2 * Copyright © 2013 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 #include <ao_serial.h>
21 struct ao_fifo ao_usart_rx_fifo;
22 struct ao_fifo ao_usart_tx_fifo;
23 uint8_t ao_usart_tx_avail;
24 uint8_t ao_usart_tx_avail_min;
26 #define LPC_USART_TX_FIFO_SIZE 16
33 while (!(lpc_usart.lsr & (1 << LPC_USART_LSR_TEMT)))
35 lpc_usart.rbr_thr = c;
39 _ao_serial_tx_start(void)
41 if (!ao_fifo_empty(ao_usart_tx_fifo) && ao_usart_tx_avail) {
43 if (ao_usart_tx_avail < ao_usart_tx_avail_min)
44 ao_usart_tx_avail_min = ao_usart_tx_avail;
45 ao_fifo_remove(ao_usart_tx_fifo, lpc_usart.rbr_thr);
52 (void) lpc_usart.iir_fcr;
54 while (lpc_usart.lsr & (1 << LPC_USART_LSR_RDR)) {
55 char c = lpc_usart.rbr_thr;
56 if (!ao_fifo_full(ao_usart_rx_fifo))
57 ao_fifo_insert(ao_usart_rx_fifo, c);
58 ao_wakeup(&ao_usart_rx_fifo);
60 ao_wakeup(&ao_stdin_ready);
62 if (lpc_usart.lsr & (1 << LPC_USART_LSR_THRE)) {
63 ao_usart_tx_avail = LPC_USART_TX_FIFO_SIZE;
64 _ao_serial_tx_start();
65 ao_wakeup(&ao_usart_tx_fifo);
70 _ao_serial_pollchar(void)
74 if (ao_fifo_empty(ao_usart_rx_fifo))
78 ao_fifo_remove(ao_usart_rx_fifo,u);
85 ao_serial_getchar(void)
88 ao_arch_block_interrupts();
89 while ((c = _ao_serial_pollchar()) == AO_READ_AGAIN)
90 ao_sleep(&ao_usart_rx_fifo);
91 ao_arch_release_interrupts();
96 ao_serial_putchar(char c)
98 ao_arch_block_interrupts();
99 while (ao_fifo_full(ao_usart_tx_fifo))
100 ao_sleep(&ao_usart_tx_fifo);
101 ao_fifo_insert(ao_usart_tx_fifo, c);
102 _ao_serial_tx_start();
103 ao_arch_release_interrupts();
107 ao_serial_drain(void)
109 ao_arch_block_interrupts();
110 while (!ao_fifo_empty(ao_usart_tx_fifo))
111 ao_sleep(&ao_usart_tx_fifo);
112 ao_arch_release_interrupts();
115 #include "ao_serial_lpc.h"
118 ao_serial_set_speed(uint8_t speed)
120 if (speed > AO_SERIAL_SPEED_115200)
123 /* Flip to allow access to divisor latches */
124 lpc_usart.lcr |= (1 << LPC_USART_LCR_DLAB);
127 lpc_usart.rbr_thr = ao_usart_speeds[speed].dl & 0xff;
130 lpc_usart.ier = (ao_usart_speeds[speed].dl >> 8) & 0xff;
132 lpc_usart.fdr = ((ao_usart_speeds[speed].divaddval << LPC_USART_FDR_DIVADDVAL) |
133 (ao_usart_speeds[speed].mulval << LPC_USART_FDR_MULVAL));
135 /* Turn access to divisor latches back off */
136 lpc_usart.lcr &= ~(1 << LPC_USART_LCR_DLAB);
143 lpc_ioconf.pio0_18 = ((LPC_IOCONF_FUNC_PIO0_18_RXD << LPC_IOCONF_FUNC) |
144 (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
145 (0 << LPC_IOCONF_HYS) |
146 (0 << LPC_IOCONF_INV) |
147 (0 << LPC_IOCONF_OD));
148 lpc_ioconf.pio0_19 = ((LPC_IOCONF_FUNC_PIO0_19_TXD << LPC_IOCONF_FUNC) |
149 (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
150 (0 << LPC_IOCONF_HYS) |
151 (0 << LPC_IOCONF_INV) |
152 (0 << LPC_IOCONF_OD));
155 /* Turn on the USART */
156 lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_USART);
158 /* Turn on the USART clock */
159 lpc_scb.uartclkdiv = AO_LPC_CLKOUT / AO_LPC_USARTCLK;
161 /* Configure USART */
163 /* Enable FIFOs, reset fifo contents, interrupt on 1 received char */
164 lpc_usart.iir_fcr = ((1 << LPC_USART_FCR_FIFOEN) |
165 (1 << LPC_USART_FCR_RXFIFORES) |
166 (1 << LPC_USART_FCR_TXFIFORES) |
167 (LPC_USART_FCR_RXTL_1 << LPC_USART_FCR_RXTL));
169 ao_usart_tx_avail = LPC_USART_TX_FIFO_SIZE;
170 ao_usart_tx_avail_min = LPC_USART_TX_FIFO_SIZE;
173 lpc_usart.lcr = ((LPC_USART_LCR_WLS_8 << LPC_USART_LCR_WLS) |
174 (LPC_USART_LCR_SBS_1 << LPC_USART_LCR_SBS) |
175 (0 << LPC_USART_LCR_PE) |
176 (LPC_USART_LCR_PS_ODD << LPC_USART_LCR_PS) |
177 (0 << LPC_USART_LCR_BC) |
178 (0 << LPC_USART_LCR_DLAB));
180 /* Disable flow control */
181 lpc_usart.mcr = ((0 << LPC_USART_MCR_DTRCTRL) |
182 (0 << LPC_USART_MCR_RTSCTRL) |
183 (0 << LPC_USART_MCR_LMS) |
184 (0 << LPC_USART_MCR_RTSEN) |
185 (0 << LPC_USART_MCR_CTSEN));
187 /* 16x oversampling */
188 lpc_usart.osr = ((0 << LPC_USART_OSR_OSFRAC) |
189 ((16 - 1) << LPC_USART_OSR_OSINT) |
190 (0 << LPC_USART_OSR_FDINT));
193 lpc_usart.hden = ((0 << LPC_USART_HDEN_HDEN));
196 ao_serial_set_speed(AO_SERIAL_SPEED_9600);
198 /* Enable interrupts */
199 lpc_usart.ier = ((1 << LPC_USART_IER_RBRINTEN) |
200 (1 << LPC_USART_IER_THREINTEN));
202 lpc_nvic_set_enable(LPC_ISR_USART_POS);
203 lpc_nvic_set_priority(LPC_ISR_USART_POS, 0);
204 #if USE_SERIAL_0_STDIN
205 ao_add_stdio(_ao_serial_pollchar,