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-rw-r--r--src/kernel/ao.h2
-rw-r--r--src/stm/ao_arch_funcs.h23
-rw-r--r--src/stm/ao_serial_stm.c154
3 files changed, 140 insertions, 39 deletions
diff --git a/src/kernel/ao.h b/src/kernel/ao.h
index a794ba71..6ed0299e 100644
--- a/src/kernel/ao.h
+++ b/src/kernel/ao.h
@@ -820,6 +820,8 @@ struct ao_fifo {
} while(0)
#define ao_fifo_full(f) ((((f).insert + 1) & (AO_FIFO_SIZE-1)) == (f).remove)
+#define ao_fifo_mostly(f) ((((f).insert - (f).remove) & (AO_FIFO_SIZE-1)) >= (AO_FIFO_SIZE * 3 / 4))
+#define ao_fifo_barely(f) ((((f).insert - (f).remove) & (AO_FIFO_SIZE-1)) >= (AO_FIFO_SIZE * 1 / 4))
#define ao_fifo_empty(f) ((f).insert == (f).remove)
#if PACKET_HAS_MASTER || PACKET_HAS_SLAVE
diff --git a/src/stm/ao_arch_funcs.h b/src/stm/ao_arch_funcs.h
index 6fcfd5f8..5a7782de 100644
--- a/src/stm/ao_arch_funcs.h
+++ b/src/stm/ao_arch_funcs.h
@@ -278,14 +278,35 @@ ao_i2c_recv(void *block, uint16_t len, uint8_t i2c_index, uint8_t stop);
void
ao_i2c_init(void);
+#if USE_SERIAL_1_SW_FLOW || USE_SERIAL_2_SW_FLOW || USE_SERIAL_3_SW_FLOW
+#define HAS_SERIAL_SW_FLOW 1
+#else
+#define HAS_SERIAL_SW_FLOW 0
+#endif
+
+#if USE_SERIAL_1_FLOW && !USE_SERIAL_1_SW_FLOW || USE_SERIAL_2_FLOW && !USE_SERIAL_2_SW_FLOW || USE_SERIAL_3_FLOW && !USE_SERIAL_3_SW_FLOW
+#define HAS_SERIAL_HW_FLOW 1
+#else
+#define HAS_SERIAL_HW_FLOW 0
+#endif
+
/* ao_serial_stm.c */
struct ao_stm_usart {
struct ao_fifo rx_fifo;
struct ao_fifo tx_fifo;
struct stm_usart *reg;
- uint8_t tx_started;
uint8_t tx_running;
uint8_t draining;
+#if HAS_SERIAL_SW_FLOW
+ /* RTS - 0 if we have FIFO space, 1 if not
+ * CTS - 0 if we can send, 0 if not
+ */
+ struct stm_gpio *gpio_rts;
+ struct stm_gpio *gpio_cts;
+ uint8_t pin_rts;
+ uint8_t pin_cts;
+ uint8_t rts;
+#endif
};
#if HAS_SERIAL_1
diff --git a/src/stm/ao_serial_stm.c b/src/stm/ao_serial_stm.c
index e7b6ab78..bf079060 100644
--- a/src/stm/ao_serial_stm.c
+++ b/src/stm/ao_serial_stm.c
@@ -16,6 +16,7 @@
*/
#include <ao.h>
+#include <ao_exti.h>
void
ao_debug_out(char c)
@@ -29,40 +30,67 @@ ao_debug_out(char c)
static int
_ao_usart_tx_start(struct ao_stm_usart *usart)
{
- if (!ao_fifo_empty(usart->tx_fifo) && !usart->tx_started)
- {
- usart->tx_started = 1;
- 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->dr);
- ao_wakeup(&usart->tx_fifo);
- return 1;
+ 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, foo) == 1) {
+ ao_exti_enable(usart->gpio_cts, usart->pin_cts);
+ return 0;
+ }
+#endif
+ if (usart->reg->sr & (1 << STM_USART_SR_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->dr);
+ 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 stdin)
+{
+ if (usart->reg->sr & (1 << STM_USART_SR_RXNE)) {
+ if (!ao_fifo_full(usart->rx_fifo)) {
+ ao_fifo_insert(usart->rx_fifo, usart->reg->dr);
+ ao_wakeup(&usart->rx_fifo);
+ if (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, 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 stdin)
{
- uint32_t sr;
+ _ao_usart_rx(usart, stdin);
- sr = usart->reg->sr;
- usart->reg->sr = 0;
+ if (!_ao_usart_tx_start(usart))
+ usart->reg->cr1 &= ~(1<< STM_USART_CR1_TXEIE);
- if (sr & (1 << STM_USART_SR_RXNE)) {
- char c = usart->reg->dr;
- if (!ao_fifo_full(usart->rx_fifo))
- ao_fifo_insert(usart->rx_fifo, c);
- ao_wakeup(&usart->rx_fifo);
- if (stdin)
- ao_wakeup(&ao_stdin_ready);
- }
- if (sr & (1 << STM_USART_SR_TXE)) {
- usart->tx_started = 0;
- if (!_ao_usart_tx_start(usart))
- usart->reg->cr1 &= ~(1<< STM_USART_CR1_TXEIE);
- }
- if (sr & (1 << STM_USART_SR_TC)) {
+ if (usart->reg->sr & (1 << STM_USART_SR_TC)) {
usart->tx_running = 0;
usart->reg->cr1 &= ~(1 << STM_USART_CR1_TCIE);
if (usart->draining) {
@@ -72,7 +100,7 @@ ao_usart_isr(struct ao_stm_usart *usart, int stdin)
}
}
-int
+static int
_ao_usart_pollchar(struct ao_stm_usart *usart)
{
int c;
@@ -82,13 +110,23 @@ _ao_usart_pollchar(struct ao_stm_usart *usart)
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, foo, 0);
+ usart->rts = 1;
+ }
+#endif
c = u;
- ao_usb_putchar(c); ao_usb_flush();
}
return c;
}
-char
+static char
ao_usart_getchar(struct ao_stm_usart *usart)
{
int c;
@@ -96,7 +134,6 @@ ao_usart_getchar(struct ao_stm_usart *usart)
while ((c = _ao_usart_pollchar(usart)) == AO_READ_AGAIN)
ao_sleep(&usart->rx_fifo);
ao_arch_release_interrupts();
- ao_usb_putchar(c); ao_usb_flush();
return (char) c;
}
@@ -106,10 +143,9 @@ _ao_usart_sleep_for(struct ao_stm_usart *usart, uint16_t timeout)
return ao_sleep_for(&usart->rx_fifo, timeout);
}
-void
+static void
ao_usart_putchar(struct ao_stm_usart *usart, char c)
{
- ao_usb_putchar(c); ao_usb_flush();
ao_arch_block_interrupts();
while (ao_fifo_full(usart->tx_fifo))
ao_sleep(&usart->tx_fifo);
@@ -149,7 +185,7 @@ static const struct {
},
};
-void
+static void
ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
{
if (speed > AO_SERIAL_SPEED_115200)
@@ -157,7 +193,7 @@ ao_usart_set_speed(struct ao_stm_usart *usart, uint8_t speed)
usart->reg->brr = ao_usart_speeds[speed].brr;
}
-void
+static void
ao_usart_init(struct ao_stm_usart *usart)
{
usart->reg->cr1 = ((0 << STM_USART_CR1_OVER8) |
@@ -203,12 +239,14 @@ ao_usart_init(struct ao_stm_usart *usart)
ao_usart_set_speed(usart, AO_SERIAL_SPEED_9600);
}
-void
+#if HAS_SERIAL_HW_FLOW
+static void
ao_usart_set_flow(struct ao_stm_usart *usart)
{
usart->reg->cr3 |= ((1 << STM_USART_CR3_CTSE) |
(1 << STM_USART_CR3_RTSE));
}
+#endif
#if HAS_SERIAL_1
@@ -296,13 +334,22 @@ ao_serial2_set_speed(uint8_t speed)
ao_usart_drain(&ao_stm_usart2);
ao_usart_set_speed(&ao_stm_usart2, speed);
}
+
+#if HAS_SERIAL_SW_FLOW
+void
+ao_serial2_cts(void)
+{
+ _ao_usart_cts(&ao_stm_usart2);
+}
+#endif
+
#endif /* HAS_SERIAL_2 */
#if HAS_SERIAL_3
struct ao_stm_usart ao_stm_usart3;
-void stm_usart3_isr(void) { ao_usart_isr(&ao_stm_usart3, USE_SERIAL_2_STDIN); }
+void stm_usart3_isr(void) { ao_usart_isr(&ao_stm_usart3, USE_SERIAL_3_STDIN); }
char
ao_serial3_getchar(void)
@@ -342,6 +389,28 @@ ao_serial3_drain(void)
}
#endif /* HAS_SERIAL_3 */
+#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, foo, 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_init(void)
{
@@ -394,10 +463,19 @@ ao_serial_init(void)
stm_afr_set(&stm_gpioa, 2, STM_AFR_AF7);
stm_afr_set(&stm_gpioa, 3, STM_AFR_AF7);
-#if USE_SERIAL_2_FLOW
+# if USE_SERIAL_2_FLOW
+# if USE_SERIAL_2_SW_FLOW
+ ao_serial_set_sw_rts_cts(&ao_stm_usart2,
+ ao_serial2_cts,
+ SERIAL_2_PORT_RTS,
+ SERIAL_2_PIN_RTS,
+ SERIAL_2_PORT_CTS,
+ SERIAL_2_PIN_CTS);
+# else
stm_afr_set(&stm_gpioa, 0, STM_AFR_AF7);
stm_afr_set(&stm_gpioa, 1, STM_AFR_AF7);
-#endif
+# endif
+# endif
#else
#if SERIAL_2_PD5_PD6
stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIODEN);
@@ -416,7 +494,7 @@ ao_serial_init(void)
ao_stm_usart2.reg = &stm_usart2;
ao_usart_init(&ao_stm_usart2);
-#if USE_SERIAL_2_FLOW
+#if USE_SERIAL_2_FLOW && !USE_SERIAL_2_SW_FLOW
ao_usart_set_flow(&ao_stm_usart2);
#endif
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-15 22:22:01 +0000