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 "migration/vmstate.h"
  18 #include "qemu/module.h"
  19
  20 struct SSIBus {
  21     BusState parent_obj;
  22 };
  23
  24 #define TYPE_SSI_BUS "SSI"
  25 #define SSI_BUS(obj) OBJECT_CHECK(SSIBus, (obj), TYPE_SSI_BUS)
  26
  27 static const TypeInfo ssi_bus_info = {
  28     .name = TYPE_SSI_BUS,
  29     .parent = TYPE_BUS,
  30     .instance_size = sizeof(SSIBus),
  31 };
  32
  33 static void ssi_cs_default(void *opaque, int n, int level)
  34 {
  35     SSISlave *s = SSI_SLAVE(opaque);
  36     bool cs = !!level;
  37     assert(n == 0);
  38     if (s->cs != cs) {
  39         SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  40         if (ssc->set_cs) {
  41             ssc->set_cs(s, cs);
  42         }
  43     }
  44     s->cs = cs;
  45 }
  46
  47 static uint32_t ssi_transfer_raw_default(SSISlave *dev, uint32_t val)
  48 {
  49     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(dev);
  50
  51     if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) ||
  52             (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) ||
  53             ssc->cs_polarity == SSI_CS_NONE) {
  54         return ssc->transfer(dev, val);
  55     }
  56     return 0;
  57 }
  58
  59 static void ssi_slave_realize(DeviceState *dev, Error **errp)
  60 {
  61     SSISlave *s = SSI_SLAVE(dev);
  62     SSISlaveClass *ssc = SSI_SLAVE_GET_CLASS(s);
  63
  64     if (ssc->transfer_raw == ssi_transfer_raw_default &&
  65             ssc->cs_polarity != SSI_CS_NONE) {
  66         qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1);
  67     }
  68
  69     ssc->realize(s, errp);
  70 }
  71
  72 static void ssi_slave_class_init(ObjectClass *klass, void *data)
  73 {
  74     SSISlaveClass *ssc = SSI_SLAVE_CLASS(klass);
  75     DeviceClass *dc = DEVICE_CLASS(klass);
  76
  77     dc->realize = ssi_slave_realize;
  78     dc->bus_type = TYPE_SSI_BUS;
  79     if (!ssc->transfer_raw) {
  80         ssc->transfer_raw = ssi_transfer_raw_default;
  81     }
  82 }
  83
  84 static const TypeInfo ssi_slave_info = {
  85     .name = TYPE_SSI_SLAVE,
  86     .parent = TYPE_DEVICE,
  87     .class_init = ssi_slave_class_init,
  88     .class_size = sizeof(SSISlaveClass),
  89     .abstract = true,
  90 };
  91
  92 DeviceState *ssi_create_slave_no_init(SSIBus *bus, const char *name)
  93 {
  94     return qdev_create(BUS(bus), name);
  95 }
  96
  97 DeviceState *ssi_create_slave(SSIBus *bus, const char *name)
  98 {
  99     DeviceState *dev = ssi_create_slave_no_init(bus, name);
 100
 101     qdev_init_nofail(dev);
 102     return dev;
 103 }
 104
 105 SSIBus *ssi_create_bus(DeviceState *parent, const char *name)
 106 {
 107     BusState *bus;
 108     bus = qbus_create(TYPE_SSI_BUS, parent, name);
 109     return SSI_BUS(bus);
 110 }
 111
 112 uint32_t ssi_transfer(SSIBus *bus, uint32_t val)
 113 {
 114     BusState *b = BUS(bus);
 115     BusChild *kid;
 116     SSISlaveClass *ssc;
 117     uint32_t r = 0;
 118
 119     QTAILQ_FOREACH(kid, &b->children, sibling) {
 120         SSISlave *slave = SSI_SLAVE(kid->child);
 121         ssc = SSI_SLAVE_GET_CLASS(slave);
 122         r |= ssc->transfer_raw(slave, val);
 123     }
 124
 125     return r;
 126 }
 127
 128 const VMStateDescription vmstate_ssi_slave = {
 129     .name = "SSISlave",
 130     .version_id = 1,
 131     .minimum_version_id = 1,
 132     .fields = (VMStateField[]) {
 133         VMSTATE_BOOL(cs, SSISlave),
 134         VMSTATE_END_OF_LIST()
 135     }
 136 };
 137
 138 static void ssi_slave_register_types(void)
 139 {
 140     type_register_static(&ssi_bus_info);
 141     type_register_static(&ssi_slave_info);
 142 }
 143
 144 type_init(ssi_slave_register_types)
 145
 146 typedef struct SSIAutoConnectArg {
 147     qemu_irq **cs_linep;
 148     SSIBus *bus;
 149 } SSIAutoConnectArg;
 150
 151 static int ssi_auto_connect_slave(Object *child, void *opaque)
 152 {
 153     SSIAutoConnectArg *arg = opaque;
 154     SSISlave *dev = (SSISlave *)object_dynamic_cast(child, TYPE_SSI_SLAVE);
 155     qemu_irq cs_line;
 156
 157     if (!dev) {
 158         return 0;
 159     }
 160
 161     cs_line = qdev_get_gpio_in_named(DEVICE(dev), SSI_GPIO_CS, 0);
 162     qdev_set_parent_bus(DEVICE(dev), BUS(arg->bus));
 163     **arg->cs_linep = cs_line;
 164     (*arg->cs_linep)++;
 165     return 0;
 166 }
 167
 168 void ssi_auto_connect_slaves(DeviceState *parent, qemu_irq *cs_line,
 169                              SSIBus *bus)
 170 {
 171     SSIAutoConnectArg arg = {
 172         .cs_linep = &cs_line,
 173         .bus = bus
 174     };
 175
 176     object_child_foreach(OBJECT(parent), ssi_auto_connect_slave, &arg);
 177 }