diff options
Diffstat (limited to 'hw/char/goldfish_tty.c')
-rw-r--r-- | hw/char/goldfish_tty.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/hw/char/goldfish_tty.c b/hw/char/goldfish_tty.c new file mode 100644 index 0000000000..8365a18761 --- /dev/null +++ b/hw/char/goldfish_tty.c @@ -0,0 +1,285 @@ +/* + * SPDX-License-Identifer: GPL-2.0-or-later + * + * Goldfish TTY + * + * (c) 2020 Laurent Vivier <laurent@vivier.eu> + * + */ + +#include "qemu/osdep.h" +#include "hw/irq.h" +#include "hw/qdev-properties-system.h" +#include "hw/sysbus.h" +#include "migration/vmstate.h" +#include "chardev/char-fe.h" +#include "qemu/log.h" +#include "trace.h" +#include "exec/address-spaces.h" +#include "hw/char/goldfish_tty.h" + +#define GOLDFISH_TTY_VERSION 1 + +/* registers */ + +enum { + REG_PUT_CHAR = 0x00, + REG_BYTES_READY = 0x04, + REG_CMD = 0x08, + REG_DATA_PTR = 0x10, + REG_DATA_LEN = 0x14, + REG_DATA_PTR_HIGH = 0x18, + REG_VERSION = 0x20, +}; + +/* commands */ + +enum { + CMD_INT_DISABLE = 0x00, + CMD_INT_ENABLE = 0x01, + CMD_WRITE_BUFFER = 0x02, + CMD_READ_BUFFER = 0x03, +}; + +static uint64_t goldfish_tty_read(void *opaque, hwaddr addr, + unsigned size) +{ + GoldfishTTYState *s = opaque; + uint64_t value = 0; + + switch (addr) { + case REG_BYTES_READY: + value = fifo8_num_used(&s->rx_fifo); + break; + case REG_VERSION: + value = GOLDFISH_TTY_VERSION; + break; + default: + qemu_log_mask(LOG_UNIMP, + "%s: unimplemented register read 0x%02"HWADDR_PRIx"\n", + __func__, addr); + break; + } + + trace_goldfish_tty_read(s, addr, size, value); + + return value; +} + +static void goldfish_tty_cmd(GoldfishTTYState *s, uint32_t cmd) +{ + uint32_t to_copy; + uint8_t *buf; + uint8_t data_out[GOLFISH_TTY_BUFFER_SIZE]; + int len; + uint64_t ptr; + + switch (cmd) { + case CMD_INT_DISABLE: + if (s->int_enabled) { + if (!fifo8_is_empty(&s->rx_fifo)) { + qemu_set_irq(s->irq, 0); + } + s->int_enabled = false; + } + break; + case CMD_INT_ENABLE: + if (!s->int_enabled) { + if (!fifo8_is_empty(&s->rx_fifo)) { + qemu_set_irq(s->irq, 1); + } + s->int_enabled = true; + } + break; + case CMD_WRITE_BUFFER: + len = s->data_len; + ptr = s->data_ptr; + while (len) { + to_copy = MIN(GOLFISH_TTY_BUFFER_SIZE, len); + + address_space_rw(&address_space_memory, ptr, + MEMTXATTRS_UNSPECIFIED, data_out, to_copy, 0); + qemu_chr_fe_write_all(&s->chr, data_out, to_copy); + + len -= to_copy; + ptr += to_copy; + } + break; + case CMD_READ_BUFFER: + len = s->data_len; + ptr = s->data_ptr; + while (len && !fifo8_is_empty(&s->rx_fifo)) { + buf = (uint8_t *)fifo8_pop_buf(&s->rx_fifo, len, &to_copy); + address_space_rw(&address_space_memory, ptr, + MEMTXATTRS_UNSPECIFIED, buf, to_copy, 1); + + len -= to_copy; + ptr += to_copy; + } + if (s->int_enabled && fifo8_is_empty(&s->rx_fifo)) { + qemu_set_irq(s->irq, 0); + } + break; + } +} + +static void goldfish_tty_write(void *opaque, hwaddr addr, + uint64_t value, unsigned size) +{ + GoldfishTTYState *s = opaque; + unsigned char c; + + trace_goldfish_tty_write(s, addr, size, value); + + switch (addr) { + case REG_PUT_CHAR: + c = value; + qemu_chr_fe_write_all(&s->chr, &c, sizeof(c)); + break; + case REG_CMD: + goldfish_tty_cmd(s, value); + break; + case REG_DATA_PTR: + s->data_ptr = value; + break; + case REG_DATA_PTR_HIGH: + s->data_ptr = deposit64(s->data_ptr, 32, 32, value); + break; + case REG_DATA_LEN: + s->data_len = value; + break; + default: + qemu_log_mask(LOG_UNIMP, + "%s: unimplemented register write 0x%02"HWADDR_PRIx"\n", + __func__, addr); + break; + } +} + +static const MemoryRegionOps goldfish_tty_ops = { + .read = goldfish_tty_read, + .write = goldfish_tty_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .valid.max_access_size = 4, + .impl.max_access_size = 4, + .impl.min_access_size = 4, +}; + +static int goldfish_tty_can_receive(void *opaque) +{ + GoldfishTTYState *s = opaque; + int available = fifo8_num_free(&s->rx_fifo); + + trace_goldfish_tty_can_receive(s, available); + + return available; +} + +static void goldfish_tty_receive(void *opaque, const uint8_t *buffer, int size) +{ + GoldfishTTYState *s = opaque; + + trace_goldfish_tty_receive(s, size); + + g_assert(size <= fifo8_num_free(&s->rx_fifo)); + + fifo8_push_all(&s->rx_fifo, buffer, size); + + if (s->int_enabled && !fifo8_is_empty(&s->rx_fifo)) { + qemu_set_irq(s->irq, 1); + } +} + +static void goldfish_tty_reset(DeviceState *dev) +{ + GoldfishTTYState *s = GOLDFISH_TTY(dev); + + trace_goldfish_tty_reset(s); + + fifo8_reset(&s->rx_fifo); + s->int_enabled = false; + s->data_ptr = 0; + s->data_len = 0; +} + +static void goldfish_tty_realize(DeviceState *dev, Error **errp) +{ + GoldfishTTYState *s = GOLDFISH_TTY(dev); + + trace_goldfish_tty_realize(s); + + fifo8_create(&s->rx_fifo, GOLFISH_TTY_BUFFER_SIZE); + memory_region_init_io(&s->iomem, OBJECT(s), &goldfish_tty_ops, s, + "goldfish_tty", 0x24); + + if (qemu_chr_fe_backend_connected(&s->chr)) { + qemu_chr_fe_set_handlers(&s->chr, goldfish_tty_can_receive, + goldfish_tty_receive, NULL, NULL, + s, NULL, true); + } +} + +static void goldfish_tty_unrealize(DeviceState *dev) +{ + GoldfishTTYState *s = GOLDFISH_TTY(dev); + + trace_goldfish_tty_unrealize(s); + + fifo8_destroy(&s->rx_fifo); +} + +static const VMStateDescription vmstate_goldfish_tty = { + .name = "goldfish_tty", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(data_len, GoldfishTTYState), + VMSTATE_UINT64(data_ptr, GoldfishTTYState), + VMSTATE_BOOL(int_enabled, GoldfishTTYState), + VMSTATE_FIFO8(rx_fifo, GoldfishTTYState), + VMSTATE_END_OF_LIST() + } +}; + +static Property goldfish_tty_properties[] = { + DEFINE_PROP_CHR("chardev", GoldfishTTYState, chr), + DEFINE_PROP_END_OF_LIST(), +}; + +static void goldfish_tty_instance_init(Object *obj) +{ + SysBusDevice *dev = SYS_BUS_DEVICE(obj); + GoldfishTTYState *s = GOLDFISH_TTY(obj); + + trace_goldfish_tty_instance_init(s); + + sysbus_init_mmio(dev, &s->iomem); + sysbus_init_irq(dev, &s->irq); +} + +static void goldfish_tty_class_init(ObjectClass *oc, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(oc); + + device_class_set_props(dc, goldfish_tty_properties); + dc->reset = goldfish_tty_reset; + dc->realize = goldfish_tty_realize; + dc->unrealize = goldfish_tty_unrealize; + dc->vmsd = &vmstate_goldfish_tty; + set_bit(DEVICE_CATEGORY_INPUT, dc->categories); +} + +static const TypeInfo goldfish_tty_info = { + .name = TYPE_GOLDFISH_TTY, + .parent = TYPE_SYS_BUS_DEVICE, + .class_init = goldfish_tty_class_init, + .instance_init = goldfish_tty_instance_init, + .instance_size = sizeof(GoldfishTTYState), +}; + +static void goldfish_tty_register_types(void) +{ + type_register_static(&goldfish_tty_info); +} + +type_init(goldfish_tty_register_types) |