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/*
* 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>
__xdata struct ao_fifo ao_usart1_rx_fifo;
__xdata struct ao_fifo ao_usart1_tx_fifo;
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;
}
void
outbyte(char c)
{
putchar(c);
}
static __xdata uint8_t ao_serial_tx1_started;
static void
ao_serial_tx1_start(void)
{
if (!ao_fifo_empty(ao_usart1_tx_fifo) &&
!ao_serial_tx1_started)
{
ao_serial_tx1_started = 1;
ao_fifo_remove(ao_usart1_tx_fifo, stm_usart1.dr);
}
}
void stm_usart1_isr(void)
{
uint32_t sr;
cli();
sr = stm_usart1.sr;
stm_usart1.sr = 0;
sei();
if (sr & (1 << STM_USART_SR_RXNE)) {
if (!ao_fifo_full(ao_usart1_rx_fifo))
ao_fifo_insert(ao_usart1_rx_fifo, stm_usart1.dr);
ao_wakeup(&ao_usart1_rx_fifo);
#if USE_SERIAL_STDIN
ao_wakeup(&ao_stdin_ready);
#endif
}
if (sr & (1 << STM_USART_SR_TXE)) {
ao_serial_tx1_started = 0;
ao_serial_tx1_start();
ao_wakeup(&ao_usart1_tx_fifo);
}
}
char
ao_serial_getchar(void) __critical
{
char c;
cli();
while (ao_fifo_empty(ao_usart1_rx_fifo))
ao_sleep(&ao_usart1_rx_fifo);
ao_fifo_remove(ao_usart1_rx_fifo, c);
sei();
return c;
}
#if USE_SERIAL_STDIN
char
ao_serial_pollchar(void) __critical
{
char c;
cli();
if (ao_fifo_empty(ao_usart1_rx_fifo)) {
sei();
return AO_READ_AGAIN;
}
ao_fifo_remove(ao_usart1_rx_fifo,c);
sei();
return c;
}
#endif
void
ao_serial_putchar(char c) __critical
{
cli();
while (ao_fifo_full(ao_usart1_tx_fifo))
ao_sleep(&ao_usart1_tx_fifo);
ao_fifo_insert(ao_usart1_tx_fifo, c);
ao_serial_tx1_start();
sei();
}
void
ao_serial_drain(void) __critical
{
cli();
while (!ao_fifo_empty(ao_usart1_tx_fifo))
ao_sleep(&ao_usart1_tx_fifo);
sei();
}
int _write(int file, char *ptr, int len)
{
int l = len;
while (l--)
ao_debug_out(*ptr++);
return len;
}
static const struct {
uint32_t brr;
} ao_serial_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_serial_set_speed(uint8_t speed)
{
#if 0
ao_serial_drain();
#endif
if (speed > AO_SERIAL_SPEED_57600)
return;
stm_usart1.brr = ao_serial_speeds[speed].brr;
}
void
ao_serial_init(void)
{
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 USART1 */
stm_rcc.apb2enr |= (1 << STM_RCC_APB2ENR_USART1EN);
stm_usart1.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) |
(1 << STM_USART_CR1_TXEIE) |
(0 << 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));
stm_usart1.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));
stm_usart1.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_serial_set_speed(AO_SERIAL_SPEED_9600);
printf ("serial initialized\n");
#if 0
#if USE_SERIAL_STDIN
ao_add_stdio(ao_serial_pollchar,
ao_serial_putchar,
NULL);
#endif
#endif
stm_nvic_set_enable(STM_ISR_USART1_POS);
stm_nvic_set_priority(STM_ISR_USART1_POS, 4);
}
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