From patchwork Wed Oct 6 03:53:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 12538515 X-Patchwork-Delegate: johannes@sipsolutions.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19A70C4332F for ; Wed, 6 Oct 2021 03:55:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 019C861248 for ; Wed, 6 Oct 2021 03:55:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237896AbhJFD5P (ORCPT ); Tue, 5 Oct 2021 23:57:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237284AbhJFD4G (ORCPT ); Tue, 5 Oct 2021 23:56:06 -0400 Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 093AAC061749 for ; Tue, 5 Oct 2021 20:54:15 -0700 (PDT) Received: by mail-lf1-x12b.google.com with SMTP id j5so4511469lfg.8 for ; Tue, 05 Oct 2021 20:54:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=00n7CaYRtB/oPVPJyhNLQU99dusIfQvK/8kpoba23hk=; b=zX40LljGN0ujw8Ut02so9lFStCBV0UifqUNXL0ScIn+t056lOtA+NXl2HUma6WEbyT iHzvQr0fA86NTJ4WX5zvV5ZnwjUSwpP/AwO/AwfBrPb1A8whPKrmDYhypIwS4dCm5FoD bmfAAvbSh4JeEKf64NBq1URR/KeBWwDXLtCFaQynpl06NivcC6ju2RPI7kY1Ob5KKcVz bXnsCjZCPmcAj2ljhIDXY54cOk34otVfOdrOChtE0ZWY/q5NJ/7iIwEdU9+ZHTzTOkmu qwOnrOaBCTqAqiCzzhD7u6T0KPw3Q0+yWQ4cJRx0JymQl+BaZAaA7vUcHz3TvNhFsiX3 uNMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=00n7CaYRtB/oPVPJyhNLQU99dusIfQvK/8kpoba23hk=; b=WXR154g18xzFU2z9uTyULHgr0aRV808KiWbPjWIw+Z5rJRgl7GRl4PbX23tCiu7MkZ 6Dl1OdceQbxqww2a1Q/rQ1Qjo46ljYDjAwNCXbmryfj7qKsy2hxnxmGbxxQzn7nGiNWU dTFFztFZv1ZOvQSeJQ7AKQm3vryFv1YkmI1oItb1O2w+HMf+DEq2KPuG+GKJTJk2oH2X /RG6v/+BiUAKuJZH5lpy/+t2Nk2c3bfxhZEeJpD4emp/RVGjE436JiPPG7bpdn6Lqytd /uurC3trYuw1BYMftfzkWFQqfX7JD+yuSkAjr6I9NEUydFtvG16l1ZwWD0xGf2ApPoZh gTHA== X-Gm-Message-State: AOAM531mctrzzhm2Ii23Fly4PNtN6SwFjVI3CpLBuhkV8/8nrOVUKhix +Fk0Ti6vUZTmGP9t6XGm7aV5sQ== X-Google-Smtp-Source: ABdhPJy3e+mVycCeMiNKlisUqhg9bBIUp1+fzuK3w4Wx3UkS+S2PGMaTnxZyiwjLhZdx7FUZNywDSw== X-Received: by 2002:a05:6512:2614:: with SMTP id bt20mr7043195lfb.506.1633492453152; Tue, 05 Oct 2021 20:54:13 -0700 (PDT) Received: from eriador.lan ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id s4sm2142967lfd.103.2021.10.05.20.54.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Oct 2021 20:54:12 -0700 (PDT) From: Dmitry Baryshkov To: Andy Gross , Bjorn Andersson , Ulf Hansson , Marcel Holtmann , Johan Hedberg , Luiz Augusto von Dentz , Kalle Valo , "David S. Miller" , Jakub Kicinski , Stanimir Varbanov Cc: linux-arm-msm@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org, ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v1 02/15] power: add power sequencer subsystem Date: Wed, 6 Oct 2021 06:53:54 +0300 Message-Id: <20211006035407.1147909-3-dmitry.baryshkov@linaro.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211006035407.1147909-1-dmitry.baryshkov@linaro.org> References: <20211006035407.1147909-1-dmitry.baryshkov@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Basing on MMC's pwrseq support code, add separate power sequencer subsystem. It will be used by other drivers to handle device power up requirements. Signed-off-by: Dmitry Baryshkov --- Documentation/driver-api/index.rst | 1 + Documentation/driver-api/pwrseq.rst | 77 +++++ drivers/power/Kconfig | 1 + drivers/power/Makefile | 1 + drivers/power/pwrseq/Kconfig | 14 + drivers/power/pwrseq/Makefile | 6 + drivers/power/pwrseq/core.c | 448 ++++++++++++++++++++++++++++ include/linux/pwrseq/consumer.h | 82 +++++ include/linux/pwrseq/driver.h | 160 ++++++++++ 9 files changed, 790 insertions(+) create mode 100644 Documentation/driver-api/pwrseq.rst create mode 100644 drivers/power/pwrseq/Kconfig create mode 100644 drivers/power/pwrseq/Makefile create mode 100644 drivers/power/pwrseq/core.c create mode 100644 include/linux/pwrseq/consumer.h create mode 100644 include/linux/pwrseq/driver.h diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst index c57c609ad2eb..15f51c08db1f 100644 --- a/Documentation/driver-api/index.rst +++ b/Documentation/driver-api/index.rst @@ -94,6 +94,7 @@ available subsections can be seen below. ptp phy/index pwm + pwrseq pldmfw/index rfkill serial/index diff --git a/Documentation/driver-api/pwrseq.rst b/Documentation/driver-api/pwrseq.rst new file mode 100644 index 000000000000..df7cfce0f792 --- /dev/null +++ b/Documentation/driver-api/pwrseq.rst @@ -0,0 +1,77 @@ +.. Copyright 2021 Linaro Ltd. + +.. This documentation is free software; you can redistribute +.. it and/or modify it under the terms of the GNU General Public +.. License version 2 as published by the Free Software Foundation. + +==================== +Power Sequencing API +==================== + +:Author: Dmitry Baryshkov +:Author: Ulf Hansson (original MMC pwrseq) + +Introduction +============ + +This framework is designed to provide a standard kernel interface to +handle power sequencing requirements for different devices. + +The intention is to provide a generic way to handle power sequencing of complex +devices sitting on a variety of busses. First implementation comes from MMC +SDIO/eMMC code, not generified to support other kinds of devices. + +Glossary +-------- + +The pwrseq API uses a number of terms which may not be familiar: + +Power sequencer + + Electronic device (or part of it) that supplies power to other devices. + Unlike regulators (which typically handle single voltage), power sequencer + handles several voltage inputs. Also it does not provide an exact voltage + output. Instead it makes sure that the consumers (see below) are powered on + when required. + +Consumer + + Electronic device which consumes power provided by a power sequencer. + +Consumer driver interface +========================= + +This offers a similar API to the kernel clock or regulator framework. Consumer +drivers use `get <#API-pwrseq-get>`__ and +`put <#API-pwrseq-put>`__ operations to acquire and release +power sequencers. Functions are provided to `power on +<#API-pwrseq-full-power-on>`__ and `power off <#API-pwrseq-power-off>`__ the +power sequencer. + +A stub version of this API is provided when the power sequencer framework is +not in use in order to minimise the need to use ifdefs. + +Power sequencer driver interface +================================ + +Drivers for power sequencers register the sequencer within the pwrseq +core, providing operations structures to the core. + +API reference +============= + +Due to limitations of the kernel documentation framework and the +existing layout of the source code the entire regulator API is +documented here. + +.. kernel-doc:: include/linux/pwrseq/consumer.h + :internal: + +.. kernel-doc:: include/linux/pwrseq/driver.h + :internal: + +.. kernel-doc:: include/linux/pwrseq/fallback.h + :internal: + +.. kernel-doc:: drivers/power/pwrseq/core.c + :export: diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig index 696bf77a7042..c87cd2240a74 100644 --- a/drivers/power/Kconfig +++ b/drivers/power/Kconfig @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only +source "drivers/power/pwrseq/Kconfig" source "drivers/power/reset/Kconfig" source "drivers/power/supply/Kconfig" diff --git a/drivers/power/Makefile b/drivers/power/Makefile index effbf0377f32..1dbce454a8c4 100644 --- a/drivers/power/Makefile +++ b/drivers/power/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_POWER_RESET) += reset/ obj-$(CONFIG_POWER_SUPPLY) += supply/ +obj-$(CONFIG_PWRSEQ) += pwrseq/ diff --git a/drivers/power/pwrseq/Kconfig b/drivers/power/pwrseq/Kconfig new file mode 100644 index 000000000000..dab8f4d860fe --- /dev/null +++ b/drivers/power/pwrseq/Kconfig @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-2.0-only +menuconfig PWRSEQ + bool "Power Sequencer drivers" + help + Provides support for special power sequencing drivers. Power + sequencer is an entity providing abstraced power on/power off/reset + operations for the connected devices. Possible usages include MMC + SDIO devices, some complex WiFi/BT chips, controlled USB hubs, etc. + + Say Y here to enable support for such devices. + +if PWRSEQ + +endif diff --git a/drivers/power/pwrseq/Makefile b/drivers/power/pwrseq/Makefile new file mode 100644 index 000000000000..108429ff6445 --- /dev/null +++ b/drivers/power/pwrseq/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for power sequencer drivers. +# + +obj-$(CONFIG_PWRSEQ) += core.o diff --git a/drivers/power/pwrseq/core.c b/drivers/power/pwrseq/core.c new file mode 100644 index 000000000000..d29b4b97b95c --- /dev/null +++ b/drivers/power/pwrseq/core.c @@ -0,0 +1,448 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2021 (c) Linaro Ltd. + * Author: Dmitry Baryshkov + * + * Based on phy-core.c: + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define to_pwrseq(a) (container_of((a), struct pwrseq, dev)) + +static DEFINE_IDA(pwrseq_ida); +static DEFINE_MUTEX(pwrseq_provider_mutex); +static LIST_HEAD(pwrseq_provider_list); + +/** + * struct pwrseq_provider - a + */ +struct pwrseq_provider { + struct device *dev; + struct module *owner; + struct list_head list; + void *data; + struct pwrseq * (*of_xlate)(void *data, struct of_phandle_args *args); +}; + +/** + * pwrseq_put() - release the pwrseq + * @pwrseq: the pwrseq returned by pwrseq_get() + * + * Releases a refcount on the pwrseq instance received from pwrseq_get(). + */ +void pwrseq_put(struct pwrseq *pwrseq) +{ + module_put(pwrseq->owner); + put_device(&pwrseq->dev); +} +EXPORT_SYMBOL_GPL(pwrseq_put); + +static struct pwrseq_provider *of_pwrseq_provider_lookup(struct device_node *node) +{ + struct pwrseq_provider *pwrseq_provider; + + list_for_each_entry(pwrseq_provider, &pwrseq_provider_list, list) { + if (pwrseq_provider->dev->of_node == node) + return pwrseq_provider; + } + + return ERR_PTR(-EPROBE_DEFER); +} + +static struct pwrseq *_of_pwrseq_get(struct device *dev, const char *id) +{ + struct pwrseq_provider *pwrseq_provider; + struct pwrseq *pwrseq; + struct of_phandle_args args; + char prop_name[64]; /* 64 is max size of property name */ + int ret; + + snprintf(prop_name, sizeof(prop_name), "%s-pwrseq", id); + ret = of_parse_phandle_with_args(dev->of_node, prop_name, "#pwrseq-cells", 0, &args); + if (ret == -ENOENT) + return NULL; + else if (ret < 0) + return ERR_PTR(ret); + + mutex_lock(&pwrseq_provider_mutex); + pwrseq_provider = of_pwrseq_provider_lookup(args.np); + if (IS_ERR(pwrseq_provider) || !try_module_get(pwrseq_provider->owner)) { + pwrseq = ERR_PTR(-EPROBE_DEFER); + goto out_unlock; + } + + if (!of_device_is_available(args.np)) { + dev_warn(pwrseq_provider->dev, "Requested pwrseq is disabled\n"); + pwrseq = ERR_PTR(-ENODEV); + goto out_put_module; + } + + pwrseq = pwrseq_provider->of_xlate(pwrseq_provider->data, &args); + +out_put_module: + module_put(pwrseq_provider->owner); + +out_unlock: + mutex_unlock(&pwrseq_provider_mutex); + of_node_put(args.np); + + return pwrseq; +} + +/** + * pwrseq_get() - lookup and obtain a reference to a pwrseq + * @dev: device for which to get the pwrseq + * @id: name of the pwrseq from device's point of view + * + * Returns the pwrseq instance, after getting a refcount to it; or + * NULL if there is no such pwrseq. The caller is responsible for + * calling pwrseq_put() to release that count. + */ +struct pwrseq * pwrseq_get(struct device *dev, const char *id) +{ + struct pwrseq *pwrseq; + + pwrseq = _of_pwrseq_get(dev, id); + if (IS_ERR_OR_NULL(pwrseq)) + return pwrseq; + + if (!try_module_get(pwrseq->owner)) + return ERR_PTR(-EPROBE_DEFER); + + get_device(&pwrseq->dev); + + return pwrseq; +} +EXPORT_SYMBOL_GPL(pwrseq_get); + +static void devm_pwrseq_release(struct device *dev, void *res) +{ + struct pwrseq *pwrseq = *(struct pwrseq **)res; + + pwrseq_put(pwrseq); +} + +/** + * devm_pwrseq_get() - lookup and obtain a reference to a pwrseq + * @dev: device for which to get the pwrseq + * @id: name of the pwrseq from device's point of view + * + * Devres-managed variant of pwrseq_get(). + * Returns the pwrseq instance, after getting a refcount to it; or + * NULL if there is no such pwrseq. Gets the pwrseq using pwrseq_get(), and + * associates it with the a device using devres. On driver detach, returned + * pwrseq is automatically put using pwrseq_put(), removing the need to call it + * manually. + */ +struct pwrseq * devm_pwrseq_get(struct device *dev, const char *id) +{ + struct pwrseq **ptr, *pwrseq; + + ptr = devres_alloc(devm_pwrseq_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + pwrseq = pwrseq_get(dev, id); + if (!IS_ERR_OR_NULL(pwrseq)) { + *ptr = pwrseq; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return pwrseq; +} +EXPORT_SYMBOL_GPL(devm_pwrseq_get); + +/** + * pwrseq_pre_power_on() - perform pre-power on actions + * @pwrseq: pwrseq instance + * + * Perform pre-powering on actions, like pulling reset pin. This function + * should be called before device is being powered on. Typical usage would + * include MMC cards, where pwrseq subsystem is combined with the MMC power + * controls. + * In most cases there is no need to call it directly, use + * @pwrseq_full_power_on() instead. + */ +int pwrseq_pre_power_on(struct pwrseq *pwrseq) +{ + if (pwrseq && pwrseq->ops->pre_power_on) + return pwrseq->ops->pre_power_on(pwrseq); + + return 0; +} +EXPORT_SYMBOL_GPL(pwrseq_pre_power_on); + +/** + * pwrseq_power_on() - power on the device + * @pwrseq: pwrseq instance + * + * Power on the device and perform post-power on actions, like pulling reset + * or enable pin. In most cases there is no need to call it directly, use + * @pwrseq_full_power_on() instead. + */ +int pwrseq_power_on(struct pwrseq *pwrseq) +{ + if (pwrseq && pwrseq->ops->power_on) + return pwrseq->ops->power_on(pwrseq); + + return 0; +} +EXPORT_SYMBOL_GPL(pwrseq_power_on); + +/** + * pwrseq_power_off() - power off the device + * @pwrseq: pwrseq instance + * + * Power off the device clearly. + */ +void pwrseq_power_off(struct pwrseq *pwrseq) +{ + if (pwrseq && pwrseq->ops->power_off) + pwrseq->ops->power_off(pwrseq); +} +EXPORT_SYMBOL_GPL(pwrseq_power_off); + +/** + * pwrseq_reset() - reset powered device + * @pwrseq: pwrseq instance + * + * Reset the device controlled by the power sequencer. + */ +void pwrseq_reset(struct pwrseq *pwrseq) +{ + if (pwrseq && pwrseq->ops->reset) + pwrseq->ops->reset(pwrseq); +} +EXPORT_SYMBOL_GPL(pwrseq_reset); + +static void pwrseq_dev_release(struct device *dev) +{ + struct pwrseq *pwrseq = to_pwrseq(dev); + + ida_free(&pwrseq_ida, pwrseq->id); + of_node_put(dev->of_node); + kfree(pwrseq); +} + +static struct class pwrseq_class = { + .name = "pwrseq", + .dev_release = pwrseq_dev_release, +}; + +/** + * __pwrseq_create() - internal helper for pwrseq_create + * @dev: parent device + * @owner: the module providing callbacks. + * @ops: pwrseq device callbacks + * + * This is an internal helper for pwrseq_create which should not be called + * directly. + * + * Return: created instance or the wrapped error code. + */ +struct pwrseq *__pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops) +{ + struct pwrseq *pwrseq; + int ret; + + if (WARN_ON(!dev)) + return ERR_PTR(-EINVAL); + + pwrseq = kzalloc(sizeof(*pwrseq), GFP_KERNEL); + if (!pwrseq) + return ERR_PTR(-ENOMEM); + + ret = ida_alloc(&pwrseq_ida, GFP_KERNEL); + if (ret < 0) + goto free_pwrseq; + + pwrseq->id = ret; + + device_initialize(&pwrseq->dev); + + pwrseq->dev.class = &pwrseq_class; + pwrseq->dev.parent = dev; + pwrseq->dev.of_node = of_node_get(dev->of_node); + pwrseq->ops = ops; + pwrseq->owner = owner; + + ret = dev_set_name(&pwrseq->dev, "pwrseq-%s.%u", dev_name(dev), pwrseq->id); + if (ret) + goto put_dev; + + ret = device_add(&pwrseq->dev); + if (ret) + goto put_dev; + + return pwrseq; + +put_dev: + /* will call pwrseq_dev_release() to free resources */ + put_device(&pwrseq->dev); + + return ERR_PTR(ret); + +free_pwrseq: + kfree(pwrseq); + + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(__pwrseq_create); + +void pwrseq_destroy(struct pwrseq *pwrseq) +{ + device_unregister(&pwrseq->dev); +} +EXPORT_SYMBOL_GPL(pwrseq_destroy); + +static void devm_pwrseq_destroy(struct device *dev, void *res) +{ + struct pwrseq *pwrseq = *(struct pwrseq **)res; + + pwrseq_destroy(pwrseq); +} + +/** + * __devm_pwrseq_create() - devres-managed version of __pwrseq_create + * @dev: parent device + * @owner: the module providing callbacks. + * @ops: pwrseq device callbacks + * + * This is the devres-managed version of __pwrseq_create(). It is an internal + * helper which should not be called directly. + * + * Return: created instance or the wrapped error code. + */ +struct pwrseq *__devm_pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops) +{ + struct pwrseq **ptr, *pwrseq; + + ptr = devres_alloc(devm_pwrseq_destroy, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + pwrseq = __pwrseq_create(dev, owner, ops); + if (!IS_ERR(pwrseq)) { + *ptr = pwrseq; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return pwrseq; +} +EXPORT_SYMBOL_GPL(__devm_pwrseq_create); + +/** + * __of_pwrseq_provider_register - internal version of of_pwrseq_provider_register + * @dev: handling device + * @owner: the module providing callbacks. + * @xlate: xlate function returning pwrseq instance corresponding to OF args + * @data: provider-specific data to be passed to xlate function + * + * This is an internal helper of of_pwrseq_provider_register, it should not be + * called directly. + */ +struct pwrseq_provider *__of_pwrseq_provider_register(struct device *dev, + struct module *owner, + struct pwrseq * (*of_xlate)(void *data, + struct of_phandle_args *args), + void *data) +{ + struct pwrseq_provider *pwrseq_provider; + + pwrseq_provider = kzalloc(sizeof(*pwrseq_provider), GFP_KERNEL); + if (!pwrseq_provider) + return ERR_PTR(-ENOMEM); + + if (!fwnode_property_present(dev->fwnode, "#pwrseq-cells")) + dev_warn(dev, "no #pwrseq-cells property found, please add the property to the provider\n"); + + pwrseq_provider->dev = dev; + pwrseq_provider->owner = owner; + pwrseq_provider->of_xlate = of_xlate; + pwrseq_provider->data = data; + + mutex_lock(&pwrseq_provider_mutex); + list_add_tail(&pwrseq_provider->list, &pwrseq_provider_list); + mutex_unlock(&pwrseq_provider_mutex); + + return pwrseq_provider; +} +EXPORT_SYMBOL_GPL(__of_pwrseq_provider_register); + +/** + * of_pwrseq_provider_unregister() - unregister pwrseq provider + * @pwrseq_provider: pwrseq provider to unregister + * + * Unregister pwrseq provider previously registered by of_pwrseq_provider_register(). + */ +void of_pwrseq_provider_unregister(struct pwrseq_provider *pwrseq_provider) +{ + if (IS_ERR(pwrseq_provider)) + return; + + mutex_lock(&pwrseq_provider_mutex); + list_del(&pwrseq_provider->list); + kfree(pwrseq_provider); + mutex_unlock(&pwrseq_provider_mutex); +} +EXPORT_SYMBOL_GPL(of_pwrseq_provider_unregister); + +static void devm_pwrseq_provider_unregister(struct device *dev, void *res) +{ + struct pwrseq_provider *pwrseq_provider = *(struct pwrseq_provider **)res; + + of_pwrseq_provider_unregister(pwrseq_provider); +} + +/** + * __devm_of_pwrseq_provider_register - internal version of devm_of_pwrseq_provider_register + * @dev: handling device + * @owner: the module providing callbacks. + * @xlate: xlate function returning pwrseq instance corresponding to OF args + * @data: provider-specific data to be passed to xlate function + * + * This is an internal helper of devm_of_pwrseq_provider_register, it should + * not be called directly. + */ +struct pwrseq_provider *__devm_of_pwrseq_provider_register(struct device *dev, + struct module *owner, + struct pwrseq * (*of_xlate)(void *data, + struct of_phandle_args *args), + void *data) +{ + struct pwrseq_provider **ptr, *pwrseq_provider; + + ptr = devres_alloc(devm_pwrseq_provider_unregister, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return ERR_PTR(-ENOMEM); + + pwrseq_provider = __of_pwrseq_provider_register(dev, owner, of_xlate, data); + if (!IS_ERR(pwrseq_provider)) { + *ptr = pwrseq_provider; + devres_add(dev, ptr); + } else { + devres_free(ptr); + } + + return pwrseq_provider; +} +EXPORT_SYMBOL_GPL(__devm_of_pwrseq_provider_register); + +static int __init pwrseq_core_init(void) +{ + return class_register(&pwrseq_class); +} +device_initcall(pwrseq_core_init); diff --git a/include/linux/pwrseq/consumer.h b/include/linux/pwrseq/consumer.h new file mode 100644 index 000000000000..7c8efefd3184 --- /dev/null +++ b/include/linux/pwrseq/consumer.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2021 Linaro Ltd. + */ + +#ifndef __LINUX_PWRSEQ_CONSUMER_H__ +#define __LINUX_PWRSEQ_CONSUMER_H__ + +struct pwrseq; +struct device; + +#if defined(CONFIG_PWRSEQ) + +struct pwrseq *__must_check pwrseq_get(struct device *dev, const char *id); +struct pwrseq *__must_check devm_pwrseq_get(struct device *dev, const char *id); + +void pwrseq_put(struct pwrseq *pwrseq); + +int pwrseq_pre_power_on(struct pwrseq *pwrseq); +int pwrseq_power_on(struct pwrseq *pwrseq); +void pwrseq_power_off(struct pwrseq *pwrseq); +void pwrseq_reset(struct pwrseq *pwrseq); + +#else + +static inline struct pwrseq *__must_check +pwrseq_get(struct device *dev, const char *id) +{ + return NULL; +} + +static inline struct pwrseq *__must_check +devm_pwrseq_get(struct device *dev, const char *id) +{ + return NULL; +} + +static inline void pwrseq_put(struct pwrseq *pwrseq) +{ +} + +static inline int pwrseq_pre_power_on(struct pwrseq *pwrseq) +{ + return -ENOSYS; +} + +static inline int pwrseq_power_on(struct pwrseq *pwrseq) +{ + return -ENOSYS; +} + +static inline void pwrseq_power_off(struct pwrseq *pwrseq) +{ +} + +static inline void pwrseq_reset(struct pwrseq *pwrseq) +{ +} + +#endif + +/** + * pwrseq_full_power_on() - Perform full power on of the sequencer + * @pwrseq: the power sequencer to power on + * + * Perform full power on of the sequencer, including pre power on and + * power on steps. + * + * Return: 0 upon no error; -error upon error. + */ +static inline int pwrseq_full_power_on(struct pwrseq *pwrseq) +{ + int ret; + + ret = pwrseq_pre_power_on(pwrseq); + if (ret) + return ret; + + return pwrseq_power_on(pwrseq); +} + +#endif /* __LINUX_PWRSEQ_CONSUMER_H__ */ diff --git a/include/linux/pwrseq/driver.h b/include/linux/pwrseq/driver.h new file mode 100644 index 000000000000..bdb8a25a8504 --- /dev/null +++ b/include/linux/pwrseq/driver.h @@ -0,0 +1,160 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2021 Linaro Ltd. + */ + +#ifndef __LINUX_PWRSEQ_DRIVER_H__ +#define __LINUX_PWRSEQ_DRIVER_H__ + +#include + +struct pwrseq; + +/** + * struct pwrseq_ops - power sequencer operations. + * + * @pre_power_on: Perform pre powering operations (like ensuring that the + * device will be held in the reset) + * @power_on: Power on the sequencer, making sure that the consumer + * devices can be operated + * @power_off: Power off the sequencer, removing power from the comsumer + * device (if possible) + * @reset: Reset the consumer device + */ +struct pwrseq_ops { + int (*pre_power_on)(struct pwrseq *pwrseq); + int (*power_on)(struct pwrseq *pwrseq); + void (*power_off)(struct pwrseq *pwrseq); + void (*reset)(struct pwrseq *pwrseq); +}; + +struct module; + +/** + * struct pwrseq - private pwrseq data + * + * Power sequencer device, one for each power sequencer. + * + * This should *not* be used directly by anything except the pwrseq core. + */ +struct pwrseq { + struct device dev; + const struct pwrseq_ops *ops; + unsigned int id; + struct module *owner; +}; + +struct pwrseq *__pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops); +struct pwrseq *__devm_pwrseq_create(struct device *dev, struct module *owner, const struct pwrseq_ops *ops); + +/** + * pwrseq_create() - create pwrseq instance + * @dev: parent device + * @ops: pwrseq device callbacks + * + * Create new pwrseq instance parenting with @dev using provided @ops set of + * callbacks. Create instance should be destroyed using @pwrseq_destroy(). + * + * Return: created instance or the wrapped error code. + */ +#define pwrseq_create(dev, ops, data) __pwrseq_create((dev), THIS_MODULE, (ops)) + +/** + * devm_pwrseq_create() - devres-managed version of pwrseq_create + * @dev: parent device + * @ops: pwrseq device callbacks + * + * This is the devres-managed version of pwrseq_create(). It creates new + * pwrseq instance parenting with @dev using provided @ops set of + * callbacks. Returned object is destroyed automatically, one must not call + * pwrseq_destroy(). + * + * Return: created instance or the wrapped error code. + */ +#define devm_pwrseq_create(dev, ops, data) __devm_pwrseq_create((dev), THIS_MODULE, (ops)) + +void pwrseq_destroy(struct pwrseq *pwrseq); + +/** + * pwrseq_set_data() - get drv-specific data for the pwrseq + * @pwrseq: the pwrseq to get driver data for + * @data: the data to set + * + * Sets the driver-specific data for the provided powrseq instance. + */ +static inline void pwrseq_set_drvdata(struct pwrseq *pwrseq, void *data) +{ + dev_set_drvdata(&pwrseq->dev, data); +} + +/** + * pwrseq_get_data() - get drv-specific data for the pwrseq + * @pwrseq: the pwrseq to get driver data for + * + * Returns driver-specific data for the provided powrseq instance. + */ +static inline void *pwrseq_get_drvdata(struct pwrseq *pwrseq) +{ + return dev_get_drvdata(&pwrseq->dev); +} + +/** + * of_pwrseq_provider_register() - register OF pwrseq provider + * @dev: handling device + * @xlate: xlate function returning pwrseq instance corresponding to OF args + * @data: provider-specific data to be passed to xlate function + * + * This macros registers OF-specific pwrseq provider. Pwrseq core will call + * specified @xlate function to retrieve pwrseq instance corresponding to + * device tree arguments. Returned pwrseq provider should be unregistered using + * of_pwrseq_provider_unregister(). + */ +#define of_pwrseq_provider_register(dev, xlate, data) \ + __of_pwrseq_provider_register((dev), THIS_MODULE, (xlate), (data)) + +/** + * devm_of_pwrseq_provider_register() - devres-managed version of of_pwrseq_provider_register + * @dev: handling device + * @xlate: xlate function returning pwrseq instance corresponding to OF args + * @data: provider-specific data to be passed to xlate function + * + * This is a devres-managed version of of_pwrseq_provider_register(). + * This macros registers OF-specific pwrseq provider. Pwrseq core will call + * specified @xlate function to retrieve pwrseq instance corresponding to + * device tree arguments. Returned pwrseq provider is automatically + * unregistered, without the need to call of_pwrseq_provider_unregister(). + */ +#define devm_of_pwrseq_provider_register(dev, xlate, data) \ + __devm_of_pwrseq_provider_register((dev), THIS_MODULE, (xlate), (data)) + +struct of_phandle_args; + +struct pwrseq_provider *__of_pwrseq_provider_register(struct device *dev, + struct module *owner, + struct pwrseq * (*of_xlate)(void *data, + struct of_phandle_args *args), + void *data); +struct pwrseq_provider *__devm_of_pwrseq_provider_register(struct device *dev, + struct module *owner, + struct pwrseq * (*of_xlate)(void *data, + struct of_phandle_args *args), + void *data); +void of_pwrseq_provider_unregister(struct pwrseq_provider *pwrseq_provider); + +/** + * of_pwrseq_xlate_single() - returns the pwrseq instance from pwrseq provider + * @data: the pwrseq provider data + * @args: of_phandle_args (not used here) + * + * Intended to be used by pwrseq provider for the common case where + * #pwrseq-cells is 0. For other cases where #pwrseq-cells is greater than '0', + * the pwrseq provider should provide a custom of_xlate function that reads the + * *args* and returns the appropriate pwrseq. + */ +static inline struct pwrseq *of_pwrseq_xlate_single(void *data, + struct of_phandle_args *args) +{ + return data; +} + +#endif /* __LINUX_PWRSEQ_DRIVER_H__ */