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/ssi/ssi.h"
  17
  18 struct SSIBus {
  19     BusState parent_obj;
  20 };
  21
  22 #define TYPE_SSI_BUS "SSI"
  23 #define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  24
  25 static const TypeInfo ssi_bus_info = {
  26     .name = TYPE_SSI_BUS,
  27     .parent = TYPE_BUS,
  28     .instance_size = sizeof(SSIBus),
  29 };
  30
  31 static void ssi_cs_default(void *opaque, int n, int level)
  32 {
  33     SSISlave *s = SSI_SLAVE(opaque);
  34     bool cs = !!level;
  35     assert(n == 0);
  36     if (s->cs != cs) {
  37         SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  38         if (ssc->set_cs) {
  39             ssc->set_cs(s, cs);
  40         }
  41     }
  42     s->cs = cs;
  43 }
  44
  45 static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
  46 {
  47     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
  48
  49     if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  50             (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  51             ssc->cs_polarity == SSI_CS_NONE) {
  52         return ssc->transfer(dev, val);
  53     }
  54     return 0;
  55 }
  56
  57 static void ssi_slave_realize(DeviceState *dev, Error **errp)
  58 {
  59     SSISlave *s = SSI_SLAVE(dev);
  60     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  61
  62     if (ssc->transfer_raw == ssi_transfer_raw_default &&
  63             ssc->cs_polarity != SSI_CS_NONE) {
  64         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  65     }
  66
  67     ssc->realize(s, errp);
  68 }
  69
  70 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  71 {
  72     SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
  73     DeviceClass *dc = DEVICE_CLASS(klass);
  74
  75     dc->realize = ssi_slave_realize;
  76     dc->bus_type = TYPE_SSI_BUS;
  77     if (!ssc->transfer_raw) {
  78         ssc->transfer_raw = ssi_transfer_raw_default;
  79     }
  80 }
  81
  82 static const TypeInfo ssi_slave_info = {
  83     .name = TYPE_SSI_SLAVE,
  84     .parent = TYPE_DEVICE,
  85     .class_init = ssi_slave_class_init,
  86     .class_size = sizeof(SSISlaveClass),
  87     .abstract = true,
  88 };
  89
  90 DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
  91 {
  92     return qdev_create(BUS(bus), name);
  93 }
  94
  95 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  96 {
  97     DeviceState *dev = ssi_create_slave_no_init(bus, name);
  98
  99     qdev_init_nofail(dev);
 100     return dev;
 101 }
 102
 103 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 104 {
 105     BusState *bus;
 106     bus = qbus_create(TYPE_SSI_BUS, parent, name);
 107     return SSI_BUS(bus);
 108 }
 109
 110 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 111 {
 112     BusState *b = BUS(bus);
 113     BusChild *kid;
 114     SSISlaveClass *ssc;
 115     uint32_t r = 0;
 116
 117     QTAILQ_FOREACH(kid, &b->children, sibling) {
 118         SSISlave *slave = SSI_SLAVE(kid->child);
 119         ssc = SSI_SLAVE_GET_CLASS(slave);
 120         r |= ssc->transfer_raw(slave, val);
 121     }
 122
 123     return r;
 124 }
 125
 126 const VMStateDescription vmstate_ssi_slave = {
 127     .name = "SSISlave",
 128     .version_id = 1,
 129     .minimum_version_id = 1,
 130     .fields = (VMStateField[]) {
 131         VMSTATE_BOOL(cs, SSISlave),
 132         VMSTATE_END_OF_LIST()
 133     }
 134 };
 135
 136 static void ssi_slave_register_types(void)
 137 {
 138     type_register_static(&ssi_bus_info);
 139     type_register_static(&ssi_slave_info);
 140 }
 141
 142 type_init(ssi_slave_register_types)
 143
 144 typedef struct SSIAutoConnectArg {
 145     qemu_irq **cs_linep;
 146     SSIBus *bus;
 147 } SSIAutoConnectArg;
 148
 149 static int ssi_auto_connect_slave(Object *child, void *opaque)
 150 {
 151     SSIAutoConnectArg *arg = opaque;
 152     SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
 153     qemu_irq cs_line;
 154
 155     if (!dev) {
 156         return 0;
 157     }
 158
 159     cs_line = qdev_get_gpio_in_named(DEVICE(dev), SSI_GPIO_CS, 0);
 160     qdev_set_parent_bus(DEVICE(dev), BUS(arg->bus));
 161     **arg->cs_linep = cs_line;
 162     (*arg->cs_linep)++;
 163     return 0;
 164 }
 165
 166 void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
 167                              SSIBus *bus)
 168 {
 169     SSIAutoConnectArg arg = {
 170         .cs_linep = &cs_line,
 171         .bus = bus
 172     };
 173
 174     object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
 175 }