PPS-GPIO

[Sebastian]

Hello Forum,

 

please excuse my bad English.

 

I try setting up a stratum1-server. Based on GPS.

For this I use the Banana Pi with kernel 4.6.2 and the Adafruit GPS.

The GPS is connected to GPIO J12 and works. RX/TX is not the problem. The problem is the right pin for the PPS-signal.

 dmesg|grep pps*
[    0.001207] Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00 BogoMIPS (lpj=240000)
[    0.067281] VFP support v0.3: implementor 41 architecture 2 part 30 variant 7 rev 4
[    3.260009] pps_core: LinuxPPS API ver. 1 registered
[    3.260018] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti <giometti@linux.it>
[    3.260048] PTP clock support registered
[    3.322715] simple-framebuffer 7fe79000.framebuffer: framebuffer at 0x7fe79000, 0x178e00 bytes, mapped to 0xf0900000
[    3.987818] 8021q: 802.1Q VLAN Support v1.8
[    4.023716] mmc0: host does not support reading read-only switch, assuming write-enable
[    4.122304]  No HW DMA feature register supported
[    4.122317]  TX Checksum insertion supported
[    4.298551] usb_phy_generic.0.auto supply vcc not found, using dummy regulator
[    6.863909] pps_gpio: unknown parameter 'gpio_pin' ignored
[    7.002898] systemd[1]: Starting Apply Kernel Variables...
[    7.989677] sun4i-codec 1c22c00.codec: Codec <-> 1c22c00.codec mapping ok

 lsmod | grep pps
pps_gpio                2655  0

My question: How do I specify that (maybe) PIN 18 is for PPS.

I tried /etc/modprobe.d/pps-gpio.conf with

options pps-gpio gpio_pin=18

But in dmesg appears 

[    6.863909] pps_gpio: unknown parameter 'gpio_pin' ignored

Probably it is not a major problem, but I'm stuck at this point.

 

 

Greetings from Berlin

[zador.blood.stained]

My question: How do I specify that (maybe) PIN 18 is for PPS.

I tried /etc/modprobe.d/pps-gpio.conf with

options pps-gpio gpio_pin=18

But in dmesg appears 

[    6.863909] pps_gpio: unknown parameter 'gpio_pin' ignored

Probably it is not a major problem, but I'm stuck at this point.

Module pps_gpio doesn't have any parameters

➜  ~  % modinfo pps_gpio
filename:       /lib/modules/4.6.3-sunxi/kernel/drivers/pps/clients/pps-gpio.ko
version:        1.0.0
license:        GPL
description:    Use GPIO pin as PPS source
author:         James Nuss <jamesnuss@nanometrics.ca>
author:         Ricardo Martins <rasm@fe.up.pt>
srcversion:     D2C22B0A465DA63746EFB59
alias:          of:N*T*Cpps-gpioC*
alias:          of:N*T*Cpps-gpio
depends:
intree:         Y
vermagic:       4.6.3-sunxi SMP mod_unload ARMv7 p2v8

For mainline kernel you have to add node to Device Tree like this: https://www.kernel.org/doc/Documentation/devicetree/bindings/pps/pps-gpio.txt

For GPIO pin you have to use something like

<&pio 7 1 GPIO_ACTIVE_HIGH>

for example, for pin PH1, and if I understand it correctly, you have to find pin that supports IRQs.