Dear all,
I'm working on an iMX6 based board with a PCA9555 which is used both to
drive LEDs and manage some GPIOs.
My current kernel is quite old (4.1.15) but I've found Cédric patches on
mainline and backported to this old revision.
I'm facing an issue with it, because it seems that it fails when it's
used in a mixed (led/gpios) environment.
E.g.: let's say that I have one led connected to LED0 output and one
GPIO connected at LED1 output.
I define it as
pca9551: pca9551@60 {
compatible = "nxp,pca9551";
reg = <0x60>;
#address-cells = <1>;
#size-cells = <0>;
#gpio-cells = <1>;
led@0 {
label = "led0";
reg = <0>;
linux,default-trigger = "none";
};
gpio@1 {
label = "gpio1";
reg = <1>;
type = <2>; /* GPIO */
};
};
At boot it's probed as
root@sbc-lynx:~# dmesg | grep pca
[ 5.315425] leds-pca955x 5-0060: leds-pca955x: Using pca9551 8-bit
LED driver at slave address 0x60
[ 5.350349] leds-pca955x 5-0060: gpios 511...511
But I cannot access it:
root@sbc-lynx:~# echo 511 > /sys/class/gpio/export
-sh: echo: write error: Device or resource busy
Because for pca955x_gpio_request_pin() this is at offset 0 (in fact is
the first gpio registered of this gpio_chip) but it's the index 1 inside
pca955x->leds[]
Am I missing something? (maybe I made a mistake in my backport and/or
I'm missing some patches about the GPIO subsystems).
If I'm right I think I can send a patch to fix this (I'm thinking about
having an array of GPIO index to map offset -> pca955x->leds[] index or
just register all pins as GPIOs and then just report the busy state)
WDYT?
Kind Regards,
--
Andrea SCIAN
*DAVE Embedded Systems*
via Talponedo 29/A 33080 Porcia (PN) - Italy
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