From patchwork Wed Nov 11 19:45:30 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Torokhov X-Patchwork-Id: 543065 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E9EDE1402D1 for ; Thu, 12 Nov 2015 06:45:35 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=I9oJZ6bj; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752764AbbKKTpe (ORCPT ); Wed, 11 Nov 2015 14:45:34 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:33152 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752761AbbKKTpd (ORCPT ); Wed, 11 Nov 2015 14:45:33 -0500 Received: by pabfh17 with SMTP id fh17so39612484pab.0; Wed, 11 Nov 2015 11:45:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; bh=ZKNG5yXExtSFYd7xl6w+duR/hO7BEO7SPpiRhbKu/KM=; b=I9oJZ6bjqvitlZZJ9SqxFKTl65D+cPIsy9KyGYiN9q6DN0X/SNk4mx/N0DEtTuMeaL vFctJk5d555dv3KZJPjheF75iJtQ2AkOHSq9SURpVbMHOp2NW7ZMnB8GOURwm82/3rmi Py4XW8OC//Kts4mPwYnG4k1aRSiSp5/uq9oxkB9oWiq7MMg2wUqrLelJ+Dibd8Ejs3t+ aQ32IpAL0zajEoyAbTe1aYPl+Cyr9leCg6RIALkerH2NHjlGBJ8OdUoAZELbHodNk5Oz xS81/T5WXnSWgtEcQvA9wjJe666SboXy4G2OMI9/obwHMJCSff9MvfofNogKcKopTBo5 dGCQ== X-Received: by 10.69.0.69 with SMTP id aw5mr17128141pbd.19.1447271133115; Wed, 11 Nov 2015 11:45:33 -0800 (PST) Received: from dtor-ws ([2620:0:1000:1301:506b:7324:3980:905a]) by smtp.gmail.com with ESMTPSA id w11sm10755700pbs.87.2015.11.11.11.45.31 (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Wed, 11 Nov 2015 11:45:32 -0800 (PST) Date: Wed, 11 Nov 2015 11:45:30 -0800 From: Dmitry Torokhov To: Linus Walleij Cc: Alexandre Courbot , Mika Westerberg , "Rafael J. Wysocki" , Johan Hovold , "Tirdea, Irina" , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] gpiolib: tighten up ACPI legacy gpio lookups Message-ID: <20151111194530.GA26559@dtor-ws> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org We should not fall back to the legacy unnamed gpio lookup style if the driver requests gpios with different names, because we'll give out the same gpio twice. Let's keep track of the names that were used for the device and only do the fallback for the first name used. Signed-off-by: Dmitry Torokhov Acked-by: Mika Westerberg --- v1: incorporated changes suggested by Mika Westerberg in response to the draft patch I posted in Goodix thread. v2: moved acpi_can_fallback_to_crs body to drivers/gpio/gpiolib-acpi.c and provided stub for !CONFIG_ACPI case to fix build error if ACPI is disabled. drivers/gpio/gpiolib-acpi.c | 43 +++++++++++++++++++++++++++++++++++++++++++ drivers/gpio/gpiolib.c | 3 +++ drivers/gpio/gpiolib.h | 8 ++++++++ 3 files changed, 54 insertions(+) diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c index 143a9bd..d5f3008 100644 --- a/drivers/gpio/gpiolib-acpi.c +++ b/drivers/gpio/gpiolib-acpi.c @@ -838,3 +838,46 @@ int acpi_gpio_count(struct device *dev, const char *con_id) } return count; } + +struct acpi_crs_lookup { + struct list_head node; + struct acpi_device *adev; + const char *con_id; +}; + +static DEFINE_MUTEX(acpi_crs_lookup_lock); +static LIST_HEAD(acpi_crs_lookup_list); + +bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id) +{ + struct acpi_crs_lookup *l, *lookup = NULL; + + /* Never allow fallback if the device has properties */ + if (adev->data.properties || adev->driver_gpios) + return false; + + mutex_lock(&acpi_crs_lookup_lock); + + list_for_each_entry(l, &acpi_crs_lookup_list, node) { + if (l->adev == adev) { + lookup = l; + break; + } + } + + if (!lookup) { + lookup = kmalloc(sizeof(*lookup), GFP_KERNEL); + if (lookup) { + lookup->adev = adev; + lookup->con_id = con_id; + list_add_tail(&lookup->node, &acpi_crs_lookup_list); + } + } + + mutex_unlock(&acpi_crs_lookup_lock); + + return lookup && + ((!lookup->con_id && !con_id) || + (lookup->con_id && con_id && + strcmp(lookup->con_id, con_id) == 0)); +} diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5db3445..0faf4b7 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1765,6 +1765,9 @@ static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, /* Then from plain _CRS GPIOs */ if (IS_ERR(desc)) { + if (!acpi_can_fallback_to_crs(adev, con_id)) + return ERR_PTR(-ENOENT); + desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info); if (IS_ERR(desc)) return desc; diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index bf34300..986eb5c 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -44,6 +44,8 @@ struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev, struct acpi_gpio_info *info); int acpi_gpio_count(struct device *dev, const char *con_id); + +bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id); #else static inline void acpi_gpiochip_add(struct gpio_chip *chip) { } static inline void acpi_gpiochip_remove(struct gpio_chip *chip) { } @@ -65,6 +67,12 @@ static inline int acpi_gpio_count(struct device *dev, const char *con_id) { return -ENODEV; } + +static inline bool acpi_can_fallback_to_crs(struct acpi_device *adev, + const char *con_id) +{ + return false; +} #endif struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,