[PATCH] bsps/arm/stm32f4: Enable USART RX interrupts
Jacob Killelea
jkillelea344 at gmail.com
Thu Dec 14 00:49:18 UTC 2023
Hi all,
A quick bump, is anyone able to take a look at this?
Best,
Jacob
On Thu, Dec 7, 2023, 9:00 PM Jacob Killelea <jkillelea344 at gmail.com> wrote:
> From: Jacob Killelea <jkillelea344 at gmail.com>
>
> Hi all, this is my first email patch submission and my first contribution
> to RTEMS, so please give any feedback you have!
>
> This patch enables interrupt driven data reception on USART ports on
> STM32F4 series chips. This feature is gated behind the config flag
> BSP_CONSOLE_USE_INTERRUPTS. If this flag is not set to True, the older
> polling implementation will be used. I tested this feature on STM32F401CE
> (blackpill) and STM32 Nucleo F411RE boards, with both capable of keeping
> up with a 115200 baud continous data stream. With the older polling
> implementation, both would drop bytes at 9600 baud. In addition, I
> updated the implementation of usart_set_attributes to support changing
> the baud rate of the USART port based on the input speed.
> ---
> bsps/arm/stm32f4/console/usart.c | 81 ++++++++++++++++++++++++-----
> spec/build/bsps/arm/stm32f4/grp.yml | 2 +
> 2 files changed, 69 insertions(+), 14 deletions(-)
>
> diff --git a/bsps/arm/stm32f4/console/usart.c
> b/bsps/arm/stm32f4/console/usart.c
> index 37566ef9d7..129249dc29 100644
> --- a/bsps/arm/stm32f4/console/usart.c
> +++ b/bsps/arm/stm32f4/console/usart.c
> @@ -14,6 +14,8 @@
> #include <bsp/irq.h>
> #include <bsp/usart.h>
> #include <bsp/stm32f4.h>
> +#include <termios.h>
> +#include <string.h>
>
> static volatile stm32f4_usart *usart_get_regs(const console_tbl *ct)
> {
> @@ -27,6 +29,24 @@ static rtems_vector_number usart_get_irq_number(const
> console_tbl *ct)
> }
> #endif
>
> +#ifdef BSP_CONSOLE_USE_INTERRUPTS
> +/**
> + * Read characters in an interrupt
> + */
> +static void stm32f4_usart_interrupt(void *arg)
> +{
> + rtems_termios_tty *tty = (rtems_termios_tty *) arg;
> + const console_tbl *ct = Console_Port_Tbl [tty->minor];
> + volatile stm32f4_usart *usart = usart_get_regs(ct);
> +
> + while ((usart->sr & STM32F4_USART_SR_RXNE) == STM32F4_USART_SR_RXNE)
> + {
> + char data = STM32F4_USART_DR_GET(usart->dr);
> + rtems_termios_enqueue_raw_characters(tty, &data, sizeof(data));
> + }
> +}
> +#endif
> +
> static const stm32f4_rcc_index usart_rcc_index [] = {
> STM32F4_RCC_USART1,
> STM32F4_RCC_USART2,
> @@ -128,29 +148,50 @@ static void usart_initialize(int minor)
> usart->cr2 = 0;
> usart->cr3 = 0;
> usart->bbr = usart_get_bbr(usart, pclk, baud);
> - usart->cr1 = STM32F4_USART_CR1_UE
> - | STM32F4_USART_CR1_TE
> - | STM32F4_USART_CR1_RE;
> + usart->cr1 = STM32F4_USART_CR1_UE // UART enable
> +#ifdef BSP_CONSOLE_USE_INTERRUPTS
> + | STM32F4_USART_CR1_RXNEIE // RX interrupt
> +#endif
> + | STM32F4_USART_CR1_TE // TX enable
> + | STM32F4_USART_CR1_RE; // RX enable
> }
>
> static int usart_first_open(int major, int minor, void *arg)
> {
> + rtems_status_code sc = RTEMS_SUCCESSFUL;
> rtems_libio_open_close_args_t *oc = (rtems_libio_open_close_args_t *)
> arg;
> - struct rtems_termios_tty *tty = (struct rtems_termios_tty *)
> oc->iop->data1;
> + rtems_termios_tty *tty = (struct rtems_termios_tty *) oc->iop->data1;
> const console_tbl *ct = Console_Port_Tbl [minor];
> console_data *cd = &Console_Port_Data [minor];
>
> cd->termios_data = tty;
> rtems_termios_set_initial_baud(tty, ct->ulClock);
>
> - return 0;
> +#ifdef BSP_CONSOLE_USE_INTERRUPTS
> + sc = rtems_interrupt_handler_install(ct->ulIntVector,
> + ct->sDeviceName,
> + RTEMS_INTERRUPT_UNIQUE,
> + stm32f4_usart_interrupt,
> + tty);
> +#endif
> +
> + return sc;
> }
>
> static int usart_last_close(int major, int minor, void *arg)
> {
> - return 0;
> + rtems_status_code sc = RTEMS_SUCCESSFUL;
> +#ifdef BSP_CONSOLE_USE_INTERRUPTS
> + rtems_libio_open_close_args_t *oc = (rtems_libio_open_close_args_t *)
> arg;
> + rtems_termios_tty *tty = (struct rtems_termios_tty *) oc->iop->data1;
> + const console_tbl *ct = Console_Port_Tbl [minor];
> +
> + sc = rtems_interrupt_handler_remove(ct->ulIntVector,
> stm32f4_usart_interrupt, tty);
> +#endif
> + return sc;
> }
>
> +#ifndef BSP_CONSOLE_USE_INTERRUPTS
> static int usart_read_polled(int minor)
> {
> const console_tbl *ct = Console_Port_Tbl [minor];
> @@ -162,6 +203,7 @@ static int usart_read_polled(int minor)
> return -1;
> }
> }
> +#endif
>
> static void usart_write_polled(int minor, char c)
> {
> @@ -175,11 +217,7 @@ static void usart_write_polled(int minor, char c)
> usart->dr = STM32F4_USART_DR(c);
> }
>
> -static ssize_t usart_write_support_polled(
> - int minor,
> - const char *s,
> - size_t n
> -)
> +static ssize_t usart_write_support_polled(int minor, const char *s,
> size_t n)
> {
> ssize_t i = 0;
>
> @@ -190,19 +228,34 @@ static ssize_t usart_write_support_polled(
> return n;
> }
>
> +/**
> + * Configure settings from a termios call to tcsetattr()
> + */
> static int usart_set_attributes(int minor, const struct termios *term)
> {
> - return -1;
> + console_tbl *ct = Console_Port_Tbl[minor];
> + volatile stm32f4_usart *usart = usart_get_regs(ct);
> + uint32_t pclk = usart_get_pclk(ct);
> + uint32_t baud = term->c_ispeed;
> +
> + ct->ulClock = baud;
> + usart->bbr = usart_get_bbr(usart, pclk, baud);
> + return 0;
> }
>
> -const console_fns stm32f4_usart_fns = {
> +const console_fns stm32f4_usart_fns =
> +{
> .deviceProbe = libchip_serial_default_probe,
> .deviceFirstOpen = usart_first_open,
> .deviceLastClose = usart_last_close,
> +#ifdef BSP_CONSOLE_USE_INTERRUPTS
> + .deviceRead = NULL,
> +#else
> .deviceRead = usart_read_polled,
> +#endif
> .deviceWrite = usart_write_support_polled,
> .deviceInitialize = usart_initialize,
> .deviceWritePolled = usart_write_polled,
> .deviceSetAttributes = usart_set_attributes,
> - .deviceOutputUsesInterrupts = false
> + .deviceOutputUsesInterrupts = false,
> };
> diff --git a/spec/build/bsps/arm/stm32f4/grp.yml
> b/spec/build/bsps/arm/stm32f4/grp.yml
> index 2257fdf015..27e2197e46 100644
> --- a/spec/build/bsps/arm/stm32f4/grp.yml
> +++ b/spec/build/bsps/arm/stm32f4/grp.yml
> @@ -50,6 +50,8 @@ links:
> uid: optsysclk
> - role: build-dependency
> uid: optusartbaud
> +- role: build-dependency
> + uid: ../../optconsoleirq
> - role: build-dependency
> uid: ../../linkcmds
> - role: build-dependency
> --
> 2.34.1
>
>
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