On Mon, Mar 27, 2006 at 01:27:34PM +0200, Jon Anders Haugum wrote:
> Alchemy SoC uart have got a non-standard divisor register that needs some
> special handling.
>
> This patch adds divisor read/write functions with test and special
> handling for Alchemy internal uart.
>
> @@ -533,22 +565,20 @@ static int size_fifo(struct uart_8250_po
> */
> static unsigned int autoconfig_read_divisor_id(struct uart_8250_port *p)
> {
> - unsigned char old_dll, old_dlm, old_lcr;
> + unsigned char old_lcr;
> unsigned int id;
> + unsigned short old_dl;
>
> old_lcr = serial_inp(p, UART_LCR);
> serial_outp(p, UART_LCR, UART_LCR_DLAB);
>
> - old_dll = serial_inp(p, UART_DLL);
> - old_dlm = serial_inp(p, UART_DLM);
> + old_dl = serial_dl_read(p);
>
> - serial_outp(p, UART_DLL, 0);
> - serial_outp(p, UART_DLM, 0);
> + serial_dl_write(p, 0);
>
> - id = serial_inp(p, UART_DLL) | serial_inp(p, UART_DLM) << 8;
> + id = serial_dl_read(p);
>
> - serial_outp(p, UART_DLL, old_dll);
> - serial_outp(p, UART_DLM, old_dlm);
> + serial_dl_write(p, old_dl);
> serial_outp(p, UART_LCR, old_lcr);
>
> return id;
I'm not sure whether this is a good idea - this is used to detect
an 16C850 UART, so probably should be kept as is.
In other words, we should use serial_dl_read() / serial_dl_write()
when we're actually wanting to read or set the actual divisor, but
not for the autoconfiguration stuff.
--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
