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
|
/*
* Copyright © 2013 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>
#include <ao_serial.h>
struct ao_fifo ao_usart_rx_fifo;
struct ao_fifo ao_usart_tx_fifo;
uint8_t ao_usart_tx_avail;
uint8_t ao_usart_tx_avail_min;
#define LPC_USART_TX_FIFO_SIZE 16
void
ao_debug_out(char c)
{
if (c == '\n')
ao_debug_out('\r');
while (!(lpc_usart.lsr & (1 << LPC_USART_LSR_TEMT)))
;
lpc_usart.rbr_thr = c;
}
static void
_ao_serial_tx_start(void)
{
if (!ao_fifo_empty(ao_usart_tx_fifo) && ao_usart_tx_avail) {
ao_usart_tx_avail--;
if (ao_usart_tx_avail < ao_usart_tx_avail_min)
ao_usart_tx_avail_min = ao_usart_tx_avail;
ao_fifo_remove(ao_usart_tx_fifo, lpc_usart.rbr_thr);
}
}
void
lpc_usart_isr(void)
{
uint8_t wake_input = 0;
(void) lpc_usart.iir_fcr;
while (lpc_usart.lsr & (1 << LPC_USART_LSR_RDR)) {
char c = lpc_usart.rbr_thr;
if (!ao_fifo_full(ao_usart_rx_fifo))
ao_fifo_insert(ao_usart_rx_fifo, c);
wake_input = 1;
}
if (lpc_usart.lsr & (1 << LPC_USART_LSR_THRE)) {
ao_usart_tx_avail = LPC_USART_TX_FIFO_SIZE;
_ao_serial_tx_start();
ao_wakeup(&ao_usart_tx_fifo);
}
if (wake_input) {
ao_wakeup(&ao_usart_rx_fifo);
if (stdin)
ao_wakeup(&ao_stdin_ready);
}
}
int
_ao_serial0_pollchar(void)
{
int c;
if (ao_fifo_empty(ao_usart_rx_fifo))
c = AO_READ_AGAIN;
else {
uint8_t u;
ao_fifo_remove(ao_usart_rx_fifo,u);
c = u;
}
return c;
}
char
ao_serial0_getchar(void)
{
int c;
ao_arch_block_interrupts();
while ((c = _ao_serial0_pollchar()) == AO_READ_AGAIN)
ao_sleep(&ao_usart_rx_fifo);
ao_arch_release_interrupts();
return (char) c;
}
void
ao_serial0_putchar(char c)
{
ao_arch_block_interrupts();
while (ao_fifo_full(ao_usart_tx_fifo))
ao_sleep(&ao_usart_tx_fifo);
ao_fifo_insert(ao_usart_tx_fifo, c);
_ao_serial_tx_start();
ao_arch_release_interrupts();
}
void
ao_serial0_drain(void)
{
ao_arch_block_interrupts();
while (!ao_fifo_empty(ao_usart_tx_fifo))
ao_sleep(&ao_usart_tx_fifo);
ao_arch_release_interrupts();
}
#include "ao_serial_lpc.h"
void
ao_serial0_set_speed(uint8_t speed)
{
if (speed > AO_SERIAL_SPEED_115200)
return;
/* Flip to allow access to divisor latches */
lpc_usart.lcr |= (1 << LPC_USART_LCR_DLAB);
/* DL LSB */
lpc_usart.rbr_thr = ao_usart_speeds[speed].dl & 0xff;
/* DL MSB */
lpc_usart.ier = (ao_usart_speeds[speed].dl >> 8) & 0xff;
lpc_usart.fdr = ((ao_usart_speeds[speed].divaddval << LPC_USART_FDR_DIVADDVAL) |
(ao_usart_speeds[speed].mulval << LPC_USART_FDR_MULVAL));
/* Turn access to divisor latches back off */
lpc_usart.lcr &= ~(1 << LPC_USART_LCR_DLAB);
}
void
ao_serial_init(void)
{
#if SERIAL_0_18_19
lpc_ioconf.pio0_18 = ((LPC_IOCONF_FUNC_PIO0_18_RXD << LPC_IOCONF_FUNC) |
(LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
(0 << LPC_IOCONF_HYS) |
(0 << LPC_IOCONF_INV) |
(0 << LPC_IOCONF_OD));
lpc_ioconf.pio0_19 = ((LPC_IOCONF_FUNC_PIO0_19_TXD << LPC_IOCONF_FUNC) |
(LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
(0 << LPC_IOCONF_HYS) |
(0 << LPC_IOCONF_INV) |
(0 << LPC_IOCONF_OD));
#endif
/* Turn on the USART */
lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_USART);
/* Turn on the USART clock */
lpc_scb.uartclkdiv = AO_LPC_CLKOUT / AO_LPC_USARTCLK;
/* Configure USART */
/* Enable FIFOs, reset fifo contents, interrupt on 1 received char */
lpc_usart.iir_fcr = ((1 << LPC_USART_FCR_FIFOEN) |
(1 << LPC_USART_FCR_RXFIFORES) |
(1 << LPC_USART_FCR_TXFIFORES) |
(LPC_USART_FCR_RXTL_1 << LPC_USART_FCR_RXTL));
ao_usart_tx_avail = LPC_USART_TX_FIFO_SIZE;
ao_usart_tx_avail_min = LPC_USART_TX_FIFO_SIZE;
/* 8 n 1 */
lpc_usart.lcr = ((LPC_USART_LCR_WLS_8 << LPC_USART_LCR_WLS) |
(LPC_USART_LCR_SBS_1 << LPC_USART_LCR_SBS) |
(0 << LPC_USART_LCR_PE) |
(LPC_USART_LCR_PS_ODD << LPC_USART_LCR_PS) |
(0 << LPC_USART_LCR_BC) |
(0 << LPC_USART_LCR_DLAB));
/* Disable flow control */
lpc_usart.mcr = ((0 << LPC_USART_MCR_DTRCTRL) |
(0 << LPC_USART_MCR_RTSCTRL) |
(0 << LPC_USART_MCR_LMS) |
(0 << LPC_USART_MCR_RTSEN) |
(0 << LPC_USART_MCR_CTSEN));
/* 16x oversampling */
lpc_usart.osr = ((0 << LPC_USART_OSR_OSFRAC) |
((16 - 1) << LPC_USART_OSR_OSINT) |
(0 << LPC_USART_OSR_FDINT));
/* Full duplex */
lpc_usart.hden = ((0 << LPC_USART_HDEN_HDEN));
/* Set baud rate */
ao_serial0_set_speed(AO_SERIAL_SPEED_9600);
/* Enable interrupts */
lpc_usart.ier = ((1 << LPC_USART_IER_RBRINTEN) |
(1 << LPC_USART_IER_THREINTEN));
lpc_nvic_set_enable(LPC_ISR_USART_POS);
lpc_nvic_set_priority(LPC_ISR_USART_POS, 0);
#if USE_SERIAL_0_STDIN
ao_add_stdio(_ao_serial_pollchar,
ao_serial_putchar,
NULL);
#endif
}
|
