]>
Commit | Line | Data |
---|---|---|
19790847 JS |
1 | /* |
2 | * nRF51 SoC UART emulation | |
3 | * | |
4 | * See nRF51 Series Reference Manual, "29 Universal Asynchronous | |
5 | * Receiver/Transmitter" for hardware specifications: | |
6 | * http://infocenter.nordicsemi.com/pdf/nRF51_RM_v3.0.pdf | |
7 | * | |
8 | * Copyright (c) 2018 Julia Suvorova <jusual@mail.ru> | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or modify | |
11 | * it under the terms of the GNU General Public License version 2 or | |
12 | * (at your option) any later version. | |
13 | */ | |
14 | ||
15 | #include "qemu/osdep.h" | |
16 | #include "qemu/log.h" | |
0b8fa32f | 17 | #include "qemu/module.h" |
19790847 | 18 | #include "hw/char/nrf51_uart.h" |
64552b6b | 19 | #include "hw/irq.h" |
a27bd6c7 | 20 | #include "hw/qdev-properties.h" |
d6454270 | 21 | #include "migration/vmstate.h" |
19790847 JS |
22 | #include "trace.h" |
23 | ||
24 | static void nrf51_uart_update_irq(NRF51UARTState *s) | |
25 | { | |
26 | bool irq = false; | |
27 | ||
28 | irq |= (s->reg[R_UART_RXDRDY] && | |
29 | (s->reg[R_UART_INTEN] & R_UART_INTEN_RXDRDY_MASK)); | |
30 | irq |= (s->reg[R_UART_TXDRDY] && | |
31 | (s->reg[R_UART_INTEN] & R_UART_INTEN_TXDRDY_MASK)); | |
32 | irq |= (s->reg[R_UART_ERROR] && | |
33 | (s->reg[R_UART_INTEN] & R_UART_INTEN_ERROR_MASK)); | |
34 | irq |= (s->reg[R_UART_RXTO] && | |
35 | (s->reg[R_UART_INTEN] & R_UART_INTEN_RXTO_MASK)); | |
36 | ||
37 | qemu_set_irq(s->irq, irq); | |
38 | } | |
39 | ||
40 | static uint64_t uart_read(void *opaque, hwaddr addr, unsigned int size) | |
41 | { | |
42 | NRF51UARTState *s = NRF51_UART(opaque); | |
43 | uint64_t r; | |
44 | ||
45 | if (!s->enabled) { | |
46 | return 0; | |
47 | } | |
48 | ||
49 | switch (addr) { | |
50 | case A_UART_RXD: | |
51 | r = s->rx_fifo[s->rx_fifo_pos]; | |
52 | if (s->rx_started && s->rx_fifo_len) { | |
53 | s->rx_fifo_pos = (s->rx_fifo_pos + 1) % UART_FIFO_LENGTH; | |
54 | s->rx_fifo_len--; | |
55 | if (s->rx_fifo_len) { | |
56 | s->reg[R_UART_RXDRDY] = 1; | |
57 | nrf51_uart_update_irq(s); | |
58 | } | |
59 | qemu_chr_fe_accept_input(&s->chr); | |
60 | } | |
61 | break; | |
62 | case A_UART_INTENSET: | |
63 | case A_UART_INTENCLR: | |
64 | case A_UART_INTEN: | |
65 | r = s->reg[R_UART_INTEN]; | |
66 | break; | |
67 | default: | |
68 | r = s->reg[addr / 4]; | |
69 | break; | |
70 | } | |
71 | ||
72 | trace_nrf51_uart_read(addr, r, size); | |
73 | ||
74 | return r; | |
75 | } | |
76 | ||
77 | static gboolean uart_transmit(GIOChannel *chan, GIOCondition cond, void *opaque) | |
78 | { | |
79 | NRF51UARTState *s = NRF51_UART(opaque); | |
80 | int r; | |
81 | uint8_t c = s->reg[R_UART_TXD]; | |
82 | ||
83 | s->watch_tag = 0; | |
84 | ||
85 | r = qemu_chr_fe_write(&s->chr, &c, 1); | |
86 | if (r <= 0) { | |
87 | s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, | |
88 | uart_transmit, s); | |
89 | if (!s->watch_tag) { | |
90 | /* The hardware has no transmit error reporting, | |
91 | * so silently drop the byte | |
92 | */ | |
93 | goto buffer_drained; | |
94 | } | |
95 | return FALSE; | |
96 | } | |
97 | ||
98 | buffer_drained: | |
99 | s->reg[R_UART_TXDRDY] = 1; | |
100 | s->pending_tx_byte = false; | |
101 | return FALSE; | |
102 | } | |
103 | ||
104 | static void uart_cancel_transmit(NRF51UARTState *s) | |
105 | { | |
106 | if (s->watch_tag) { | |
107 | g_source_remove(s->watch_tag); | |
108 | s->watch_tag = 0; | |
109 | } | |
110 | } | |
111 | ||
112 | static void uart_write(void *opaque, hwaddr addr, | |
113 | uint64_t value, unsigned int size) | |
114 | { | |
115 | NRF51UARTState *s = NRF51_UART(opaque); | |
116 | ||
117 | trace_nrf51_uart_write(addr, value, size); | |
118 | ||
119 | if (!s->enabled && (addr != A_UART_ENABLE)) { | |
120 | return; | |
121 | } | |
122 | ||
123 | switch (addr) { | |
124 | case A_UART_TXD: | |
125 | if (!s->pending_tx_byte && s->tx_started) { | |
126 | s->reg[R_UART_TXD] = value; | |
127 | s->pending_tx_byte = true; | |
128 | uart_transmit(NULL, G_IO_OUT, s); | |
129 | } | |
130 | break; | |
131 | case A_UART_INTEN: | |
132 | s->reg[R_UART_INTEN] = value; | |
133 | break; | |
134 | case A_UART_INTENSET: | |
135 | s->reg[R_UART_INTEN] |= value; | |
136 | break; | |
137 | case A_UART_INTENCLR: | |
138 | s->reg[R_UART_INTEN] &= ~value; | |
139 | break; | |
140 | case A_UART_TXDRDY ... A_UART_RXTO: | |
141 | s->reg[addr / 4] = value; | |
142 | break; | |
143 | case A_UART_ERRORSRC: | |
144 | s->reg[addr / 4] &= ~value; | |
145 | break; | |
146 | case A_UART_RXD: | |
147 | break; | |
148 | case A_UART_RXDRDY: | |
149 | if (value == 0) { | |
150 | s->reg[R_UART_RXDRDY] = 0; | |
151 | } | |
152 | break; | |
153 | case A_UART_STARTTX: | |
154 | if (value == 1) { | |
155 | s->tx_started = true; | |
156 | } | |
157 | break; | |
158 | case A_UART_STARTRX: | |
159 | if (value == 1) { | |
160 | s->rx_started = true; | |
161 | } | |
162 | break; | |
163 | case A_UART_ENABLE: | |
164 | if (value) { | |
165 | if (value == 4) { | |
166 | s->enabled = true; | |
167 | } | |
168 | break; | |
169 | } | |
170 | s->enabled = false; | |
171 | value = 1; | |
172 | /* fall through */ | |
173 | case A_UART_SUSPEND: | |
174 | case A_UART_STOPTX: | |
175 | if (value == 1) { | |
176 | s->tx_started = false; | |
177 | } | |
178 | /* fall through */ | |
179 | case A_UART_STOPRX: | |
180 | if (addr != A_UART_STOPTX && value == 1) { | |
181 | s->rx_started = false; | |
182 | s->reg[R_UART_RXTO] = 1; | |
183 | } | |
184 | break; | |
185 | default: | |
186 | s->reg[addr / 4] = value; | |
187 | break; | |
188 | } | |
189 | nrf51_uart_update_irq(s); | |
190 | } | |
191 | ||
192 | static const MemoryRegionOps uart_ops = { | |
193 | .read = uart_read, | |
194 | .write = uart_write, | |
195 | .endianness = DEVICE_LITTLE_ENDIAN, | |
196 | }; | |
197 | ||
198 | static void nrf51_uart_reset(DeviceState *dev) | |
199 | { | |
200 | NRF51UARTState *s = NRF51_UART(dev); | |
201 | ||
202 | s->pending_tx_byte = 0; | |
203 | ||
204 | uart_cancel_transmit(s); | |
205 | ||
206 | memset(s->reg, 0, sizeof(s->reg)); | |
207 | ||
208 | s->reg[R_UART_PSELRTS] = 0xFFFFFFFF; | |
209 | s->reg[R_UART_PSELTXD] = 0xFFFFFFFF; | |
210 | s->reg[R_UART_PSELCTS] = 0xFFFFFFFF; | |
211 | s->reg[R_UART_PSELRXD] = 0xFFFFFFFF; | |
212 | s->reg[R_UART_BAUDRATE] = 0x4000000; | |
213 | ||
214 | s->rx_fifo_len = 0; | |
215 | s->rx_fifo_pos = 0; | |
216 | s->rx_started = false; | |
217 | s->tx_started = false; | |
218 | s->enabled = false; | |
219 | } | |
220 | ||
221 | static void uart_receive(void *opaque, const uint8_t *buf, int size) | |
222 | { | |
223 | ||
224 | NRF51UARTState *s = NRF51_UART(opaque); | |
225 | int i; | |
226 | ||
227 | if (size == 0 || s->rx_fifo_len >= UART_FIFO_LENGTH) { | |
228 | return; | |
229 | } | |
230 | ||
231 | for (i = 0; i < size; i++) { | |
232 | uint32_t pos = (s->rx_fifo_pos + s->rx_fifo_len) % UART_FIFO_LENGTH; | |
233 | s->rx_fifo[pos] = buf[i]; | |
234 | s->rx_fifo_len++; | |
235 | } | |
236 | ||
237 | s->reg[R_UART_RXDRDY] = 1; | |
238 | nrf51_uart_update_irq(s); | |
239 | } | |
240 | ||
241 | static int uart_can_receive(void *opaque) | |
242 | { | |
243 | NRF51UARTState *s = NRF51_UART(opaque); | |
244 | ||
245 | return s->rx_started ? (UART_FIFO_LENGTH - s->rx_fifo_len) : 0; | |
246 | } | |
247 | ||
083b266f | 248 | static void uart_event(void *opaque, QEMUChrEvent event) |
19790847 JS |
249 | { |
250 | NRF51UARTState *s = NRF51_UART(opaque); | |
251 | ||
252 | if (event == CHR_EVENT_BREAK) { | |
253 | s->reg[R_UART_ERRORSRC] |= 3; | |
254 | s->reg[R_UART_ERROR] = 1; | |
255 | nrf51_uart_update_irq(s); | |
256 | } | |
257 | } | |
258 | ||
259 | static void nrf51_uart_realize(DeviceState *dev, Error **errp) | |
260 | { | |
261 | NRF51UARTState *s = NRF51_UART(dev); | |
262 | ||
263 | qemu_chr_fe_set_handlers(&s->chr, uart_can_receive, uart_receive, | |
264 | uart_event, NULL, s, NULL, true); | |
265 | } | |
266 | ||
267 | static void nrf51_uart_init(Object *obj) | |
268 | { | |
269 | NRF51UARTState *s = NRF51_UART(obj); | |
270 | SysBusDevice *sbd = SYS_BUS_DEVICE(obj); | |
271 | ||
272 | memory_region_init_io(&s->iomem, obj, &uart_ops, s, | |
273 | "nrf51_soc.uart", UART_SIZE); | |
274 | sysbus_init_mmio(sbd, &s->iomem); | |
275 | sysbus_init_irq(sbd, &s->irq); | |
276 | } | |
277 | ||
278 | static int nrf51_uart_post_load(void *opaque, int version_id) | |
279 | { | |
280 | NRF51UARTState *s = NRF51_UART(opaque); | |
281 | ||
282 | if (s->pending_tx_byte) { | |
283 | s->watch_tag = qemu_chr_fe_add_watch(&s->chr, G_IO_OUT | G_IO_HUP, | |
284 | uart_transmit, s); | |
285 | } | |
286 | ||
287 | return 0; | |
288 | } | |
289 | ||
290 | static const VMStateDescription nrf51_uart_vmstate = { | |
291 | .name = "nrf51_soc.uart", | |
292 | .post_load = nrf51_uart_post_load, | |
293 | .fields = (VMStateField[]) { | |
294 | VMSTATE_UINT32_ARRAY(reg, NRF51UARTState, 0x56C), | |
295 | VMSTATE_UINT8_ARRAY(rx_fifo, NRF51UARTState, UART_FIFO_LENGTH), | |
296 | VMSTATE_UINT32(rx_fifo_pos, NRF51UARTState), | |
297 | VMSTATE_UINT32(rx_fifo_len, NRF51UARTState), | |
298 | VMSTATE_BOOL(rx_started, NRF51UARTState), | |
299 | VMSTATE_BOOL(tx_started, NRF51UARTState), | |
300 | VMSTATE_BOOL(pending_tx_byte, NRF51UARTState), | |
301 | VMSTATE_BOOL(enabled, NRF51UARTState), | |
302 | VMSTATE_END_OF_LIST() | |
303 | } | |
304 | }; | |
305 | ||
306 | static Property nrf51_uart_properties[] = { | |
307 | DEFINE_PROP_CHR("chardev", NRF51UARTState, chr), | |
308 | DEFINE_PROP_END_OF_LIST(), | |
309 | }; | |
310 | ||
311 | static void nrf51_uart_class_init(ObjectClass *klass, void *data) | |
312 | { | |
313 | DeviceClass *dc = DEVICE_CLASS(klass); | |
314 | ||
315 | dc->reset = nrf51_uart_reset; | |
316 | dc->realize = nrf51_uart_realize; | |
4f67d30b | 317 | device_class_set_props(dc, nrf51_uart_properties); |
19790847 JS |
318 | dc->vmsd = &nrf51_uart_vmstate; |
319 | } | |
320 | ||
321 | static const TypeInfo nrf51_uart_info = { | |
322 | .name = TYPE_NRF51_UART, | |
323 | .parent = TYPE_SYS_BUS_DEVICE, | |
324 | .instance_size = sizeof(NRF51UARTState), | |
325 | .instance_init = nrf51_uart_init, | |
326 | .class_init = nrf51_uart_class_init | |
327 | }; | |
328 | ||
329 | static void nrf51_uart_register_types(void) | |
330 | { | |
331 | type_register_static(&nrf51_uart_info); | |
332 | } | |
333 | ||
334 | type_init(nrf51_uart_register_types) |