On 10/17/2017 10:20 AM, Andrea Scian - DAVE Embedded Systems wrote: > > Il 17/10/2017 10:18, Cédric Le Goater ha scritto: >> On 10/17/2017 09:36 AM, Andrea Scian - DAVE Embedded Systems wrote: >>> Dear all, >>> >>> I'm working on an iMX6 based board with a PCA9555 which is used both to >>> drive LEDs and manage some GPIOs. >> The PCA9555 chip and the PCA955[0-3] chips have different control >> registers. You need a different led driver for it. > > My typo sorry, as you can see in the device tree below, I'm using pca9551
ok. You might want to take a look at how we mixed gpios and leds on the witherspoon system using pca9552 chips. we added a gpio-leds binding. https://github.com/openbmc/linux/blob/dev-4.10/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts Cheers, C. > >>> 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, >>> >
