Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933769AbaJUVR4 (ORCPT ); Tue, 21 Oct 2014 17:17:56 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:61604 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S933709AbaJUVRs (ORCPT ); Tue, 21 Oct 2014 17:17:48 -0400 From: "Rafael J. Wysocki" To: Linux Kernel Mailing List , Arnd Bergmann Cc: ACPI Devel Maling List , Greg Kroah-Hartman , Darren Hart , Mika Westerberg , Aaron Lu , Grant Likely , devicetree@vger.kernel.org, Linus Walleij , Alexandre Courbot , Dmitry Torokhov , Bryan Wu Subject: [PATCH v6 10/12] gpio: Support for unified device properties interface Date: Tue, 21 Oct 2014 23:33:48 +0200 Message-ID: <2352441.eF6l9XxxSb@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <13750506.S2yVlRRDa2@vostro.rjw.lan> References: <13750506.S2yVlRRDa2@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mika Westerberg Some drivers need to deal with only firmware representation of its GPIOs. An example would be a GPIO button array driver where each button is described as a separate firmware node in device tree. Typically these child nodes do not have physical representation in the Linux device model. In order to help device drivers to handle such firmware child nodes we add dev[m]_get_named_gpiod_from_child() that takes a child firmware node pointer as its second argument (the first one is the parent device itself), finds the GPIO using whatever is the underlying firmware method, and requests the GPIO properly. Signed-off-by: Mika Westerberg Acked-by: Alexandre Courbot Signed-off-by: Rafael J. Wysocki --- Changes from v5: - fwnode_get_named_gpiod() takes 2 arguments (instead of 3; index has been dropped). - devm_get_gpiod_from_child() (renamed from devm_get_named_gpiod_from_child()) takes 2 arguments (instead of 4; the name and index have been dropped). It passes "gpios" to fwnode_get_named_gpiod() as the name, because both its callers in the subsequent patches would do that anyway. --- drivers/gpio/devres.c | 32 ++++++++++++++++++++++++ drivers/gpio/gpiolib.c | 55 ++++++++++++++++++++++++++++++++++++++++++ include/linux/gpio/consumer.h | 7 +++++ 3 files changed, 94 insertions(+) Index: linux-pm/drivers/gpio/devres.c =================================================================== --- linux-pm.orig/drivers/gpio/devres.c +++ linux-pm/drivers/gpio/devres.c @@ -109,6 +109,38 @@ struct gpio_desc *__must_check __devm_gp EXPORT_SYMBOL(__devm_gpiod_get_index); /** + * devm_get_gpiod_from_child - get a GPIO descriptor from a device's child node + * @dev: GPIO consumer + * @child: firmware node (child of @dev) + * + * GPIO descriptors returned from this function are automatically disposed on + * driver detach. + */ +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev, + struct fwnode_handle *child) +{ + struct gpio_desc **dr; + struct gpio_desc *desc; + + dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *), + GFP_KERNEL); + if (!dr) + return ERR_PTR(-ENOMEM); + + desc = fwnode_get_named_gpiod(child, "gpios"); + if (IS_ERR(desc)) { + devres_free(dr); + return desc; + } + + *dr = desc; + devres_add(dev, dr); + + return desc; +} +EXPORT_SYMBOL(devm_get_gpiod_from_child); + +/** * devm_gpiod_get_index_optional - Resource-managed gpiod_get_index_optional() * @dev: GPIO consumer * @con_id: function within the GPIO consumer Index: linux-pm/drivers/gpio/gpiolib.c =================================================================== --- linux-pm.orig/drivers/gpio/gpiolib.c +++ linux-pm/drivers/gpio/gpiolib.c @@ -1735,6 +1735,61 @@ struct gpio_desc *__must_check __gpiod_g EXPORT_SYMBOL_GPL(__gpiod_get_index); /** + * fwnode_get_named_gpiod - obtain a GPIO from firmware node + * @fwnode: handle of the firmware node + * @propname: name of the firmware property representing the GPIO + * + * This function can be used for drivers that get their configuration + * from firmware. + * + * Function properly finds the corresponding GPIO using whatever is the + * underlying firmware interface and then makes sure that the GPIO + * descriptor is requested before it is returned to the caller. + * + * In case of error an ERR_PTR() is returned. + */ +struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, + const char *propname) +{ + struct gpio_desc *desc = ERR_PTR(-ENODEV); + bool active_low = false; + int ret; + + if (!fwnode) + return ERR_PTR(-EINVAL); + + if (is_of_node(fwnode)) { + enum of_gpio_flags flags; + + desc = of_get_named_gpiod_flags(of_node(fwnode), propname, 0, + &flags); + if (!IS_ERR(desc)) + active_low = flags & OF_GPIO_ACTIVE_LOW; + } else if (is_acpi_node(fwnode)) { + struct acpi_gpio_info info; + + desc = acpi_get_gpiod_by_index(acpi_node(fwnode), propname, 0, + &info); + if (!IS_ERR(desc)) + active_low = info.active_low; + } + + if (IS_ERR(desc)) + return desc; + + ret = gpiod_request(desc, NULL); + if (ret) + return ERR_PTR(ret); + + /* Only value flag can be set from both DT and ACPI is active_low */ + if (active_low) + set_bit(FLAG_ACTIVE_LOW, &desc->flags); + + return desc; +} +EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); + +/** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs Index: linux-pm/include/linux/gpio/consumer.h =================================================================== --- linux-pm.orig/include/linux/gpio/consumer.h +++ linux-pm/include/linux/gpio/consumer.h @@ -94,6 +94,13 @@ int gpiod_to_irq(const struct gpio_desc struct gpio_desc *gpio_to_desc(unsigned gpio); int desc_to_gpio(const struct gpio_desc *desc); +/* Child properties interface */ +struct fwnode_handle; + +struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, + const char *propname); +struct gpio_desc *devm_get_gpiod_from_child(struct device *dev, + struct fwnode_handle *child); #else /* CONFIG_GPIOLIB */ static inline struct gpio_desc *__must_check __gpiod_get(struct device *dev, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/