--- /dev/null
+/*
+ * Copyright © 2020 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, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ */
+
+#include <ao.h>
+#include <ao_exti.h>
+
+void
+ao_debug_out(char c)
+{
+ if (c == '\n')
+ ao_debug_out('\r');
+ while (!(stm_usart1.isr & (1 << STM_USART_ISR_TXE)));
+ stm_usart1.tdr = c;
+}
+
+static int
+_ao_usart_tx_start(struct ao_stm_usart *usart)
+{
+ if (!ao_fifo_empty(usart->tx_fifo)) {
+#if HAS_SERIAL_SW_FLOW
+ if (usart->gpio_cts && ao_gpio_get(usart->gpio_cts, usart->pin_cts) == 1) {
+ ao_exti_enable(usart->gpio_cts, usart->pin_cts);
+ return 0;
+ }
+#endif
+ if (usart->reg->isr & (1 << STM_USART_ISR_TXE))
+ {
+ usart->tx_running = 1;
+ usart->reg->cr1 |= (1 << STM_USART_CR1_TXEIE) | (1 << STM_USART_CR1_TCIE);
+ ao_fifo_remove(usart->tx_fifo, usart->reg->tdr);
+ ao_wakeup(&usart->tx_fifo);
+ return 1;
+ }
+ }
+ return 0;
+}
+
+#if HAS_SERIAL_SW_FLOW
+static void
+_ao_usart_cts(struct ao_stm_usart *usart)
+{
+ if (_ao_usart_tx_start(usart))
+ ao_exti_disable(usart->gpio_cts, usart->pin_cts);
+}
+#endif
+
+static void
+_ao_usart_rx(struct ao_stm_usart *usart, int is_stdin)
+{
+ if (usart->reg->isr & (1 << STM_USART_ISR_RXNE)) {
+ usart->reg->icr = (1 << STM_USART_ICR_ORECF);
+ if (!ao_fifo_full(usart->rx_fifo)) {
+ ao_fifo_insert(usart->rx_fifo, usart->reg->rdr);
+ ao_wakeup(&usart->rx_fifo);
+ if (is_stdin)
+ ao_wakeup(&ao_stdin_ready);
+#if HAS_SERIAL_SW_FLOW
+ /* If the fifo is nearly full, turn off RTS and wait
+ * for it to drain a bunch
+ */
+ if (usart->gpio_rts && ao_fifo_mostly(usart->rx_fifo)) {
+ ao_gpio_set(usart->gpio_rts, usart->pin_rts, 1);
+ usart->rts = 0;
+ }
+#endif
+ } else {
+ usart->reg->cr1 &= ~(1 << STM_USART_CR1_RXNEIE);
+ }
+ }
+}
+
+static void
+ao_usart_isr(struct ao_stm_usart *usart, int is_stdin)
+{
+ _ao_usart_rx(usart, is_stdin);
+
+ if (!_ao_usart_tx_start(usart))
+ usart->reg->cr1 &= ~(1<< STM_USART_CR1_TXEIE);
+
+ if (usart->reg->isr & (1 << STM_USART_ISR_TC)) {
+ usart->tx_running = 0;
+ usart->reg->cr1 &= ~(1 << STM_USART_CR1_TCIE);
+ if (usart->draining) {
+ usart->draining = 0;
+ ao_wakeup(&usart->tx_fifo);
+ }
+ }
+}
+
+static int
+_ao_usart_pollchar(struct ao_stm_usart *usart)
+{
+ int c;
+
+ if (ao_fifo_empty(usart->rx_fifo))
+ c = AO_READ_AGAIN;
+ else {
+ uint8_t u;
+ ao_fifo_remove(usart->rx_fifo,u);
+ if ((usart->reg->cr1 & (1 << STM_USART_CR1_RXNEIE)) == 0) {
+ if (ao_fifo_barely(usart->rx_fifo))
+ usart->reg->cr1 |= (1 << STM_USART_CR1_RXNEIE);
+ }
+#if HAS_SERIAL_SW_FLOW
+ /* If we've cleared RTS, check if there's space now and turn it back on */
+ if (usart->gpio_rts && usart->rts == 0 && ao_fifo_barely(usart->rx_fifo)) {
+ ao_gpio_set(usart->gpio_rts, usart->pin_rts, 0);
+ usart->rts = 1;
+ }
+#endif
+ c = u;
+ }
+ return c;
+}
+
+static char
+ao_usart_getchar(struct ao_stm_usart *usart)
+{
+ int c;
+ ao_arch_block_interrupts();
+ while ((c = _ao_usart_pollchar(usart)) == AO_READ_AGAIN)
+ ao_sleep(&usart->rx_fifo);
+ ao_arch_release_interrupts();
+ return (char) c;
+}
+
+#if 0
+static inline uint8_t
+_ao_usart_sleep_for(struct ao_stm_usart *usart, uint16_t timeout)
+{
+ return ao_sleep_for(&usart->rx_fifo, timeout);
+}
+#endif
+
+static void
+ao_usart_putchar(struct ao_stm_usart *usart, char c)
+{
+ ao_arch_block_interrupts();
+ while (ao_fifo_full(usart->tx_fifo))
+ ao_sleep(&usart->tx_fifo);
+ ao_fifo_insert(usart->tx_fifo, c);
+ _ao_usart_tx_start(usart);
+ ao_arch_release_interrupts();
+}
+
+static void
+ao_usart_drain(struct ao_stm_usart *usart)
+{
+ ao_arch_block_interrupts();
+ while (!ao_fifo_empty(usart->tx_fifo) || usart->tx_running) {
+ usart->draining = 1;
+ ao_sleep(&usart->tx_fifo);
+ }
+ ao_arch_release_interrupts();
+}
+
+static const uint32_t ao_usart_speeds[] = {
+ [AO_SERIAL_SPEED_4800] = 4800,
+ [AO_SERIAL_SPEED_9600] = 9600,
+ [AO_SERIAL_SPEED_19200] = 19200,
+ [AO_SERIAL_SPEED_57600] = 57600,
+ [AO_SERIAL_SPEED_115200] = 115200,
+};
+
+static void
+ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
+{
+ if (speed > AO_SERIAL_SPEED_115200)
+ return;
+ usart->reg->brr = AO_PCLK2 / ao_usart_speeds[speed];
+}
+
+static void
+ao_usart_init(struct ao_stm_usart *usart, int hw_flow)
+{
+ usart->reg->cr1 = ((0 << STM_USART_CR1_M1) |
+ (0 << STM_USART_CR1_EOBIE) |
+ (0 << STM_USART_CR1_RTOIE) |
+ (0 << STM_USART_CR1_DEAT) |
+ (0 << STM_USART_CR1_DEDT) |
+ (0 << STM_USART_CR1_OVER8) |
+ (0 << STM_USART_CR1_CMIE) |
+ (0 << STM_USART_CR1_MME) |
+ (0 << STM_USART_CR1_M0) |
+ (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) |
+ (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_UESM) |
+ (0 << STM_USART_CR1_UE));
+
+ usart->reg->cr2 = ((0 << STM_USART_CR2_ADD) |
+ (0 << STM_USART_CR2_RTOEN) |
+ (0 << STM_USART_CR2_ABRMOD) |
+ (0 << STM_USART_CR2_ABREN) |
+ (0 << STM_USART_CR2_MSBFIRST) |
+ (0 << STM_USART_CR2_DATAINV) |
+ (0 << STM_USART_CR2_TXINV) |
+ (0 << STM_USART_CR2_RXINV) |
+ (0 << STM_USART_CR2_SWAP) |
+ (0 << STM_USART_CR2_LINEN) |
+ (0 << STM_USART_CR2_STOP) |
+ (0 << STM_USART_CR2_CLKEN) |
+ (0 << STM_USART_CR2_CPOL) |
+ (0 << STM_USART_CR2_CHPA) |
+ (0 << STM_USART_CR2_LBCL) |
+ (0 << STM_USART_CR2_LBDIE) |
+ (0 << STM_USART_CR2_LBDL) |
+ (0 << STM_USART_CR2_ADDM7));
+
+ uint32_t cr3 = ((0 << STM_USART_CR3_WUFIE) |
+ (0 << STM_USART_CR3_WUS) |
+ (0 << STM_USART_CR3_SCARCNT) |
+ (0 << STM_USART_CR3_DEP) |
+ (0 << STM_USART_CR3_DEM) |
+ (0 << STM_USART_CR3_DDRE) |
+ (0 << STM_USART_CR3_OVRDIS) |
+ (0 << STM_USART_CR3_ONEBIT) |
+ (0 << STM_USART_CR3_CTIIE) |
+ (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));
+
+ if (hw_flow)
+ cr3 |= ((1 << STM_USART_CR3_CTSE) |
+ (1 << STM_USART_CR3_RTSE));
+
+ usart->reg->cr3 = cr3;
+
+ /* Pick a 9600 baud rate */
+ ao_usart_set_speed(usart, AO_SERIAL_SPEED_9600);
+
+ /* Enable the usart */
+ usart->reg->cr1 |= (1 << STM_USART_CR1_UE);
+}
+
+#if HAS_SERIAL_1
+
+struct ao_stm_usart ao_stm_usart1;
+
+void stm_usart1_isr(void) { ao_usart_isr(&ao_stm_usart1, USE_SERIAL_1_STDIN); }
+
+char
+ao_serial1_getchar(void)
+{
+ return ao_usart_getchar(&ao_stm_usart1);
+}
+
+void
+ao_serial1_putchar(char c)
+{
+ ao_usart_putchar(&ao_stm_usart1, c);
+}
+
+int
+_ao_serial1_pollchar(void)
+{
+ return _ao_usart_pollchar(&ao_stm_usart1);
+}
+
+#if 0
+uint8_t
+_ao_serial1_sleep_for(uint16_t timeout)
+{
+ return _ao_usart_sleep_for(&ao_stm_usart1, timeout);
+}
+#endif
+
+void
+ao_serial1_drain(void)
+{
+ ao_usart_drain(&ao_stm_usart1);
+}
+
+void
+ao_serial1_set_speed(uint8_t speed)
+{
+ ao_usart_drain(&ao_stm_usart1);
+ ao_usart_set_speed(&ao_stm_usart1, speed);
+}
+#endif /* HAS_SERIAL_1 */
+
+#if HAS_SERIAL_2
+
+struct ao_stm_usart ao_stm_usart2;
+
+void stm_usart2_isr(void) { ao_usart_isr(&ao_stm_usart2, USE_SERIAL_2_STDIN); }
+
+char
+ao_serial2_getchar(void)
+{
+ return ao_usart_getchar(&ao_stm_usart2);
+}
+
+void
+ao_serial2_putchar(char c)
+{
+ ao_usart_putchar(&ao_stm_usart2, c);
+}
+
+int
+_ao_serial2_pollchar(void)
+{
+ return _ao_usart_pollchar(&ao_stm_usart2);
+}
+
+#if 0
+uint8_t
+_ao_serial2_sleep_for(uint16_t timeout)
+{
+ return _ao_usart_sleep_for(&ao_stm_usart2, timeout);
+}
+#endif
+
+void
+ao_serial2_drain(void)
+{
+ ao_usart_drain(&ao_stm_usart2);
+}
+
+void
+ao_serial2_set_speed(uint8_t speed)
+{
+ ao_usart_drain(&ao_stm_usart2);
+ ao_usart_set_speed(&ao_stm_usart2, speed);
+}
+
+#if USE_SERIAL_2_FLOW && USE_SERIAL_2_SW_FLOW
+void
+ao_serial2_cts(void)
+{
+ _ao_usart_cts(&ao_stm_usart2);
+}
+#endif
+
+#endif /* HAS_SERIAL_2 */
+
+#if HAS_SERIAL_SW_FLOW
+static void
+ao_serial_set_sw_rts_cts(struct ao_stm_usart *usart,
+ void (*isr)(void),
+ struct stm_gpio *port_rts,
+ int pin_rts,
+ struct stm_gpio *port_cts,
+ int pin_cts)
+{
+ /* Pull RTS low to note that there's space in the FIFO
+ */
+ ao_enable_output(port_rts, pin_rts, 0);
+ usart->gpio_rts = port_rts;
+ usart->pin_rts = pin_rts;
+ usart->rts = 1;
+
+ ao_exti_setup(port_cts, pin_cts, AO_EXTI_MODE_FALLING|AO_EXTI_PRIORITY_MED, isr);
+ usart->gpio_cts = port_cts;
+ usart->pin_cts = pin_cts;
+}
+#endif
+
+void
+ao_serial_shutdown(void)
+{
+#if HAS_SERIAL_1
+ stm_rcc.apb2enr &= ~(1 << STM_RCC_APB2ENR_USART1EN);
+#endif
+#if HAS_SERIAL_2
+ stm_rcc.apb1enr &= ~(1 << STM_RCC_APB1ENR_USART2EN);
+#endif
+}
+
+void
+ao_serial_init(void)
+{
+#if HAS_SERIAL_1
+#endif
+
+#if HAS_SERIAL_2
+ /*
+ * TX RX
+ * PA2 PA3
+ * PA9 PA10
+ * PA14 PA15
+ * PB6 PB7
+ */
+
+# if SERIAL_2_PA2_PA3
+ ao_enable_port(&stm_gpioa);
+ stm_afr_set(&stm_gpioa, 2, STM_AFR_AF4);
+ stm_afr_set(&stm_gpioa, 3, STM_AFR_AF4);
+# elif SERIAL_2_PA9_PA10
+ ao_enable_port(&stm_gpioa);
+ stm_afr_set(&stm_gpioa, 9, STM_AFR_AF4);
+ stm_afr_set(&stm_gpioa, 10, STM_AFR_AF4);
+# elif SERIAL_2_PA14_PA15
+ ao_enable_port(&stm_gpioa);
+ stm_afr_set(&stm_gpioa, 14, STM_AFR_AF4);
+ stm_afr_set(&stm_gpioa, 15, STM_AFR_AF4);
+# elif SERIAL_2_PB6_PB7
+ ao_enable_port(&stm_gpiob);
+ stm_afr_set(&stm_gpiob, 6, STM_AFR_AF0);
+ stm_afr_set(&stm_gpiob, 7, STM_AFR_AF0);
+# else
+# error "No SERIAL_2 port configuration specified"
+# endif
+ /* Enable USART */
+ stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_USART2EN);
+
+ ao_stm_usart2.reg = &stm_usart2;
+ ao_usart_init(&ao_stm_usart2, USE_SERIAL_2_FLOW && !USE_SERIAL_2_SW_FLOW);
+
+ stm_nvic_set_enable(STM_ISR_USART2_POS);
+ stm_nvic_set_priority(STM_ISR_USART2_POS, 4);
+# if USE_SERIAL_2_STDIN && !DELAY_SERIAL_2_STDIN
+ ao_add_stdio(_ao_serial2_pollchar,
+ ao_serial2_putchar,
+ NULL);
+# endif
+#endif
+}
projects / fw / altos / blobdiff