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Re: [PATCH 2/3] hw/char: Add Shakti UART emulation
From: |
Vijai Kumar K |
Subject: |
Re: [PATCH 2/3] hw/char: Add Shakti UART emulation |
Date: |
Sat, 20 Mar 2021 15:11:58 +0530 |
User-agent: |
Zoho Mail |
---- On Fri, 19 Mar 2021 19:14:31 +0530 Alistair Francis <alistair23@gmail.com>
wrote ----
> 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
I felt the tracing infra was a bit difficult to work with in this scenario,
hence the DPRINTF.
This is not needed anymore. I will drop the DPRINTF logs.
>
>
> > +
> > +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.
Yes. Will drop it.
>
> > + 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
I believe this is sufficient. Anyway we are going to throw the same log.
Thanks,
Vijai Kumar K
>
> > + }
> > +
> > + 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
> >
> >
> >
>