous Serial Interface support
   3  *
   4  * Copyright (c) 2009 CodeSourcery.
   5  * Copyright (c) 2012 Peter A.G. Crosthwaite (peter.crosthwaite@petalogix.com)
   6  * Copyright (c) 2012 PetaLogix Pty Ltd.
   7  * Written by Paul Brook
   8  *
   9  * This code is licensed under the GNU GPL v2.
  10  *
  11  * Contributions after 2012-01-13 are licensed under the terms of the
  12  * GNU GPL, version 2 or (at your option) any later version.
  13  */
  14
  15 #include "qemu/osdep.h"
  16 #include "hw/qdev-properties.h"
  17 #include "hw/ssi/ssi.h"
  18 #include "migration/vmstate.h"
  19 #include "qemu/module.h"
  20 #include "qapi/error.h"
  21 #include "qom/object.h"
  22
  23 struct SSIBus {
  24     BusState parent_obj;
  25 };
  26
  27 #define TYPE_SSI_BUS "SSI"
  28 OBJECT_DECLARE_SIMPLE_TYPE(SSIBus, SSI_BUS)
  29
  30 DeviceState *ssi_get_cs(SSIBus *bus, uint8_t cs_index)
  31 {
  32     BusState *b = BUS(bus);
  33     BusChild *kid;
  34
  35     QTAILQ_FOREACH(kid, &b->children, sibling) {
  36         SSIPeripheral *kid_ssi = SSI_PERIPHERAL(kid->child);
  37         if (kid_ssi->cs_index == cs_index) {
  38             return kid->child;
  39         }
  40     }
  41
  42     return NULL;
  43 }
  44
  45 static const TypeInfo ssi_bus_info = {
  46     .name = TYPE_SSI_BUS,
  47     .parent = TYPE_BUS,
  48     .instance_size = sizeof(SSIBus),
  49 };
  50
  51 static void ssi_cs_default(void *opaque, int n, int level)
  52 {
  53     SSIPeripheral *s = SSI_PERIPHERAL(opaque);
  54     bool cs = !!level;
  55     assert(n == 0);
  56     if (s->cs != cs) {
  57         if (s->spc->set_cs) {
  58             s->spc->set_cs(s, cs);
  59         }
  60     }
  61     s->cs = cs;
  62 }
  63
  64 static uint32_t ssi_transfer_raw_default(SSIPeripheral *dev, uint32_t val)
  65 {
  66     SSIPeripheralClass *ssc = dev->spc;
  67
  68     if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  69         (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  70         ssc->cs_polarity == SSI_CS_NONE) {
  71         return ssc->transfer(dev, val);
  72     }
  73     return 0;
  74 }
  75
  76 static void ssi_peripheral_realize(DeviceState *dev, Error **errp)
  77 {
  78     SSIPeripheral *s = SSI_PERIPHERAL(dev);
  79     SSIPeripheralClass *ssc = SSI_PERIPHERAL_GET_CLASS(s);
  80
  81     if (ssc->transfer_raw == ssi_transfer_raw_default &&
  82             ssc->cs_polarity != SSI_CS_NONE) {
  83         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  84     }
  85     s->spc = ssc;
  86
  87     ssc->realize(s, errp);
  88 }
  89
  90 static Property ssi_peripheral_properties[] = {
  91     DEFINE_PROP_UINT8("cs", SSIPeripheral, cs_index, 0),
  92     DEFINE_PROP_END_OF_LIST(),
  93 };
  94
  95 static void ssi_peripheral_class_init(ObjectClass *klass, void *data)
  96 {
  97     SSIPeripheralClass *ssc = SSI_PERIPHERAL_CLASS(klass);
  98     DeviceClass *dc = DEVICE_CLASS(klass);
  99
 100     dc->realize = ssi_peripheral_realize;
 101     dc->bus_type = TYPE_SSI_BUS;
 102     if (!ssc->transfer_raw) {
 103         ssc->transfer_raw = ssi_transfer_raw_default;
 104     }
 105     device_class_set_props(dc, ssi_peripheral_properties);
 106 }
 107
 108 static const TypeInfo ssi_peripheral_info = {
 109     .name = TYPE_SSI_PERIPHERAL,
 110     .parent = TYPE_DEVICE,
 111     .class_init = ssi_peripheral_class_init,
 112     .class_size = sizeof(SSIPeripheralClass),
 113     .abstract = true,
 114 };
 115
 116 bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp)
 117 {
 118     return qdev_realize_and_unref(dev, &bus->parent_obj, errp);
 119 }
 120
 121 DeviceState *ssi_create_peripheral(SSIBus *bus, const char *name)
 122 {
 123     DeviceState *dev = qdev_new(name);
 124
 125     ssi_realize_and_unref(dev, bus, &error_fatal);
 126     return dev;
 127 }
 128
 129 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 130 {
 131     BusState *bus;
 132     bus = qbus_new(TYPE_SSI_BUS, parent, name);
 133     return SSI_BUS(bus);
 134 }
 135
 136 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 137 {
 138     BusState *b = BUS(bus);
 139     BusChild *kid;
 140     uint32_t r = 0;
 141
 142     QTAILQ_FOREACH(kid, &b->children, sibling) {
 143         SSIPeripheral *p = SSI_PERIPHERAL(kid->child);
 144         r |= p->spc->transfer_raw(p, val);
 145     }
 146
 147     return r;
 148 }
 149
 150 const VMStateDescription vmstate_ssi_peripheral = {
 151     .name = "SSISlave",
 152     .version_id = 1,
 153     .minimum_version_id = 1,
 154     .fields = (VMStateField[]) {
 155         VMSTATE_BOOL(cs, SSIPeripheral),
 156         VMSTATE_END_OF_LIST()
 157     }
 158 };
 159
 160 static void ssi_peripheral_register_types(void)
 161 {
 162     type_register_static(&ssi_bus_info);
 163     type_register_static(&ssi_peripheral_info);
 164 }
 165
 166 type_init(ssi_peripheral_register_types)