interrupt in button_pio

[Altera_Forum]

HI, 

 Does anyone know how to get button_pio to run a function based on interrupt.  E.g. Press a button, it generates an interrupt so that cpu can read the status and do something.  I am currently using polling which is a waste of cpu resources.  Any pointers or code that would help. Thanks.

[Altera_Forum]

\com.microtronix.nios2linux.kernel_1.4.0\linux-2.6.x\drivers\char\altera_pio_button.c 

 you can find a lot about pio buttons in the forum.

[Altera_Forum]

Hi, 

 I have looked at the example as suggested, but just couldn't understand it.  It looks like it's a driver.  I am just trying to write an application is based on pio interrupt. Anyone has some simple example application that allow me to that ?  Thanks.

[Altera_Forum]

You cannot use interrupts under uClinux in a userapplication. Interrupts can only handled in kernel drivers.

[Altera_Forum]

--- Quote Start ---  originally posted by albertyong88@Nov 15 2006, 05:14 PM hi,  i have looked at the example as suggested, but just couldn&#39;t understand it.  it looks like it&#39;s a driver.  i am just trying to write an application is based on pio interrupt. anyone has some simple example application that allow me to that ?  thanks. <div align='right'><{post_snapback}> (index.php?act=findpost&pid=19440)  --- quote end ---    --- Quote End ---   You need to read the book "linux device driver 3rd ed" . seperate device driver from your application improve your program.

[Altera_Forum]

Hi, 

 What I have done now is included the altera_pio_button.c into the source tree locally, and change Makefile and Kconfig accordingly, and then compile by doing  make; make linux image;  All seems to be fine, but when I look at /proc/interrupts, there is no list of pio_buttons nor is there /dev/btn  Any ideas what went wrong ?

[Altera_Forum]

--- Quote Start ---  originally posted by albertyong88@Nov 15 2006, 11:44 PM hi,  what i have done now is included the altera_pio_button.c into the source tree locally, and change makefile and kconfig accordingly, and then compile by doing  make; make linux image;  all seems to be fine, but when i look at /proc/interrupts, there is no list of pio_buttons nor is there /dev/btn  any ideas what went wrong ? <div align='right'><{post_snapback}> (index.php?act=findpost&pid=19452)  --- quote end ---    --- Quote End ---   you need to open and read the char dev /dev/btn. eg, cat /dev/btn  The nios2 patches (ver17) to uClinux-dist are updated to include button and lcd drivers now.

[Altera_Forum]

Sorry, did this twice.

[Altera_Forum]

Hi Hippo, 

 I got the new kernel patches, and included in my new built.  However, it booted up, there was nothing indicating the driver is loaded.  I am attaching the boot screen  <div class='quotetop'>QUOTE </div>  --- Quote Start ---  Uncompressing Linux... Ok, booting the kernel. Linux version 2.6.17-uc1 (uclinux@colinux) (gcc version 3.4.6)# 29 PREEMPT Tue N ov 21 10:20:08 EST 2006   uClinux/Nios II Altera Nios II support © 2004 Microtronix Datacom Ltd. Built 1 zonelists Kernel command line: PID hash table entries: 256 (order: 8, 1024 bytes) Dentry cache hash table entries: 4096 (order: 2, 16384 bytes) Inode-cache hash table entries: 2048 (order: 1, 8192 bytes) Memory available: 30312k/32768k RAM, 0k/0k ROM (1475k kernel code, 663k data) Mount-cache hash table entries: 512 NET: Registered protocol family 16 NET: Registered protocol family 2 IP route cache hash table entries: 1024 (order: 0, 4096 bytes) TCP established hash table entries: 1024 (order: 0, 4096 bytes) TCP bind hash table entries: 1024 (order: 0, 4096 bytes) TCP: Hash tables configured (established 1024 bind 1024) TCP reno registered io scheduler noop registered io scheduler deadline registered (default) You have init Device 250 Serial: JTAG UART driver $Revision: 1.1 $ ttyJ0 at MMIO 0x822208b0 (irq = 1) is a jtag_uart smc91x.c: v1.1, sep 22 2004 by Nicolas Pitre <nico@cam.org> eth0: SMC91C11xFD (rev 1) at 82210300 IRQ 6 [nowait] eth0: Ethernet addr: 00:07:ed:0f:06:92 i2c /dev entries driver i2c-oc: i2c Opencores adapter driver Opencores i2c algorithm module TCP bic registered NET: Registered protocol family 1 NET: Registered protocol family 17 Freeing unused kernel memory: 532k freed (0x4182000 - 0x4206000) Shell invoked to run file: /etc/rc Command: hostname uClinux Command: mount -t proc proc /proc Command: mount -t sysfs sysfs /sys Command: mount -t usbfs none /proc/bus/usb mount: Mounting none on /proc/bus/usb failed: No such file or directory Command: mkdir /var/tmp Command: mkdir /var/log Command: mkdir /var/run Command: mkdir /var/lock Command: mkdir /var/empty Command: ifconfig lo 127.0.0.1 Command: route add -net 127.0.0.0 netmask 255.0.0.0 lo Command: ifconfig eth0 192.168.50.63eth0: link down  Command: cat /etc/motd Welcome to           ____ _  _         /  __| ||_|     _  _| |  | | _ ____  _  _  _  _   | | | | |  | || |  _ \| | | |\ \/ /   | |_| | |__| || | | | | |_| |/       |  ___\____|_||_|_| |_|\____|\_/\_/   | |   |_|  For further information check: http://www.uclinux.org/ (http://www.uclinux.org/)  Command: inetd & [18] Command: mkdir /nios2bin Command: mount -t nfs -n -o nolock,rsize=1024,wsize=1024 192.168.50.62:/home/ucl inux/nios2bin /nios2bin eth0: link up, 100Mbps, full-duplex, lpa 0x45E1 Command: boa & [21] Command: Execution Finished, Exiting  Sash command shell (version 1.1.1) />[/b]  --- Quote End ---    Also, I added nod /dev/btn 666 0 0 c 62 0 in romfs_list  After booting, check /dev dir, btn seems to be there.  When I did cat /proc/devices, I get  <div class='quotetop'>QUOTE </div>  --- Quote Start ---  /> cat /proc/devices Character devices:   1 mem   2 pty   3 ttyp   5 /dev/tty   5 /dev/console  10 misc  89 i2c 232 ttyJ 240 iodata 241 iodir 250 LCD_PIO[/b]  --- Quote End ---    And when I did cat /proc/interrupts, I get <div class='quotetop'>QUOTE </div>  --- Quote Start ---    :          0  spurious   0:      15431 L timer   1:        24  jtag_uart   2:        30  pio_button   6:        602 L eth0   7:          1  Opencores I2C[/b]  --- Quote End ---    I also read the aritcle in icwin by Wyouken.  http://www.icwin.net/source/pdf/nios2_linu...nux_nios2_3.pdf (http://www.icwin.net/source/pdf/nios2_linux/run_uclinux_nios2_3.pdf)  So, it seems that the driver is NOT loaded. Can you help ?