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