[PATCH 08/30] leon, apbuart: RX delayed interrupt

[Chris Johns]

On 14/4/17 5:31 am, Daniel Hellstrom wrote:
> From: Martin Aberg <maberg at gaisler.com>
> 
> Utilize the APBUART RX delayed interrupt if available. It also
> enables RX FIFO interrupt when used.
> 
> The APBUART RX delayed interrupt is supported by the GR740.
> ---
>  c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c | 44 +++++++++++++++++++++--
>  1 file changed, 42 insertions(+), 2 deletions(-)
> 
> diff --git a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
> index b070db5..e6cbd82 100644
> --- a/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
> +++ b/c/src/lib/libbsp/sparc/shared/uart/apbuart_cons.c
> @@ -50,6 +50,11 @@ extern void apbuart_outbyte_polled(
>  extern int apbuart_inbyte_nonblocking(struct apbuart_regs *regs);
>  extern struct apbuart_regs *dbg_uart; /* The debug UART */

A minor nit, this name pollutes the application namespace.

>  
> +/* Probed hardware capabilities */
> +enum {
> +	CAP_FIFO = 0x01, /* FIFO available */
> +	CAP_DI   = 0x02, /* RX delayed interrupt available */
> +};
>  struct apbuart_priv {
>  	struct console_dev condev;
>  	struct drvmgr_dev *dev;
> @@ -58,6 +63,7 @@ struct apbuart_priv {
>  	char devName[32];
>  	volatile int sending;
>  	int mode;
> +	int cap;
>  };
>  
>  /* Getters for different interfaces. It happens to be just casting which we do
> @@ -186,6 +192,30 @@ static const rtems_termios_device_handler handler_polled = {
>  	.mode           = TERMIOS_POLLED
>  };
>  
> +/*
> + * APBUART hardware instantiation is flexible. Probe features here and driver
> + * can select appropriate routines for the hardware. probecap() return value
> + * is a CAP_ bitmask.
> + */
> +static int probecap(volatile struct apbuart_regs *regs)

Why is there a volatile in this decl?

I do not see volatile used like this else where in the patches.

Chris