[PATCH 3/4] bsps/riscv: UART - Comment code that queries UART interrupts

[Sebastian Huber]

On 31/03/2019 16:33, Hesham Almatary wrote:
> * Different RISC-V DTBs use different names for UART interrupts such as
> "interrupts" and "interrupts-extended", so it is not portable.
> * polling functions are currently used, so there is no need to query interrupts.
> ---
>   bsps/riscv/riscv/console/console-config.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/bsps/riscv/riscv/console/console-config.c b/bsps/riscv/riscv/console/console-config.c
> index 04d0b28361..81e46f304f 100644
> --- a/bsps/riscv/riscv/console/console-config.c
> +++ b/bsps/riscv/riscv/console/console-config.c
> @@ -183,13 +183,20 @@ static void riscv_console_probe(void)
>   
>         ctx->clock = fdt32_to_cpu(val[0]);
>   
> -      val = (fdt32_t *) fdt_getprop(fdt, node, "interrupts", &len);
> +      /* XXX Different RISC-V DTBs use different property names for interrupt
> +      sources. If an interrupt-driven driver is needed, uncomment, replace the
> +      "interrupts-extended" string below with your target's DTB name for UART
> +      interrupts, and use interrupt-driven UART functions instead of
> +      ns16550_polled_* functions */
> +
> +      /* val = (fdt32_t *) fdt_getprop(fdt, node, "interrupts-extended", &len);
>   
>         if (val == NULL || len != 4) {
>           bsp_fatal(RISCV_FATAL_NO_NS16550_INTERRUPTS_IN_DEVICE_TREE);
>         }
>   
>         ctx->irq = RISCV_INTERRUPT_VECTOR_EXTERNAL(fdt32_to_cpu(val[0]));
> +      */
>   
>         if (node == console_node) {
>           riscv_console.context = &ctx->base;

The driver uses interrupts:

rtems_status_code console_initialize(
   rtems_device_major_number major,
   rtems_device_minor_number minor,
   void *arg
)
...
     rtems_termios_device_install(
       path,
       &ns16550_handler_interrupt,
       NULL,
       &ctx->base
     );

In the long run we need some standard support for device trees similar 
to what Linux or FreeBSD has. Unfortunately, this is a multiple man-week 
work package.

-- 
Sebastian Huber, embedded brains GmbH

Address : Dornierstr. 4, D-82178 Puchheim, Germany
Phone   : +49 89 189 47 41-16
Fax     : +49 89 189 47 41-09
E-Mail  : sebastian.huber at embedded-brains.de
PGP     : Public key available on request.

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