Re: [PATCH] Exar quad port serial

[Paul B Schroeder <pschroeder@uplogix.com>]

Lennart Sorensen wrote:
> On Thu, Oct 05, 2006 at 12:13:21PM -0500, Paul B Schroeder wrote:
>  > I put this together real quick to get all of the ports of my "dumb" Exar
>  > quad uart card to work..  Patch applies against 2.6.19-rc1 just fine..
>  >
>  >
>  > 
> ---------------------------------------------------------------------------
>  >
>  > diff -urN linux-2.6.17.i686.orig/drivers/serial/8250_exar.c 
> linux-2.6.17.i686/drivers/serial/8250_exar.c
>  > --- linux-2.6.17.i686.orig/drivers/serial/8250_exar.c 1969-12-31 
> 18:00:00.000000000 -0600
>  > +++ linux-2.6.17.i686/drivers/serial/8250_exar.c      2006-10-02 
> 17:11:31.000000000 -0500
>  > @@ -0,0 +1,52 @@
>  > +/*
>  > + *  linux/drivers/serial/8250_exar.c
>  > + *
>  > + *  Written by Paul B Schroeder < pschroeder "at" uplogix "dot" com >
>  > + *  Based on 8250_boca.
>  > + *
>  > + *  Copyright (C) 2005 Russell King.
>  > + *  Data taken from include/asm-i386/serial.h
>  > + *
>  > + * This program is free software; you can redistribute it and/or modify
>  > + * it under the terms of the GNU General Public License version 2 as
>  > + * published by the Free Software Foundation.
>  > + */
>  > +#include <linux/module.h>
>  > +#include <linux/init.h>
>  > +#include <linux/serial_8250.h>
>  > +
>  > +#define PORT(_base,_irq)                             \
>  > +     {                                               \
>  > +             .iobase         = _base,                \
>  > +             .irq            = _irq,                 \
>  > +             .uartclk        = 1843200,              \
>  > +             .iotype         = UPIO_PORT,            \
>  > +             .flags          = UPF_BOOT_AUTOCONF,    \
>  > +     }
>  > +
>  > +static struct plat_serial8250_port exar_data[] = {
>  > +     PORT(0x100, 5),
>  > +     PORT(0x108, 5),
>  > +     PORT(0x110, 5),
>  > +     PORT(0x118, 5),
>  > +     { },
>  > +};
>  > +
>  > +static struct platform_device exar_device = {
>  > +     .name                   = "serial8250",
>  > +     .id                     = PLAT8250_DEV_EXAR,
>  > +     .dev                    = {
>  > +             .platform_data  = exar_data,
>  > +     },
>  > +};
>  > +
>  > +static int __init exar_init(void)
>  > +{
>  > +     return platform_device_register(&exar_device);
>  > +}
>  > +
>  > +module_init(exar_init);
>  > +
>  > +MODULE_AUTHOR("Paul B Schroeder");
>  > +MODULE_DESCRIPTION("8250 serial probe module for Exar cards");
>  > +MODULE_LICENSE("GPL");
>  > diff -urN linux-2.6.17.i686.orig/drivers/serial/Kconfig 
> linux-2.6.17.i686/drivers/serial/Kconfig
>  > --- linux-2.6.17.i686.orig/drivers/serial/Kconfig     2006-09-06 
> 14:50:05.000000000 -0500
>  > +++ linux-2.6.17.i686/drivers/serial/Kconfig  2006-10-02 
> 17:13:25.000000000 -0500
>  > @@ -211,6 +211,16 @@
>  >         To compile this driver as a module, choose M here: the module
>  >         will be called 8250_boca.
>  > 
>  > +config SERIAL_8250_EXAR
>  > +     tristate "Support Exar cards"
>  > +     depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
>  > +     help
>  > +       Say Y here if you have a Exar serial board.  Please read the Boca
>  > +       mini-HOWTO, avaialble from <http://www.tldp.org/docs.html#howto>
>  > +
>  > +       To compile this driver as a module, choose M here: the module
>  > +       will be called 8250_exar.
>  > +
>  >  config SERIAL_8250_HUB6
>  >       tristate "Support Hub6 cards"
>  >       depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
>  > diff -urN linux-2.6.17.i686.orig/drivers/serial/Makefile 
> linux-2.6.17.i686/drivers/serial/Makefile
>  > --- linux-2.6.17.i686.orig/drivers/serial/Makefile    2006-06-17 
> 20:49:35.000000000 -0500
>  > +++ linux-2.6.17.i686/drivers/serial/Makefile 2006-10-02 
> 17:13:52.000000000 -0500
>  > @@ -17,6 +17,7 @@
>  >  obj-$(CONFIG_SERIAL_8250_FOURPORT) += 8250_fourport.o
>  >  obj-$(CONFIG_SERIAL_8250_ACCENT) += 8250_accent.o
>  >  obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o
>  > +obj-$(CONFIG_SERIAL_8250_EXAR) += 8250_exar.o
>  >  obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
>  >  obj-$(CONFIG_SERIAL_8250_MCA) += 8250_mca.o
>  >  obj-$(CONFIG_SERIAL_8250_AU1X00) += 8250_au1x00.o
>  > diff -urN linux-2.6.17.i686.orig/include/linux/serial_8250.h 
> linux-2.6.17.i686/include/linux/serial_8250.h
>  > --- linux-2.6.17.i686.orig/include/linux/serial_8250.h        
> 2006-06-17 20:49:35.000000000 -0500
>  > +++ linux-2.6.17.i686/include/linux/serial_8250.h     2006-10-02 
> 17:12:34.000000000 -0500
>  > @@ -41,6 +41,7 @@
>  >       PLAT8250_DEV_FOURPORT,
>  >       PLAT8250_DEV_ACCENT,
>  >       PLAT8250_DEV_BOCA,
>  > +     PLAT8250_DEV_EXAR,
>  >       PLAT8250_DEV_HUB6,
>  >       PLAT8250_DEV_MCA,
>  >       PLAT8250_DEV_AU1X00,
> 
> With 2.6 kernels at least a lot of Exar chips already work.  Perhaps you
> could be more explicit about which Exar chips/boards this is supposed to
> cover.
Sorry for the late response..  Here is a fuller explanation.  Maybe somebody out 
there has a better solution:

This is on our "Envoy" boxes which we have, according to the documentation, an 
"Exar ST16C554/554D Quad UART with 16-byte Fifo's".  The box also has two other 
"on-board" serial ports and a modem chip.

The two on-board serial UARTs were being detected along with the first two Exar 
UARTs.  The last two Exar UARTs were not showing up and neither was the modem.

This patch was the only way I could the kernel to see beyond the standard four 
serial ports and get all four of the Exar UARTs to show up.

I hope this explains it well enough..


Cheers...Paul..


-- 
---

Paul B Schroeder <pschroeder "at" uplogix "dot" com>
Senior Software Engineer
Uplogix, Inc. (http://www.uplogix.com/)