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_started;
30 while (!(lpc_usart.lsr & (1 << LPC_USART_LSR_TEMT)))
32 lpc_usart.rbr_thr = c;
36 _ao_serial_tx_start(void)
38 if (!ao_fifo_empty(ao_usart_tx_fifo) & !ao_usart_tx_started)
40 ao_usart_tx_started = 1;
41 ao_fifo_remove(ao_usart_tx_fifo, lpc_usart.rbr_thr);
48 (void) lpc_usart.iir_fcr;
50 while (lpc_usart.lsr & (1 << LPC_USART_LSR_RDR)) {
51 char c = lpc_usart.rbr_thr;
52 if (!ao_fifo_full(ao_usart_rx_fifo))
53 ao_fifo_insert(ao_usart_rx_fifo, c);
54 ao_wakeup(&ao_usart_rx_fifo);
56 ao_wakeup(&ao_stdin_ready);
58 if (lpc_usart.lsr & (1 << LPC_USART_LSR_THRE)) {
59 ao_usart_tx_started = 0;
60 _ao_serial_tx_start();
61 ao_wakeup(&ao_usart_tx_fifo);
66 _ao_serial_pollchar(void)
70 if (ao_fifo_empty(ao_usart_rx_fifo))
74 ao_fifo_remove(ao_usart_rx_fifo,u);
81 ao_serial_getchar(void)
84 ao_arch_block_interrupts();
85 while ((c = _ao_serial_pollchar()) == AO_READ_AGAIN)
86 ao_sleep(&ao_usart_rx_fifo);
87 ao_arch_release_interrupts();
92 ao_serial_putchar(char c)
94 ao_arch_block_interrupts();
95 while (ao_fifo_full(ao_usart_tx_fifo))
96 ao_sleep(&ao_usart_tx_fifo);
97 ao_fifo_insert(ao_usart_tx_fifo, c);
98 _ao_serial_tx_start();
99 ao_arch_release_interrupts();
103 ao_serial_drain(void)
105 ao_arch_block_interrupts();
106 while (!ao_fifo_empty(ao_usart_tx_fifo))
107 ao_sleep(&ao_usart_tx_fifo);
108 ao_arch_release_interrupts();
111 #include "ao_serial_lpc.h"
114 ao_serial_set_speed(uint8_t speed)
116 if (speed > AO_SERIAL_SPEED_115200)
119 /* Flip to allow access to divisor latches */
120 lpc_usart.lcr |= (1 << LPC_USART_LCR_DLAB);
123 lpc_usart.rbr_thr = ao_usart_speeds[speed].dl & 0xff;
126 lpc_usart.ier = (ao_usart_speeds[speed].dl >> 8) & 0xff;
128 lpc_usart.fdr = ((ao_usart_speeds[speed].divaddval << LPC_USART_FDR_DIVADDVAL) |
129 (ao_usart_speeds[speed].mulval << LPC_USART_FDR_MULVAL));
131 /* Turn access to divisor latches back off */
132 lpc_usart.lcr &= ~(1 << LPC_USART_LCR_DLAB);
139 lpc_ioconf.pio0_18 = ((LPC_IOCONF_FUNC_PIO0_18_RXD << LPC_IOCONF_FUNC) |
140 (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
141 (0 << LPC_IOCONF_HYS) |
142 (0 << LPC_IOCONF_INV) |
143 (0 << LPC_IOCONF_OD));
144 lpc_ioconf.pio0_19 = ((LPC_IOCONF_FUNC_PIO0_19_TXD << LPC_IOCONF_FUNC) |
145 (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
146 (0 << LPC_IOCONF_HYS) |
147 (0 << LPC_IOCONF_INV) |
148 (0 << LPC_IOCONF_OD));
151 /* Turn on the USART */
152 lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_USART);
154 /* Turn on the USART clock */
155 lpc_scb.uartclkdiv = AO_LPC_CLKOUT / AO_LPC_USARTCLK;
157 /* Configure USART */
159 /* Enable FIFOs, reset fifo contents, interrupt on 1 received char */
160 lpc_usart.iir_fcr = ((1 << LPC_USART_FCR_FIFOEN) |
161 (1 << LPC_USART_FCR_RXFIFORES) |
162 (1 << LPC_USART_FCR_TXFIFORES) |
163 (LPC_USART_FCR_RXTL_1 << LPC_USART_FCR_RXTL));
166 lpc_usart.lcr = ((LPC_USART_LCR_WLS_8 << LPC_USART_LCR_WLS) |
167 (LPC_USART_LCR_SBS_1 << LPC_USART_LCR_SBS) |
168 (0 << LPC_USART_LCR_PE) |
169 (LPC_USART_LCR_PS_ODD << LPC_USART_LCR_PS) |
170 (0 << LPC_USART_LCR_BC) |
171 (0 << LPC_USART_LCR_DLAB));
173 /* Disable flow control */
174 lpc_usart.mcr = ((0 << LPC_USART_MCR_DTRCTRL) |
175 (0 << LPC_USART_MCR_RTSCTRL) |
176 (0 << LPC_USART_MCR_LMS) |
177 (0 << LPC_USART_MCR_RTSEN) |
178 (0 << LPC_USART_MCR_CTSEN));
180 /* 16x oversampling */
181 lpc_usart.osr = ((0 << LPC_USART_OSR_OSFRAC) |
182 ((16 - 1) << LPC_USART_OSR_OSINT) |
183 (0 << LPC_USART_OSR_FDINT));
186 lpc_usart.hden = ((0 << LPC_USART_HDEN_HDEN));
189 ao_serial_set_speed(AO_SERIAL_SPEED_9600);
191 /* Enable interrupts */
192 lpc_usart.ier = ((1 << LPC_USART_IER_RBRINTEN) |
193 (1 << LPC_USART_IER_THREINTEN));
195 lpc_nvic_set_enable(LPC_ISR_USART_POS);
196 lpc_nvic_set_priority(LPC_ISR_USART_POS, 0);
197 #if USE_SERIAL_0_STDIN
198 ao_add_stdio(_ao_serial_pollchar,