On Sun, Nov 9, 2014 at 2:55 AM, Kevin Cernekee <cernekee@xxxxxxxxx> wrote:
> By default, bcm63xx_uart.c uses the standard 8250 device naming and
> major/minor numbers. There are at least two situations where this could
> be a problem:
>
> 1) Multiplatform kernels that need to support some chips that have 8250
> UARTs and other chips that have bcm63xx UARTs.
>
> 2) Some older chips like BCM7125 have a mix of both UART types.
>
> Add a new Kconfig option to tell the driver whether to register itself
> as ttyS or ttyBCM. By default it will retain the existing "ttyS"
> behavior to avoid surprises.
While I understand the desire to have stable names, this is the
opposite direction we want to go. Per platform tty names complicates
having a generic userspace. It is not so bad since most ARM platforms
use ttyS or ttyAMA, but just think what the kernel and userspace side
would look like if every single platform did this. We can't change
everything to ttyS because the other names are already an ABI.
This can be solved with a udev rule to create sym links. Or if you
just need to know which dev node is h/w uart X, you can get that from
sysfs.
Rob
> Signed-off-by: Kevin Cernekee <cernekee@xxxxxxxxx>
> ---
> drivers/tty/serial/Kconfig | 11 +++++++++++
> drivers/tty/serial/bcm63xx_uart.c | 8 ++++++++
> 2 files changed, 19 insertions(+)
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index fdd851e..c82cfd2 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1302,6 +1302,17 @@ config SERIAL_BCM63XX_CONSOLE
> If you have enabled the serial port on the BCM63xx CPU
> you can make it the console by answering Y to this option.
>
> +config SERIAL_BCM63XX_TTYS
> + bool "Use ttyS[01] device nodes for bcm63xx_uart"
> + depends on SERIAL_BCM63XX
> + default y
> + help
> + Say Y to name the serial ports /dev/ttyS0, ttyS1, ...
> + This conflicts with the 8250 driver but may avoid breaking
> + compatibility with existing init scripts.
> +
> + Say N to name the serial ports /dev/ttyBCM0, ttyBCM1, ...
> +
> config SERIAL_GRLIB_GAISLER_APBUART
> tristate "GRLIB APBUART serial support"
> depends on OF && SPARC
> diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
> index e04e580..9f3dcc8 100644
> --- a/drivers/tty/serial/bcm63xx_uart.c
> +++ b/drivers/tty/serial/bcm63xx_uart.c
> @@ -751,7 +751,11 @@ static int bcm_console_setup(struct console *co, char *options)
> static struct uart_driver bcm_uart_driver;
>
> static struct console bcm63xx_console = {
> +#ifdef CONFIG_SERIAL_BCM63XX_TTYS
> .name = "ttyS",
> +#else
> + .name = "ttyBCM",
> +#endif
> .write = bcm_console_write,
> .device = uart_console_device,
> .setup = bcm_console_setup,
> @@ -796,9 +800,13 @@ OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
> static struct uart_driver bcm_uart_driver = {
> .owner = THIS_MODULE,
> .driver_name = "bcm63xx_uart",
> +#ifdef CONFIG_SERIAL_BCM63XX_TTYS
> .dev_name = "ttyS",
> .major = TTY_MAJOR,
> .minor = 64,
> +#else
> + .dev_name = "ttyBCM",
> +#endif
> .nr = BCM63XX_NR_UARTS,
> .cons = BCM63XX_CONSOLE,
> };
> --
> 2.1.1
>
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