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hw/char: Add Shakti UART emulation
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This is the initial implementation of Shakti UART.

Signed-off-by: Vijai Kumar K <vijai@behindbytes.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20210401181457.73039-4-vijai@behindbytes.com
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
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@vj-kumar @alistair23
vj-kumar authored and alistair23 committed May 11, 2021
1 parent 7a261ba commit 07f334d
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2 changes: 2 additions & 0 deletions MAINTAINERS
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Expand Up @@ -1420,7 +1420,9 @@ 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>
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1 change: 1 addition & 0 deletions hw/char/meson.build
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Expand Up @@ -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'))
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185 changes: 185 additions & 0 deletions hw/char/shakti_uart.c
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@@ -0,0 +1,185 @@
/*
* 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);
}

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)
4 changes: 4 additions & 0 deletions hw/char/trace-events
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Expand Up @@ -90,6 +90,10 @@ 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"
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74 changes: 74 additions & 0 deletions include/hw/char/shakti_uart.h
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@@ -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 */

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