From patchwork Tue Mar 24 13:56:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 207155 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 A64DEC54FCF for ; Tue, 24 Mar 2020 13:57:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89EFB2076E for ; Tue, 24 Mar 2020 13:57:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728128AbgCXN52 (ORCPT ); Tue, 24 Mar 2020 09:57:28 -0400 Received: from michel.telenet-ops.be ([195.130.137.88]:37856 "EHLO michel.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728130AbgCXN5V (ORCPT ); Tue, 24 Mar 2020 09:57:21 -0400 Received: from ramsan ([84.195.182.253]) by michel.telenet-ops.be with bizsmtp id JDwu2200M5USYZQ06Dwu4g; Tue, 24 Mar 2020 14:57:19 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1jGk34-0006Oc-Ga; Tue, 24 Mar 2020 14:56:54 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1jGk34-0001kW-Ey; Tue, 24 Mar 2020 14:56:54 +0100 From: Geert Uytterhoeven To: Linus Walleij , Bartosz Golaszewski , Jonathan Corbet , Harish Jenny K N , Eugeniu Rosca Cc: Alexander Graf , Peter Maydell , Paolo Bonzini , Phil Reid , Marc Zyngier , Christoffer Dall , Magnus Damm , Rob Herring , Mark Rutland , linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Geert Uytterhoeven , linux-arm-kernel@lists.infradead.org Subject: [PATCH v6 1/8] ARM: integrator: impd1: Use GPIO_LOOKUP() helper macro Date: Tue, 24 Mar 2020 14:56:46 +0100 Message-Id: <20200324135653.6676-1-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324135328.5796-1-geert+renesas@glider.be> References: <20200324135328.5796-1-geert+renesas@glider.be> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org impd1_probe() fills in the GPIO lookup table by manually populating an array of gpiod_lookup structures. Use the existing GPIO_LOOKUP() helper macro instead, to relax a dependency on the gpiod_lookup structure's member names. Signed-off-by: Geert Uytterhoeven Cc: linux-arm-kernel@lists.infradead.org --- While this patch is a dependency for "[PATCH v6 4/8] gpiolib: Add support for GPIO lookup by line name", it can be applied independently. But an Acked-by would be nice, too. Cover letter and full series at https://lore.kernel.org/r/20200324135328.5796-1-geert+renesas@glider.be/ v6: - New. --- arch/arm/mach-integrator/impd1.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/arm/mach-integrator/impd1.c b/arch/arm/mach-integrator/impd1.c index 1ecbea5331d6ed8b..6f875ded841924d8 100644 --- a/arch/arm/mach-integrator/impd1.c +++ b/arch/arm/mach-integrator/impd1.c @@ -410,13 +410,10 @@ static int __ref impd1_probe(struct lm_device *dev) * 5 = Key lower right */ /* We need the two MMCI GPIO entries */ - lookup->table[0].chip_label = chipname; - lookup->table[0].chip_hwnum = 3; - lookup->table[0].con_id = "wp"; - lookup->table[1].chip_label = chipname; - lookup->table[1].chip_hwnum = 4; - lookup->table[1].con_id = "cd"; - lookup->table[1].flags = GPIO_ACTIVE_LOW; + lookup->table[0] = (struct gpiod_lookup) + GPIO_LOOKUP(chipname, 3, "wp", 0); + lookup->table[1] = (struct gpiod_lookup) + GPIO_LOOKUP(chipname, 4, "cd", GPIO_ACTIVE_LOW); gpiod_add_lookup_table(lookup); } From patchwork Tue Mar 24 13:56:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 207156 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 54802C54FD0 for ; Tue, 24 Mar 2020 13:57:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 387DF20714 for ; Tue, 24 Mar 2020 13:57:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727924AbgCXN5K (ORCPT ); Tue, 24 Mar 2020 09:57:10 -0400 Received: from laurent.telenet-ops.be ([195.130.137.89]:36974 "EHLO laurent.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727592AbgCXN5J (ORCPT ); Tue, 24 Mar 2020 09:57:09 -0400 Received: from ramsan ([84.195.182.253]) by laurent.telenet-ops.be with bizsmtp id JDwu2200H5USYZQ01Dwulu; Tue, 24 Mar 2020 14:57:05 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1jGk34-0006Ol-KV; Tue, 24 Mar 2020 14:56:54 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1jGk34-0001kf-Ih; Tue, 24 Mar 2020 14:56:54 +0100 From: Geert Uytterhoeven To: Linus Walleij , Bartosz Golaszewski , Jonathan Corbet , Harish Jenny K N , Eugeniu Rosca Cc: Alexander Graf , Peter Maydell , Paolo Bonzini , Phil Reid , Marc Zyngier , Christoffer Dall , Magnus Damm , Rob Herring , Mark Rutland , linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Geert Uytterhoeven Subject: [PATCH v6 4/8] gpiolib: Add support for GPIO lookup by line name Date: Tue, 24 Mar 2020 14:56:49 +0100 Message-Id: <20200324135653.6676-4-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324135653.6676-1-geert+renesas@glider.be> References: <20200324135328.5796-1-geert+renesas@glider.be> <20200324135653.6676-1-geert+renesas@glider.be> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Currently a GPIO lookup table can only refer to a specific GPIO by a tuple, consisting of a GPIO controller label and a GPIO offset inside the controller. However, a GPIO may also carry a line name, defined by DT or ACPI. If present, the line name is the most use-centric way to refer to a GPIO. Hence add support for looking up GPIOs by line name. Implement this by reusing the existing gpiod_lookup infrastructure. Rename gpiod_lookup.chip_label to gpiod_lookup.key, to make it clear that this field can have two meanings, and update the kerneldoc and GPIO_LOOKUP*() macros. Signed-off-by: Geert Uytterhoeven Reviewed-by: Ulrich Hecht Reviewed-by: Eugeniu Rosca Tested-by: Eugeniu Rosca --- v6: - Update Documentation/driver-api/gpio/board.rst, - Reword rationale, v5: - Add Reviewed-by, Tested-by, v4: - Add Reviewed-by, - Rename gpiod_lookup.chip_label. - Use U16_MAX instead of (u16)-1, v3: - New. --- Documentation/driver-api/gpio/board.rst | 10 ++++++---- drivers/gpio/gpiolib.c | 22 +++++++++++++++++----- include/linux/gpio/machine.h | 15 ++++++++------- 3 files changed, 31 insertions(+), 16 deletions(-) diff --git a/Documentation/driver-api/gpio/board.rst b/Documentation/driver-api/gpio/board.rst index ce91518bf9f48ded..0ad1f8cacf5e5d26 100644 --- a/Documentation/driver-api/gpio/board.rst +++ b/Documentation/driver-api/gpio/board.rst @@ -113,13 +113,15 @@ files that desire to do so need to include the following header:: GPIOs are mapped by the means of tables of lookups, containing instances of the gpiod_lookup structure. Two macros are defined to help declaring such mappings:: - GPIO_LOOKUP(chip_label, chip_hwnum, con_id, flags) - GPIO_LOOKUP_IDX(chip_label, chip_hwnum, con_id, idx, flags) + GPIO_LOOKUP(key, chip_hwnum, con_id, flags) + GPIO_LOOKUP_IDX(key, chip_hwnum, con_id, idx, flags) where - - chip_label is the label of the gpiod_chip instance providing the GPIO - - chip_hwnum is the hardware number of the GPIO within the chip + - key is either the label of the gpiod_chip instance providing the GPIO, or + the GPIO line name + - chip_hwnum is the hardware number of the GPIO within the chip, or U16_MAX + to indicate that key is a GPIO line name - con_id is the name of the GPIO function from the device point of view. It can be NULL, in which case it will match any function. - idx is the index of the GPIO within the function. diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 8d7366f4451fe695..c756602e249c052e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -4643,7 +4643,7 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, if (!table) return desc; - for (p = &table->table[0]; p->chip_label; p++) { + for (p = &table->table[0]; p->key; p++) { struct gpio_chip *chip; /* idx must always match exactly */ @@ -4654,18 +4654,30 @@ static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) continue; - chip = find_chip_by_name(p->chip_label); + if (p->chip_hwnum == U16_MAX) { + desc = gpio_name_to_desc(p->key); + if (desc) { + *flags = p->flags; + return desc; + } + + dev_warn(dev, "cannot find GPIO line %s, deferring\n", + p->key); + return ERR_PTR(-EPROBE_DEFER); + } + + chip = find_chip_by_name(p->key); if (!chip) { /* * As the lookup table indicates a chip with - * p->chip_label should exist, assume it may + * p->key should exist, assume it may * still appear later and let the interested * consumer be probed again or let the Deferred * Probe infrastructure handle the error. */ dev_warn(dev, "cannot find GPIO chip %s, deferring\n", - p->chip_label); + p->key); return ERR_PTR(-EPROBE_DEFER); } @@ -4696,7 +4708,7 @@ static int platform_gpio_count(struct device *dev, const char *con_id) if (!table) return -ENOENT; - for (p = &table->table[0]; p->chip_label; p++) { + for (p = &table->table[0]; p->key; p++) { if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || (!con_id && !p->con_id)) count++; diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h index 1ebe5be05d5f81fa..84c66fbf54fd5811 100644 --- a/include/linux/gpio/machine.h +++ b/include/linux/gpio/machine.h @@ -20,8 +20,9 @@ enum gpio_lookup_flags { /** * struct gpiod_lookup - lookup table - * @chip_label: name of the chip the GPIO belongs to - * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO + * @key: either the name of the chip the GPIO belongs to, or the GPIO line name + * @chip_hwnum: hardware number (i.e. relative to the chip) of the GPIO, or + * U16_MAX to indicate that @key is a GPIO line name * @con_id: name of the GPIO from the device's point of view * @idx: index of the GPIO in case several GPIOs share the same name * @flags: bitmask of gpio_lookup_flags GPIO_* values @@ -30,7 +31,7 @@ enum gpio_lookup_flags { * functions using platform data. */ struct gpiod_lookup { - const char *chip_label; + const char *key; u16 chip_hwnum; const char *con_id; unsigned int idx; @@ -63,17 +64,17 @@ struct gpiod_hog { /* * Simple definition of a single GPIO under a con_id */ -#define GPIO_LOOKUP(_chip_label, _chip_hwnum, _con_id, _flags) \ - GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, 0, _flags) +#define GPIO_LOOKUP(_key, _chip_hwnum, _con_id, _flags) \ + GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, 0, _flags) /* * Use this macro if you need to have several GPIOs under the same con_id. * Each GPIO needs to use a different index and can be accessed using * gpiod_get_index() */ -#define GPIO_LOOKUP_IDX(_chip_label, _chip_hwnum, _con_id, _idx, _flags) \ +#define GPIO_LOOKUP_IDX(_key, _chip_hwnum, _con_id, _idx, _flags) \ { \ - .chip_label = _chip_label, \ + .key = _key, \ .chip_hwnum = _chip_hwnum, \ .con_id = _con_id, \ .idx = _idx, \ From patchwork Tue Mar 24 13:56:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 207158 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 45CBBC2BAEE for ; Tue, 24 Mar 2020 13:57:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24B742073E for ; Tue, 24 Mar 2020 13:57:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727901AbgCXN5I (ORCPT ); Tue, 24 Mar 2020 09:57:08 -0400 Received: from albert.telenet-ops.be ([195.130.137.90]:55846 "EHLO albert.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727522AbgCXN5I (ORCPT ); Tue, 24 Mar 2020 09:57:08 -0400 Received: from ramsan ([84.195.182.253]) by albert.telenet-ops.be with bizsmtp id JDwu2200P5USYZQ06Dwua9; Tue, 24 Mar 2020 14:57:06 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1jGk34-0006On-Ln; Tue, 24 Mar 2020 14:56:54 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1jGk34-0001ki-Jv; Tue, 24 Mar 2020 14:56:54 +0100 From: Geert Uytterhoeven To: Linus Walleij , Bartosz Golaszewski , Jonathan Corbet , Harish Jenny K N , Eugeniu Rosca Cc: Alexander Graf , Peter Maydell , Paolo Bonzini , Phil Reid , Marc Zyngier , Christoffer Dall , Magnus Damm , Rob Herring , Mark Rutland , linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Geert Uytterhoeven Subject: [PATCH v6 5/8] gpiolib: Introduce gpiod_set_config() Date: Tue, 24 Mar 2020 14:56:50 +0100 Message-Id: <20200324135653.6676-5-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324135653.6676-1-geert+renesas@glider.be> References: <20200324135328.5796-1-geert+renesas@glider.be> <20200324135653.6676-1-geert+renesas@glider.be> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The GPIO Aggregator will need a method to forward a .set_config() call to its parent gpiochip. This requires obtaining the gpio_chip and offset for a given gpio_desc. While gpiod_to_chip() is public, gpio_chip_hwgpio() is not, so there is currently no method to obtain the needed GPIO offset parameter. Hence introduce a public gpiod_set_config() helper, which invokes the .set_config() callback through a gpio_desc pointer, like is done for most other gpio_chip callbacks. Rewrite the existing gpiod_set_debounce() helper as a wrapper around gpiod_set_config(), to avoid duplication. Signed-off-by: Geert Uytterhoeven --- v6: - New. --- drivers/gpio/gpiolib.c | 28 ++++++++++++++++++++++------ include/linux/gpio/consumer.h | 8 ++++++++ 2 files changed, 30 insertions(+), 6 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index c756602e249c052e..30ea75e972b5a3b1 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -3478,6 +3478,26 @@ int gpiod_direction_output(struct gpio_desc *desc, int value) } EXPORT_SYMBOL_GPL(gpiod_direction_output); +/** + * gpiod_set_config - sets @config for a GPIO + * @desc: descriptor of the GPIO for which to set the configuration + * @config: Same packed config format as generic pinconf + * + * Returns: + * 0 on success, %-ENOTSUPP if the controller doesn't support setting the + * configuration. + */ +int gpiod_set_config(struct gpio_desc *desc, unsigned long config) +{ + struct gpio_chip *chip; + + VALIDATE_DESC(desc); + chip = desc->gdev->chip; + + return gpio_do_set_config(chip, gpio_chip_hwgpio(desc), config); +} +EXPORT_SYMBOL_GPL(gpiod_set_config); + /** * gpiod_set_debounce - sets @debounce time for a GPIO * @desc: descriptor of the GPIO for which to set debounce time @@ -3489,14 +3509,10 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output); */ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { - struct gpio_chip *chip; - unsigned long config; - - VALIDATE_DESC(desc); - chip = desc->gdev->chip; + unsigned long config; config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce); - return gpio_do_set_config(chip, gpio_chip_hwgpio(desc), config); + return gpiod_set_config(desc, config); } EXPORT_SYMBOL_GPL(gpiod_set_debounce); diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 0a72fccf60fff230..901aab89d025f3ff 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -157,6 +157,7 @@ int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_array *array_info, unsigned long *value_bitmap); +int gpiod_set_config(struct gpio_desc *desc, unsigned long config); int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); void gpiod_toggle_active_low(struct gpio_desc *desc); @@ -473,6 +474,13 @@ static inline int gpiod_set_raw_array_value_cansleep(unsigned int array_size, return 0; } +static inline int gpiod_set_config(struct gpio_desc *desc, unsigned long config) +{ + /* GPIO can never have been requested */ + WARN_ON(desc); + return -ENOSYS; +} + static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) { /* GPIO can never have been requested */ From patchwork Tue Mar 24 13:56:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geert Uytterhoeven X-Patchwork-Id: 207157 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 5D8D5C2BAEE for ; Tue, 24 Mar 2020 13:57:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27D4A2073E for ; Tue, 24 Mar 2020 13:57:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727948AbgCXN5K (ORCPT ); Tue, 24 Mar 2020 09:57:10 -0400 Received: from albert.telenet-ops.be ([195.130.137.90]:55904 "EHLO albert.telenet-ops.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727553AbgCXN5K (ORCPT ); Tue, 24 Mar 2020 09:57:10 -0400 Received: from ramsan ([84.195.182.253]) by albert.telenet-ops.be with bizsmtp id JDwu2200R5USYZQ06DwuaA; Tue, 24 Mar 2020 14:57:06 +0100 Received: from rox.of.borg ([192.168.97.57]) by ramsan with esmtp (Exim 4.90_1) (envelope-from ) id 1jGk34-0006Oq-N4; Tue, 24 Mar 2020 14:56:54 +0100 Received: from geert by rox.of.borg with local (Exim 4.90_1) (envelope-from ) id 1jGk34-0001kl-LB; Tue, 24 Mar 2020 14:56:54 +0100 From: Geert Uytterhoeven To: Linus Walleij , Bartosz Golaszewski , Jonathan Corbet , Harish Jenny K N , Eugeniu Rosca Cc: Alexander Graf , Peter Maydell , Paolo Bonzini , Phil Reid , Marc Zyngier , Christoffer Dall , Magnus Damm , Rob Herring , Mark Rutland , linux-gpio@vger.kernel.org, linux-doc@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, Geert Uytterhoeven Subject: [PATCH v6 6/8] gpio: Add GPIO Aggregator Date: Tue, 24 Mar 2020 14:56:51 +0100 Message-Id: <20200324135653.6676-6-geert+renesas@glider.be> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200324135653.6676-1-geert+renesas@glider.be> References: <20200324135328.5796-1-geert+renesas@glider.be> <20200324135653.6676-1-geert+renesas@glider.be> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org GPIO controllers are exported to userspace using /dev/gpiochip* character devices. Access control to these devices is provided by standard UNIX file system permissions, on an all-or-nothing basis: either a GPIO controller is accessible for a user, or it is not. Currently no mechanism exists to control access to individual GPIOs. Hence add a GPIO driver to aggregate existing GPIOs, and expose them as a new gpiochip. This supports the following use cases: - Aggregating GPIOs using Sysfs This is useful for implementing access control, and assigning a set of GPIOs to a specific user or virtual machine. - Generic GPIO Driver This is useful for industrial control, where it can provide userspace access to a simple GPIO-operated device described in DT, cfr. e.g. spidev for SPI-operated devices. Signed-off-by: Geert Uytterhoeven Reviewed-by: Eugeniu Rosca Tested-by: Eugeniu Rosca --- v6: - Use gpiod_to_chip() instead of open-coding, - Drop debug print of gpio_desc.label, as it usually just points to the GPIO Aggregator itself, - Drop no longer needed #include "gpiolib.h", - Fix missing offset translation in gpio_fwd_set_config(), - Use GPIO_LOOKUP_IDX() to populate struct gpiod_lookup, v5: - Add Reviewed-by, Tested-by, v4: - Remove unused assignment to n in isrange(), - Check correct pointer after aggr->lookups->dev_id allocation, - Preinitialize flags to 0 in gpio_fwd_[gs]et_multiple() to avoid may-be-used-uninitialized warning, - Drop controversial GPIO repeater, - Update for gpiod_lookup.chip_label rename, - Use %pe to format error pointers, - Use U16_MAX instead of (u16)-1, - Correct comment indentation, - Use skip_spaces() helper, - Rename a and b to first_index resp. last_index, - Add comment to tmp[] use, - Improve Kconfig help text, - Include for gpiod_[gs]et_*(), - Drop unneeded valid_mask handling, - Add comment about sleeping and .set_config() support, v3: - Absorb GPIO forwarder, - Integrate GPIO Repeater and Generic GPIO driver functionality, - Use the aggregator parameters to create a GPIO lookup table instead of an array of GPIO descriptors, which allows to simplify the code: 1. This removes the need for calling gpio_name_to_desc(), gpiochip_find(), gpiochip_get_desc(), and gpiod_request(), 2. This allows the platform device to always use devm_gpiod_get_index(), regardless of the origin of the GPIOs, - Move parameter parsing from platform device probe to sysfs attribute store, removing the need for platform data passing, - Use more devm_*() functions to simplify cleanup, - Add pr_fmt(), - General refactoring, v2: - Add missing initialization of i in gpio_virt_agg_probe(), - Update for removed .need_valid_mask field and changed .init_valid_mask() signature, - Drop "virtual", rename to gpio-aggregator, - Drop bogus FIXME related to gpiod_set_transitory() expectations, - Use new GPIO Forwarder Helper, - Lift limit on the maximum number of GPIOs, - Improve parsing: - add support for specifying GPIOs by line name, - add support for specifying GPIO chips by ID, - add support for GPIO offset ranges, - names and offset specifiers must be separated by whitespace, - GPIO offsets must separated by spaces, - Use str_has_prefix() and kstrtouint(). --- drivers/gpio/Kconfig | 12 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-aggregator.c | 568 +++++++++++++++++++++++++++++++++ 3 files changed, 581 insertions(+) create mode 100644 drivers/gpio/gpio-aggregator.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 6234ccc90e7eb4a1..6ddc7353a46afdf6 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1541,6 +1541,18 @@ config GPIO_VIPERBOARD endmenu +config GPIO_AGGREGATOR + tristate "GPIO Aggregator" + help + Say yes here to enable the GPIO Aggregator, which provides a way to + aggregate existing GPIO lines into a new virtual GPIO chip. + This can serve the following purposes: + - Assign permissions for a collection of GPIO lines to a user, + - Export a collection of GPIO lines to a virtual machine, + - Provide a generic driver for a GPIO-operated device in an + industrial control context, to be operated from userspace using + the GPIO chardev interface. + config GPIO_MOCKUP tristate "GPIO Testing Driver" select IRQ_SIM diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index b2cfc21a97f3e52b..65bf3940e33cf734 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o +obj-$(CONFIG_GPIO_AGGREGATOR) += gpio-aggregator.o obj-$(CONFIG_GPIO_ALTERA_A10SR) += gpio-altera-a10sr.o obj-$(CONFIG_GPIO_ALTERA) += gpio-altera.o obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c new file mode 100644 index 0000000000000000..9b0adbdddbfccb30 --- /dev/null +++ b/drivers/gpio/gpio-aggregator.c @@ -0,0 +1,568 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// GPIO Aggregator +// +// Copyright (C) 2019-2020 Glider bv + +#define DRV_NAME "gpio-aggregator" +#define pr_fmt(fmt) DRV_NAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* + * GPIO Aggregator sysfs interface + */ + +struct gpio_aggregator { + struct gpiod_lookup_table *lookups; + struct platform_device *pdev; + char args[]; +}; + +static DEFINE_MUTEX(gpio_aggregator_lock); /* protects idr */ +static DEFINE_IDR(gpio_aggregator_idr); + +static char *get_arg(char **args) +{ + char *start = *args, *end; + + start = skip_spaces(start); + if (!*start) + return NULL; + + if (*start == '"') { + /* Quoted arg */ + end = strchr(++start, '"'); + if (!end) + return ERR_PTR(-EINVAL); + } else { + /* Unquoted arg */ + for (end = start; *end && !isspace(*end); end++) ; + } + + if (*end) + *end++ = '\0'; + + *args = end; + return start; +} + +static bool isrange(const char *s) +{ + size_t n; + + if (IS_ERR_OR_NULL(s)) + return false; + + while (1) { + n = strspn(s, "0123456789"); + if (!n) + return false; + + s += n; + + switch (*s++) { + case '\0': + return true; + + case '-': + case ',': + break; + + default: + return false; + } + } +} + +static int aggr_add_gpio(struct gpio_aggregator *aggr, const char *key, + int hwnum, unsigned int *n) +{ + struct gpiod_lookup_table *lookups; + + lookups = krealloc(aggr->lookups, struct_size(lookups, table, *n + 2), + GFP_KERNEL); + if (!lookups) + return -ENOMEM; + + lookups->table[*n] = + (struct gpiod_lookup)GPIO_LOOKUP_IDX(key, hwnum, NULL, *n, 0); + + (*n)++; + memset(&lookups->table[*n], 0, sizeof(lookups->table[*n])); + + aggr->lookups = lookups; + return 0; +} + +static int aggr_parse(struct gpio_aggregator *aggr) +{ + unsigned int first_index, last_index, i, n = 0; + char *name, *offsets, *first, *last, *next; + char *args = aggr->args; + int error; + + for (name = get_arg(&args), offsets = get_arg(&args); name; + offsets = get_arg(&args)) { + if (IS_ERR(name)) { + pr_err("Cannot get GPIO specifier: %pe\n", name); + return PTR_ERR(name); + } + + if (!isrange(offsets)) { + /* Named GPIO line */ + error = aggr_add_gpio(aggr, name, U16_MAX, &n); + if (error) + return error; + + name = offsets; + continue; + } + + /* GPIO chip + offset(s) */ + for (first = offsets; *first; first = next) { + next = strchrnul(first, ','); + if (*next) + *next++ = '\0'; + + last = strchr(first, '-'); + if (last) + *last++ = '\0'; + + if (kstrtouint(first, 10, &first_index)) { + pr_err("Cannot parse GPIO index %s\n", first); + return -EINVAL; + } + + if (!last) { + last_index = first_index; + } else if (kstrtouint(last, 10, &last_index)) { + pr_err("Cannot parse GPIO index %s\n", last); + return -EINVAL; + } + + for (i = first_index; i <= last_index; i++) { + error = aggr_add_gpio(aggr, name, i, &n); + if (error) + return error; + } + } + + name = get_arg(&args); + } + + if (!n) { + pr_err("No GPIOs specified\n"); + return -EINVAL; + } + + return 0; +} + +static ssize_t new_device_store(struct device_driver *driver, const char *buf, + size_t count) +{ + struct gpio_aggregator *aggr; + struct platform_device *pdev; + int res, id; + + /* kernfs guarantees string termination, so count + 1 is safe */ + aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL); + if (!aggr) + return -ENOMEM; + + memcpy(aggr->args, buf, count + 1); + + aggr->lookups = kzalloc(struct_size(aggr->lookups, table, 1), + GFP_KERNEL); + if (!aggr->lookups) { + res = -ENOMEM; + goto free_ga; + } + + mutex_lock(&gpio_aggregator_lock); + id = idr_alloc(&gpio_aggregator_idr, aggr, 0, 0, GFP_KERNEL); + mutex_unlock(&gpio_aggregator_lock); + + if (id < 0) { + res = id; + goto free_table; + } + + aggr->lookups->dev_id = kasprintf(GFP_KERNEL, "%s.%d", DRV_NAME, id); + if (!aggr->lookups->dev_id) { + res = -ENOMEM; + goto remove_idr; + } + + res = aggr_parse(aggr); + if (res) + goto free_dev_id; + + gpiod_add_lookup_table(aggr->lookups); + + pdev = platform_device_register_simple(DRV_NAME, id, NULL, 0); + if (IS_ERR(pdev)) { + res = PTR_ERR(pdev); + goto remove_table; + } + + aggr->pdev = pdev; + return count; + +remove_table: + gpiod_remove_lookup_table(aggr->lookups); +free_dev_id: + kfree(aggr->lookups->dev_id); +remove_idr: + mutex_lock(&gpio_aggregator_lock); + idr_remove(&gpio_aggregator_idr, id); + mutex_unlock(&gpio_aggregator_lock); +free_table: + kfree(aggr->lookups); +free_ga: + kfree(aggr); + return res; +} + +static DRIVER_ATTR_WO(new_device); + +static void gpio_aggregator_free(struct gpio_aggregator *aggr) +{ + platform_device_unregister(aggr->pdev); + gpiod_remove_lookup_table(aggr->lookups); + kfree(aggr->lookups->dev_id); + kfree(aggr->lookups); + kfree(aggr); +} + +static ssize_t delete_device_store(struct device_driver *driver, + const char *buf, size_t count) +{ + struct gpio_aggregator *aggr; + unsigned int id; + int error; + + if (!str_has_prefix(buf, DRV_NAME ".")) + return -EINVAL; + + error = kstrtouint(buf + strlen(DRV_NAME "."), 10, &id); + if (error) + return error; + + mutex_lock(&gpio_aggregator_lock); + aggr = idr_remove(&gpio_aggregator_idr, id); + mutex_unlock(&gpio_aggregator_lock); + if (!aggr) + return -ENOENT; + + gpio_aggregator_free(aggr); + return count; +} +static DRIVER_ATTR_WO(delete_device); + +static struct attribute *gpio_aggregator_attrs[] = { + &driver_attr_new_device.attr, + &driver_attr_delete_device.attr, + NULL, +}; +ATTRIBUTE_GROUPS(gpio_aggregator); + +static int __exit gpio_aggregator_idr_remove(int id, void *p, void *data) +{ + gpio_aggregator_free(p); + return 0; +} + +static void __exit gpio_aggregator_remove_all(void) +{ + mutex_lock(&gpio_aggregator_lock); + idr_for_each(&gpio_aggregator_idr, gpio_aggregator_idr_remove, NULL); + idr_destroy(&gpio_aggregator_idr); + mutex_unlock(&gpio_aggregator_lock); +} + + +/* + * GPIO Forwarder + */ + +struct gpiochip_fwd { + struct gpio_chip chip; + struct gpio_desc **descs; + union { + struct mutex mlock; /* protects tmp[] if can_sleep */ + spinlock_t slock; /* protects tmp[] if !can_sleep */ + }; + unsigned long tmp[]; /* values and descs for multiple ops */ +}; + +static int gpio_fwd_get_direction(struct gpio_chip *chip, unsigned int offset) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + return gpiod_get_direction(fwd->descs[offset]); +} + +static int gpio_fwd_direction_input(struct gpio_chip *chip, unsigned int offset) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + return gpiod_direction_input(fwd->descs[offset]); +} + +static int gpio_fwd_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + return gpiod_direction_output(fwd->descs[offset], value); +} + +static int gpio_fwd_get(struct gpio_chip *chip, unsigned int offset) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + return gpiod_get_value(fwd->descs[offset]); +} + +static int gpio_fwd_get_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + unsigned long *values, flags = 0; + struct gpio_desc **descs; + unsigned int i, j = 0; + int error; + + if (chip->can_sleep) + mutex_lock(&fwd->mlock); + else + spin_lock_irqsave(&fwd->slock, flags); + + /* Both values bitmap and desc pointers are stored in tmp[] */ + values = &fwd->tmp[0]; + descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)]; + + bitmap_clear(values, 0, fwd->chip.ngpio); + for_each_set_bit(i, mask, fwd->chip.ngpio) + descs[j++] = fwd->descs[i]; + + error = gpiod_get_array_value(j, descs, NULL, values); + if (!error) { + j = 0; + for_each_set_bit(i, mask, fwd->chip.ngpio) + __assign_bit(i, bits, test_bit(j++, values)); + } + + if (chip->can_sleep) + mutex_unlock(&fwd->mlock); + else + spin_unlock_irqrestore(&fwd->slock, flags); + + return error; +} + +static void gpio_fwd_set(struct gpio_chip *chip, unsigned int offset, int value) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + gpiod_set_value(fwd->descs[offset], value); +} + +static void gpio_fwd_set_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + unsigned long *values, flags = 0; + struct gpio_desc **descs; + unsigned int i, j = 0; + + if (chip->can_sleep) + mutex_lock(&fwd->mlock); + else + spin_lock_irqsave(&fwd->slock, flags); + + /* Both values bitmap and desc pointers are stored in tmp[] */ + values = &fwd->tmp[0]; + descs = (void *)&fwd->tmp[BITS_TO_LONGS(fwd->chip.ngpio)]; + + for_each_set_bit(i, mask, fwd->chip.ngpio) { + __assign_bit(j, values, test_bit(i, bits)); + descs[j++] = fwd->descs[i]; + } + + gpiod_set_array_value(j, descs, NULL, values); + + if (chip->can_sleep) + mutex_unlock(&fwd->mlock); + else + spin_unlock_irqrestore(&fwd->slock, flags); +} + +static int gpio_fwd_set_config(struct gpio_chip *chip, unsigned int offset, + unsigned long config) +{ + struct gpiochip_fwd *fwd = gpiochip_get_data(chip); + + return gpiod_set_config(fwd->descs[offset], config); +} + +/** + * gpiochip_fwd_create() - Create a new GPIO forwarder + * @dev: Parent device pointer + * @ngpios: Number of GPIOs in the forwarder. + * @descs: Array containing the GPIO descriptors to forward to. + * This array must contain @ngpios entries, and must not be deallocated + * before the forwarder has been destroyed again. + * + * This function creates a new gpiochip, which forwards all GPIO operations to + * the passed GPIO descriptors. + * + * Return: An opaque object pointer, or an ERR_PTR()-encoded negative error + * code on failure. + */ +static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev, + unsigned int ngpios, + struct gpio_desc *descs[]) +{ + const char *label = dev_name(dev); + struct gpiochip_fwd *fwd; + struct gpio_chip *chip; + unsigned int i; + int error; + + fwd = devm_kzalloc(dev, struct_size(fwd, tmp, + BITS_TO_LONGS(ngpios) + ngpios), GFP_KERNEL); + if (!fwd) + return ERR_PTR(-ENOMEM); + + chip = &fwd->chip; + + /* + * If any of the GPIO lines are sleeping, then the entire forwarder + * will be sleeping. + * If any of the chips support .set_config(), then the forwarder will + * support setting configs. + */ + for (i = 0; i < ngpios; i++) { + struct gpio_chip *parent = gpiod_to_chip(descs[i]); + + dev_dbg(dev, "%u => gpio-%d\n", i, desc_to_gpio(descs[i])); + + if (gpiod_cansleep(descs[i])) + chip->can_sleep = true; + if (parent && parent->set_config) + chip->set_config = gpio_fwd_set_config; + } + + chip->label = label; + chip->parent = dev; + chip->owner = THIS_MODULE; + chip->get_direction = gpio_fwd_get_direction; + chip->direction_input = gpio_fwd_direction_input; + chip->direction_output = gpio_fwd_direction_output; + chip->get = gpio_fwd_get; + chip->get_multiple = gpio_fwd_get_multiple; + chip->set = gpio_fwd_set; + chip->set_multiple = gpio_fwd_set_multiple; + chip->base = -1; + chip->ngpio = ngpios; + fwd->descs = descs; + + if (chip->can_sleep) + mutex_init(&fwd->mlock); + else + spin_lock_init(&fwd->slock); + + error = devm_gpiochip_add_data(dev, chip, fwd); + if (error) + return ERR_PTR(error); + + return fwd; +} + + +/* + * GPIO Aggregator platform device + */ + +static int gpio_aggregator_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct gpio_desc **descs; + struct gpiochip_fwd *fwd; + int i, n; + + n = gpiod_count(dev, NULL); + if (n < 0) + return n; + + descs = devm_kmalloc_array(dev, n, sizeof(*descs), GFP_KERNEL); + if (!descs) + return -ENOMEM; + + for (i = 0; i < n; i++) { + descs[i] = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS); + if (IS_ERR(descs[i])) + return PTR_ERR(descs[i]); + } + + fwd = gpiochip_fwd_create(dev, n, descs); + if (IS_ERR(fwd)) + return PTR_ERR(fwd); + + platform_set_drvdata(pdev, fwd); + return 0; +} + +#ifdef CONFIG_OF +static const struct of_device_id gpio_aggregator_dt_ids[] = { + /* + * Add GPIO-operated devices controlled from userspace below, + * or use "driver_override" in sysfs + */ + {}, +}; +MODULE_DEVICE_TABLE(of, gpio_aggregator_dt_ids); +#endif + +static struct platform_driver gpio_aggregator_driver = { + .probe = gpio_aggregator_probe, + .driver = { + .name = DRV_NAME, + .groups = gpio_aggregator_groups, + .of_match_table = of_match_ptr(gpio_aggregator_dt_ids), + }, +}; + +static int __init gpio_aggregator_init(void) +{ + return platform_driver_register(&gpio_aggregator_driver); +} +module_init(gpio_aggregator_init); + +static void __exit gpio_aggregator_exit(void) +{ + gpio_aggregator_remove_all(); + platform_driver_unregister(&gpio_aggregator_driver); +} +module_exit(gpio_aggregator_exit); + +MODULE_AUTHOR("Geert Uytterhoeven "); +MODULE_DESCRIPTION("GPIO Aggregator"); +MODULE_LICENSE("GPL v2");