Re: serial console: platform_device

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello.

Ashlesha Shintre wrote:

> There is already an interrupt handler in place for the AU1000_GPIO_0
> that takes care of the cascaded interrupts -- so I *can* say 
>  .irq= AU1000_GPIO_0 ----right?

    No, you can't. You'll have to specify to what 8259's IRQ4 maps to on your 
platform.

> Also, how will I make sure my board specific encm3_platform_init is
> called during the arch init calls?

    Mentioning it in arch_initcall() arranges for that. :-/

> I have put in an entry in the Makefile for the board specific
> encm3_platform.c file -- so it is built - but when control goes to the 
> static int __devinit serial8250_probe(struct device *dev) function in
> the 8250.c it never executes the serial8250_register_port function.
> I know this cus I m using the JTAG port on the board to look inside and
> step through the code..

    That's strange. Although the UART declaration has a grave defect....

> Here is my /arch/mips/au1000/encm3/encm3_platform.c file:

>>/*
>> * Platform device support for Au1x00 SoCs.
>> *
>> * Copyright 2004, Matt Porter <mporter@kernel.crashing.org>
>> *
>> * This file is licensed under the terms of the GNU General Public
>> * License version 2.  This program is licensed "as is" without any
>> * warranty of any kind, whether express or implied.
>> */

    That boilerplate is no longer applicable. :-)

>>#include <linux/device.h>
>>#include <linux/kernel.h>
>>#include <linux/init.h>
>>#include <linux/resource.h>
>>#include <linux/serial_8250.h>
>>#include <linux/tty.h>
>>
>>#include <asm/mach-au1x00/au1000.h>
>>#include <asm/mach-encm3/encm3.h>
>>static struct plat_serial8250_port encm3_via_uart_data[] = {
>>                {
>>                        .mapbase        =
>>0x3f8,                        //resource base

    Damn, I didn't notice: .mapbase should be changed to .iobase!

>>//                      .membase        = (char *)(0x50000000 +
>>0x3f8),         // is a pointer - ioremap cookie or NULL
>>                        .irq            = AU1000_GPIO_0,
>>                        .flags          = UPF_SHARE_IRQ, //|
>>UPF_IOREMAP, //UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
>>                        .iotype         = UPIO_PORT,
>>                        .regshift       = 1,
>>                        .uartclk        = 1843200,
>>
>>                  },
>>                        { },
>>};

>>static struct resource encm3_via_uart_resource = {
>>                .start  = VIA_COM1_ADDR,
>>                .end    = VIA_COM1_ADDR + 0x7,
>>                .flags  = IORESOURCE_IO,
>>};

    Still, you don't need to declare the resources for the 8250 devices -- the 
driver should handle requesting them for you -- as they're alredy specified by 
struct plat_serial8250_port.

>>static struct platform_device encm3_via_uart = {
>>                .name           = "serial8250",
>>                .id             = 1,

    I guess it should be PLAT8250_DEV_LEGACY...

>>                .dev                    = {
>>                                .platform_data  = encm3_via_uart_data,
>>                 },

    So, you also don't need the following 2 lines:

>>                .num_resources  = 1,
>>                .resource       = &encm3_via_uart_resource,
>>};

>>static struct platform_device *encm3_platform_devices[] __initdata = {
>>        &encm3_via_uart,
>>};

>>int encm3_platform_init(void)
>>{
>>        printk("size of encm3 platform devices is %d
>>\n",ARRAY_SIZE(encm3_platform_devices));
>>        return platform_add_devices(encm3_platform_devices,
>>ARRAY_SIZE(encm3_platform_devices));

    I think it's better to call platform_device_register() for a single device...

WBR, Sergei