From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753692AbbKETio (ORCPT ); Thu, 5 Nov 2015 14:38:44 -0500 Received: from mail-pa0-f51.google.com ([209.85.220.51]:33107 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbbKETim (ORCPT ); Thu, 5 Nov 2015 14:38:42 -0500 Date: Thu, 5 Nov 2015 11:38:38 -0800 From: Dmitry Torokhov To: Linus Walleij Cc: Alexandre Courbot , Johan Hovold , "Rafael J. Wysocki" , mika.westerberg@linux.intel.com, "Tirdea, Irina" , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] gpiolib: tighten up ACPI legacy gpio lookups Message-ID: <20151105193838.GA33410@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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. Also disable fallback to _CRS gpios if ACPI device has DT-like properties or driver-supplied gpio mappings. Signed-off-by: Dmitry Torokhov --- This version incorporates changes suggested by Mika Westerberg in response to the draft patch I posted in Goodix thread. drivers/gpio/gpiolib.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index a18f00f..9631ee8 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1841,6 +1841,50 @@ static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, return desc; } +struct acpi_gpio_lookup { + struct list_head node; + struct acpi_device *adev; + const char *con_id; +}; + +static DEFINE_MUTEX(acpi_gpio_lookup_lock); +static LIST_HEAD(acpi_gpio_lookup_list); + +static bool acpi_can_fallback_to_crs(struct acpi_device *adev, + const char *con_id) +{ + struct acpi_gpio_lookup *l, *lookup = NULL; + + /* Never fallback if the device has properties */ + if (adev->data.properties || adev->driver_gpios) + return false; + + mutex_lock(&acpi_gpio_lookup_lock); + + list_for_each_entry(l, &acpi_gpio_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_gpio_lookup_list); + } + } + + mutex_unlock(&acpi_gpio_lookup_lock); + + return lookup && + ((!lookup->con_id && !con_id) || + (lookup->con_id && con_id && + strcmp(lookup->con_id, con_id) == 0)); +} + static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id, unsigned int idx, enum gpio_lookup_flags *flags) @@ -1868,6 +1912,9 @@ 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; -- 2.6.0.rc2.230.g3dd15c0 -- Dmitry