Hi,
I m working on porting the 2.6.14.6 kernel to the Encore M3 (AU1500)
board --
The kernel mounts the NFS root and executes the init=/bin/sh program --
however I dont see it on the console (standard 8250 UART)
The reason is that there was no platform_device structure defined for
the serial console in the platform.c file.
I therefore added the following to the
arch/mips/au1000/common/platform.c file,
>
> #ifdef CONFIG_MIPS_AMPRO_M3
> static struct plat_serial8250_port encm3_via_uart_data[] = {
> {
> .mapbase = 0x50000000 + 0x3f8,
> .membase = (char *)(0x50000000 +0x3f8),
> .irq = AU1000_GPIO_0,
> .flags = UPF_SHARE_IRQ,
> .iotype = UPIO_PORT,
> .regshift = 1,
> .uartclk = 1843200,
>
> },
> { },
> };
>
> static struct resource encm3_via_uart_resource = {
> .start = VIA_COM1_ADDR, // this is 0x3f8
> .end = VIA_COM1_ADDR + 0x7,
> .flags = IORESOURCE_IO,
> };
>
>
> static struct platform_device encm3_via_uart = {
> .name = "serial8250",
> .id = 1,
> .dev = {
> .platform_data = encm3_via_uart_data,
> },
> .num_resources = 1,
> .resource = &encm3_via_uart_resource,
> };
> #endif
>
I have a these queries about the above entries:
1) The serial console is on a VIA 686B southbridge which is on the PCI
bus -- however, because of the way the VIA is designed, any references
from the processor to port 0x3f8 are routed to the console --
- the 0x50000000 is the mips_io_port_base address for the Southbridge
so should the resource.flags be IORESOURCE_IO or IORESOURCE_MEM -- what
does this signify exactly? I tried both and neither makes a difference
to the output from the log buffer which I have pasted below. Does this
have to do with whether the ports are i/o or memory mapped -- cus in
that case it should be IORESOURCE_MEM as all io ports on MIPS processors
are memory mapped -- right?
2) in the platform_device structure, does the name of the device have to
be coherent with a name given to it elsewhere, if yes, where?
3) control goes into the serial8250_probe function and assigns values
from the plat_serial8250_port encm3_via_uart_data to the port..so what
is the basic difference between registration of "probe device" versus
"platform bus" devices in the 2.6 kernel?
When I build the kernel with this platform.c file and run it, I see an
error in the pci_register_driver function executed to register the usb
port which is on the AU1500 chip, which is the other platform device --
I did not get such an error before the above entries were added to the
file! I have pasted the contents of the entire file below.
Sorry about the length of this email and Thank you,
Ashlesha.
> /*
> * Platform device support for Au1x00 SoCs.
> *
> * Copyright 2004, Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
> *
> * 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.
> */
> #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 resource au1xxx_usb_ohci_resources[] = {
> [0] = {
> .start = USB_OHCI_BASE,
> .end = USB_OHCI_BASE + USB_OHCI_LEN,
> .flags = IORESOURCE_MEM,
> },
> [1] = {
> .start = AU1000_USB_HOST_INT,
> .end = AU1000_USB_HOST_INT,
> .flags = IORESOURCE_IRQ,
> },
> };
>
> /* The dmamask must be set for OHCI to work */
> static u64 ohci_dmamask = ~(u32)0;
>
> static struct platform_device au1xxx_usb_ohci_device = {
> .name = "au1xxx-ohci",
> .id = 0,
> .dev = {
> .dma_mask = &ohci_dmamask,
> .coherent_dma_mask = 0xffffffff,
> },
> .num_resources = ARRAY_SIZE(au1xxx_usb_ohci_resources),
> .resource = au1xxx_usb_ohci_resources,
> 44,2-9 Top
>
> };
>
>
>
> #ifdef CONFIG_MIPS_AMPRO_M3
> static struct plat_serial8250_port encm3_via_uart_data[] = {
> {
> // .mapbase = 0x50000000 + 0x3f8, //resource base
> .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,
> };
>
>
> static struct platform_device encm3_via_uart = { // coyote_uart arm/mach-ixp4xx/coyote-setup.c
> .name = "serial8250",
> .id = 1,
> .dev = {
> .platform_data = encm3_via_uart_data,
> },
> .num_resources = 1,
> .resource = &encm3_via_uart_resource,
> };
> #endif
>
> static struct platform_device *au1xxx_platform_devices[] __initdata = {
> &au1xxx_usb_ohci_device,
> &encm3_via_uart,
> };
> int au1xxx_platform_init(void)
> {
> printk("size of au1xxx platform devices is %d\n",ARRAY_SIZE(au1xxx_platform_devices));
> return platform_add_devices(au1xxx_platform_devices, ARRAY_SIZE(au1xxx_platform_devices));
> }
>
> arch_initcall(au1xxx_platform_init);
>
