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) 167