RE: The new "real" console doesn't display printk() messages like "early" console!

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Hi Sergei,

"     Are your UART registers identity mapped to virtual address space?"

My system has DDR memory 0x80000000..0x90000000 (kseg0) and UART is
mapped starting with bbf01000 (kseg1). Can you give me some details
about your question? 

I didn't do anything special for the port other than 
	set_io_port_base(GD_PORT_BASE); 
in gd-init.c


Thanks,
Andrei
 



-----Original Message-----
From: Sergei Shtylyov [mailto:sshtylyov@xxxxxxxxxx] 
Sent: Friday, November 19, 2010 11:09 AM
To: Ardelean, Andrei
Cc: Ricardo Mendoza; linux-mips@xxxxxxxxxxxxxx
Subject: Re: The new "real" console doesn't display printk() messages
like "early" console!

Ardelean, Andrei wrote:

> Hi Ricardo,

> I implemented serial platform driver taking as model serial.c from
> cavium-octeon.

    I think you should really have used something simpler as an example.

> Here is my code:


> /*
>  * This file is subject to the terms and conditions of the GNU General
> Public
>  * License.  See the file "COPYING" in the main directory of this
> archive
>  * for more details.
>  *
>  * Copyright (C) 2004-2007 Cavium Networks
>  */
>  
> #include <linux/console.h>
> #include <linux/module.h>
> #include <linux/init.h>
> #include <linux/platform_device.h>
> #include <linux/serial.h>
> #include <linux/serial_8250.h>
> #include <linux/serial_reg.h>
> #include <linux/tty.h>
> #include <asm/time.h>
> #include <sys_defs.h>
> 
> 
> #ifdef CONFIG_GDB_CONSOLE

    This is never defined for MIPS. And there shouldn't be such
dependencies.

> #define DEBUG_UART 0
> #else
> #define DEBUG_UART 1
> #endif
> 
> unsigned int gd_serial_in(struct uart_port *up, int offset)
> {
> 	int rv = inl((unsigned int)(up->membase + (offset << 2)));

    Should be an empty line here.

> 	if (offset == UART_IIR && (rv & 0xf) == 7) {

    Are you sure this Octeon specific quirk also allpies to your UART?

> 		/* Busy interrupt, read the USR (39) and try again. */
> 		inl((unsigned int)(up->membase + (39 << 2)));
> 		rv = inl((unsigned int)(up->membase + (offset << 2)));
> 	}
> 	return rv;
> }
> 
> void gd_serial_out(struct uart_port *up, int offset, int value)
> {
> 	outl( value & 0xff, (unsigned int)(up->membase + (offset <<

    No spaces allowed after (.

> 2)));
> }
> 
> /*
>  * Allocated in .bss, so it is all zeroed.
>  */
> #define GD_MAX_UARTS 1

    Then how DEBUG_UART can be 1?

> static struct plat_serial8250_port gd_uart8250_data[GD_MAX_UARTS + 1];
> static struct platform_device gd_uart8250_device = {
> 	.name			= "serial8250",
> 	.id			= PLAT8250_DEV_PLATFORM,
> 	.dev			= {
> 		.platform_data	= gd_uart8250_data,

    Where is 'gd_uart8250_data'?

> 	},
> };

> static void __init gd_uart_set_common(struct plat_serial8250_port *p)
> {
> 	p->flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
> 	p->type = PORT_GD;

    What is PORT_GD?

> 	p->iotype = UPIO_MEM;

    Judging from your code, it should be UPIO_MEM32.

> 	p->regshift = 2;	/* I/O addresses are every 4 bytes */
> 	p->uartclk = UART_CLK;  
> 	p->serial_in = gd_serial_in;
> 	p->serial_out = gd_serial_out;
> }
> 
> static int __init gd_serial_init(void)
> {
> 	int enable_uart0;
> 	struct plat_serial8250_port *p;
> 
> 	enable_uart0 = 1;

    What's the point in existence of this variable?

> 	p = gd_uart8250_data;
> 	if (enable_uart0) {
> 		/* Add a ttyS device for hardware uart 0 */
> 		gd_uart_set_common(p);
> 		p->membase = (void *) offMCU_UART_THR_OR_RBR_OR_DLL;
> 		p->mapbase = offMCU_UART_THR_OR_RBR_OR_DLL;

     Are your UART registers identity mapped to virtual address space?
You are not obliged to pass 'membase', unless you have pre-existing
mapping but 
in this case you also need to pass UPF_IOREMAP in 'flags'.

> 		p->irq = MIPSCPU_INT_UART;
> 		p++;
> 	}

> 	return platform_device_register(&gd_uart8250_device);
> }
> 
> device_initcall(gd_serial_init);


>
------------------------------------------------------------------------
> -----------------------
> 
> Thanks,
> Andrei

WBR, Sergei




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