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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82D1FC54FCB for ; Thu, 23 Apr 2020 12:02:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6674720781 for ; Thu, 23 Apr 2020 12:02:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728131AbgDWMCr (ORCPT ); Thu, 23 Apr 2020 08:02:47 -0400 Received: from foss.arm.com ([217.140.110.172]:38532 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728083AbgDWMCq (ORCPT ); Thu, 23 Apr 2020 08:02:46 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A995431B; Thu, 23 Apr 2020 05:02:45 -0700 (PDT) Received: from [10.57.33.170] (unknown [10.57.33.170]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0ACE73F6CF; Thu, 23 Apr 2020 05:02:42 -0700 (PDT) Subject: Re: [PATCH] usb: fusb302: Convert to use GPIO descriptors To: Linus Walleij , Greg Kroah-Hartman Cc: linux-usb@vger.kernel.org, Tobias Schramm , Heikki Krogerus , Yueyao Zhu , Guenter Roeck , devicetree@vger.kernel.org, Heiko Stuebner , linux-rockchip@lists.infradead.org References: <20200415192448.305257-1-linus.walleij@linaro.org> From: Robin Murphy Message-ID: <22317f07-ad49-ada2-b323-ad16695ae3d2@arm.com> Date: Thu, 23 Apr 2020 13:02:42 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200415192448.305257-1-linus.walleij@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 2020-04-15 8:24 pm, Linus Walleij wrote: > This converts the FUSB302 driver to use GPIO descriptors. > The conversion to descriptors per se is pretty straight-forward. > > In the process I discovered that: > > 1. The driver uses a completely undocumented device tree binding > for the interrupt GPIO line, "fcs,int_n". Ooops. > > 2. The undocumented binding, presumably since it has not seen > review, is just "fcs,int_n", lacking the compulsory "-gpios" > suffix and also something that is not a good name because > the "_n" implies the line is inverted which is something we > handle with flags in the device tree. Ooops. > > 3. Possibly the driver should not be requesting the line as a > GPIO and request the corresponding interrupt line by open > coding, the GPIO chip is very likely doubleing as an IRQ > controller and can probably provide an interrupt directly > for this line with interrupts-extended = <&gpio0 ...>; > > 4. Possibly the IRQ should just be tagged on the I2C client node > in the device tree like apparently ACPI does, as it overrides > this IRQ with client->irq if that exists. > > But now it is too late to do much about that and as I can see > this is used like this in the Pinebook which is a shipping product > so let'a just contain the mess and move on. > > The property currently appears in: > arch/arm64/boot/dts/rockchip/rk3399-pinebook-pro.dts > > Create a quirk in the GPIO OF library to allow this property > specifically to be specified without the "-gpios" suffix, we have > other such bindings already. FWIW, the datasheet makes it clear than INT_N is just a regular IRQ output, so it really should be specified as an interrupt targeting the GPIO controller just like any other I2C chip, and the FUSB302 binding itself supports. The Pinebook Pro devicetree has only just landed this cycle, so there should still be plenty of time to fix it and not have to worry about an ugly undocumented quirk. The downstream vendor kernels use a totally different FUSB302 driver from the upstream one (based on extcon rather than the typec framework) so I don't think downstream DTBs are a concern. Robin. > Cc: Tobias Schramm > Cc: Heikki Krogerus > Cc: Yueyao Zhu > Cc: Guenter Roeck > Cc: devicetree@vger.kernel.org > Signed-off-by: Linus Walleij > --- > This is now covered as far as GPIO is concerned but you might > want to look into creating proper bindings for this or > correcting the devicetree. > --- > drivers/gpio/gpiolib-of.c | 21 +++++++++++++++++++++ > drivers/usb/typec/tcpm/fusb302.c | 32 +++++++++----------------------- > 2 files changed, 30 insertions(+), 23 deletions(-) > > diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c > index ccc449df3792..20c2c428168e 100644 > --- a/drivers/gpio/gpiolib-of.c > +++ b/drivers/gpio/gpiolib-of.c > @@ -460,6 +460,24 @@ static struct gpio_desc *of_find_arizona_gpio(struct device *dev, > return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags); > } > > +static struct gpio_desc *of_find_usb_gpio(struct device *dev, > + const char *con_id, > + enum of_gpio_flags *of_flags) > +{ > + /* > + * Currently this USB quirk is only for the Fairchild FUSB302 host which is using > + * an undocumented DT GPIO line named "fcs,int_n" without the compulsory "-gpios" > + * suffix. > + */ > + if (!IS_ENABLED(CONFIG_TYPEC_FUSB302)) > + return ERR_PTR(-ENOENT); > + > + if (!con_id || strcmp(con_id, "fcs,int_n")) > + return ERR_PTR(-ENOENT); > + > + return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags); > +} > + > struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, > unsigned int idx, unsigned long *flags) > { > @@ -504,6 +522,9 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, > if (PTR_ERR(desc) == -ENOENT) > desc = of_find_arizona_gpio(dev, con_id, &of_flags); > > + if (PTR_ERR(desc) == -ENOENT) > + desc = of_find_usb_gpio(dev, con_id, &of_flags); > + > if (IS_ERR(desc)) > return desc; > > diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c > index b498960ff72b..b28facece43c 100644 > --- a/drivers/usb/typec/tcpm/fusb302.c > +++ b/drivers/usb/typec/tcpm/fusb302.c > @@ -9,14 +9,13 @@ > #include > #include > #include > -#include > +#include > #include > #include > #include > #include > #include > #include > -#include > #include > #include > #include > @@ -83,7 +82,7 @@ struct fusb302_chip { > struct work_struct irq_work; > bool irq_suspended; > bool irq_while_suspended; > - int gpio_int_n; > + struct gpio_desc *gpio_int_n; > int gpio_int_n_irq; > struct extcon_dev *extcon; > > @@ -1618,30 +1617,17 @@ static void fusb302_irq_work(struct work_struct *work) > > static int init_gpio(struct fusb302_chip *chip) > { > - struct device_node *node; > + struct device *dev = chip->dev; > int ret = 0; > > - node = chip->dev->of_node; > - chip->gpio_int_n = of_get_named_gpio(node, "fcs,int_n", 0); > - if (!gpio_is_valid(chip->gpio_int_n)) { > - ret = chip->gpio_int_n; > - dev_err(chip->dev, "cannot get named GPIO Int_N, ret=%d", ret); > - return ret; > - } > - ret = devm_gpio_request(chip->dev, chip->gpio_int_n, "fcs,int_n"); > - if (ret < 0) { > - dev_err(chip->dev, "cannot request GPIO Int_N, ret=%d", ret); > - return ret; > - } > - ret = gpio_direction_input(chip->gpio_int_n); > - if (ret < 0) { > - dev_err(chip->dev, > - "cannot set GPIO Int_N to input, ret=%d", ret); > - return ret; > + chip->gpio_int_n = devm_gpiod_get(dev, "fcs,int_n", GPIOD_IN); > + if (IS_ERR(chip->gpio_int_n)) { > + dev_err(dev, "failed to request gpio_int_n\n"); > + return PTR_ERR(chip->gpio_int_n); > } > - ret = gpio_to_irq(chip->gpio_int_n); > + ret = gpiod_to_irq(chip->gpio_int_n); > if (ret < 0) { > - dev_err(chip->dev, > + dev_err(dev, > "cannot request IRQ for GPIO Int_N, ret=%d", ret); > return ret; > } >