From patchwork Wed Oct 6 03:53:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dmitry Baryshkov X-Patchwork-Id: 12538469 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 1C9EDC4332F for ; Wed, 6 Oct 2021 03:54:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08EF761423 for ; Wed, 6 Oct 2021 03:54:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237570AbhJFD41 (ORCPT ); Tue, 5 Oct 2021 23:56:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237371AbhJFD4L (ORCPT ); Tue, 5 Oct 2021 23:56:11 -0400 Received: from mail-lf1-x130.google.com (mail-lf1-x130.google.com [IPv6:2a00:1450:4864:20::130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 41684C06174E for ; Tue, 5 Oct 2021 20:54:19 -0700 (PDT) Received: by mail-lf1-x130.google.com with SMTP id m3so4628334lfu.2 for ; Tue, 05 Oct 2021 20:54:19 -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=NeHIhsZMUr5ykJB6Caqyp6Vh5XIKp8x7h5mO8Gk2lJA=; b=JUxbS46H6NBi4pyhUO9ZGHUxljkmmFsu0pJ1MztZTmIx0lOvzlLsrza/qzXhdcfkqA tzHNBu7cho4Ik8BtD9OCsxGoTX0Zhkwq7V+9F31Nt/K4XnLL1j9MSWzoIl+BfwAi2zvB cnoAJpYHzi8Km7qVHJnTMsUttYGJWKqH5V5h3gMpzb4xJ14mpDQrGrl7RvE2hInpCSoP MSAkuk5ii1PH1RSLcCglGm7JDtaOdzA5caqSLHHPViXNkIbGS7xeO+YNFWkqoYHM5IAS MMI7xXBA/oj04pXU6xndAQjW3s2+1gueXHAu78GYMaidhyyqvCgOyGi6JYaoeHC87Xo2 bLQw== 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=NeHIhsZMUr5ykJB6Caqyp6Vh5XIKp8x7h5mO8Gk2lJA=; b=02DBAXl89AwOVPM4aCjm3WqvrE0c/WafFVKYhPAmSl0GnyzXQjLfRkYjTFgVkO9Xkx stQN3YGPo31aQ6mYvRolHxmjOz4rOQ3jpXAiLHzEH+W1Pb8V85B72aYBQ0TTbjQXgV2f v93OzMKoi1v/KeiDI+mZEZavGu8uF/vtL2UWA1UXq0b66Aee+r+j5M56tBsH/GBkMYLV AXZ+VKXdfwEAiB8acSAUdG2z+y6GD9o0vALeygEIu5WyWQ2Gj0pYXYC7BtJ4UimjVZBR rf4o0QFLf2FonTCRQtWbV0mOCT6ZNpZVujZGYcfXXuvEiREPnDBxBIQWaL0XoqlpXDQs h1uA== X-Gm-Message-State: AOAM530O9Figff4aAAA3ZWeP8CnLXLCeirDYWuZcmdgBlmmbVTbLhJsF lgqV1tRVBOkA8jvxqHLhMqeLSg== X-Google-Smtp-Source: ABdhPJyK9tu7tnCJm/AWi0OyoXXi8YhLObOtc76v0sfowxgHmlXe9CSRMktSA+i8KUxBsBoAP8bIPg== X-Received: by 2002:a19:7109:: with SMTP id m9mr7621114lfc.112.1633492457604; Tue, 05 Oct 2021 20:54:17 -0700 (PDT) Received: from eriador.lan ([37.153.55.125]) by smtp.gmail.com with ESMTPSA id s4sm2142967lfd.103.2021.10.05.20.54.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Oct 2021 20:54:16 -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 07/15] pwrseq: add fallback support Date: Wed, 6 Oct 2021 06:53:59 +0300 Message-Id: <20211006035407.1147909-8-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-mmc@vger.kernel.org Power sequencer support requires changing device tree. To ease migration to pwrseq, add support for pwrseq 'fallback': let the power sequencer driver register special handler that if matched will create pwrseq instance basing on the consumer device tree data. Signed-off-by: Dmitry Baryshkov --- drivers/power/pwrseq/Makefile | 2 +- drivers/power/pwrseq/core.c | 3 ++ drivers/power/pwrseq/fallback.c | 88 +++++++++++++++++++++++++++++++++ include/linux/pwrseq/fallback.h | 60 ++++++++++++++++++++++ 4 files changed, 152 insertions(+), 1 deletion(-) create mode 100644 drivers/power/pwrseq/fallback.c create mode 100644 include/linux/pwrseq/fallback.h diff --git a/drivers/power/pwrseq/Makefile b/drivers/power/pwrseq/Makefile index 556bf5582d47..949ec848cf00 100644 --- a/drivers/power/pwrseq/Makefile +++ b/drivers/power/pwrseq/Makefile @@ -3,7 +3,7 @@ # Makefile for power sequencer drivers. # -obj-$(CONFIG_PWRSEQ) += core.o +obj-$(CONFIG_PWRSEQ) += core.o fallback.o obj-$(CONFIG_PWRSEQ_EMMC) += pwrseq_emmc.o obj-$(CONFIG_PWRSEQ_QCA) += pwrseq_qca.o diff --git a/drivers/power/pwrseq/core.c b/drivers/power/pwrseq/core.c index 3dffa52f65ee..30380ca6159a 100644 --- a/drivers/power/pwrseq/core.c +++ b/drivers/power/pwrseq/core.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #define to_pwrseq(a) (container_of((a), struct pwrseq, dev)) @@ -120,6 +121,8 @@ struct pwrseq * pwrseq_get(struct device *dev, const char *id) struct pwrseq *pwrseq; pwrseq = _of_pwrseq_get(dev, id); + if (pwrseq == NULL) + pwrseq = pwrseq_fallback_get(dev, id); if (IS_ERR_OR_NULL(pwrseq)) return pwrseq; diff --git a/drivers/power/pwrseq/fallback.c b/drivers/power/pwrseq/fallback.c new file mode 100644 index 000000000000..b83bd5795ccb --- /dev/null +++ b/drivers/power/pwrseq/fallback.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2021 (c) Linaro Ltd. + * Author: Dmitry Baryshkov + */ + +#include +#include +#include +#include +#include +#include + +static DEFINE_MUTEX(pwrseq_fallback_mutex); +static LIST_HEAD(pwrseq_fallback_list); + +/** + * __pwrseq_fallback_register - internal helper for pwrseq_fallback_register + * @fallback - struct pwrseq_fallback to be registered + * @owner: module containing fallback callback + * + * Internal helper for pwrseq_fallback_register. It should not be called directly. + */ +int __pwrseq_fallback_register(struct pwrseq_fallback *fallback, struct module *owner) +{ + if (!try_module_get(owner)) + return -EPROBE_DEFER; + + fallback->owner = owner; + + mutex_lock(&pwrseq_fallback_mutex); + list_add_tail(&fallback->list, &pwrseq_fallback_list); + mutex_unlock(&pwrseq_fallback_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(__pwrseq_fallback_register); + +/** + * pwrseq_fallback_unregister() - unregister fallback helper + * @fallback - struct pwrseq_fallback to unregister + * + * Unregister pwrseq fallback handler registered by pwrseq_fallback_handler. + */ +void pwrseq_fallback_unregister(struct pwrseq_fallback *fallback) +{ + mutex_lock(&pwrseq_fallback_mutex); + list_del(&fallback->list); + mutex_unlock(&pwrseq_fallback_mutex); + + module_put(fallback->owner); + + kfree(fallback); +} +EXPORT_SYMBOL_GPL(pwrseq_fallback_unregister); + +static bool pwrseq_fallback_match(struct device *dev, struct pwrseq_fallback *fallback) +{ + if (of_match_device(fallback->of_match_table, dev) != NULL) + return true; + + /* We might add support for other matching options later */ + + return false; +} + +struct pwrseq *pwrseq_fallback_get(struct device *dev, const char *id) +{ + struct pwrseq_fallback *fallback; + struct pwrseq *pwrseq = ERR_PTR(-ENODEV); + + mutex_lock(&pwrseq_fallback_mutex); + + list_for_each_entry(fallback, &pwrseq_fallback_list, list) { + if (!pwrseq_fallback_match(dev, fallback)) + continue; + + pwrseq = fallback->get(dev, id); + break; + } + + mutex_unlock(&pwrseq_fallback_mutex); + + if (!IS_ERR_OR_NULL(pwrseq)) + dev_warn(dev, "legacy pwrseq support used for the device\n"); + + return pwrseq; +} diff --git a/include/linux/pwrseq/fallback.h b/include/linux/pwrseq/fallback.h new file mode 100644 index 000000000000..14f9aa527692 --- /dev/null +++ b/include/linux/pwrseq/fallback.h @@ -0,0 +1,60 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (c) 2021 Linaro Ltd. + */ + +#ifndef __LINUX_PWRSEQ_FALLBACK_H__ +#define __LINUX_PWRSEQ_FALLBACK_H__ + +#include + +struct pwrseq; + +struct device; +struct module; +struct of_device_id; + +/** + * struct pwrseq_fallback - structure providing fallback data/ + * @list: a list node for the fallback handlers + * @owner: module containing fallback callback + * @of_match_table: match table for this fallback + * + * Pwrseq fallback is a mechanism for handling backwards compatibility in the + * case device tree was not updated to use proper pwrseq providers. + * + * In case the pwrseq instance is not registered, core will automatically try + * locating and calling fallback getter. If the requesting device matches + * against @of_match_table, the @get callback will be called to retrieve pwrseq + * instance. + * + * The driver should fill of_match_table and @get fields only. @list and @owner + * will be filled by the core code. + */ +struct pwrseq_fallback { + struct list_head list; + struct module *owner; + + const struct of_device_id *of_match_table; + + struct pwrseq *(*get)(struct device *dev, const char *id); +}; + +/* provider interface */ + +int __pwrseq_fallback_register(struct pwrseq_fallback *fallback, struct module *owner); + +/** + * pwrseq_fallback_register() - register fallback helper + * @fallback - struct pwrseq_fallback to be registered + * + * Register pwrseq fallback handler to assist pwrseq core. + */ +#define pwrseq_fallback_register(fallback) __pwrseq_fallback_register(fallback, THIS_MODULE) + +void pwrseq_fallback_unregister(struct pwrseq_fallback *fallback); + +/* internal interface to be used by pwrseq core */ +struct pwrseq *pwrseq_fallback_get(struct device *dev, const char *id); + +#endif /* __LINUX_PWRSEQ_DRIVER_H__ */