Merge remote-tracking branch 'remotes/philmd-gitlab/tags/renesas-20201027' into staging
[qemu.git] / hw / char / lm32_uart.c
1 /*
2 * QEMU model of the LatticeMico32 UART block.
3 *
4 * Copyright (c) 2010 Michael Walle <michael@walle.cc>
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 *
20 * Specification available at:
21 * http://www.latticesemi.com/documents/mico32uart.pdf
22 */
23
24
25 #include "qemu/osdep.h"
26 #include "hw/irq.h"
27 #include "hw/qdev-properties.h"
28 #include "hw/sysbus.h"
29 #include "migration/vmstate.h"
30 #include "trace.h"
31 #include "chardev/char-fe.h"
32 #include "qemu/error-report.h"
33 #include "qemu/module.h"
34 #include "qom/object.h"
35
36 enum {
37 R_RXTX = 0,
38 R_IER,
39 R_IIR,
40 R_LCR,
41 R_MCR,
42 R_LSR,
43 R_MSR,
44 R_DIV,
45 R_MAX
46 };
47
48 enum {
49 IER_RBRI = (1<<0),
50 IER_THRI = (1<<1),
51 IER_RLSI = (1<<2),
52 IER_MSI = (1<<3),
53 };
54
55 enum {
56 IIR_STAT = (1<<0),
57 IIR_ID0 = (1<<1),
58 IIR_ID1 = (1<<2),
59 };
60
61 enum {
62 LCR_WLS0 = (1<<0),
63 LCR_WLS1 = (1<<1),
64 LCR_STB = (1<<2),
65 LCR_PEN = (1<<3),
66 LCR_EPS = (1<<4),
67 LCR_SP = (1<<5),
68 LCR_SB = (1<<6),
69 };
70
71 enum {
72 MCR_DTR = (1<<0),
73 MCR_RTS = (1<<1),
74 };
75
76 enum {
77 LSR_DR = (1<<0),
78 LSR_OE = (1<<1),
79 LSR_PE = (1<<2),
80 LSR_FE = (1<<3),
81 LSR_BI = (1<<4),
82 LSR_THRE = (1<<5),
83 LSR_TEMT = (1<<6),
84 };
85
86 enum {
87 MSR_DCTS = (1<<0),
88 MSR_DDSR = (1<<1),
89 MSR_TERI = (1<<2),
90 MSR_DDCD = (1<<3),
91 MSR_CTS = (1<<4),
92 MSR_DSR = (1<<5),
93 MSR_RI = (1<<6),
94 MSR_DCD = (1<<7),
95 };
96
97 #define TYPE_LM32_UART "lm32-uart"
98 OBJECT_DECLARE_SIMPLE_TYPE(LM32UartState, LM32_UART)
99
100 struct LM32UartState {
101 SysBusDevice parent_obj;
102
103 MemoryRegion iomem;
104 CharBackend chr;
105 qemu_irq irq;
106
107 uint32_t regs[R_MAX];
108 };
109
110 static void uart_update_irq(LM32UartState *s)
111 {
112 unsigned int irq;
113
114 if ((s->regs[R_LSR] & (LSR_OE | LSR_PE | LSR_FE | LSR_BI))
115 && (s->regs[R_IER] & IER_RLSI)) {
116 irq = 1;
117 s->regs[R_IIR] = IIR_ID1 | IIR_ID0;
118 } else if ((s->regs[R_LSR] & LSR_DR) && (s->regs[R_IER] & IER_RBRI)) {
119 irq = 1;
120 s->regs[R_IIR] = IIR_ID1;
121 } else if ((s->regs[R_LSR] & LSR_THRE) && (s->regs[R_IER] & IER_THRI)) {
122 irq = 1;
123 s->regs[R_IIR] = IIR_ID0;
124 } else if ((s->regs[R_MSR] & 0x0f) && (s->regs[R_IER] & IER_MSI)) {
125 irq = 1;
126 s->regs[R_IIR] = 0;
127 } else {
128 irq = 0;
129 s->regs[R_IIR] = IIR_STAT;
130 }
131
132 trace_lm32_uart_irq_state(irq);
133 qemu_set_irq(s->irq, irq);
134 }
135
136 static uint64_t uart_read(void *opaque, hwaddr addr,
137 unsigned size)
138 {
139 LM32UartState *s = opaque;
140 uint32_t r = 0;
141
142 addr >>= 2;
143 switch (addr) {
144 case R_RXTX:
145 r = s->regs[R_RXTX];
146 s->regs[R_LSR] &= ~LSR_DR;
147 uart_update_irq(s);
148 qemu_chr_fe_accept_input(&s->chr);
149 break;
150 case R_IIR:
151 case R_LSR:
152 case R_MSR:
153 r = s->regs[addr];
154 break;
155 case R_IER:
156 case R_LCR:
157 case R_MCR:
158 case R_DIV:
159 error_report("lm32_uart: read access to write only register 0x"
160 TARGET_FMT_plx, addr << 2);
161 break;
162 default:
163 error_report("lm32_uart: read access to unknown register 0x"
164 TARGET_FMT_plx, addr << 2);
165 break;
166 }
167
168 trace_lm32_uart_memory_read(addr << 2, r);
169 return r;
170 }
171
172 static void uart_write(void *opaque, hwaddr addr,
173 uint64_t value, unsigned size)
174 {
175 LM32UartState *s = opaque;
176 unsigned char ch = value;
177
178 trace_lm32_uart_memory_write(addr, value);
179
180 addr >>= 2;
181 switch (addr) {
182 case R_RXTX:
183 /* XXX this blocks entire thread. Rewrite to use
184 * qemu_chr_fe_write and background I/O callbacks */
185 qemu_chr_fe_write_all(&s->chr, &ch, 1);
186 break;
187 case R_IER:
188 case R_LCR:
189 case R_MCR:
190 case R_DIV:
191 s->regs[addr] = value;
192 break;
193 case R_IIR:
194 case R_LSR:
195 case R_MSR:
196 error_report("lm32_uart: write access to read only register 0x"
197 TARGET_FMT_plx, addr << 2);
198 break;
199 default:
200 error_report("lm32_uart: write access to unknown register 0x"
201 TARGET_FMT_plx, addr << 2);
202 break;
203 }
204 uart_update_irq(s);
205 }
206
207 static const MemoryRegionOps uart_ops = {
208 .read = uart_read,
209 .write = uart_write,
210 .endianness = DEVICE_NATIVE_ENDIAN,
211 .valid = {
212 .min_access_size = 4,
213 .max_access_size = 4,
214 },
215 };
216
217 static void uart_rx(void *opaque, const uint8_t *buf, int size)
218 {
219 LM32UartState *s = opaque;
220
221 if (s->regs[R_LSR] & LSR_DR) {
222 s->regs[R_LSR] |= LSR_OE;
223 }
224
225 s->regs[R_LSR] |= LSR_DR;
226 s->regs[R_RXTX] = *buf;
227
228 uart_update_irq(s);
229 }
230
231 static int uart_can_rx(void *opaque)
232 {
233 LM32UartState *s = opaque;
234
235 return !(s->regs[R_LSR] & LSR_DR);
236 }
237
238 static void uart_event(void *opaque, QEMUChrEvent event)
239 {
240 }
241
242 static void uart_reset(DeviceState *d)
243 {
244 LM32UartState *s = LM32_UART(d);
245 int i;
246
247 for (i = 0; i < R_MAX; i++) {
248 s->regs[i] = 0;
249 }
250
251 /* defaults */
252 s->regs[R_LSR] = LSR_THRE | LSR_TEMT;
253 }
254
255 static void lm32_uart_init(Object *obj)
256 {
257 LM32UartState *s = LM32_UART(obj);
258 SysBusDevice *dev = SYS_BUS_DEVICE(obj);
259
260 sysbus_init_irq(dev, &s->irq);
261
262 memory_region_init_io(&s->iomem, obj, &uart_ops, s,
263 "uart", R_MAX * 4);
264 sysbus_init_mmio(dev, &s->iomem);
265 }
266
267 static void lm32_uart_realize(DeviceState *dev, Error **errp)
268 {
269 LM32UartState *s = LM32_UART(dev);
270
271 qemu_chr_fe_set_handlers(&s->chr, uart_can_rx, uart_rx,
272 uart_event, NULL, s, NULL, true);
273 }
274
275 static const VMStateDescription vmstate_lm32_uart = {
276 .name = "lm32-uart",
277 .version_id = 1,
278 .minimum_version_id = 1,
279 .fields = (VMStateField[]) {
280 VMSTATE_UINT32_ARRAY(regs, LM32UartState, R_MAX),
281 VMSTATE_END_OF_LIST()
282 }
283 };
284
285 static Property lm32_uart_properties[] = {
286 DEFINE_PROP_CHR("chardev", LM32UartState, chr),
287 DEFINE_PROP_END_OF_LIST(),
288 };
289
290 static void lm32_uart_class_init(ObjectClass *klass, void *data)
291 {
292 DeviceClass *dc = DEVICE_CLASS(klass);
293
294 dc->reset = uart_reset;
295 dc->vmsd = &vmstate_lm32_uart;
296 device_class_set_props(dc, lm32_uart_properties);
297 dc->realize = lm32_uart_realize;
298 }
299
300 static const TypeInfo lm32_uart_info = {
301 .name = TYPE_LM32_UART,
302 .parent = TYPE_SYS_BUS_DEVICE,
303 .instance_size = sizeof(LM32UartState),
304 .instance_init = lm32_uart_init,
305 .class_init = lm32_uart_class_init,
306 };
307
308 static void lm32_uart_register_types(void)
309 {
310 type_register_static(&lm32_uart_info);
311 }
312
313 type_init(lm32_uart_register_types)