goldfish_tty.c (7278B)
1/* 2 * SPDX-License-Identifer: GPL-2.0-or-later 3 * 4 * Goldfish TTY 5 * 6 * (c) 2020 Laurent Vivier <laurent@vivier.eu> 7 * 8 */ 9 10#include "qemu/osdep.h" 11#include "hw/irq.h" 12#include "hw/qdev-properties-system.h" 13#include "hw/sysbus.h" 14#include "migration/vmstate.h" 15#include "chardev/char-fe.h" 16#include "qemu/log.h" 17#include "trace.h" 18#include "exec/address-spaces.h" 19#include "hw/char/goldfish_tty.h" 20 21#define GOLDFISH_TTY_VERSION 1 22 23/* registers */ 24 25enum { 26 REG_PUT_CHAR = 0x00, 27 REG_BYTES_READY = 0x04, 28 REG_CMD = 0x08, 29 REG_DATA_PTR = 0x10, 30 REG_DATA_LEN = 0x14, 31 REG_DATA_PTR_HIGH = 0x18, 32 REG_VERSION = 0x20, 33}; 34 35/* commands */ 36 37enum { 38 CMD_INT_DISABLE = 0x00, 39 CMD_INT_ENABLE = 0x01, 40 CMD_WRITE_BUFFER = 0x02, 41 CMD_READ_BUFFER = 0x03, 42}; 43 44static uint64_t goldfish_tty_read(void *opaque, hwaddr addr, 45 unsigned size) 46{ 47 GoldfishTTYState *s = opaque; 48 uint64_t value = 0; 49 50 switch (addr) { 51 case REG_BYTES_READY: 52 value = fifo8_num_used(&s->rx_fifo); 53 break; 54 case REG_VERSION: 55 value = GOLDFISH_TTY_VERSION; 56 break; 57 default: 58 qemu_log_mask(LOG_UNIMP, 59 "%s: unimplemented register read 0x%02"HWADDR_PRIx"\n", 60 __func__, addr); 61 break; 62 } 63 64 trace_goldfish_tty_read(s, addr, size, value); 65 66 return value; 67} 68 69static void goldfish_tty_cmd(GoldfishTTYState *s, uint32_t cmd) 70{ 71 uint32_t to_copy; 72 uint8_t *buf; 73 uint8_t data_out[GOLFISH_TTY_BUFFER_SIZE]; 74 int len; 75 uint64_t ptr; 76 77 switch (cmd) { 78 case CMD_INT_DISABLE: 79 if (s->int_enabled) { 80 if (!fifo8_is_empty(&s->rx_fifo)) { 81 qemu_set_irq(s->irq, 0); 82 } 83 s->int_enabled = false; 84 } 85 break; 86 case CMD_INT_ENABLE: 87 if (!s->int_enabled) { 88 if (!fifo8_is_empty(&s->rx_fifo)) { 89 qemu_set_irq(s->irq, 1); 90 } 91 s->int_enabled = true; 92 } 93 break; 94 case CMD_WRITE_BUFFER: 95 len = s->data_len; 96 ptr = s->data_ptr; 97 while (len) { 98 to_copy = MIN(GOLFISH_TTY_BUFFER_SIZE, len); 99 100 address_space_rw(&address_space_memory, ptr, 101 MEMTXATTRS_UNSPECIFIED, data_out, to_copy, 0); 102 qemu_chr_fe_write_all(&s->chr, data_out, to_copy); 103 104 len -= to_copy; 105 ptr += to_copy; 106 } 107 break; 108 case CMD_READ_BUFFER: 109 len = s->data_len; 110 ptr = s->data_ptr; 111 while (len && !fifo8_is_empty(&s->rx_fifo)) { 112 buf = (uint8_t *)fifo8_pop_buf(&s->rx_fifo, len, &to_copy); 113 address_space_rw(&address_space_memory, ptr, 114 MEMTXATTRS_UNSPECIFIED, buf, to_copy, 1); 115 116 len -= to_copy; 117 ptr += to_copy; 118 } 119 if (s->int_enabled && fifo8_is_empty(&s->rx_fifo)) { 120 qemu_set_irq(s->irq, 0); 121 } 122 break; 123 } 124} 125 126static void goldfish_tty_write(void *opaque, hwaddr addr, 127 uint64_t value, unsigned size) 128{ 129 GoldfishTTYState *s = opaque; 130 unsigned char c; 131 132 trace_goldfish_tty_write(s, addr, size, value); 133 134 switch (addr) { 135 case REG_PUT_CHAR: 136 c = value; 137 qemu_chr_fe_write_all(&s->chr, &c, sizeof(c)); 138 break; 139 case REG_CMD: 140 goldfish_tty_cmd(s, value); 141 break; 142 case REG_DATA_PTR: 143 s->data_ptr = value; 144 break; 145 case REG_DATA_PTR_HIGH: 146 s->data_ptr = deposit64(s->data_ptr, 32, 32, value); 147 break; 148 case REG_DATA_LEN: 149 s->data_len = value; 150 break; 151 default: 152 qemu_log_mask(LOG_UNIMP, 153 "%s: unimplemented register write 0x%02"HWADDR_PRIx"\n", 154 __func__, addr); 155 break; 156 } 157} 158 159static const MemoryRegionOps goldfish_tty_ops = { 160 .read = goldfish_tty_read, 161 .write = goldfish_tty_write, 162 .endianness = DEVICE_NATIVE_ENDIAN, 163 .valid.max_access_size = 4, 164 .impl.max_access_size = 4, 165 .impl.min_access_size = 4, 166}; 167 168static int goldfish_tty_can_receive(void *opaque) 169{ 170 GoldfishTTYState *s = opaque; 171 int available = fifo8_num_free(&s->rx_fifo); 172 173 trace_goldfish_tty_can_receive(s, available); 174 175 return available; 176} 177 178static void goldfish_tty_receive(void *opaque, const uint8_t *buffer, int size) 179{ 180 GoldfishTTYState *s = opaque; 181 182 trace_goldfish_tty_receive(s, size); 183 184 g_assert(size <= fifo8_num_free(&s->rx_fifo)); 185 186 fifo8_push_all(&s->rx_fifo, buffer, size); 187 188 if (s->int_enabled && !fifo8_is_empty(&s->rx_fifo)) { 189 qemu_set_irq(s->irq, 1); 190 } 191} 192 193static void goldfish_tty_reset(DeviceState *dev) 194{ 195 GoldfishTTYState *s = GOLDFISH_TTY(dev); 196 197 trace_goldfish_tty_reset(s); 198 199 fifo8_reset(&s->rx_fifo); 200 s->int_enabled = false; 201 s->data_ptr = 0; 202 s->data_len = 0; 203} 204 205static void goldfish_tty_realize(DeviceState *dev, Error **errp) 206{ 207 GoldfishTTYState *s = GOLDFISH_TTY(dev); 208 209 trace_goldfish_tty_realize(s); 210 211 fifo8_create(&s->rx_fifo, GOLFISH_TTY_BUFFER_SIZE); 212 memory_region_init_io(&s->iomem, OBJECT(s), &goldfish_tty_ops, s, 213 "goldfish_tty", 0x24); 214 215 if (qemu_chr_fe_backend_connected(&s->chr)) { 216 qemu_chr_fe_set_handlers(&s->chr, goldfish_tty_can_receive, 217 goldfish_tty_receive, NULL, NULL, 218 s, NULL, true); 219 } 220} 221 222static void goldfish_tty_unrealize(DeviceState *dev) 223{ 224 GoldfishTTYState *s = GOLDFISH_TTY(dev); 225 226 trace_goldfish_tty_unrealize(s); 227 228 fifo8_destroy(&s->rx_fifo); 229} 230 231static const VMStateDescription vmstate_goldfish_tty = { 232 .name = "goldfish_tty", 233 .version_id = 1, 234 .minimum_version_id = 1, 235 .fields = (VMStateField[]) { 236 VMSTATE_UINT32(data_len, GoldfishTTYState), 237 VMSTATE_UINT64(data_ptr, GoldfishTTYState), 238 VMSTATE_BOOL(int_enabled, GoldfishTTYState), 239 VMSTATE_FIFO8(rx_fifo, GoldfishTTYState), 240 VMSTATE_END_OF_LIST() 241 } 242}; 243 244static Property goldfish_tty_properties[] = { 245 DEFINE_PROP_CHR("chardev", GoldfishTTYState, chr), 246 DEFINE_PROP_END_OF_LIST(), 247}; 248 249static void goldfish_tty_instance_init(Object *obj) 250{ 251 SysBusDevice *dev = SYS_BUS_DEVICE(obj); 252 GoldfishTTYState *s = GOLDFISH_TTY(obj); 253 254 trace_goldfish_tty_instance_init(s); 255 256 sysbus_init_mmio(dev, &s->iomem); 257 sysbus_init_irq(dev, &s->irq); 258} 259 260static void goldfish_tty_class_init(ObjectClass *oc, void *data) 261{ 262 DeviceClass *dc = DEVICE_CLASS(oc); 263 264 device_class_set_props(dc, goldfish_tty_properties); 265 dc->reset = goldfish_tty_reset; 266 dc->realize = goldfish_tty_realize; 267 dc->unrealize = goldfish_tty_unrealize; 268 dc->vmsd = &vmstate_goldfish_tty; 269 set_bit(DEVICE_CATEGORY_INPUT, dc->categories); 270} 271 272static const TypeInfo goldfish_tty_info = { 273 .name = TYPE_GOLDFISH_TTY, 274 .parent = TYPE_SYS_BUS_DEVICE, 275 .class_init = goldfish_tty_class_init, 276 .instance_init = goldfish_tty_instance_init, 277 .instance_size = sizeof(GoldfishTTYState), 278}; 279 280static void goldfish_tty_register_types(void) 281{ 282 type_register_static(&goldfish_tty_info); 283} 284 285type_init(goldfish_tty_register_types)