[PATCH] serial: rewrite pxa2xx-uart to use 8250_core

James Cameron
2013-12-06T02:42:11Z

On Fri, Dec 06, 2013 at 03:28:37AM +0400, Sergei Ianovich wrote:
> pxa2xx-uart was a separate uart platform driver. It was declaring
> the same device names and numbers as 8250 driver. As a result,
> it was impossible to use 8250 driver on PXA SoCs.
>
> Upon closer examination pxa2xx-uart turned out to be a clone of
> 8250_core driver.

[...]

> +/* Uart divisor latch write */
> +static void serial_pxa_dl_write(struct uart_8250_port *up, int value)
> +{
> + serial_out(up, UART_DLL, value & 0xff);
> + serial_out(up, UART_DLM, value >> 8 & 0xff);
> +}

This is a change. drivers/tty/serial/pxa.c did read back UART_DLL as
an errata work around:

> - /*
> - * work around Errata #75 according to Intel(R) PXA27x Processor Family
> - * Specification Update (Nov 2005)
> - */
> - dll = serial_in(up, UART_DLL);
> - WARN_ON(dll != (quot & 0xff));

If this is no longer needed, serial_pxa_dl_write can be removed
because it is same as default_serial_dl_write.

I did not check the other errata work arounds.

--
James Cameron