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 bool ssi_bus_check_address(BusState *b, DeviceState *dev, Error **errp) 46 { 47 SSIPeripheral *s = SSI_PERIPHERAL(dev); 48 49 if (ssi_get_cs(SSI_BUS(b), s->cs_index)) { 50 error_setg(errp, "CS index '0x%x' in use by a %s device", s->cs_index, 51 object_get_typename(OBJECT(dev))); 52 return false; 53 } 54 55 return true; 56 } 57 58 static void ssi_bus_class_init(ObjectClass *klass, void *data) 59 { 60 BusClass *k = BUS_CLASS(klass); 61 62 k->check_address = ssi_bus_check_address; 63 } 64 65 static const TypeInfo ssi_bus_info = { 66 .name = TYPE_SSI_BUS, 67 .parent = TYPE_BUS, 68 .instance_size = sizeof(SSIBus), 69 .class_init = ssi_bus_class_init, 70 }; 71 72 static void ssi_cs_default(void *opaque, int n, int level) 73 { 74 SSIPeripheral *s = SSI_PERIPHERAL(opaque); 75 bool cs = !!level; 76 assert(n == 0); 77 if (s->cs != cs) { 78 if (s->spc->set_cs) { 79 s->spc->set_cs(s, cs); 80 } 81 } 82 s->cs = cs; 83 } 84 85 static uint32_t ssi_transfer_raw_default(SSIPeripheral *dev, uint32_t val) 86 { 87 SSIPeripheralClass *ssc = dev->spc; 88 89 if ((dev->cs && ssc->cs_polarity == SSI_CS_HIGH) || 90 (!dev->cs && ssc->cs_polarity == SSI_CS_LOW) || 91 ssc->cs_polarity == SSI_CS_NONE) { 92 return ssc->transfer(dev, val); 93 } 94 return 0; 95 } 96 97 static void ssi_peripheral_realize(DeviceState *dev, Error **errp) 98 { 99 SSIPeripheral *s = SSI_PERIPHERAL(dev); 100 SSIPeripheralClass *ssc = SSI_PERIPHERAL_GET_CLASS(s); 101 102 if (ssc->transfer_raw == ssi_transfer_raw_default && 103 ssc->cs_polarity != SSI_CS_NONE) { 104 qdev_init_gpio_in_named(dev, ssi_cs_default, SSI_GPIO_CS, 1); 105 } 106 s->spc = ssc; 107 108 ssc->realize(s, errp); 109 } 110 111 static Property ssi_peripheral_properties[] = { 112 DEFINE_PROP_UINT8("cs", SSIPeripheral, cs_index, 0), 113 DEFINE_PROP_END_OF_LIST(), 114 }; 115 116 static void ssi_peripheral_class_init(ObjectClass *klass, void *data) 117 { 118 SSIPeripheralClass *ssc = SSI_PERIPHERAL_CLASS(klass); 119 DeviceClass *dc = DEVICE_CLASS(klass); 120 121 dc->realize = ssi_peripheral_realize; 122 dc->bus_type = TYPE_SSI_BUS; 123 if (!ssc->transfer_raw) { 124 ssc->transfer_raw = ssi_transfer_raw_default; 125 } 126 device_class_set_props(dc, ssi_peripheral_properties); 127 } 128 129 static const TypeInfo ssi_peripheral_info = { 130 .name = TYPE_SSI_PERIPHERAL, 131 .parent = TYPE_DEVICE, 132 .class_init = ssi_peripheral_class_init, 133 .class_size = sizeof(SSIPeripheralClass), 134 .abstract = true, 135 }; 136 137 bool ssi_realize_and_unref(DeviceState *dev, SSIBus *bus, Error **errp) 138 { 139 return qdev_realize_and_unref(dev, &bus->parent_obj, errp); 140 } 141 142 DeviceState *ssi_create_peripheral(SSIBus *bus, const char *name) 143 { 144 DeviceState *dev = qdev_new(name); 145 146 ssi_realize_and_unref(dev, bus, &error_fatal); 147 return dev; 148 } 149 150 SSIBus *ssi_create_bus(DeviceState *parent, const char *name) 151 { 152 BusState *bus; 153 bus = qbus_new(TYPE_SSI_BUS, parent, name); 154 return SSI_BUS(bus); 155 } 156 157 uint32_t ssi_transfer(SSIBus *bus, uint32_t val) 158 { 159 BusState *b = BUS(bus); 160 BusChild *kid; 161 uint32_t r = 0; 162 163 QTAILQ_FOREACH(kid, &b->children, sibling) { 164 SSIPeripheral *p = SSI_PERIPHERAL(kid->child); 165 r |= p->spc->transfer_raw(p, val); 166 } 167 168 return r; 169 } 170 171 const VMStateDescription vmstate_ssi_peripheral = { 172 .name = "SSISlave", 173 .version_id = 1, 174 .minimum_version_id = 1, 175 .fields = (const VMStateField[]) { 176 VMSTATE_BOOL(cs, SSIPeripheral), 177 VMSTATE_END_OF_LIST() 178 } 179 }; 180 181 static void ssi_peripheral_register_types(void) 182 { 183 type_register_static(&ssi_bus_info); 184 type_register_static(&ssi_peripheral_info); 185 } 186 187 type_init(ssi_peripheral_register_types) 188