From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51E2DC433F5 for ; Mon, 16 May 2022 07:14:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240886AbiEPHOJ (ORCPT ); Mon, 16 May 2022 03:14:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240893AbiEPHOI (ORCPT ); Mon, 16 May 2022 03:14:08 -0400 Received: from mail-qt1-f169.google.com (mail-qt1-f169.google.com [209.85.160.169]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 660A1E00A; Mon, 16 May 2022 00:14:07 -0700 (PDT) Received: by mail-qt1-f169.google.com with SMTP id h3so11488619qtn.4; Mon, 16 May 2022 00:14:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=qT8j8L7uNx5sDff0l6NOcZAPsZPi+eXxzYca7p6X+Hk=; b=EkJITXybDoSzhCxAWvMUnHKHrmCllBRGiMnXubX4gF+mfPODLRGgk+a8uguUVziGAC J7ckgXinyy0TuENtf9AZlGk+yZfHOY0ddf2R1uGPBKl4XQ6VxCuRANVeckr21xJtpIJ2 kuYuXp8ioZy/7ERCR5lqPZeo7lSZllUhM3GbYGrceT3M5brsbXUmhc8KFWx/xCF0t19X tJH0f1stidYQ0tylxXx2nZT394+FdOi3oIHRO7VAiYTA2ZP3CYXOPfw7ZfJ+HFC1baoX Z771UINJ5OZY20OuvHuY43JHrbr1r9CjuLV26JgSjWlgYSiSJAsAwO5+kBbY9WdxEiB0 De+w== X-Gm-Message-State: AOAM532X4oJZzDSRV5Osy1etfoLoWrpwp8GOTUksLjv+HNmu8XbSiR2A J3neSHlskatorbzXD+tIsYm+k6S/dgTe6g== X-Google-Smtp-Source: ABdhPJz3XVVZ8HQqnKduafIN5GuXr/OmWV+IGU3pUsQEIm4hUiU/iBhDCxuaVVXYa4OrcfT3ppN7NQ== X-Received: by 2002:ac8:5c95:0:b0:2f3:da4c:6ac0 with SMTP id r21-20020ac85c95000000b002f3da4c6ac0mr13831512qta.531.1652685246070; Mon, 16 May 2022 00:14:06 -0700 (PDT) Received: from mail-yw1-f178.google.com (mail-yw1-f178.google.com. [209.85.128.178]) by smtp.gmail.com with ESMTPSA id k5-20020a378805000000b0069fc13ce1ddsm5400430qkd.14.2022.05.16.00.14.04 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 16 May 2022 00:14:05 -0700 (PDT) Received: by mail-yw1-f178.google.com with SMTP id 00721157ae682-2f83983782fso142702007b3.6; Mon, 16 May 2022 00:14:04 -0700 (PDT) X-Received: by 2002:a81:2143:0:b0:2fb:1274:247e with SMTP id h64-20020a812143000000b002fb1274247emr18073703ywh.384.1652685244634; Mon, 16 May 2022 00:14:04 -0700 (PDT) MIME-Version: 1.0 References: <20220511183210.5248-1-prabhakar.mahadev-lad.rj@bp.renesas.com> <20220511183210.5248-6-prabhakar.mahadev-lad.rj@bp.renesas.com> In-Reply-To: From: Geert Uytterhoeven Date: Mon, 16 May 2022 09:13:53 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v3 5/5] pinctrl: renesas: pinctrl-rzg2l: Add IRQ domain to handle GPIO interrupt To: "Lad, Prabhakar" Cc: Lad Prabhakar , Linus Walleij , Thomas Gleixner , Marc Zyngier , Rob Herring , Krzysztof Kozlowski , Bartosz Golaszewski , Philipp Zabel , "open list:GPIO SUBSYSTEM" , Linux Kernel Mailing List , Linux-Renesas , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Phil Edworthy , Biju Das Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi Prabhakar, On Fri, May 13, 2022 at 8:13 PM Lad, Prabhakar wrote: > On Fri, May 13, 2022 at 3:29 PM Geert Uytterhoeven wrote: > > On Fri, May 13, 2022 at 3:56 PM Lad, Prabhakar > > wrote: > > > On Fri, May 13, 2022 at 7:53 AM Geert Uytterhoeven wrote: > > > > On Thu, May 12, 2022 at 7:36 PM Lad, Prabhakar > > > > wrote: > > > > > On Thu, May 12, 2022 at 8:39 AM Geert Uytterhoeven wrote: > > > > > > On Wed, May 11, 2022 at 8:32 PM Lad Prabhakar > > > > > > wrote: > > > > > > > Add IRQ domian to RZ/G2L pinctrl driver to handle GPIO interrupt. > > > > > > > GPIO0-GPIO122 pins can be used as IRQ lines but only 32 pins can be > > > > > > > used as IRQ lines at given time. Selection of pins as IRQ lines > > > > > > > is handled by IA55 (which is the IRQC block) which sits in between the > > > > > > > GPIO and GIC. > > > > > > > > > > > > > > Signed-off-by: Lad Prabhakar > > > > > > > > > > > > Thanks for your patch! > > > > > > > > > > > > > --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c > > > > > > > +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c > > > > > > > > > > > > > static int rzg2l_gpio_register(struct rzg2l_pinctrl *pctrl) > > > > > > > { > > > > > > > struct device_node *np = pctrl->dev->of_node; > > > > > > > struct gpio_chip *chip = &pctrl->gpio_chip; > > > > > > > const char *name = dev_name(pctrl->dev); > > > > > > > + struct irq_domain *parent_domain; > > > > > > > struct of_phandle_args of_args; > > > > > > > + struct device_node *parent_np; > > > > > > > + struct gpio_irq_chip *girq; > > > > > > > int ret; > > > > > > > > > > > > > > + parent_np = of_irq_find_parent(np); > > > > > > > + if (!parent_np) > > > > > > > + return -ENXIO; > > > > > > > + > > > > > > > + parent_domain = irq_find_host(parent_np); > > > > > > > + of_node_put(parent_np); > > > > > > > + if (!parent_domain) > > > > > > > + return -EPROBE_DEFER; > > > > > > > + > > > > > > > ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &of_args); > > > > > > > if (ret) { > > > > > > > dev_err(pctrl->dev, "Unable to parse gpio-ranges\n"); > > > > > > > @@ -1138,6 +1330,15 @@ static int rzg2l_gpio_register(struct rzg2l_pinctrl *pctrl) > > > > > > > chip->base = -1; > > > > > > > chip->ngpio = of_args.args[2]; > > > > > > > > > > > > > > + girq = &chip->irq; > > > > > > > + girq->chip = &rzg2l_gpio_irqchip; > > > > > > > + girq->fwnode = of_node_to_fwnode(np); > > > > > > > + girq->parent_domain = parent_domain; > > > > > > > + girq->child_to_parent_hwirq = rzg2l_gpio_child_to_parent_hwirq; > > > > > > > + girq->populate_parent_alloc_arg = rzg2l_gpio_populate_parent_fwspec; > > > > > > > + girq->child_irq_domain_ops.free = rzg2l_gpio_irq_domain_free; > > > > > > > + girq->ngirq = RZG2L_TINT_MAX_INTERRUPT; > > > > > > > + > > > > > > > > > > > > I think you need to provide a .init_valid_mask() callback, as > > > > > > gpiochip_irqchip_remove() relies on that for destroying interrupts. > > > > > Are you suggesting the callback to avoid looping through all the GPIO pins? > > > > > > > > gpiochip_irqchip_remove() does: > > > > > > > > /* Remove all IRQ mappings and delete the domain */ > > > > if (gc->irq.domain) { > > > > unsigned int irq; > > > > > > > > for (offset = 0; offset < gc->ngpio; offset++) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > if (!gpiochip_irqchip_irq_valid(gc, offset)) > > > > continue; > > > > > > > > irq = irq_find_mapping(gc->irq.domain, offset); > > > > irq_dispose_mapping(irq); > > > > } > > > > > > > > irq_domain_remove(gc->irq.domain); > > > > > > > > } > > > > > > > > The main thing is not about avoiding to loop through all GPIO pins, > > > > but to avoid irq_{find,dispose}_mapping() doing the wrong thing. > > > So in our case if we don't implement valid masks, that would mean all > > > the pins are valid. irq_find_mapping() would return 0 if no mapping is > > > found to the corresponding offset and irq_dispose_mapping() would > > > simply return back without doing anything if virq == 0.(In this patch > > > rzg2l_gpio_free() does call irq_{find,dispose}_mapping()) > > > > But "offset" is a number from the GPIO offset space (0-122), while > > The "offset" reported by kernel is 120-511: Offsets 120-511 are global GPIO numbers, i.e. starting from gpio_chip.base. The loop in gpiochip_irqchip_remove() uses local GPIO numbers, starting from zero. So these offsets are not the same. Likewise, I believe the "offset" passed to irq_find_mapping() is an irq number (hwirq) local to the domain, i.e. also starting at 0. And it must be smaller than the size (32) passed to irq_domain_create_hierarchy(). When passed a non-zero size, irq_domain_create_hierarchy() calls into __irq_domain_add(), with size == hwirq_max == 32: /** * __irq_domain_add() - Allocate a new irq_domain data structure * @fwnode: firmware node for the interrupt controller * @size: Size of linear map; 0 for radix mapping only * @hwirq_max: Maximum number of interrupts supported by controller * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no * direct mapping * @ops: domain callbacks * @host_data: Controller private data pointer * * Allocates and initializes an irq_domain structure. * Returns pointer to IRQ domain, or NULL on failure. */ struct irq_domain *__irq_domain_add(struct fwnode_handle *fwnode, unsigned int size, irq_hw_number_t hwirq_max, int direct_max, const struct irq_domain_ops *ops, void *host_data) > > > > But we do need to handle the (possible) mismatch between GPIO > > > > offset (index) and IRQ offset in the above code. > > > > > > > Agreed, do you see any possibility of the mismatch I have missed? > > > > gpiochip_to_irq(): > > > > if (irq_domain_is_hierarchy(domain)) { > > struct irq_fwspec spec; > > > > spec.fwnode = domain->fwnode; > > spec.param_count = 2; > > spec.param[0] = gc->irq.child_offset_to_irq(gc, offset); > > spec.param[1] = IRQ_TYPE_NONE; > > > > return irq_create_fwspec_mapping(&spec); > > } > > > > Same here: in the absence of a child_offset_to_irq() callback, > > the default gpiochip_child_offset_to_irq_noop() will be used, > > assuming an identity mapping between GPIO numbers and IRQ > > numbers. > > > Agreed, gpiochip_child_offset_to_irq_noop will return the "offset", > but irq_create_fwspec_mapping() in gpiochip_to_irq() will return the > virq number which will not be equal to the offset. Shouldn't spec.param[0] be in the range 0-31, as 32 is the size of the IRQ domain allocated? Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds