SPI based GPIO Expander issue on IMX51.

nit123 · ‎01-30-2012

Hi

I am trying to make GPIO expander driver on IMX51.

I have a chip mcp23s17 i added the driver for the same.

But whenever its going in to the read function of the driver it throws the below error.

root@freescale/home/modules_install$ insmod mcp23s08.ko

Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = 80004000
[00000000] *pgd=00000000
Internal error: Oops: 17 [#1] PREEMPT
last sysfs file:
Modules linked in: mcp23s08(+)
CPU: 0    Not tainted (2.6.35.3-g2d4b922-dirty #19)
PC is at mxc_spi_buf_tx_u8+0x8/0x14
LR is at spi_put_tx_data+0x24/0x50
pc : [<802794dc>]    lr : [<802795bc>]    psr: 80000013
sp : 9a1c7f28 ip : 00000008 fp : 00000000
r10: 9a0bf318 r9 : 9a0bf800 r8 : 9b86e004
r7 : 00000001 r6 : 9a0bf318 r5 : 00000002 r4 : 9b86e000
r3 : 00000000 r2 : 9a0bf318 r1 : 00000002 r0 : 9a0bf318
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: 10c5387d Table: aa41c019 DAC: 00000017
Process mxc_spi.0 (pid: 249, stack limit = 0x9a1c62e8)
Stack: (0x9a1c7f28 to 0x9a1c8000)
7f20:                   9a0bf318 9a419e08 9a0bf800 00000001 9a419e2c 8027a248
7f40: 9a419e08 00000000 9a1c6000 9a419e4c 9a419e2c 80279168 9a1c6000 ffffffff
7f60: 80279600 9a0bf32c 9a1a02e0 9a1c6000 9a1a02e0 9a1a02e8 80278fe8 9a1c7f94
7f80: 9a0bf320 00000000 9a0bf31c 800786b0 9a1c6000 00000000 9a1bae60 8007c044
7fa0: 9a1c7fa0 9a1c7fa0 00000000 9a029e78 9a1c7fd4 80078530 9a1a02e0 00000000
7fc0: 00000000 00000000 00000000 8007bd00 00000000 00000000 9a1c7fd8 9a1c7fd8
7fe0: 00000000 9a029e78 8007bc88 800389e0 00000013 800389e0 ffffbfdf 00000002
[<802794dc>] (mxc_spi_buf_tx_u8+0x8/0x14) from [<802795bc>] (spi_put_tx_data+0x24/0x50)
[<802795bc>] (spi_put_tx_data+0x24/0x50) from [<8027a248>] (mxc_spi_transfer+0xdc/0x15c)
[<8027a248>] (mxc_spi_transfer+0xdc/0x15c) from [<80279168>] (bitbang_work+0x180/0x304)
[<80279168>] (bitbang_work+0x180/0x304) from [<800786b0>] (worker_thread+0x180/0x22c)
[<800786b0>] (worker_thread+0x180/0x22c) from [<8007bd00>] (kthread+0x78/0x80)
[<8007bd00>] (kthread+0x78/0x80) from [<800389e0>] (kernel_thread_exit+0x0/0x8)
Code: e5803050 e12fff1e e590304c e1a02000 (e4d30001)
---[ end trace 1b027d2e3a77bec4 ]---

So i am not getting any idea why this error is coming while trying to read some register value.

Any help will be thankful.

nit123 · ‎02-20-2012

Thanks Fabio the issue is got resolved with latest kernel.

But need to backport for old kernel also still.

Fabio Estevam said:

Ok, let us know how it goes.
Good luck!

fabio_estevam · ‎02-09-2012

Ok, let us know how it goes.

Good luck!

nit123 · ‎02-08-2012

Thanks Fabio it got booted.

Now i will try for SPI GPIO expander issue on this kernel.

fabio_estevam · ‎02-08-2012

After you clone the u-boot-imx git:

make mx51evk_config

make u-boot.imx

Then copy u-boot.imx to the SD card:

sudo dd if=u-boot.imx of=/dev/mmcblk0 bs=512 seek=2

This process is explained at: http://git.denx.de/?p=u-boot/u-boot-imx.git;a=blob;f=doc/README.imximage;h=073e3fcb3c6ecc9a7dfa8af46...

Then boot the board and setup the env variables.

I used TFTP to transfer the kernel and NFS to mount the rootfs.

Good luck!

Regards,

Fabio Estevam

nit123 · ‎02-08-2012

Ok Thanks i will try.

Fabio Estevam said:

You need to use the latest U-boot from the git I sent you.

fabio_estevam · ‎02-08-2012

You need to use the latest U-boot from the git I sent you.

nit123 · ‎02-08-2012

Hi Fabio,

thanks for reply.

that toolchain problem is solved by just giving the latest arm tool chain path.

Now i am not able to boot the kernel strucking kernel boot with followin log.

As i am in hurry to solve the SPI GPIO expander issue so please give me your suggestion how you booted it properly with steps if possible.

## Booting kernel from Legacy Image at 90800000 ...
   Image Name:   Linux-3.3.0-rc2
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2972216 Bytes = 2.8 MB
   Load Address: 90008000
   Entry Point: 90008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.

fabio_estevam · ‎02-08-2012

Please check my kernel log and you will see that I used gcc4.4.4 that comes with FSL BSP.

What are the errors you get when building the kernel?

Also, please use the latest U-boot from http://git.denx.de/?p=u-boot/u-boot-imx.git;a=summary

Regards,

Fabio Estevam

nit123 · ‎02-07-2012

Hi Fabio

I compiled and trying to boot it.

but getting following messaage alone.

## Booting kernel from Legacy Image at 90800000 ...
   Image Name:   Linux-3.3.0-rc2
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2972216 Bytes = 2.8 MB
   Load Address: 90008000
   Entry Point: 90008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.

nit123 · ‎02-07-2012

Hi Fabio,

One more doubt i have which tool chain version u have used for it.

As i am getting some of the errors with existing toolchain for compilation of latest kernel.

And is it mendetory to take latest uboot also.Can i use my old uboot only.

if you downloaded uboot also somewhere please send me the link for the same.

nit123 · ‎02-07-2012

Hi Fabio thanks for reply.

So are you able to get the prompt also?

fabio_estevam · ‎02-07-2012

I have just installed the latest u-boot from denx and latest kernel from kernel.org and my mx51evk boots fine.

make imx_v6_v7_defconfig (this is the defconfig for all i.MX of v6 and v7 types, which include mx51)

make uImage LOADADDR=0x90008000 (The 0x90008000 address for mx51 can be verified at arch/mach-imx/Makefile.boot)

This will generate a uImage at arch/arm/boot . Then I copied uImage to /tftpboot so that U-boot can load it via TFTP

This is my bootlog:

U-Boot 2011.12-06915-g290b53f (Feb 07 2012 - 15:18:57)

CPU:   Freescale i.MX51 family rev3.0 at 800 MHz
Reset cause: POR
Board: MX51EVK
DRAM: 512 MiB
WARNING: Caches not enabled
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
In:    serial
Out:   serial
Err:   serial
Net:   FEC
Warning: failed to set MAC address

Hit any key to stop autoboot: 0
** Partition 2 not valid on device 0 **

** Unable to use mmc 0:2 for fatload **
** Partition 2 not valid on device 0 **

** Unable to use mmc 0:2 for fatload **
Using FEC device
TFTP from server 192.168.1.100; our IP address is 192.168.1.101
Filename 'uImage'.
Load address: 0x90800000
Loading: #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         #################################################################
         ############################################################
done
Bytes transferred = 2965656 (2d4098 hex)
## Booting kernel from Legacy Image at 90800000 ...
   Image Name:   Linux-3.3.0-rc2+
   Created:      2012-02-07 17:26:06 UTC
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2965592 Bytes = 2.8 MiB
   Load Address: 90008000
   Entry Point: 90008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
Booting Linux on physical CPU 0
Linux version 3.3.0-rc2+ (fabio@fabio-Latitude-E6410) (gcc version 4.4.4 (4.4.42
CPU: ARMv7 Processor [412fc085] revision 5 (ARMv7), cr=10c53c7d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine: Freescale MX51 Babbage Board
Memory policy: ECC disabled, Data cache writeback
PERCPU: Embedded 7 pages/cpu @809a2000 s4928 r8192 d15552 u32768
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 130048
Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp nfsroot=192.1p
PID hash table entries: 2048 (order: 1, 8192 bytes)
Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
Memory: 512MB = 512MB total
Memory: 513992k/513992k available, 10296k reserved, 0K highmem
Virtual kernel memory layout:
    vector : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap : 0xfff00000 - 0xfffe0000   ( 896 kB)
    vmalloc : 0xa0800000 - 0xff000000   (1512 MB)
    lowmem : 0x80000000 - 0xa0000000   ( 512 MB)
    modules : 0x7f000000 - 0x80000000   ( 16 MB)
      .text : 0x80008000 - 0x804d3000   (4908 kB)
      .init : 0x804d3000 - 0x80509340   ( 217 kB)
      .data : 0x8050a000 - 0x80549fc0   ( 256 kB)
       .bss : 0x80549fe4 - 0x8059dc34   ( 336 kB)
SLUB: Genslabs=11, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Hierarchical RCU implementation.
NR_IRQS:436
TrustZone Interrupt Controller (TZIC) initialized
CPU identified as i.MX51, silicon rev 3.0
sched_clock: 32 bits at 66MHz, resolution 15ns, wraps every 64585ms
Console: colour dummy device 80x30
Calibrating delay loop... 795.44 BogoMIPS (lpj=3977216)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
CPU0: thread -1, cpu 0, socket -1, mpidr 0
Setting up static identity map for 0x903ca8e8 - 0x903ca958
Brought up 1 CPUs
SMP: Total of 1 processors activated (795.44 BogoMIPS).
devtmpfs: initialized
print_constraints: dummy:
NET: Registered protocol family 16
gpiochip_add: registered GPIOs 0 to 31 on device: imx31-gpio.0
gpiochip_add: registered GPIOs 32 to 63 on device: imx31-gpio.1
gpiochip_add: registered GPIOs 64 to 95 on device: imx31-gpio.2
gpiochip_add: registered GPIOs 96 to 127 on device: imx31-gpio.3
bio: create slab <bio-0> at 0
SCSI subsystem initialized
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
Switching to clocksource mxc_timer1
NET: Registered protocol family 2
IP route cache hash table entries: 4096 (order: 2, 16384 bytes)
TCP established hash table entries: 16384 (order: 5, 131072 bytes)
TCP bind hash table entries: 16384 (order: 5, 131072 bytes)
TCP: Hash tables configured (established 16384 bind 16384)
TCP reno registered
UDP hash table entries: 256 (order: 1, 8192 bytes)
UDP-Lite hash table entries: 256 (order: 1, 8192 bytes)
NET: Registered protocol family 1
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
VFS: Disk quotas dquot_6.5.2
Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
fuse init (API version 7.18)
msgmni has been set to 1003
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
imx-sdma imx35-sdma: initialized
Serial: IMX driver
imx21-uart.0: ttymxc0 at MMIO 0x73fbc000 (irq = 31) is a IMX
console [ttymxc0] enabled
imx21-uart.1: ttymxc1 at MMIO 0x73fc0000 (irq = 32) is a IMX
imx21-uart.2: ttymxc2 at MMIO 0x7000c000 (irq = 33) is a IMX
brd: module loaded
loop: module loaded
spi_imx imx51-ecspi.0: probed
FEC Ethernet Driver
fec_enet_mii_bus: probed
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
mxc-ehci mxc-ehci.1: initializing i.MX USB Controller
mxc-ehci mxc-ehci.1: Freescale On-Chip EHCI Host Controller
mxc-ehci mxc-ehci.1: new USB bus registered, assigned bus number 1
mxc-ehci mxc-ehci.1: irq 14, io mem 0x73f80200
mxc-ehci mxc-ehci.1: USB 2.0 started, EHCI 1.00
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
mousedev: PS/2 mouse device common for all mice
i2c /dev entries driver
imx2-wdt imx2-wdt.0: IMX2+ Watchdog Timer enabled. timeout=60s (nowayout=0)
sdhci: Secure Digital Host Controller Interface driver
sdhci: Copyright(c) Pierre Ossman
sdhci-pltfm: SDHCI platform and OF driver helper
mmc0: no vmmc regulator found
mmc0: SDHCI controller on sdhci-esdhc-imx51.0 [sdhci-esdhc-imx51.0] using DMA
mmc1: no vmmc regulator found
mmc1: SDHCI controller on sdhci-esdhc-imx51.1 [sdhci-esdhc-imx51.1] using DMA
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
TCP cubic registered
NET: Registered protocol family 10
IPv6 over IPv4 tunneling driver
NET: Registered protocol family 17
Registering the dns_resolver key type
VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 2
input: gpio-keys as /devices/platform/gpio-keys/input/input0
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
eth0: Freescale FEC PHY driver [Generic PHY] (mii_bus:phy_addr=imx27-fec-1:00, )
ADDRCONF(NETDEV_UP): eth0: link is not ready
mmc0: new high speed SDHC card at address 8551
mmcblk0: mmc0:8551 SD08G 7.40 GiB
mmcblk0: p1
usb 1-1: new high-speed USB device number 2 using mxc-ehci
hub 1-1:1.0: USB hub found
hub 1-1:1.0: 7 ports detected
PHY: imx27-fec-1:00 - Link is Up - 100/Full
ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
Sending DHCP requests ., OK
IP-Config: Got DHCP answer from 192.168.1.1, my address is 192.168.1.101
IP-Config: Complete:
     device=eth0, addr=192.168.1.101, mask=255.255.255.0, gw=192.168.1.1,
     host=192.168.1.101, domain=cps.virtua.com.br, nis-domain=(none),
     bootserver=192.168.1.1, rootserver=192.168.1.100, rootpath=
usb 1-1.6: new high-speed USB device number 3 using mxc-ehci
scsi0 : usb-storage 1-1.6:1.0
scsi 0:0:0:0: Direct-Access     USB TO I DE/SATA Device   0009 PQ: 0 ANSI: 0
sd 0:0:0:0: [sda] Test WP failed, assume Write Enabled
sd 0:0:0:0: [sda] Asking for cache data failed
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] Test WP failed, assume Write Enabled
sd 0:0:0:0: [sda] Asking for cache data failed
sd 0:0:0:0: [sda] Assuming drive cache: write through
sd 0:0:0:0: [sda] Attached SCSI disk
usb 1-1.1: new high-speed USB device number 4 using mxc-ehci
usb-storage 1-1.1:1.0: Quirks match for vid 0457 pid 0151: 80
scsi1 : usb-storage 1-1.1:1.0
scsi 1:0:0:0: Direct-Access     Ut163    USB2FlashStorage 0.00 PQ: 0 ANSI: 2
sd 1:0:0:0: [sdb] 248000 512-byte logical blocks: (126 MB/121 MiB)
sd 1:0:0:0: [sdb] Write Protect is off
sd 1:0:0:0: [sdb] Asking for cache data failed
sd 1:0:0:0: [sdb] Assuming drive cache: write through
sd 1:0:0:0: [sdb] Asking for cache data failed
sd 1:0:0:0: [sdb] Assuming drive cache: write through
sdb: sdb1
sd 1:0:0:0: [sdb] Asking for cache data failed
sd 1:0:0:0: [sdb] Assuming drive cache: write through
sd 1:0:0:0: [sdb] Attached SCSI removable disk

nit123 · ‎02-06-2012

Is any body know about this type of issue.I am still not finding any solution for it.

nit123 · ‎01-31-2012

Yes i tried to boot the kernel 3.2.1 version,but it did not boot.so it needs some more extra effot and for imx51.Pls tell if somebody have compiled and used the latest kernel for imx51 target and tell me the customization procedure as i am running out of time so i can not dig it more due to my current task for spi gpio expander.

Fabio Estevam said:

Can you try this with the latest kernel from kernel.org?
Regards,
Fabio Estevam

fabio_estevam · ‎01-31-2012

Can you try this with the latest kernel from kernel.org?

Regards,

Fabio Estevam

KursadOney · ‎01-31-2012

You need to enable CONFIG_DEBUG_INFO so you can use addr2line to find out exactly where the crash is. If you also enable CONFIG_KCORE_ELF, you can run gdb on your /proc/kcore file and inspect the memory. See this link for various kernel debugging techniques.

nit123 · ‎01-30-2012

I have patched also mcp23s08 driver for mcp23s17 chip.

I tried to test alone spi functionality with spi test program but i did not get any spi device for testing spi1.2.

so from user space application for testing the spidev functionality also i could not get any solution,as i could not get any device for testing using it.

my device is connected to spi1 chip select2.

So please advise me how i can proceed further.As i am running out of time so i need to solve it urgently and complete the driver.