From patchwork Tue Sep 9 11:36:03 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ulf Hansson X-Patchwork-Id: 37096 Return-Path: X-Original-To: linaro@patches.linaro.org Delivered-To: linaro@patches.linaro.org Received: from mail-qc0-f200.google.com (mail-qc0-f200.google.com [209.85.216.200]) by ip-10-151-82-157.ec2.internal (Postfix) with ESMTPS id F0BA520491 for ; Tue, 9 Sep 2014 11:36:50 +0000 (UTC) Received: by mail-qc0-f200.google.com with SMTP id w7sf48905485qcr.11 for ; Tue, 09 Sep 2014 04:36:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:delivered-to:from:to:cc:subject :date:message-id:in-reply-to:references:x-original-sender :x-original-authentication-results:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-unsubscribe; bh=GIygVX16CGMUKIaqLY/l2g40lJY3Oc5ruSXXK45LXvc=; b=Nd5kzDA0YHlpm6LxFN+Yhk0v1qrvwVF2OJyOy0iEcGC29F4rbGlh7/ip0dmWNIRWOg xEHn/TVRE7rb9prDujiO2ax67WYxwXeA+bj+gk8iqM84JttEvI8JayAtkctbwv6GUpOb 3uecyOmBmACQX8kXtzZIxVGcWayVn/M8RcG5/6oTIrIG2PpFBOVCUoEW/sdmD4kNMHwz /wkRRT5U7f3/88S7jmjclSxzxXnH7VZ/L8xg39pxN69wMIYPLP3X6OjnCNVHtv/+h/qH CHZrZG0WSFElT7eSOhh25xC/mIGNBLZf+++EFSaAqTQXgoeF3S+lWCWr4cnwjRS/4RgP 7FUg== X-Gm-Message-State: ALoCoQlctpb25xzby+G+VtxplILIJwjd/K9tE9kRfKLsHxJeUNQcrueNif3Tsj388K1oSkiiO8Bw X-Received: by 10.224.29.1 with SMTP id o1mr21412390qac.0.1410262610810; Tue, 09 Sep 2014 04:36:50 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: patchwork-forward@linaro.org Received: by 10.140.105.247 with SMTP id c110ls2225213qgf.5.gmail; Tue, 09 Sep 2014 04:36:50 -0700 (PDT) X-Received: by 10.221.24.135 with SMTP id re7mr1589141vcb.53.1410262610720; Tue, 09 Sep 2014 04:36:50 -0700 (PDT) Received: from mail-vc0-f169.google.com (mail-vc0-f169.google.com [209.85.220.169]) by mx.google.com with ESMTPS id k10si5653314vdb.46.2014.09.09.04.36.50 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 09 Sep 2014 04:36:50 -0700 (PDT) Received-SPF: pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.169 as permitted sender) client-ip=209.85.220.169; Received: by mail-vc0-f169.google.com with SMTP id ik5so298175vcb.28 for ; Tue, 09 Sep 2014 04:36:50 -0700 (PDT) X-Received: by 10.220.99.71 with SMTP id t7mr3219012vcn.8.1410262606623; Tue, 09 Sep 2014 04:36:46 -0700 (PDT) X-Forwarded-To: patchwork-forward@linaro.org X-Forwarded-For: patch@linaro.org patchwork-forward@linaro.org Delivered-To: patches@linaro.org Received: by 10.221.45.67 with SMTP id uj3csp270169vcb; Tue, 9 Sep 2014 04:36:45 -0700 (PDT) X-Received: by 10.152.179.226 with SMTP id dj2mr23319066lac.40.1410262604609; Tue, 09 Sep 2014 04:36:44 -0700 (PDT) Received: from mail-la0-f45.google.com (mail-la0-f45.google.com [209.85.215.45]) by mx.google.com with ESMTPS id k5si17413931laa.119.2014.09.09.04.36.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 09 Sep 2014 04:36:44 -0700 (PDT) Received-SPF: pass (google.com: domain of ulf.hansson@linaro.org designates 209.85.215.45 as permitted sender) client-ip=209.85.215.45; Received: by mail-la0-f45.google.com with SMTP id pn19so19223561lab.4 for ; Tue, 09 Sep 2014 04:36:44 -0700 (PDT) X-Received: by 10.112.50.52 with SMTP id z20mr8593677lbn.87.1410262604061; Tue, 09 Sep 2014 04:36:44 -0700 (PDT) Received: from uffe-Latitude-E6430s.lan (90-231-160-185-no158.tbcn.telia.com. [90.231.160.185]) by mx.google.com with ESMTPSA id gn7sm4476961lbc.10.2014.09.09.04.36.40 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 09 Sep 2014 04:36:42 -0700 (PDT) From: Ulf Hansson To: "Rafael J. Wysocki" , Len Brown , Pavel Machek , Greg Kroah-Hartman , linux-pm@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, Geert Uytterhoeven , Kevin Hilman , Alan Stern , Daniel Lezcano , Tomasz Figa , devicetree@vger.kernel.org, Linus Walleij , Simon Horman , Magnus Damm , Ben Dooks , Kukjin Kim , Stephen Boyd , Philipp Zabel , Mark Brown , Wolfram Sang , Chris Ball , Russell King , Ulf Hansson Subject: [PATCH v4 2/9] PM / Domains: Add generic OF-based PM domain look-up Date: Tue, 9 Sep 2014 13:36:03 +0200 Message-Id: <1410262570-22785-3-git-send-email-ulf.hansson@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1410262570-22785-1-git-send-email-ulf.hansson@linaro.org> References: <1409838756-31963-1-git-send-email-ulf.hansson@linaro.org> <1410262570-22785-1-git-send-email-ulf.hansson@linaro.org> X-Removed-Original-Auth: Dkim didn't pass. X-Original-Sender: ulf.hansson@linaro.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of patch+caf_=patchwork-forward=linaro.org@linaro.org designates 209.85.220.169 as permitted sender) smtp.mail=patch+caf_=patchwork-forward=linaro.org@linaro.org Precedence: list Mailing-list: list patchwork-forward@linaro.org; contact patchwork-forward+owners@linaro.org List-ID: X-Google-Group-Id: 836684582541 List-Post: , List-Help: , List-Archive: List-Unsubscribe: , From: Tomasz Figa This patch introduces generic code to perform PM domain look-up using device tree and automatically bind devices to their PM domains. Generic device tree bindings are introduced to specify PM domains of devices in their device tree nodes. Backwards compatibility with legacy Samsung-specific PM domain bindings is provided, but for now the new code is not compiled when CONFIG_ARCH_EXYNOS is selected to avoid collision with legacy code. This will change as soon as the Exynos PM domain code gets converted to use the generic framework in further patch. This patch was originally submitted by Tomasz Figa when he was employed by Samsung. http://marc.info/?l=linux-pm&m=139955349702152&w=2 Signed-off-by: Ulf Hansson Acked-by: Rob Herring Tested-by: Philipp Zabel Reviewed-by: Kevin Hilman --- .../devicetree/bindings/power/power_domain.txt | 49 ++++ drivers/base/power/domain.c | 291 +++++++++++++++++++++ include/linux/pm_domain.h | 57 ++++ kernel/power/Kconfig | 4 + 4 files changed, 401 insertions(+) create mode 100644 Documentation/devicetree/bindings/power/power_domain.txt diff --git a/Documentation/devicetree/bindings/power/power_domain.txt b/Documentation/devicetree/bindings/power/power_domain.txt new file mode 100644 index 0000000..98c1667 --- /dev/null +++ b/Documentation/devicetree/bindings/power/power_domain.txt @@ -0,0 +1,49 @@ +* Generic PM domains + +System on chip designs are often divided into multiple PM domains that can be +used for power gating of selected IP blocks for power saving by reduced leakage +current. + +This device tree binding can be used to bind PM domain consumer devices with +their PM domains provided by PM domain providers. A PM domain provider can be +represented by any node in the device tree and can provide one or more PM +domains. A consumer node can refer to the provider by a phandle and a set of +phandle arguments (so called PM domain specifiers) of length specified by the +#power-domain-cells property in the PM domain provider node. + +==PM domain providers== + +Required properties: + - #power-domain-cells : Number of cells in a PM domain specifier; + Typically 0 for nodes representing a single PM domain and 1 for nodes + providing multiple PM domains (e.g. power controllers), but can be any value + as specified by device tree binding documentation of particular provider. + +Example: + + power: power-controller@12340000 { + compatible = "foo,power-controller"; + reg = <0x12340000 0x1000>; + #power-domain-cells = <1>; + }; + +The node above defines a power controller that is a PM domain provider and +expects one cell as its phandle argument. + +==PM domain consumers== + +Required properties: + - power-domains : A phandle and PM domain specifier as defined by bindings of + the power controller specified by phandle. + +Example: + + leaky-device@12350000 { + compatible = "foo,i-leak-current"; + reg = <0x12350000 0x1000>; + power-domains = <&power 0>; + }; + +The node above defines a typical PM domain consumer device, which is located +inside a PM domain with index 0 of a power controller represented by a node +with the label "power". diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c index cf4651a..f09b615 100644 --- a/drivers/base/power/domain.c +++ b/drivers/base/power/domain.c @@ -8,6 +8,7 @@ #include #include +#include #include #include #include @@ -1933,3 +1934,293 @@ void pm_genpd_init(struct generic_pm_domain *genpd, list_add(&genpd->gpd_list_node, &gpd_list); mutex_unlock(&gpd_list_lock); } + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +/* + * Device Tree based PM domain providers. + * + * The code below implements generic device tree based PM domain providers that + * bind device tree nodes with generic PM domains registered in the system. + * + * Any driver that registers generic PM domains and needs to support binding of + * devices to these domains is supposed to register a PM domain provider, which + * maps a PM domain specifier retrieved from the device tree to a PM domain. + * + * Two simple mapping functions have been provided for convenience: + * - __of_genpd_xlate_simple() for 1:1 device tree node to PM domain mapping. + * - __of_genpd_xlate_onecell() for mapping of multiple PM domains per node by + * index. + */ + +/** + * struct of_genpd_provider - PM domain provider registration structure + * @link: Entry in global list of PM domain providers + * @node: Pointer to device tree node of PM domain provider + * @xlate: Provider-specific xlate callback mapping a set of specifier cells + * into a PM domain. + * @data: context pointer to be passed into @xlate callback + */ +struct of_genpd_provider { + struct list_head link; + struct device_node *node; + genpd_xlate_t xlate; + void *data; +}; + +/* List of registered PM domain providers. */ +static LIST_HEAD(of_genpd_providers); +/* Mutex to protect the list above. */ +static DEFINE_MUTEX(of_genpd_mutex); + +/** + * __of_genpd_xlate_simple() - Xlate function for direct node-domain mapping + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct generic_pm_domain + * + * This is a generic xlate function that can be used to model PM domains that + * have their own device tree nodes. The private data of xlate function needs + * to be a valid pointer to struct generic_pm_domain. + */ +struct generic_pm_domain *__of_genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data) +{ + if (genpdspec->args_count != 0) + return ERR_PTR(-EINVAL); + return data; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_simple); + +/** + * __of_genpd_xlate_onecell() - Xlate function using a single index. + * @genpdspec: OF phandle args to map into a PM domain + * @data: xlate function private data - pointer to struct genpd_onecell_data + * + * This is a generic xlate function that can be used to model simple PM domain + * controllers that have one device tree node and provide multiple PM domains. + * A single cell is used as an index into an array of PM domains specified in + * the genpd_onecell_data struct when registering the provider. + */ +struct generic_pm_domain *__of_genpd_xlate_onecell( + struct of_phandle_args *genpdspec, + void *data) +{ + struct genpd_onecell_data *genpd_data = data; + unsigned int idx = genpdspec->args[0]; + + if (genpdspec->args_count != 1) + return ERR_PTR(-EINVAL); + + if (idx >= genpd_data->num_domains) { + pr_err("%s: invalid domain index %u\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + if (!genpd_data->domains[idx]) + return ERR_PTR(-ENOENT); + + return genpd_data->domains[idx]; +} +EXPORT_SYMBOL_GPL(__of_genpd_xlate_onecell); + +/** + * __of_genpd_add_provider() - Register a PM domain provider for a node + * @np: Device node pointer associated with the PM domain provider. + * @xlate: Callback for decoding PM domain from phandle arguments. + * @data: Context pointer for @xlate callback. + */ +int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data) +{ + struct of_genpd_provider *cp; + + cp = kzalloc(sizeof(*cp), GFP_KERNEL); + if (!cp) + return -ENOMEM; + + cp->node = of_node_get(np); + cp->data = data; + cp->xlate = xlate; + + mutex_lock(&of_genpd_mutex); + list_add(&cp->link, &of_genpd_providers); + mutex_unlock(&of_genpd_mutex); + pr_debug("Added domain provider from %s\n", np->full_name); + + return 0; +} +EXPORT_SYMBOL_GPL(__of_genpd_add_provider); + +/** + * of_genpd_del_provider() - Remove a previously registered PM domain provider + * @np: Device node pointer associated with the PM domain provider + */ +void of_genpd_del_provider(struct device_node *np) +{ + struct of_genpd_provider *cp; + + mutex_lock(&of_genpd_mutex); + list_for_each_entry(cp, &of_genpd_providers, link) { + if (cp->node == np) { + list_del(&cp->link); + of_node_put(cp->node); + kfree(cp); + break; + } + } + mutex_unlock(&of_genpd_mutex); +} +EXPORT_SYMBOL_GPL(of_genpd_del_provider); + +/** + * of_genpd_get_from_provider() - Look-up PM domain + * @genpdspec: OF phandle args to use for look-up + * + * Looks for a PM domain provider under the node specified by @genpdspec and if + * found, uses xlate function of the provider to map phandle args to a PM + * domain. + * + * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR() + * on failure. + */ +static struct generic_pm_domain *of_genpd_get_from_provider( + struct of_phandle_args *genpdspec) +{ + struct generic_pm_domain *genpd = ERR_PTR(-ENOENT); + struct of_genpd_provider *provider; + + mutex_lock(&of_genpd_mutex); + + /* Check if we have such a provider in our array */ + list_for_each_entry(provider, &of_genpd_providers, link) { + if (provider->node == genpdspec->np) + genpd = provider->xlate(genpdspec, provider->data); + if (!IS_ERR(genpd)) + break; + } + + mutex_unlock(&of_genpd_mutex); + + return genpd; +} + +/** + * genpd_dev_pm_attach - Attach a device to its PM domain using DT. + * @dev: Device to attach. + * + * Parse device's OF node to find a PM domain specifier. If such is found, + * attaches the device to retrieved pm_domain ops. + * + * Both generic and legacy Samsung-specific DT bindings are supported to keep + * backwards compatibility with existing DTBs. + * + * Returns 0 on successfully attached PM domain or negative error code. + */ +int genpd_dev_pm_attach(struct device *dev) +{ + struct of_phandle_args pd_args; + struct generic_pm_domain *pd; + int ret; + + if (!dev->of_node) + return -ENODEV; + + if (dev->pm_domain) + return -EEXIST; + + ret = of_parse_phandle_with_args(dev->of_node, "power-domains", + "#power-domain-cells", 0, &pd_args); + if (ret < 0) { + if (ret != -ENOENT) + return ret; + + /* + * Try legacy Samsung-specific bindings + * (for backwards compatibility of DT ABI) + */ + pd_args.args_count = 0; + pd_args.np = of_parse_phandle(dev->of_node, + "samsung,power-domain", 0); + if (!pd_args.np) + return -ENOENT; + } + + pd = of_genpd_get_from_provider(&pd_args); + if (IS_ERR(pd)) { + dev_dbg(dev, "%s() failed to find PM domain: %ld\n", + __func__, PTR_ERR(pd)); + of_node_put(dev->of_node); + return PTR_ERR(pd); + } + + dev_dbg(dev, "adding to PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_add_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to add to PM domain %s: %d", + pd->name, ret); + of_node_put(dev->of_node); + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_attach); + +/** + * genpd_dev_pm_detach - Detach a device from its PM domain. + * @dev: Device to attach. + * + * Try to locate a corresponding generic PM domain, which the device was + * attached to previously. If such is found, the device is detached from it. + * + * Returns 0 on successfully detached PM domain or negative error code. + */ +int genpd_dev_pm_detach(struct device *dev) +{ + struct generic_pm_domain *pd = NULL, *gpd; + int ret = 0; + + if (!dev->pm_domain) + return -ENODEV; + + mutex_lock(&gpd_list_lock); + list_for_each_entry(gpd, &gpd_list, gpd_list_node) { + if (&gpd->domain == dev->pm_domain) { + pd = gpd; + break; + } + } + mutex_unlock(&gpd_list_lock); + + if (!pd) + return -ENOENT; + + dev_dbg(dev, "removing from PM domain %s\n", pd->name); + + while (1) { + ret = pm_genpd_remove_device(pd, dev); + if (ret != -EAGAIN) + break; + cond_resched(); + } + + if (ret < 0) { + dev_err(dev, "failed to remove from PM domain %s: %d", + pd->name, ret); + return ret; + } + + /* Check if PM domain can be powered off after removing this device. */ + genpd_queue_power_off_work(pd); + + return 0; +} +EXPORT_SYMBOL_GPL(genpd_dev_pm_detach); +#endif diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h index aa03586..ff128c1 100644 --- a/include/linux/pm_domain.h +++ b/include/linux/pm_domain.h @@ -264,4 +264,61 @@ static inline void pm_genpd_syscore_poweroff(struct device *dev) {} static inline void pm_genpd_syscore_poweron(struct device *dev) {} #endif +/* OF PM domain providers */ +struct of_device_id; + +struct genpd_onecell_data { + struct generic_pm_domain **domains; + unsigned int num_domains; +}; + +typedef struct generic_pm_domain *(*genpd_xlate_t)(struct of_phandle_args *args, + void *data); + +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF +int __of_genpd_add_provider(struct device_node *np, genpd_xlate_t xlate, + void *data); +void of_genpd_del_provider(struct device_node *np); + +struct generic_pm_domain *__of_genpd_xlate_simple( + struct of_phandle_args *genpdspec, + void *data); +struct generic_pm_domain *__of_genpd_xlate_onecell( + struct of_phandle_args *genpdspec, + void *data); + +int genpd_dev_pm_attach(struct device *dev); +int genpd_dev_pm_detach(struct device *dev); +#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */ +static inline int __of_genpd_add_provider(struct device_node *np, + genpd_xlate_t xlate, void *data) +{ + return 0; +} +static inline void of_genpd_del_provider(struct device_node *np) {} + +#define __of_genpd_xlate_simple NULL +#define __of_genpd_xlate_onecell NULL + +static inline int genpd_dev_pm_attach(struct device *dev) +{ + return -ENODEV; +} +static inline int genpd_dev_pm_detach(struct device *dev) +{ + return -ENODEV; +} +#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */ + +static inline int of_genpd_add_provider_simple(struct device_node *np, + struct generic_pm_domain *genpd) +{ + return __of_genpd_add_provider(np, __of_genpd_xlate_simple, genpd); +} +static inline int of_genpd_add_provider_onecell(struct device_node *np, + struct genpd_onecell_data *data) +{ + return __of_genpd_add_provider(np, __of_genpd_xlate_onecell, data); +} + #endif /* _LINUX_PM_DOMAIN_H */ diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index e4e4121..897619b 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -302,6 +302,10 @@ config PM_GENERIC_DOMAINS_RUNTIME def_bool y depends on PM_RUNTIME && PM_GENERIC_DOMAINS +config PM_GENERIC_DOMAINS_OF + def_bool y + depends on PM_GENERIC_DOMAINS && OF && !ARCH_EXYNOS + config CPU_PM bool depends on SUSPEND || CPU_IDLE