From 7569486d79ae8ec4ba9d20a629fa745a1afe04fd Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Thu, 30 Jul 2020 18:27:59 +0300 Subject: [PATCH] gpio: dwapb: Add ngpios DT-property support Indeed generic GPIO DT-schema implies that number of GPIOs should be described by the "ngpios" property located under a GPIO-provider DT node. In that case it's redundant to have a vendor-specific "snps,nr-gpios" property describing the same setting. Moreover it might be errors prone. Since commit 93d2e4322aa7 ("of: platform: Batch fwnode parsing when adding all top level devices") the fwnode parsing is resumed after the vast majority of the platform devices are added. Implicitly that commit activates re-parsing of the whole device tree GPIOs-phandle properties detected having "-gpio/-gpios" suffixes. Since the vendor-specific number of GPIOs property is defined with "-gpios" suffix, then of_link_property() will consider it as a suffix-property with "#gpio-cells" structure, which obviously it doesn't have. As a result for two DW APB GPIO controllers we'll have the next errors printed. OF: /bus@1f059000/gpio@1f044000/gpio-port@0: could not find phandle OF: /bus@1f059000/gpio@1f045000/gpio-port@0: could not get #gpio-cells for /opp-table OF: /bus@1f059000/gpio@1f044000/gpio-port@0: could not find phandle OF: /bus@1f059000/gpio@1f045000/gpio-port@0: could not get #gpio-cells for /opp-table See, the kernel fwnode parsing procedure even tried to resolve the phandle ID, which it thought was the opp-table DT-node, while in fact it was just a number "32". What would happen if that magic number actually referred to a GPIO DT-node with "#gpio-cells" property defined?.. In order to fix the problem let's mark the "snps,nr-gpios" property as deprecated and add the generic "ngpios" property support with the same purpose as the deprecated one. That and the errors log above shall motivate the platform developer to convert the DW APB GPIO DT-nodes to using the standard number of GPIOs property. Signed-off-by: Serge Semin Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20200730152808.2955-3-Sergey.Semin@baikalelectronics.ru Signed-off-by: Linus Walleij --- drivers/gpio/gpio-dwapb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-dwapb.c b/drivers/gpio/gpio-dwapb.c index 1d8d55bd63aa..ccd80df16062 100644 --- a/drivers/gpio/gpio-dwapb.c +++ b/drivers/gpio/gpio-dwapb.c @@ -594,7 +594,8 @@ static struct dwapb_platform_data *dwapb_gpio_get_pdata(struct device *dev) return ERR_PTR(-EINVAL); } - if (fwnode_property_read_u32(fwnode, "snps,nr-gpios", &pp->ngpio)) { + if (fwnode_property_read_u32(fwnode, "ngpios", &pp->ngpio) && + fwnode_property_read_u32(fwnode, "snps,nr-gpios", &pp->ngpio)) { dev_info(dev, "failed to get number of gpios for port%d\n", i);