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 #include "qemu/module.h"
  18
  19 struct SSIBus {
  20     BusState parent_obj;
  21 };
  22
  23 #define TYPE_SSI_BUS "SSI"
  24 #define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  25
  26 static const TypeInfo ssi_bus_info = {
  27     .name = TYPE_SSI_BUS,
  28     .parent = TYPE_BUS,
  29     .instance_size = sizeof(SSIBus),
  30 };
  31
  32 static void ssi_cs_default(void *opaque, int n, int level)
  33 {
  34     SSISlave *s = SSI_SLAVE(opaque);
  35     bool cs = !!level;
  36     assert(n == 0);
  37     if (s->cs != cs) {
  38         SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  39         if (ssc->set_cs) {
  40             ssc->set_cs(s, cs);
  41         }
  42     }
  43     s->cs = cs;
  44 }
  45
  46 static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
  47 {
  48     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
  49
  50     if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  51             (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  52             ssc->cs_polarity == SSI_CS_NONE) {
  53         return ssc->transfer(dev, val);
  54     }
  55     return 0;
  56 }
  57
  58 static void ssi_slave_realize(DeviceState *dev, Error **errp)
  59 {
  60     SSISlave *s = SSI_SLAVE(dev);
  61     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  62
  63     if (ssc->transfer_raw == ssi_transfer_raw_default &&
  64             ssc->cs_polarity != SSI_CS_NONE) {
  65         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  66     }
  67
  68     ssc->realize(s, errp);
  69 }
  70
  71 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  72 {
  73     SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
  74     DeviceClass *dc = DEVICE_CLASS(klass);
  75
  76     dc->realize = ssi_slave_realize;
  77     dc->bus_type = TYPE_SSI_BUS;
  78     if (!ssc->transfer_raw) {
  79         ssc->transfer_raw = ssi_transfer_raw_default;
  80     }
  81 }
  82
  83 static const TypeInfo ssi_slave_info = {
  84     .name = TYPE_SSI_SLAVE,
  85     .parent = TYPE_DEVICE,
  86     .class_init = ssi_slave_class_init,
  87     .class_size = sizeof(SSISlaveClass),
  88     .abstract = true,
  89 };
  90
  91 DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
  92 {
  93     return qdev_create(BUS(bus), name);
  94 }
  95
  96 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  97 {
  98     DeviceState *dev = ssi_create_slave_no_init(bus, name);
  99
 100     qdev_init_nofail(dev);
 101     return dev;
 102 }
 103
 104 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 105 {
 106     BusState *bus;
 107     bus = qbus_create(TYPE_SSI_BUS, parent, name);
 108     return SSI_BUS(bus);
 109 }
 110
 111 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 112 {
 113     BusState *b = BUS(bus);
 114     BusChild *kid;
 115     SSISlaveClass *ssc;
 116     uint32_t r = 0;
 117
 118     QTAILQ_FOREACH(kid, &b->children, sibling) {
 119         SSISlave *slave = SSI_SLAVE(kid->child);
 120         ssc = SSI_SLAVE_GET_CLASS(slave);
 121         r |= ssc->transfer_raw(slave, val);
 122     }
 123
 124     return r;
 125 }
 126
 127 const VMStateDescription vmstate_ssi_slave = {
 128     .name = "SSISlave",
 129     .version_id = 1,
 130     .minimum_version_id = 1,
 131     .fields = (VMStateField[]) {
 132         VMSTATE_BOOL(cs, SSISlave),
 133         VMSTATE_END_OF_LIST()
 134     }
 135 };
 136
 137 static void ssi_slave_register_types(void)
 138 {
 139     type_register_static(&ssi_bus_info);
 140     type_register_static(&ssi_slave_info);
 141 }
 142
 143 type_init(ssi_slave_register_types)
 144
 145 typedef struct SSIAutoConnectArg {
 146     qemu_irq **cs_linep;
 147     SSIBus *bus;
 148 } SSIAutoConnectArg;
 149
 150 static int ssi_auto_connect_slave(Object *child, void *opaque)
 151 {
 152     SSIAutoConnectArg *arg = opaque;
 153     SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
 154     qemu_irq cs_line;
 155
 156     if (!dev) {
 157         return 0;
 158     }
 159
 160     cs_line = qdev_get_gpio_in_named(DEVICE(dev), SSI_GPIO_CS, 0);
 161     qdev_set_parent_bus(DEVICE(dev), BUS(arg->bus));
 162     **arg->cs_linep = cs_line;
 163     (*arg->cs_linep)++;
 164     return 0;
 165 }
 166
 167 void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
 168                              SSIBus *bus)
 169 {
 170     SSIAutoConnectArg arg = {
 171         .cs_linep = &cs_line,
 172         .bus = bus
 173     };
 174
 175     object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
 176 }