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Re: [PATCH 2/3] hw/char: Add Shakti UART emulation
From: |
Alistair Francis |
Subject: |
Re: [PATCH 2/3] hw/char: Add Shakti UART emulation |
Date: |
Fri, 19 Mar 2021 09:44:31 -0400 |
On Sun, Mar 14, 2021 at 5:14 AM Vijai Kumar K <vijai@behindbytes.com> wrote:
>
> This is the initial implementation of Shakti UART.
>
> TX tested and works fine. RX is untested.
>
> Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
> ---
> MAINTAINERS | 2 +
> hw/char/meson.build | 1 +
> hw/char/shakti_uart.c | 204 ++++++++++++++++++++++++++++++++++
> hw/char/trace-events | 4 +
> include/hw/char/shakti_uart.h | 74 ++++++++++++
> 5 files changed, 285 insertions(+)
> create mode 100644 hw/char/shakti_uart.c
> create mode 100644 include/hw/char/shakti_uart.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9f71c4cc3f..be084865db 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1385,7 +1385,9 @@ M: Vijai Kumar K <vijai@behindbytes.com>
> L: qemu-riscv@nongnu.org
> S: Supported
> F: hw/riscv/shakti_c.c
> +F: hw/char/shakti_uart.c
> F: include/hw/riscv/shakti_c.h
> +F: include/hw/char/shakti_uart.h
>
> SiFive Machines
> M: Alistair Francis <Alistair.Francis@wdc.com>
> diff --git a/hw/char/meson.build b/hw/char/meson.build
> index 7ba38dbd96..61c43d4b51 100644
> --- a/hw/char/meson.build
> +++ b/hw/char/meson.build
> @@ -19,6 +19,7 @@ softmmu_ss.add(when: 'CONFIG_SERIAL', if_true:
> files('serial.c'))
> softmmu_ss.add(when: 'CONFIG_SERIAL_ISA', if_true: files('serial-isa.c'))
> softmmu_ss.add(when: 'CONFIG_SERIAL_PCI', if_true: files('serial-pci.c'))
> softmmu_ss.add(when: 'CONFIG_SERIAL_PCI_MULTI', if_true:
> files('serial-pci-multi.c'))
> +softmmu_ss.add(when: 'CONFIG_SHAKTI', if_true: files('shakti_uart.c'))
> softmmu_ss.add(when: 'CONFIG_VIRTIO_SERIAL', if_true:
> files('virtio-console.c'))
> softmmu_ss.add(when: 'CONFIG_XEN', if_true: files('xen_console.c'))
> softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_uartlite.c'))
> diff --git a/hw/char/shakti_uart.c b/hw/char/shakti_uart.c
> new file mode 100644
> index 0000000000..e1c72e8747
> --- /dev/null
> +++ b/hw/char/shakti_uart.c
> @@ -0,0 +1,204 @@
> +/*
> + * 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"
> +
> +#define DEBUG_SHAKTI_UART 0
> +#define DPRINTF(fmt, args...) \
> + do { \
> + if (DEBUG_SHAKTI_UART) { \
> + fprintf(stderr, "[%s]%s: " fmt , TYPE_SHAKTI_UART, \
> + __func__, ##args); \
> + } \
> + } while (0)
Can you use the trace infrastructure instead?
https://gitlab.com/qemu-project/qemu/-/blob/master/docs/devel/tracing.rst
> +
> +static uint64_t shakti_uart_read(void *opaque, hwaddr addr, unsigned size)
> +{
> + ShaktiUartState *s = opaque;
> + uint64_t retvalue = 0;
> +
> + switch (addr) {
> + case SHAKTI_UART_BAUD:
> + return s->uart_baud;
> + break;
You don't need a return and a break.
Also if you return in each one you don't need the retvalue variable.
> + case SHAKTI_UART_RX:
> + retvalue = s->uart_rx;
> + qemu_chr_fe_accept_input(&s->chr);
> + s->uart_status &= ~SHAKTI_UART_STATUS_RX_NOT_EMPTY;
> + return retvalue;
> + break;
> + case SHAKTI_UART_STATUS:
> + DPRINTF("uart_status: value = 0x%x)\n", s->uart_status);
> + return s->uart_status;
> + break;
> + case SHAKTI_UART_DELAY:
> + return s->uart_delay;
> + break;
> + case SHAKTI_UART_CONTROL:
> + return s->uart_control;
> + break;
> + case SHAKTI_UART_INT_EN:
> + return s->uart_interrupt;
> + break;
> + case SHAKTI_UART_IQ_CYCLES:
> + return s->uart_iq_cycles;
> + break;
> + case SHAKTI_UART_RX_THRES:
> + return s->uart_rx_threshold;
> + break;
> + default:
> + /* Also handles TX REG which is write only */
> + qemu_log_mask(LOG_GUEST_ERROR,
> + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
Maybe add a seperate log for TX then?
Alistair
> + }
> +
> + 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:
> + /* Also handles TX REG which is write only */
> + 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)
> +{
> + return 1;
> +}
> +
> +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);
> +}
> +
> +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)
> diff --git a/hw/char/trace-events b/hw/char/trace-events
> index 81026f6612..54aeeb899c 100644
> --- a/hw/char/trace-events
> +++ b/hw/char/trace-events
> @@ -80,6 +80,10 @@ cmsdk_apb_uart_set_params(int speed) "CMSDK APB UART:
> params set to %d 8N1"
> nrf51_uart_read(uint64_t addr, uint64_t r, unsigned int size) "addr 0x%"
> PRIx64 " value 0x%" PRIx64 " size %u"
> nrf51_uart_write(uint64_t addr, uint64_t value, unsigned int size) "addr
> 0x%" PRIx64 " value 0x%" PRIx64 " size %u"
>
> +# shakti_uart.c
> +shakti_uart_read(uint64_t addr, uint16_t r, unsigned int size) "addr 0x%"
> PRIx64 " value 0x%" PRIx16 " size %u"
> +shakti_uart_write(uint64_t addr, uint64_t value, unsigned int size) "addr
> 0x%" PRIx64 " value 0x%" PRIx64 " size %u"
> +
> # exynos4210_uart.c
> exynos_uart_dmabusy(uint32_t channel) "UART%d: DMA busy (Rx buffer empty)"
> exynos_uart_dmaready(uint32_t channel) "UART%d: DMA ready"
> diff --git a/include/hw/char/shakti_uart.h b/include/hw/char/shakti_uart.h
> new file mode 100644
> index 0000000000..526c408233
> --- /dev/null
> +++ b/include/hw/char/shakti_uart.h
> @@ -0,0 +1,74 @@
> +/*
> + * 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.
> + */
> +
> +#ifndef HW_SHAKTI_UART_H
> +#define HW_SHAKTI_UART_H
> +
> +#include "hw/sysbus.h"
> +#include "chardev/char-fe.h"
> +
> +#define SHAKTI_UART_BAUD 0x00
> +#define SHAKTI_UART_TX 0x04
> +#define SHAKTI_UART_RX 0x08
> +#define SHAKTI_UART_STATUS 0x0C
> +#define SHAKTI_UART_DELAY 0x10
> +#define SHAKTI_UART_CONTROL 0x14
> +#define SHAKTI_UART_INT_EN 0x18
> +#define SHAKTI_UART_IQ_CYCLES 0x1C
> +#define SHAKTI_UART_RX_THRES 0x20
> +
> +#define SHAKTI_UART_STATUS_TX_EMPTY (1 << 0)
> +#define SHAKTI_UART_STATUS_TX_FULL (1 << 1)
> +#define SHAKTI_UART_STATUS_RX_NOT_EMPTY (1 << 2)
> +#define SHAKTI_UART_STATUS_RX_FULL (1 << 3)
> +/* 9600 8N1 is the default setting */
> +/* Reg value = (50000000 Hz)/(16 * 9600)*/
> +#define SHAKTI_UART_BAUD_DEFAULT 0x0145
> +#define SHAKTI_UART_CONTROL_DEFAULT 0x0100
> +
> +#define TYPE_SHAKTI_UART "shakti-uart"
> +#define SHAKTI_UART(obj) \
> + OBJECT_CHECK(ShaktiUartState, (obj), TYPE_SHAKTI_UART)
> +
> +typedef struct {
> + /* <private> */
> + SysBusDevice parent_obj;
> +
> + /* <public> */
> + MemoryRegion mmio;
> +
> + uint32_t uart_baud;
> + uint32_t uart_tx;
> + uint32_t uart_rx;
> + uint32_t uart_status;
> + uint32_t uart_delay;
> + uint32_t uart_control;
> + uint32_t uart_interrupt;
> + uint32_t uart_iq_cycles;
> + uint32_t uart_rx_threshold;
> +
> + CharBackend chr;
> +} ShaktiUartState;
> +
> +#endif /* HW_SHAKTI_UART_H */
> --
> 2.25.1
>
>
>