Interrupt with GPIO signal using GPIO expander

Hi Jebaraj,
What GPIO IO expander are you using ?
Did you enable this IO expander in linux kernel ?

Hi Shankari,
We are using PCA9671 expander. I could able to toggle the GPIO pins.
Then I have tried to define the GPIO pins from this expander as gpio_buttons in board file. I have rebuilt the uImage. It is detecting the expander IC and the GPIO pins. But gpio-keys driver returns "unable to get irq number for GPIO error -r" error.

Thanks.

Hi,
Do you want to make one GPIO as input from IO expander ?
Or need to make one interrupt for whole IO expander GPIO pins (if anything toggling on those GPIOs)?

Hi,
My requirement is, I have to use all 16 GPIO from the expander as input and need to register interrupt for all 16 pins (so 16 interrupts).

Hello,
We are using DM8168.
We have used the following structure in board file to use the buttons.

static struct gpio_keys_button gpio_buttons[] = {
{
.code = KEY_0,
.gpio = 64,
.desc = "user1",
.wakeup = 1,
},
{
.code = KEY_1,
.gpio = 65,
.desc = "user2",
.wakeup = 1,
},
{
.code = KEY_2,
.gpio = 66,
.desc = "user3",
.wakeup = 1,
},

all 16 buttons are updated in this structure.

static struct gpio_keys_platform_data gpio_key_info = {
.buttons = gpio_buttons,
.nbuttons = ARRAY_SIZE(gpio_buttons),
};

static struct platform_device keys_gpio = {
.name = "gpio-keys",
.id = -1,
.dev = {
.platform_data = &gpio_key_info,
},
};

static struct platform_device *ti8168_devices[] __initdata = {
&keys_gpio,
};

In booting time it returns with "gpio-keys gpio-keys: Unable to get irq number for GPIO 64, error -6"

Any suggestion?

Thanks.

Hi,
Can you please provide bootup log ?
I think, you are doing this initialization and registering IRQ before PCA9671 driver comes up.
After PCA9671 driver initialization only you would get GPIO 64, 65 and 66 right.

Thank you for your efforts. I have attached the bootlog. Please go through it.

Starting kernel ...

Linux version 2.6.37 (jebaraj@IT0026-PC) (gcc version 4.3.3 (Sourcery G++ Lite 2009q1-203) ) #78 Tue Oct 13 14:54:05 IST 2015
CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7f
CPU: VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine: ti8168toii
vram size = 20971520 at 0x0
ti81xx_reserve: ### Reserved DDR region @8ff00000
reserved size = 20971520 at 0x0
FB: Reserving 20971520 bytes SDRAM for VRAM
Memory policy: ECC disabled, Data cache writeback
OMAP chip is TI8168 2.1
Built 1 zonelists in Zone order, mobility grouping on. Total pages: 59648
Kernel command line: mem=256M console=ttyO2,115200n8 root=/dev/nfs rw rootwait rootpath=/home/jebaraj/dm8168/DVRRDK_03.50.00.05/target/rfs_816=
PID hash table entries: 1024 (order: 0, 4096 bytes)
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 234MB 1MB = 235MB total
Memory: 233452k/233452k available, 28692k reserved, 0K highmem
Virtual kernel memory layout:
vector : 0xffff0000 - 0xffff1000 ( 4 kB)
fixmap : 0xfff00000 - 0xfffe0000 ( 896 kB)
DMA : 0xffc00000 - 0xffe00000 ( 2 MB)
vmalloc : 0xd0800000 - 0xf8000000 ( 632 MB)
lowmem : 0xc0000000 - 0xd0000000 ( 256 MB)
pkmap : 0xbfe00000 - 0xc0000000 ( 2 MB)
modules : 0xbf000000 - 0xbfe00000 ( 14 MB)
.init : 0xc0008000 - 0xc0040000 ( 224 kB)
.text : 0xc0040000 - 0xc0454000 (4176 kB)
.data : 0xc0454000 - 0xc048f240 ( 237 kB)
SLUB: Genslabs=11, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS:375
IRQ: Found an INTC at 0xfa200000 (revision 5.0) with 128 interrupts
Total of 128 interrupts on 1 active controller
GPMC revision 6.0
Trying to install interrupt handler for IRQ368
Trying to install interrupt handler for IRQ369
Trying to install interrupt handler for IRQ370
Trying to install interrupt handler for IRQ371
Trying to install interrupt handler for IRQ372
Trying to install interrupt handler for IRQ373
Trying to install interrupt handler for IRQ374
Trying to install type control for IRQ375
Trying to set irq flags for IRQ375
OMAP clockevent source: GPTIMER1 at 27000000 Hz
Console: colour dummy device 80x30
Calibrating delay loop... 1199.30 BogoMIPS (lpj=5996544)
pid_max: default: 32768 minimum: 301
Security Framework initialized
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
devtmpfs: initialized
TI81XX: Map 0x8ff00000 to 0xfe500000 for dram barrier
TI81XX: Map 0x40300000 to 0xfe600000 for sram barrier
omap_voltage_early_init: voltage driver support not added
regulator: core version 0.5
regulator: dummy:
NET: Registered protocol family 16
omap_voltage_domain_lookup: Voltage driver init not yet happened.Faulting!
omap_voltage_add_dev: VDD specified does not exist!
OMAP GPIO hardware version 0.1
OMAP GPIO hardware version 0.1
omap_mux_init: Add partition: #1: core, flags: 0
_omap_mux_get_by_name: Could not find signal i2c2_scl.i2c2_scl
_omap_mux_get_by_name: Could not find signal i2c2_sda.i2c2_sda
registered ti816x_sr device
Cannot clk_get ck_32
pm_dbg_init: only OMAP3 supported
registered ti81xx_vpss device
registered ti81xx_vidout device
registered ti81xx on-chip HDMI device
registered ti81xx_fb device
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
omap_i2c omap_i2c.1: bus 1 rev4.0 at 100 kHz
regulator: pmbus_vr: 800 <--> 1050 mV at 1000 mV
regulator: tps40400 probe done.
omap_i2c omap_i2c.2: bus 2 rev4.0 at 100 kHz

pcf857x 2-0027: gpios 64..79 on a pca9671
Switching to clocksource gp timer
NET: Registered protocol family 2
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
UDP hash table entries: 256 (order: 0, 4096 bytes)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes)
NET: Registered protocol family 1
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
NetWinder Floating Point Emulator V0.97 (double precision)
PMU: registered new PMU device of type 0
omap-iommu omap-iommu.0: ducati registered
omap-iommu omap-iommu.1: sys registered
JFFS2 version 2.2. (NAND) �© 2001-2006 Red Hat, Inc.
msgmni has been set to 455
io scheduler noop registered
io scheduler deadline registered
io scheduler cfq registered (default)
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
enter max14830 init
Enter max14830 probe
Enter max14830_1 init
Enter max14830_1 probe
Enter max14830_2 init
Enter max14830_2 probe
omap_uart.0: ttyO0 at MMIO 0x48020000 (irq = 72) is a OMAP UART0
omap_uart.1: ttyO1 at MMIO 0x48022000 (irq = 73) is a OMAP UART1
omap_uart.2: ttyO2 at MMIO 0x48024000 (irq = 74) is a OMAP UART2
console [ttyO2] enabled
brd: module loaded
loop: module loaded
ad_dpot 2-002f: ad5272 1024-Position Digital Potentiometer registered
at24 2-0050: 32768 byte 24c256 EEPROM (writable)
ahci probe: devid name is ahci
ahci CAP register dump =0x6726ff81
Modified ahci CAP register dump =0x6f26ff81
ahci ahci.0: forcing PORTS_IMPL to 0x3
ahci: SSS flag set, parallel bus scan disabled
ahci ahci.0: AHCI 0001.0100 32 slots 2 ports 3 Gbps 0x3 impl platform mode
ahci ahci.0: flags: ncq sntf stag pm led clo only pmp pio slum part ccc
scsi0 : ahci_platform
scsi1 : ahci_platform
ata1: SATA max UDMA/133 mmio [mem 0x4a140000-0x4a150fff] port 0x100 irq 16
ata2: SATA max UDMA/133 mmio [mem 0x4a140000-0x4a150fff] port 0x180 irq 16
omap2-nand driver initializing
ONFI flash detected
ONFI param page 0 valid
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xd3 (Micron NAND 1GiB 3,3V 8-bit)
Creating 8 MTD partitions on "omap2-nand.0":
0x000000000000-0x000000260000 : "U-Boot"
0x000000260000-0x000000280000 : "U-Boot Env"
0x000000280000-0x0000006c0000 : "Kernel"
0x0000006c0000-0x0000196c0000 : "File System"
0x0000196c0000-0x000019b00000 : "Secondary Kernel"
0x000019b00000-0x000032b00000 : "Secondary File System"
0x000032b00000-0x000032f40000 : "Configuration"
0x000032f40000-0x000040000000 : "Reserved"
davinci_mdio davinci_mdio.0: davinci mdio revision 1.6
davinci_mdio davinci_mdio.0: detected phy mask ffffff7f
davinci_mdio.0: probed
davinci_mdio davinci_mdio.0: phy[7]: device 0:07, driver unknown
mice: PS/2 mouse device common for all mice
gpio-keys gpio-keys: Unable to get irq number for GPIO 64, error -6
i2c /dev entries driver
tmp102 1-0049: initialized
htu21 2-0040: initialized
OMAP Watchdog Timer Rev 0x00: initial timeout 60 sec
usbcore: registered new interface driver usbhid
usbhid: USB HID core driver
notify_init : notify drivercreated for remote proc id 2 at physical Address 0xbee00000
Netfilter messages via NETLINK v0.30.
ip_tables: (C) 2000-2006 Netfilter Core Team
TCP cubic registered
NET: Registered protocol family 17
VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev 3
omap_voltage_late_init: Voltage driver support not added
Power Management for TI81XX.
smartreflex smartreflex: Driver initialized
drivers/rtc/hctosys.c: unable to open rtc device (rtc0)
ata1: SATA link down (SStatus 0 SControl 300)
ata2: SATA link down (SStatus 0 SControl 300)
net eth0: attached PHY driver [Generic PHY] (mii_bus:phy_addr=0:07, id=221612)
IP-Config: Complete:
device=eth0, addr=192.168.1.125, mask=255.255.255.0, gw=192.168.1.1,
host=192.168.1.125, domain=, nis-domain=(none),
bootserver=192.168.1.60, rootserver=192.168.1.60, rootpath=
Waiting 5sec before mounting root device...
PHY: 0:07 - Link is Up - 100/Full
VFS: Mounted root (nfs filesystem) on device 0:14.
devtmpfs: mounted
udevd (74): /proc/74/oom_adj is deprecated, please use /proc/74/oom_score_adj instead.
Root filesystem already rw, not remounting
Caching udev devnodes
Populating dev cachemv: cannot rename '/tmp/devices': No such file or directory
ALSA: Restoring mixer settings...
/usr/sbin/alsactl: load_state:1625: No soundcards found...
NOT configuring network interfaces: / is an NFS mount
hwclock: can't open '/dev/misc/rtc': No such file or directory
INIT: Entering runlevel: 5
Starting system message bus: dbus.
Starting telnet daemon.
Starting syslogd/klogd: done
Starting thttpd.

Thanks.

Hi Titus,

Thanks for your effort. I am sorry for my late response. I have tried with your suggestion. But there is no interrupt.

static const char const *dm8168_toii_exp[] = {
"user_0",
"user_1",
"user_2",
"user_3",
"user_4",
"user_5",
"user_6",
"user_7",
"user_8",
"user_9",
"user_10",
"user_11",
"user_12",
"user_13",
"user_14",
"user_15",
};

static struct gpio_keys_button dm8168_toii_keys[] = {
[0 ... IO_EXPANDER - 1] = {
.type = EV_KEY,
.active_low = 1,
.wakeup = 0,
.debounce_interval = KEYS_DEBOUNCE_MS,
.code = -1, /* assigned at runtime */
.gpio = -1, /* assigned at runtime */
.desc = NULL, /* assigned at runtime */
},
};


static struct gpio_keys_platform_data dm8168_toii_keys_pdata = {
.buttons = dm8168_toii_keys,
.nbuttons = ARRAY_SIZE(dm8168_toii_keys),
.poll_interval = GPIO_KEYS_POLL_MS,
};

static struct platform_device dm8168_toii_keys_device = {
.name = "gpio-Rotary-Switches",
.id = 0,
.dev = {
.platform_data = &dm8168_toii_keys_pdata
},
};

static void dm8168_toii_keys_init(unsigned gpio)
{
int i;
struct gpio_keys_button *button;
printk("Rotary switches initialized\n");
for (i = 0; i < IO_EXPANDER-1; i++) {
button = &dm8168_toii_keys[i];
button->code = KEY_F8 - i;
button->desc = (char *)dm8168_toii_exp[i];
button->gpio = gpio + i;
}
}

static struct platform_device *ti8168_devices[] __initdata = {
    &dm8168_toii_keys_device,
    &keys_gpio,
};

In the boot log there is no error message and there is no information. Am I missing anything. I am calling the dm8168_toii_keys_init function from board init function with GPIO base address as input argument.