From: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org,
wizard.kang-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org
Cc: 강상우 <ksw412-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: I can't see the SPI device file in /dev.
Date: Wed, 8 Aug 2007 10:15:49 -0700 [thread overview]
Message-ID: <200708081015.49600.david-b@pacbell.net> (raw)
In-Reply-To: <30508394.743901186538489274.JavaMail.weblogic@ep_ml20>
On Tuesday 07 August 2007, SangWoo Kang wrote:
> Hi~
> My developing Environment is below.
> Kernel-2.6.22.1
> tar jxvf linux-2.6.22.1.tar.bz2
> cd linux-2.6.22.1
> zcat ../2.6.22-rc1-at91.patch.gz | patch -p1 > patchresult.txt
2.6.22-rc1 is pretty old compared to 2.6.22.1 ... are you sure
all those patches are still relevant, and they applied OK?
> CPU-AT91SAM9260
> Through the web searching and kernel documentation, I know that use
> the spidev kernel module.
> And I modify arch/at-91/board_sam9260.c file as like below
>
> static struct spi_board_info ek_spi_devices[] = {
> { //spi1.0-slot1
> .modalias = "spidev",
> .chip_select = 0,
> .max_speed_hz = 15*1000*1000,
> .bus_num=1,
> },
> { //spi1.1-slot2
> .modalias = "spidev",
> .chip_select = 1,
> .max_speed_hz = 15*1000*1000,
> .bus_num=1,
> },
Those look right. I'd then expect /dev entries for spidev1.0
and spidev1.1 after "mdev" does its stuff.
> ~
> }
>
> After compiling the kernel, download kernel img to the target.
> Kernel menu_config.
>
> Device Drivers
> SPI support
> [*]SPI support
> [*]Debug support for SPI drivers
> SPI Master Controller Drivers
> [*]Atmel SPI controller
> [ ]Bitbanging SPI master
> SPI Protocol Masters
> [ ]SPI EEPROMs from most vendors
> [*]User mode SPI device driver support
Looks right.
> I execute the "/sbin/mdev -s" command into the target shell as expecting
> the /dev/spidev.
> But I can't see the device file for SPI in target /dev folder. And I
> examin my /sys folder at target.
> Of course, I can find the spi device nodes created from modified board_sam9260.c.
> Hum...I don't know why did not populate the SPI device file in /dev file?
I just set up spi0.2 and spi0.3 on one system and it worked fine
(2.6.23-rc2, but that shouldn't matter).
Files in /sys/bus/spi/devices/spi0.2:
lrwxrwxrwx 1 root root 0 Dec 31 2006 bus -> ../../../../bus/spi
lrwxrwxrwx 1 root root 0 Dec 31 2006 driver -> ../../../../bus/spi/drivers/spidev
-r--r--r-- 1 root root 4096 Dec 31 2006 modalias
lrwxrwxrwx 1 root root 0 Dec 31 2006 spidev:spidev0.2 -> ../../../../class/spidev/spidev0.2
lrwxrwxrwx 1 root root 0 Dec 31 2006 subsystem -> ../../../../bus/spi
-rw-r--r-- 1 root root 4096 Dec 31 2006 uevent
Files in /sys/class/spidev/spidev0.2:
-r--r--r-- 1 root root 4096 Dec 31 2006 dev
lrwxrwxrwx 1 root root 0 Dec 31 2006 device -> ../../../devices/platform/atmel_spi.0/spi0.2
lrwxrwxrwx 1 root root 0 Dec 31 2006 subsystem -> ../../../class/spidev
-rw-r--r-- 1 root root 4096 Dec 31 2006 uevent
and "dev" there contains 153:0, which "mdev" used to create
the /dev/spidev0.2 character device node.
> #dmesg | grep spi
> atmel_spi atmel_spi.1: Atmel SPI Controller at 0xfffcc000 (irq 13)
> atmel_spi atmel_spi.1: registered master spi1
> spi spi1.0: setup: 14189714 Hz bpw 8 mode 0x0 -> csr0 0a0a0702
> atmel_spi atmel_spi.1: registered child spi1.0
> spi spi1.1: setup: 14189714 Hz bpw 8 mode 0x0 -> csr1 0a0a0702
> atmel_spi atmel_spi.1: registered child spi1.1
> spi spi1.2: setup: 14189714 Hz bpw 8 mode 0x0 -> csr2 0a0a0702
> atmel_spi atmel_spi.1: registered child spi1.2
> spi spi1.3: setup: 14189714 Hz bpw 8 mode 0x0 -> csr3 0a0a0702
> atmel_spi atmel_spi.1: registered child spi1.3
>
> Does root file system (NFS) has the problem ? or Kernel menu configuration ?
> Could you teach check point for this problem?
If your sysfs looks right based on what I showed above, I'd
guess maybe you have an old "mdev" ... or maybe it depends
on the CONFIG_SYSFS_DEPRECATED variable, which I can't yet
disable.
> This project name - Access control Unit
> The system is configured two kind of board.
> Main b'd has the AT91SAM9260 which has the Linux OS.
> Sub b'd has the Atmega2560 which is developing the AVR32 studio.
I don't think AVR8 chips can be SPI slaves at 15 MHz; you
should probably change the max_speed_hz you use to set up
those devices. As I recall, 4 MHz is as fast as those chips
can talk SPI, iff everything goes well (and IRQs are blocked
during the PIO loops).
> One Main b'd is connected 5 Sub b'd by SPI
> ...
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next prev parent reply other threads:[~2007-08-08 17:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-08-08 2:01 I can't see the SPI device file in /dev SangWoo Kang
2007-08-08 17:15 ` David Brownell [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-08-08 1:27 강상우
2007-08-08 0:06 강상우
2007-08-08 0:51 ` David Brownell
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