From patchwork Wed Nov 1 04:04:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jeffery X-Patchwork-Id: 832842 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3yRZQm07Srz9t3p for ; Wed, 1 Nov 2017 15:06:24 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=aj.id.au header.i=@aj.id.au header.b="o7P8mGTA"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="iCE+gKaW"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 3yRZQl5471zDr5S for ; Wed, 1 Nov 2017 15:06:23 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=aj.id.au header.i=@aj.id.au header.b="o7P8mGTA"; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="iCE+gKaW"; dkim-atps=neutral X-Original-To: linux-aspeed@lists.ozlabs.org Delivered-To: linux-aspeed@lists.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=aj.id.au (client-ip=66.111.4.28; helo=out4-smtp.messagingengine.com; envelope-from=andrew@aj.id.au; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=aj.id.au header.i=@aj.id.au header.b="o7P8mGTA"; dkim=pass (2048-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="iCE+gKaW"; dkim-atps=neutral Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yRZQ01C6NzDr4P; Wed, 1 Nov 2017 15:05:44 +1100 (AEDT) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 10C5020B52; Wed, 1 Nov 2017 00:05:42 -0400 (EDT) Received: from frontend1 ([10.202.2.160]) by compute4.internal (MEProxy); Wed, 01 Nov 2017 00:05:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aj.id.au; h=cc :date:from:in-reply-to:message-id:references:subject:to :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=OVwJiV3niVzYlbC+3 yk7eW8K4PiDwSIqy/1vjMIEPSc=; b=o7P8mGTA2XpkQQnOe5iQUOQUVMMRyxdqV F8K2AMcs1ZBgXt44C0ckoXR3ZUgOl71lGqzUN960IWwuROeLpkqALI5tj8ZngEit gLen1NiLrhnJFNZQtDntKl8Ib6uYiu+oJ3y4EfGYJ8Bp8T8+qtkrpCgxxWOvgyAH 37XOK+f8kQFaHDvPfAMKLNyKhm9pLLchdagI6VNh2g4udIH3/orvoTnoF0B6ebD1 TD7hPlZJN96Q6CePYuU7YU2QcdSE86bWtey5XFrJbbzczTVowYG3tSmE57uTMhGX 1dt6AY6nH01idPfLHrp1C0n7wLBR+C+pkdFzkiH05oiWAdOSl73qA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s= fm1; bh=OVwJiV3niVzYlbC+3yk7eW8K4PiDwSIqy/1vjMIEPSc=; b=iCE+gKaW /1kUgWf0vRO+LvylKHmGxqod3GSuDenyGY1WIvD6h8uQl7gcW68iJDfNMpc7eUKk AjQhCGbmeK9kq7nbhr3NO6o44BdxEUzOQB4CzPI33f3TFRMh7D+lfENmajCCpn+L N3CjUzuMamx8cHt8aNjq5k4E3cf0Id5pY5xsjzOCS/4TtRNj9Vlt5s/+cZ0ZA+a0 b+y1ztczHXX3cAfZFbr6l7To7xTmS5WYkcG2wlG2ExCbhYmEIpEIEvxFQ1ILArs4 4iHh7uTooygmlrDv6XDYSX9eS9Rvbih9d7zJ/tcY7Ogpq+fKfIDxcwnRDyMvVt21 hpRAIicd/M5POw== X-ME-Sender: Received: from keelia.au.ibm.com (unknown [122.99.82.10]) by mail.messagingengine.com (Postfix) with ESMTPA id DFCD17F96B; Wed, 1 Nov 2017 00:05:37 -0400 (EDT) From: Andrew Jeffery To: linux-gpio@vger.kernel.org Subject: [PATCH v3 1/2] gpio: gpiolib: Generalise state persistence beyond sleep Date: Wed, 1 Nov 2017 15:04:56 +1100 Message-Id: <20171101040457.1200-2-andrew@aj.id.au> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20171101040457.1200-1-andrew@aj.id.au> References: <20171101040457.1200-1-andrew@aj.id.au> X-BeenThere: linux-aspeed@lists.ozlabs.org X-Mailman-Version: 2.1.24 Precedence: list List-Id: Linux ASPEED SoC development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, devicetree@vger.kernel.org, ryan_chen@aspeedtech.com, linux-aspeed@lists.ozlabs.org, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, ldewangan@nvidia.com, ckeepax@opensource.wolfsonmicro.com, frowand.list@gmail.com, openbmc@lists.ozlabs.org Errors-To: linux-aspeed-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linux-aspeed" General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery Reviewed-by: Charles Keepax Acked-by: Rob Herring --- drivers/gpio/gpiolib-of.c | 6 ++-- drivers/gpio/gpiolib-sysfs.c | 14 +++++--- drivers/gpio/gpiolib.c | 61 ++++++++++++++++++++++++++++++--- drivers/gpio/gpiolib.h | 2 +- include/dt-bindings/gpio/gpio.h | 6 ++-- include/linux/gpio/consumer.h | 8 +++++ include/linux/gpio/machine.h | 4 +-- include/linux/of_gpio.h | 2 +- include/linux/pinctrl/pinconf-generic.h | 2 ++ 9 files changed, 87 insertions(+), 18 deletions(-) diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c index e0d59e61b52f..4a2b8d3397c7 100644 --- a/drivers/gpio/gpiolib-of.c +++ b/drivers/gpio/gpiolib-of.c @@ -153,8 +153,8 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, *flags |= GPIO_OPEN_SOURCE; } - if (of_flags & OF_GPIO_SLEEP_MAY_LOSE_VALUE) - *flags |= GPIO_SLEEP_MAY_LOSE_VALUE; + if (of_flags & OF_GPIO_TRANSITORY) + *flags |= GPIO_TRANSITORY; return desc; } @@ -214,6 +214,8 @@ static struct gpio_desc *of_parse_own_gpio(struct device_node *np, if (xlate_flags & OF_GPIO_ACTIVE_LOW) *lflags |= GPIO_ACTIVE_LOW; + if (xlate_flags & OF_GPIO_TRANSITORY) + *lflags |= GPIO_TRANSITORY; if (of_property_read_bool(np, "input")) *dflags |= GPIOD_IN; diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 3f454eaf2101..0bd472ffb072 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -474,11 +474,15 @@ static ssize_t export_store(struct class *class, status = -ENODEV; goto done; } - status = gpiod_export(desc, true); - if (status < 0) - gpiod_free(desc); - else - set_bit(FLAG_SYSFS, &desc->flags); + + status = gpiod_set_transitory(desc, false); + if (!status) { + status = gpiod_export(desc, true); + if (status < 0) + gpiod_free(desc); + else + set_bit(FLAG_SYSFS, &desc->flags); + } done: if (status) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 3827f0767101..a5e81dc03aba 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -503,6 +503,10 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip) if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); + ret = gpiod_set_transitory(desc, false); + if (ret < 0) + goto out_free_descs; + /* * Lines have to be requested explicitly for input * or output, else the line will be treated "as is". @@ -2424,6 +2428,49 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) EXPORT_SYMBOL_GPL(gpiod_set_debounce); /** + * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset + * @desc: descriptor of the GPIO for which to configure persistence + * @transitory: True to lose state on suspend or reset, false for persistence + * + * Returns: + * 0 on success, otherwise a negative error code. + */ +int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) +{ + struct gpio_chip *chip; + unsigned long packed; + int gpio; + int rc; + + /* + * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for + * persistence state. + */ + if (transitory) + set_bit(FLAG_TRANSITORY, &desc->flags); + else + clear_bit(FLAG_TRANSITORY, &desc->flags); + + /* If the driver supports it, set the persistence state now */ + chip = desc->gdev->chip; + if (!chip->set_config) + return 0; + + packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE, + !transitory); + gpio = gpio_chip_hwgpio(desc); + rc = chip->set_config(chip, gpio, packed); + if (rc == -ENOTSUPP) { + dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n", + gpio); + return 0; + } + + return rc; +} +EXPORT_SYMBOL_GPL(gpiod_set_transitory); + +/** * gpiod_is_active_low - test whether a GPIO is active-low or not * @desc: the gpio descriptor to test * @@ -3010,8 +3057,7 @@ bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset) if (offset >= chip->ngpio) return false; - return !test_bit(FLAG_SLEEP_MAY_LOSE_VALUE, - &chip->gpiodev->descs[offset].flags); + return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent); @@ -3435,8 +3481,10 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, set_bit(FLAG_OPEN_DRAIN, &desc->flags); if (lflags & GPIO_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); - if (lflags & GPIO_SLEEP_MAY_LOSE_VALUE) - set_bit(FLAG_SLEEP_MAY_LOSE_VALUE, &desc->flags); + + status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY)); + if (status < 0) + return status; /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { @@ -3550,6 +3598,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, bool active_low = false; bool single_ended = false; bool open_drain = false; + bool transitory = false; int ret; if (!fwnode) @@ -3564,6 +3613,7 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, active_low = flags & OF_GPIO_ACTIVE_LOW; single_ended = flags & OF_GPIO_SINGLE_ENDED; open_drain = flags & OF_GPIO_OPEN_DRAIN; + transitory = flags & OF_GPIO_TRANSITORY; } } else if (is_acpi_node(fwnode)) { struct acpi_gpio_info info; @@ -3594,6 +3644,9 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, lflags |= GPIO_OPEN_SOURCE; } + if (transitory) + lflags |= GPIO_TRANSITORY; + ret = gpiod_configure_flags(desc, propname, lflags, dflags); if (ret < 0) { gpiod_put(desc); diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index af48322839c3..736b189d1bb5 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -205,7 +205,7 @@ struct gpio_desc { #define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */ #define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */ #define FLAG_IS_HOGGED 11 /* GPIO is hogged */ -#define FLAG_SLEEP_MAY_LOSE_VALUE 12 /* GPIO may lose value in sleep */ +#define FLAG_TRANSITORY 12 /* GPIO may lose value in sleep or reset */ /* Connection label */ const char *label; diff --git a/include/dt-bindings/gpio/gpio.h b/include/dt-bindings/gpio/gpio.h index 70de5b7a6c9b..43dc230d3921 100644 --- a/include/dt-bindings/gpio/gpio.h +++ b/include/dt-bindings/gpio/gpio.h @@ -28,8 +28,8 @@ #define GPIO_OPEN_DRAIN (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_DRAIN) #define GPIO_OPEN_SOURCE (GPIO_SINGLE_ENDED | GPIO_LINE_OPEN_SOURCE) -/* Bit 3 express GPIO suspend/resume persistence */ -#define GPIO_SLEEP_MAINTAIN_VALUE 0 -#define GPIO_SLEEP_MAY_LOSE_VALUE 8 +/* Bit 3 express GPIO suspend/resume and reset persistence */ +#define GPIO_PERSISTENT 0 +#define GPIO_TRANSITORY 8 #endif diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index d4920ec1f1da..d77e88c96f38 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -132,6 +132,7 @@ void gpiod_set_raw_array_value_cansleep(unsigned int array_size, int *value_array); int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce); +int gpiod_set_transitory(struct gpio_desc *desc, bool transitory); int gpiod_is_active_low(const struct gpio_desc *desc); int gpiod_cansleep(const struct gpio_desc *desc); @@ -424,6 +425,13 @@ static inline int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) return -ENOSYS; } +static inline int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) +{ + /* GPIO can never have been requested */ + WARN_ON(1); + return -ENOSYS; +} + static inline int gpiod_is_active_low(const struct gpio_desc *desc) { /* GPIO can never have been requested */ diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h index 5e9f294c29eb..33a97ede6404 100644 --- a/include/linux/gpio/machine.h +++ b/include/linux/gpio/machine.h @@ -9,8 +9,8 @@ enum gpio_lookup_flags { GPIO_ACTIVE_LOW = (1 << 0), GPIO_OPEN_DRAIN = (1 << 1), GPIO_OPEN_SOURCE = (1 << 2), - GPIO_SLEEP_MAINTAIN_VALUE = (0 << 3), - GPIO_SLEEP_MAY_LOSE_VALUE = (1 << 3), + GPIO_PERSISTENT = (0 << 3), + GPIO_TRANSITORY = (1 << 3), }; /** diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h index 1fe205582111..18a7f03e1182 100644 --- a/include/linux/of_gpio.h +++ b/include/linux/of_gpio.h @@ -31,7 +31,7 @@ enum of_gpio_flags { OF_GPIO_ACTIVE_LOW = 0x1, OF_GPIO_SINGLE_ENDED = 0x2, OF_GPIO_OPEN_DRAIN = 0x4, - OF_GPIO_SLEEP_MAY_LOSE_VALUE = 0x8, + OF_GPIO_TRANSITORY = 0x8, }; #ifdef CONFIG_OF_GPIO diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h index 5d8bc7f21c2a..824094f39ad2 100644 --- a/include/linux/pinctrl/pinconf-generic.h +++ b/include/linux/pinctrl/pinconf-generic.h @@ -90,6 +90,7 @@ * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to * this parameter (on a custom format) tells the driver which alternative * slew rate to use. + * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if * you need to pass in custom configurations to the pin controller, use * PIN_CONFIG_END+1 as the base offset. @@ -117,6 +118,7 @@ enum pin_config_param { PIN_CONFIG_POWER_SOURCE, PIN_CONFIG_SLEEP_HARDWARE_STATE, PIN_CONFIG_SLEW_RATE, + PIN_CONFIG_PERSIST_STATE, PIN_CONFIG_END = 0x7F, PIN_CONFIG_MAX = 0xFF, };