Hi, As some of you on IRC might have noticed the past couple of days, im trying to get interrupts working on the GPIO pins of the cubietruck. In my quest for a irq, i found something what I think is a bug in the pinctrl driver.
http://lxr.free-electrons.com/source/drivers/pinctrl/sunxi/pinctrl-sun7i-a20.c#L984 According the code pin PI[10-19] have IRQ connected to mux 0x5. While if I taker a look onto the datasheet of the a20, I see them on mux 6 ( http://dl.linux-sunxi.org/A20/A20%20Datasheet%20V1.41%2020131230.pdf page 23). First I thought this was because the muxes start counting from 0x0, so 0x5 is the 6th number. But this wont explain why all the other functions are on the correct mux number (like uart and spi) and looking at pins PH[0-21] you can see they are on 0x6 (in code). I have a patch ready, but want to get verified that this is a bug (as I refuse to believe that I found a gpio bug in almost 3 years old code and it implies nobody used gpio irq's on mainline with the a20). ~~~ Now, while the pin assignment is sorted, I still have no IRQ's in my kernel. To start with, this is the output of a logic analyzer onto the pin: http://puu.sh/ndaBJ/804665ce1d.png. <http://puu.sh/ndaBJ/804665ce1d.png> Signal is 1sec spaced and 25ms wide (@3v). If I export PI14 by running: echo 270 > /sys/class/gpio/export I get no value change in: /sys/class/gpio/gpio270/value (while the default direction is in). Only after I do: 'echo "in" > /sys/class/gpio/gpio270/direction' I get changing values. So it looks the port defaults to out direction although kernel says its in, but I do have confirmed that the gpio pin state is working and does change (so I do have signal). Now, for the irq part.... I changed my dts to include a pps device (pulse per second) - see diff on the bottom of this email. If the kernel boots, I get a message from the pps-gpio driver that it has found the device and is attached to a kernel irq: root@cubietruck:~# dmesg | grep pps [ 0.377532] pps_core: LinuxPPS API ver. 1 registered [ 0.377564] pps_core: Software ver. 5.3.6 - Copyright 2005-2007 ... [ 4.773132] pps_core: source pps.-1 got cdev (252:0) [ 4.773161] pps pps0: new PPS source pps.-1 [ 4.773289] pps pps0: Registered IRQ 79 as PPS source /sys/kernel/debug/pinctrl/pinctrl-handles device: pps current state: default state: default type: MUX_GROUP controller 1c20800.pinctrl group: PI14 (167) function: irq (27) type: CONFIGS_GROUP controller 1c20800.pinctrl group PI14 (167)config 000a0009 config 00007fff /sys/kernel/debug/pinctrl/1c20800.pinctrl/pinmux-pins pin 270 (PI14): pps 1c20800.pinctrl:270 function irq group PI14 So to my humble opinion, it looks like it is connected and should work as expected. Though if I do an output of /proc/interrupts: CPU0 CPU1 79: 0 0 sunxi_pio_edge 26 Edge pps.-1 and it looks like it is never interrupted (from the device driver point of view). Does somebody have a idea where my IRQ's went to and how to find them back? Thanks in advance, - Henry diff --git a/arch/arm/boot/dts/sun7i-a20-cubietruck.dts b/arch/arm/boot/dts/sun7i-a20-cubietruck.dts index 8da939a..58ead68 100644 --- a/arch/arm/boot/dts/sun7i-a20-cubietruck.dts +++ b/arch/arm/boot/dts/sun7i-a20-cubietruck.dts @@ -94,6 +94,14 @@ pinctrl-0 = <&mmc3_pwrseq_pin_cubietruck>; reset-gpios = <&pio 7 9 GPIO_ACTIVE_LOW>; /* PH9 WIFI_EN */ }; + + pps { + pinctrl-names = "default"; + pinctrl-0 = <&pps_pins_cubietruck>; + gpios = <&pio 8 14 GPIO_OPEN_DRAIN>; /* PI14 EINT26 */ + compatible = "pps-gpio"; + status = "okay"; + }; }; &ahci { @@ -219,6 +227,13 @@ allwinner,pull = <SUN4I_PINCTRL_NO_PULL>; }; + pps_pins_cubietruck: pps_pins@0 { + allwinner,pins = "PI14"; + allwinner,function = "irq"; + allwinner,drive = <SUN4I_PINCTRL_10_MA>; + allwinner,pull = <SUN4I_PINCTRL_NO_PULL>; + }; + mmc3_pwrseq_pin_cubietruck: mmc3_pwrseq_pin@0 { allwinner,pins = "PH9"; allwinner,function = "gpio_out"; -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
