1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
|
/*
* Copyright © 2012 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include <ao.h>
struct ao_stm_usart {
struct ao_fifo rx_fifo;
struct ao_fifo tx_fifo;
struct stm_usart *reg;
uint8_t tx_started;
};
#if HAS_SERIAL_1
struct ao_stm_usart ao_stm_usart1;
#endif
#if HAS_SERIAL_2
struct ao_stm_usart ao_stm_usart2;
#endif
#if HAS_SERIAL_3
struct ao_stm_usart ao_stm_usart3;
#endif
void
ao_debug_out(char c)
{
if (c == '\n')
ao_debug_out('\r');
while (!(stm_usart1.sr & (1 << STM_USART_SR_TXE)));
stm_usart1.dr = c;
}
#if 0
void
outbyte(char c)
{
putchar(c);
}
#endif
static void
ao_usart_tx_start(struct ao_stm_usart *usart)
{
if (!ao_fifo_empty(usart->tx_fifo) && !usart->tx_started)
{
usart->tx_started = 1;
ao_fifo_remove(usart->tx_fifo, usart->reg->dr);
}
}
static void
ao_usart_isr(struct ao_stm_usart *usart, int stdin)
{
uint32_t sr;
sr = usart->reg->sr;
usart->reg->sr = 0;
if (sr & (1 << STM_USART_SR_RXNE)) {
char c = usart->reg->dr;
if (!ao_fifo_full(usart->rx_fifo))
ao_fifo_insert(usart->rx_fifo, c);
ao_wakeup(&usart->rx_fifo);
if (stdin)
ao_wakeup(&ao_stdin_ready);
}
if (sr & (1 << STM_USART_SR_TC)) {
usart->tx_started = 0;
ao_usart_tx_start(usart);
ao_wakeup(&usart->tx_fifo);
}
}
#if HAS_SERIAL_1
void stm_usart1_isr(void) { ao_usart_isr(&ao_stm_usart1, USE_SERIAL_STDIN); }
#endif
#if HAS_SERIAL_2
void stm_usart2_isr(void) { ao_usart_isr(&ao_stm_usart2, 0); }
#endif
#if HAS_SERIAL_3
void stm_usart3_isr(void) { ao_usart_isr(&ao_stm_usart3, 0); }
#endif
char
ao_usart_getchar(struct ao_stm_usart *usart)
{
char c;
cli();
while (ao_fifo_empty(usart->rx_fifo))
ao_sleep(&usart->rx_fifo);
ao_fifo_remove(usart->rx_fifo, c);
sei();
return c;
}
char
ao_usart_pollchar(struct ao_stm_usart *usart)
{
char c;
cli();
if (ao_fifo_empty(usart->rx_fifo)) {
sei();
return AO_READ_AGAIN;
}
ao_fifo_remove(usart->rx_fifo,c);
sei();
return c;
}
void
ao_usart_putchar(struct ao_stm_usart *usart, char c)
{
cli();
while (ao_fifo_full(usart->tx_fifo))
ao_sleep(&usart->tx_fifo);
ao_fifo_insert(usart->tx_fifo, c);
ao_usart_tx_start(usart);
sei();
}
void
ao_usart_drain(struct ao_stm_usart *usart)
{
cli();
while (!ao_fifo_empty(usart->tx_fifo))
ao_sleep(&usart->tx_fifo);
sei();
}
static const struct {
uint32_t brr;
} ao_usart_speeds[] = {
[AO_SERIAL_SPEED_4800] = {
STM_APB1 / 4800
},
[AO_SERIAL_SPEED_9600] = {
STM_APB1 / 9600
},
[AO_SERIAL_SPEED_19200] = {
STM_APB1 / 19200
},
[AO_SERIAL_SPEED_57600] = {
STM_APB1 / 57600
},
};
void
ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
{
if (speed > AO_SERIAL_SPEED_57600)
return;
stm_usart1.brr = ao_usart_speeds[speed].brr;
}
void
ao_usart_init(struct ao_stm_usart *usart)
{
usart->reg->cr1 = ((0 << STM_USART_CR1_OVER8) |
(1 << STM_USART_CR1_UE) |
(0 << STM_USART_CR1_M) |
(0 << STM_USART_CR1_WAKE) |
(0 << STM_USART_CR1_PCE) |
(0 << STM_USART_CR1_PS) |
(0 << STM_USART_CR1_PEIE) |
(0 << STM_USART_CR1_TXEIE) |
(1 << STM_USART_CR1_TCIE) |
(1 << STM_USART_CR1_RXNEIE) |
(0 << STM_USART_CR1_IDLEIE) |
(1 << STM_USART_CR1_TE) |
(1 << STM_USART_CR1_RE) |
(0 << STM_USART_CR1_RWU) |
(0 << STM_USART_CR1_SBK));
usart->reg->cr2 = ((0 << STM_USART_CR2_LINEN) |
(STM_USART_CR2_STOP_1 << STM_USART_CR2_STOP) |
(0 << STM_USART_CR2_CLKEN) |
(0 << STM_USART_CR2_CPOL) |
(0 << STM_USART_CR2_CPHA) |
(0 << STM_USART_CR2_LBCL) |
(0 << STM_USART_CR2_LBDIE) |
(0 << STM_USART_CR2_LBDL) |
(0 << STM_USART_CR2_ADD));
usart->reg->cr3 = ((0 << STM_USART_CR3_ONEBITE) |
(0 << STM_USART_CR3_CTSIE) |
(0 << STM_USART_CR3_CTSE) |
(0 << STM_USART_CR3_RTSE) |
(0 << STM_USART_CR3_DMAT) |
(0 << STM_USART_CR3_DMAR) |
(0 << STM_USART_CR3_SCEN) |
(0 << STM_USART_CR3_NACK) |
(0 << STM_USART_CR3_HDSEL) |
(0 << STM_USART_CR3_IRLP) |
(0 << STM_USART_CR3_IREN) |
(0 << STM_USART_CR3_EIE));
/* Pick a 9600 baud rate */
ao_usart_set_speed(usart, AO_SERIAL_SPEED_9600);
}
void
ao_serial_init(void)
{
#ifdef HAS_SERIAL_1
/*
* TX RX
* PA9 PA10
* PB6 PB7
*/
stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
stm_moder_set(&stm_gpioa, 9, STM_MODER_ALTERNATE);
stm_moder_set(&stm_gpioa, 10, STM_MODER_ALTERNATE);
stm_afr_set(&stm_gpioa, 9, STM_AFR_AF7);
stm_afr_set(&stm_gpioa, 10, STM_AFR_AF7);
/* Enable USART */
stm_rcc.apb2enr |= (1 << STM_RCC_APB2ENR_USART1EN);
ao_stm_usart1.reg = &stm_usart1;
stm_nvic_set_enable(STM_ISR_USART1_POS);
stm_nvic_set_priority(STM_ISR_USART1_POS, 4);
#if USE_SERIAL_STDIN
ao_add_stdio(ao_serial_pollchar,
ao_serial_putchar,
NULL);
#endif
#endif
#if HAS_SERIAL_2
/*
* TX RX
* PA2 PA3
* PD5 PD6
*/
stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOAEN);
stm_moder_set(&stm_gpioa, 2, STM_MODER_ALTERNATE);
stm_moder_set(&stm_gpioa, 3, STM_MODER_ALTERNATE);
stm_afr_set(&stm_gpioa, 2, STM_AFR_AF7);
stm_afr_set(&stm_gpioa, 3, STM_AFR_AF7);
/* Enable USART */
stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_USART2EN);
ao_stm_usart2.reg = &stm_usart2;
stm_nvic_set_enable(STM_ISR_USART2_POS);
stm_nvic_set_priority(STM_ISR_USART2_POS, 4);
#endif
#if HAS_SERIAL_3
/*
* TX RX
* PB10 PB11
* PC10 PC11
* PD8 PD9
*/
stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOBEN);
stm_moder_set(&stm_gpiob, 10, STM_MODER_ALTERNATE);
stm_moder_set(&stm_gpiob, 11, STM_MODER_ALTERNATE);
stm_afr_set(&stm_gpiob, 10, STM_AFR_AF7);
stm_afr_set(&stm_gpiob, 11, STM_AFR_AF7);
/* Enable USART */
stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_USART3EN);
ao_stm_usart3.reg = &stm_usart3;
stm_nvic_set_enable(STM_ISR_USART3_POS);
stm_nvic_set_priority(STM_ISR_USART3_POS, 4);
#endif
}
#if HAS_SERIAL_1
char
ao_serial_getchar(void)
{
return ao_usart_getchar(&ao_stm_usart1);
}
#if USE_SERIAL_STDIN
char
ao_serial_pollchar(void)
{
return ao_usart_pollchar(&ao_stm_usart1);
}
#endif
void
ao_serial_putchar(char c)
{
ao_usart_putchar(&ao_stm_usart1, c);
}
#endif /* HAS_SERIAL_1 */
|
