Re: [PATCH 35/41] drivers: tty: serial: 8250: add mapsize to platform data

Esben Haabendal
2019-04-29T07:06:50Z

"Enrico Weigelt, metux IT consult" <info@metux.net> writes:

> Adding a mapsize field for the 8250 port platform data struct,
> so we can now set the resource size (eg. *1) and don't need
> funny runtime detections like serial8250_port_size() anymore.
>
> For now, serial8250_port_size() is called everytime we need
> the io resource size. That function checks which chip we
> actually have and returns the appropriate size. This approach
> is a bit clumpsy and not entirely easy to understand, and
> it's a violation of layers :p
>
> Obviously, that information cannot change after the driver init,
> so we can safely do that probing once on driver init and just
> use the stored value later.
>
> *1) arch/mips/alchemy/common/platform.c
>
> Signed-off-by: Enrico Weigelt <info@metux.net>
> ---
> drivers/tty/serial/8250/8250_core.c | 1 +
> include/linux/serial_8250.h | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index e441221..71a398b 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -814,6 +814,7 @@ static int serial8250_probe(struct platform_device *dev)
> uart.port.iotype = p->iotype;
> uart.port.flags = p->flags;
> uart.port.mapbase = p->mapbase;
> + uart.port.mapsize = p->mapsize;
> uart.port.hub6 = p->hub6;
> uart.port.private_data = p->private_data;
> uart.port.type = p->type;
> diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
> index 5a655ba..8b8183a 100644
> --- a/include/linux/serial_8250.h
> +++ b/include/linux/serial_8250.h
> @@ -22,6 +22,7 @@ struct plat_serial8250_port {
> unsigned long iobase; /* io base address */
> void __iomem *membase; /* ioremap cookie or NULL */
> resource_size_t mapbase; /* resource base */
> + resource_size_t mapsize; /* resource size */
> unsigned int irq; /* interrupt number */
> unsigned long irqflags; /* request_irq flags */
> unsigned int uartclk; /* UART clock rate */

Or replace iobase, mapbase and mapsize with a struct resource value?

/Esben