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Alistair Francis73af5d12015-03-11 13:21:05 +00001/*
2 * STM32F2XX USART
3 *
4 * Copyright (c) 2014 Alistair Francis <alistair@alistair23.me>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
Peter Maydell17b7f2d2016-01-26 18:17:28 +000025#include "qemu/osdep.h"
Alistair Francis73af5d12015-03-11 13:21:05 +000026#include "hw/char/stm32f2xx_usart.h"
Markus Armbruster64552b62019-08-12 07:23:42 +020027#include "hw/irq.h"
Markus Armbrustera27bd6c2019-08-12 07:23:51 +020028#include "hw/qdev-properties.h"
Eduardo Habkostce35e222020-12-11 17:05:12 -050029#include "hw/qdev-properties-system.h"
Paolo Bonzini03dd0242015-12-15 13:16:16 +010030#include "qemu/log.h"
Markus Armbruster0b8fa322019-05-23 16:35:07 +020031#include "qemu/module.h"
Alistair Francis73af5d12015-03-11 13:21:05 +000032
33#ifndef STM_USART_ERR_DEBUG
34#define STM_USART_ERR_DEBUG 0
35#endif
36
37#define DB_PRINT_L(lvl, fmt, args...) do { \
38 if (STM_USART_ERR_DEBUG >= lvl) { \
39 qemu_log("%s: " fmt, __func__, ## args); \
40 } \
Eric Blake25627552017-12-01 17:24:32 -060041} while (0)
Alistair Francis73af5d12015-03-11 13:21:05 +000042
43#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
44
45static int stm32f2xx_usart_can_receive(void *opaque)
46{
47 STM32F2XXUsartState *s = opaque;
48
49 if (!(s->usart_sr & USART_SR_RXNE)) {
50 return 1;
51 }
52
53 return 0;
54}
55
56static void stm32f2xx_usart_receive(void *opaque, const uint8_t *buf, int size)
57{
58 STM32F2XXUsartState *s = opaque;
59
Alistair Francis73af5d12015-03-11 13:21:05 +000060 if (!(s->usart_cr1 & USART_CR1_UE && s->usart_cr1 & USART_CR1_RE)) {
61 /* USART not enabled - drop the chars */
62 DB_PRINT("Dropping the chars\n");
63 return;
64 }
65
Philippe Mathieu-Daudé40766182019-01-21 10:23:10 +000066 s->usart_dr = *buf;
Alistair Francis73af5d12015-03-11 13:21:05 +000067 s->usart_sr |= USART_SR_RXNE;
68
69 if (s->usart_cr1 & USART_CR1_RXNEIE) {
70 qemu_set_irq(s->irq, 1);
71 }
72
73 DB_PRINT("Receiving: %c\n", s->usart_dr);
74}
75
76static void stm32f2xx_usart_reset(DeviceState *dev)
77{
78 STM32F2XXUsartState *s = STM32F2XX_USART(dev);
79
80 s->usart_sr = USART_SR_RESET;
81 s->usart_dr = 0x00000000;
82 s->usart_brr = 0x00000000;
83 s->usart_cr1 = 0x00000000;
84 s->usart_cr2 = 0x00000000;
85 s->usart_cr3 = 0x00000000;
86 s->usart_gtpr = 0x00000000;
87
88 qemu_set_irq(s->irq, 0);
89}
90
91static uint64_t stm32f2xx_usart_read(void *opaque, hwaddr addr,
92 unsigned int size)
93{
94 STM32F2XXUsartState *s = opaque;
95 uint64_t retvalue;
96
97 DB_PRINT("Read 0x%"HWADDR_PRIx"\n", addr);
98
99 switch (addr) {
100 case USART_SR:
101 retvalue = s->usart_sr;
Marc-André Lureaufa394ed2016-10-22 12:52:59 +0300102 qemu_chr_fe_accept_input(&s->chr);
Alistair Francis73af5d12015-03-11 13:21:05 +0000103 return retvalue;
104 case USART_DR:
105 DB_PRINT("Value: 0x%" PRIx32 ", %c\n", s->usart_dr, (char) s->usart_dr);
Alistair Francis73af5d12015-03-11 13:21:05 +0000106 s->usart_sr &= ~USART_SR_RXNE;
Marc-André Lureaufa394ed2016-10-22 12:52:59 +0300107 qemu_chr_fe_accept_input(&s->chr);
Alistair Francis73af5d12015-03-11 13:21:05 +0000108 qemu_set_irq(s->irq, 0);
109 return s->usart_dr & 0x3FF;
110 case USART_BRR:
111 return s->usart_brr;
112 case USART_CR1:
113 return s->usart_cr1;
114 case USART_CR2:
115 return s->usart_cr2;
116 case USART_CR3:
117 return s->usart_cr3;
118 case USART_GTPR:
119 return s->usart_gtpr;
120 default:
121 qemu_log_mask(LOG_GUEST_ERROR,
122 "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
123 return 0;
124 }
125
126 return 0;
127}
128
129static void stm32f2xx_usart_write(void *opaque, hwaddr addr,
130 uint64_t val64, unsigned int size)
131{
132 STM32F2XXUsartState *s = opaque;
133 uint32_t value = val64;
134 unsigned char ch;
135
136 DB_PRINT("Write 0x%" PRIx32 ", 0x%"HWADDR_PRIx"\n", value, addr);
137
138 switch (addr) {
139 case USART_SR:
140 if (value <= 0x3FF) {
Richard Braunf6bfe452018-02-22 15:12:51 +0000141 /* I/O being synchronous, TXE is always set. In addition, it may
142 only be set by hardware, so keep it set here. */
143 s->usart_sr = value | USART_SR_TXE;
Alistair Francis73af5d12015-03-11 13:21:05 +0000144 } else {
145 s->usart_sr &= value;
146 }
147 if (!(s->usart_sr & USART_SR_RXNE)) {
148 qemu_set_irq(s->irq, 0);
149 }
150 return;
151 case USART_DR:
152 if (value < 0xF000) {
153 ch = value;
Marc-André Lureaufa394ed2016-10-22 12:52:59 +0300154 /* XXX this blocks entire thread. Rewrite to use
155 * qemu_chr_fe_write and background I/O callbacks */
156 qemu_chr_fe_write_all(&s->chr, &ch, 1);
Richard Braunf6bfe452018-02-22 15:12:51 +0000157 /* XXX I/O are currently synchronous, making it impossible for
158 software to observe transient states where TXE or TC aren't
159 set. Unlike TXE however, which is read-only, software may
160 clear TC by writing 0 to the SR register, so set it again
161 on each write. */
Alistair Francis73af5d12015-03-11 13:21:05 +0000162 s->usart_sr |= USART_SR_TC;
Alistair Francis73af5d12015-03-11 13:21:05 +0000163 }
164 return;
165 case USART_BRR:
166 s->usart_brr = value;
167 return;
168 case USART_CR1:
169 s->usart_cr1 = value;
170 if (s->usart_cr1 & USART_CR1_RXNEIE &&
171 s->usart_sr & USART_SR_RXNE) {
172 qemu_set_irq(s->irq, 1);
173 }
174 return;
175 case USART_CR2:
176 s->usart_cr2 = value;
177 return;
178 case USART_CR3:
179 s->usart_cr3 = value;
180 return;
181 case USART_GTPR:
182 s->usart_gtpr = value;
183 return;
184 default:
185 qemu_log_mask(LOG_GUEST_ERROR,
186 "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
187 }
188}
189
190static const MemoryRegionOps stm32f2xx_usart_ops = {
191 .read = stm32f2xx_usart_read,
192 .write = stm32f2xx_usart_write,
193 .endianness = DEVICE_NATIVE_ENDIAN,
194};
195
xiaoqiang zhao7bd43512016-06-06 16:59:32 +0100196static Property stm32f2xx_usart_properties[] = {
197 DEFINE_PROP_CHR("chardev", STM32F2XXUsartState, chr),
198 DEFINE_PROP_END_OF_LIST(),
199};
200
Alistair Francis73af5d12015-03-11 13:21:05 +0000201static void stm32f2xx_usart_init(Object *obj)
202{
203 STM32F2XXUsartState *s = STM32F2XX_USART(obj);
204
205 sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq);
206
207 memory_region_init_io(&s->mmio, obj, &stm32f2xx_usart_ops, s,
Seth Kintighdd5d6932018-11-19 15:29:08 +0000208 TYPE_STM32F2XX_USART, 0x400);
Alistair Francis73af5d12015-03-11 13:21:05 +0000209 sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
xiaoqiang zhao7bd43512016-06-06 16:59:32 +0100210}
Alistair Francis73af5d12015-03-11 13:21:05 +0000211
xiaoqiang zhao7bd43512016-06-06 16:59:32 +0100212static void stm32f2xx_usart_realize(DeviceState *dev, Error **errp)
213{
214 STM32F2XXUsartState *s = STM32F2XX_USART(dev);
Alistair Francis73af5d12015-03-11 13:21:05 +0000215
Marc-André Lureaufa394ed2016-10-22 12:52:59 +0300216 qemu_chr_fe_set_handlers(&s->chr, stm32f2xx_usart_can_receive,
Anton Nefedov81517ba2017-07-06 15:08:49 +0300217 stm32f2xx_usart_receive, NULL, NULL,
218 s, NULL, true);
Alistair Francis73af5d12015-03-11 13:21:05 +0000219}
220
221static void stm32f2xx_usart_class_init(ObjectClass *klass, void *data)
222{
223 DeviceClass *dc = DEVICE_CLASS(klass);
224
225 dc->reset = stm32f2xx_usart_reset;
Marc-André Lureau4f67d302020-01-10 19:30:32 +0400226 device_class_set_props(dc, stm32f2xx_usart_properties);
xiaoqiang zhao7bd43512016-06-06 16:59:32 +0100227 dc->realize = stm32f2xx_usart_realize;
Alistair Francis73af5d12015-03-11 13:21:05 +0000228}
229
230static const TypeInfo stm32f2xx_usart_info = {
231 .name = TYPE_STM32F2XX_USART,
232 .parent = TYPE_SYS_BUS_DEVICE,
233 .instance_size = sizeof(STM32F2XXUsartState),
234 .instance_init = stm32f2xx_usart_init,
235 .class_init = stm32f2xx_usart_class_init,
236};
237
238static void stm32f2xx_usart_register_types(void)
239{
240 type_register_static(&stm32f2xx_usart_info);
241}
242
243type_init(stm32f2xx_usart_register_types)