diff options
Diffstat (limited to 'hw/char/shakti_uart.c')
| -rw-r--r-- | hw/char/shakti_uart.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/hw/char/shakti_uart.c b/hw/char/shakti_uart.c new file mode 100644 index 000000000..98b142c7d --- /dev/null +++ b/hw/char/shakti_uart.c @@ -0,0 +1,186 @@ +/* + * SHAKTI UART + * + * Copyright (c) 2021 Vijai Kumar K <vijai@behindbytes.com> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "qemu/osdep.h" +#include "hw/char/shakti_uart.h" +#include "hw/qdev-properties.h" +#include "hw/qdev-properties-system.h" +#include "qemu/log.h" + +static uint64_t shakti_uart_read(void *opaque, hwaddr addr, unsigned size) +{ + ShaktiUartState *s = opaque; + + switch (addr) { + case SHAKTI_UART_BAUD: + return s->uart_baud; + case SHAKTI_UART_RX: + qemu_chr_fe_accept_input(&s->chr); + s->uart_status &= ~SHAKTI_UART_STATUS_RX_NOT_EMPTY; + return s->uart_rx; + case SHAKTI_UART_STATUS: + return s->uart_status; + case SHAKTI_UART_DELAY: + return s->uart_delay; + case SHAKTI_UART_CONTROL: + return s->uart_control; + case SHAKTI_UART_INT_EN: + return s->uart_interrupt; + case SHAKTI_UART_IQ_CYCLES: + return s->uart_iq_cycles; + case SHAKTI_UART_RX_THRES: + return s->uart_rx_threshold; + default: + /* Also handles TX REG which is write only */ + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); + } + + return 0; +} + +static void shakti_uart_write(void *opaque, hwaddr addr, + uint64_t data, unsigned size) +{ + ShaktiUartState *s = opaque; + uint32_t value = data; + uint8_t ch; + + switch (addr) { + case SHAKTI_UART_BAUD: + s->uart_baud = value; + break; + case SHAKTI_UART_TX: + ch = value; + qemu_chr_fe_write_all(&s->chr, &ch, 1); + s->uart_status &= ~SHAKTI_UART_STATUS_TX_FULL; + break; + case SHAKTI_UART_STATUS: + s->uart_status = value; + break; + case SHAKTI_UART_DELAY: + s->uart_delay = value; + break; + case SHAKTI_UART_CONTROL: + s->uart_control = value; + break; + case SHAKTI_UART_INT_EN: + s->uart_interrupt = value; + break; + case SHAKTI_UART_IQ_CYCLES: + s->uart_iq_cycles = value; + break; + case SHAKTI_UART_RX_THRES: + s->uart_rx_threshold = value; + break; + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); + } +} + +static const MemoryRegionOps shakti_uart_ops = { + .read = shakti_uart_read, + .write = shakti_uart_write, + .endianness = DEVICE_NATIVE_ENDIAN, + .impl = {.min_access_size = 1, .max_access_size = 4}, + .valid = {.min_access_size = 1, .max_access_size = 4}, +}; + +static void shakti_uart_reset(DeviceState *dev) +{ + ShaktiUartState *s = SHAKTI_UART(dev); + + s->uart_baud = SHAKTI_UART_BAUD_DEFAULT; + s->uart_tx = 0x0; + s->uart_rx = 0x0; + s->uart_status = 0x0000; + s->uart_delay = 0x0000; + s->uart_control = SHAKTI_UART_CONTROL_DEFAULT; + s->uart_interrupt = 0x0000; + s->uart_iq_cycles = 0x00; + s->uart_rx_threshold = 0x00; +} + +static int shakti_uart_can_receive(void *opaque) +{ + ShaktiUartState *s = opaque; + + return !(s->uart_status & SHAKTI_UART_STATUS_RX_NOT_EMPTY); +} + +static void shakti_uart_receive(void *opaque, const uint8_t *buf, int size) +{ + ShaktiUartState *s = opaque; + + s->uart_rx = *buf; + s->uart_status |= SHAKTI_UART_STATUS_RX_NOT_EMPTY; +} + +static void shakti_uart_realize(DeviceState *dev, Error **errp) +{ + ShaktiUartState *sus = SHAKTI_UART(dev); + qemu_chr_fe_set_handlers(&sus->chr, shakti_uart_can_receive, + shakti_uart_receive, NULL, NULL, sus, NULL, true); +} + +static void shakti_uart_instance_init(Object *obj) +{ + ShaktiUartState *sus = SHAKTI_UART(obj); + memory_region_init_io(&sus->mmio, + obj, + &shakti_uart_ops, + sus, + TYPE_SHAKTI_UART, + 0x1000); + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &sus->mmio); +} + +static Property shakti_uart_properties[] = { + DEFINE_PROP_CHR("chardev", ShaktiUartState, chr), + DEFINE_PROP_END_OF_LIST(), +}; + +static void shakti_uart_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + dc->reset = shakti_uart_reset; + dc->realize = shakti_uart_realize; + device_class_set_props(dc, shakti_uart_properties); + set_bit(DEVICE_CATEGORY_INPUT, dc->categories); +} + +static const TypeInfo shakti_uart_info = { + .name = TYPE_SHAKTI_UART, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(ShaktiUartState), + .class_init = shakti_uart_class_init, + .instance_init = shakti_uart_instance_init, +}; + +static void shakti_uart_register_types(void) +{ + type_register_static(&shakti_uart_info); +} +type_init(shakti_uart_register_types) |