On 11/06/2019 09:45, Geert Uytterhoeven wrote: > CC irqchip > > Original thread at > https://lore.kernel.org/lkml/20190607172958.20745-1-erosca@xxxxxxxxxxxxxx/ > > On Mon, Jun 10, 2019 at 10:30 AM Tony Lindgren <tony@xxxxxxxxxxx> wrote: >> * Kalle Valo <kvalo@xxxxxxxxxxxxxx> [190610 07:01]: >>> Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> writes: >>> >>>> The wl1837mod datasheet [1] says about the WL_IRQ pin: >>>> >>>> ---8<--- >>>> SDIO available, interrupt out. Active high. [..] >>>> Set to rising edge (active high) on powerup. >>>> ---8<--- >>>> >>>> That's the reason of seeing the interrupt configured as: >>>> - IRQ_TYPE_EDGE_RISING on HiKey 960/970 >>>> - IRQ_TYPE_LEVEL_HIGH on a number of i.MX6 platforms >>>> >>>> We assert that all those platforms have the WL_IRQ pin connected >>>> to the SoC _directly_ (confirmed on HiKey 970 [2]). >>>> >>>> That's not the case for R-Car Kingfisher extension target, which carries >>>> a WL1837MODGIMOCT IC. There is an SN74LV1T04DBVR inverter present >>>> between the WLAN_IRQ pin of the WL18* chip and the SoC, effectively >>>> reversing the requirement quoted from [1]. IOW, in Kingfisher DTS >>>> configuration we would need to use IRQ_TYPE_EDGE_FALLING or >>>> IRQ_TYPE_LEVEL_LOW. >>>> >>>> Unfortunately, v4.2-rc1 commit bd763482c82ea2 ("wl18xx: wlan_irq: >>>> support platform dependent interrupt types") made a special case out >>>> of these interrupt types. After this commit, it is impossible to provide >>>> an IRQ configuration via DTS which would describe an inverter present >>>> between the WL18* chip and the SoC, generating the need for workarounds >>>> like [3]. >>>> >>>> Create a boolean OF property, called "invert-irq" to specify that >>>> the WLAN_IRQ pin of WL18* is connected to the SoC via an inverter. >>>> >>>> This solution has been successfully tested on R-Car H3ULCB-KF-M06 using >>>> the DTS configuration [4] combined with the "invert-irq" property. >>>> >>>> [1] http://www.ti.com/lit/ds/symlink/wl1837mod.pdf >>>> [2] https://www.96boards.org/documentation/consumer/hikey/hikey970/hardware-docs/ >>>> [3] https://github.com/CogentEmbedded/meta-rcar/blob/289fbd4f8354/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0024-wl18xx-do-not-invert-IRQ-on-WLxxxx-side.patch >>>> [4] https://patchwork.kernel.org/patch/10895879/ >>>> ("arm64: dts: ulcb-kf: Add support for TI WL1837") >>>> >>>> Signed-off-by: Eugeniu Rosca <erosca@xxxxxxxxxxxxxx> >>> >>> Tony&Eyal, do you agree with this? >> >> Yeah if there's some hardware between the WLAN device and the SoC >> inverting the interrupt, I don't think we have clear a way to deal >> with it short of setting up a separate irqchip that does the >> translation. > > Yeah, inverting the interrupt type in DT works only for simple devices, > that don't need configuration. > A simple irqchip driver that just inverts the type sounds like a good > solution to me. Does something like that already exists? We already have plenty of that in the tree, the canonical example probably being drivers/irqchip/irq-mtk-sysirq.c. It should be pretty easy to turn this driver into something more generic. Thanks, M. -- Jazz is not dead. It just smells funny...
