Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932814AbcCIOFG (ORCPT ); Wed, 9 Mar 2016 09:05:06 -0500 Received: from mail-lb0-f196.google.com ([209.85.217.196]:34623 "EHLO mail-lb0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbcCIOE6 (ORCPT ); Wed, 9 Mar 2016 09:04:58 -0500 MIME-Version: 1.0 In-Reply-To: <1457529213-2581-1-git-send-email-jonathanh@nvidia.com> References: <1457529213-2581-1-git-send-email-jonathanh@nvidia.com> Date: Wed, 9 Mar 2016 15:04:56 +0100 X-Google-Sender-Auth: Y76QPFGb9_X-y0ARLhq4CWyTEUU Message-ID: Subject: Re: [PATCH V2] PM / clk: Add support for obtaining clocks from device-tree From: "Rafael J. Wysocki" To: Jon Hunter Cc: "Rafael J. Wysocki" , Geert Uytterhoeven , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , linux-tegra@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7420 Lines: 215 On Wed, Mar 9, 2016 at 2:13 PM, Jon Hunter wrote: > The PM clocks framework requires clients to pass either a con-id or a > valid clk pointer in order to add a clock to a device. Add a new > function of_pm_clk_add_clks() to allows device clocks to be retrieved > from device-tree and populated for a given device. Note that > of_clk_get_from_provider() is not defined if CONFIG_OF and > CONFIG_COMMON_CLK are not selected. Therefore, make of_pm_clk_add_clks() > dependent on these options. > > An optional function pointer may be passed to of_pm_clk_add_clks() that > can be used to filter the clocks that are added for a device when > calling of_pm_clk_add_clks(). > > In order to handle errors encountered when adding clocks from > device-tree, add a function pm_clk_remove_clk() to remove any clocks > (using a pointer to the clk structure) that have been added > successfully before the error occurred. > > Signed-off-by: Jon Hunter > --- > > Changes v1-v2: > - Added support for optional filter function as suggested by Geert U. I'd like to get an ACK on this from someone more familiar with the DT stuff than I am. Thanks, Rafael > drivers/base/power/clock_ops.c | 109 +++++++++++++++++++++++++++++++++++++++++ > include/linux/pm_clock.h | 16 ++++++ > 2 files changed, 125 insertions(+) > > diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c > index 272a52ebafc0..0c2213145b4a 100644 > --- a/drivers/base/power/clock_ops.c > +++ b/drivers/base/power/clock_ops.c > @@ -137,6 +137,82 @@ int pm_clk_add_clk(struct device *dev, struct clk *clk) > return __pm_clk_add(dev, NULL, clk); > } > > + > +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) > +/** > + * of_pm_clk_add_clks - Start using device clock(s) for power management. > + * @dev: Device whose clock(s) is going to be used for power management. > + * @of_pm_clk_filter: Optional function for filtering clocks > + * > + * Add a series of clocks described in the 'clocks' device-tree node for > + * a device to the list of clocks used for the power management of @dev. > + * If 'of_pm_clk_filter' is specified, then this filter function will be > + * called for each clock found and the clock will be added to the list > + * of clocks if this function returns true. Return success if clocks are > + * added successfully and return a negative error code if adding a clock > + * fails or there are no clocks that match with the filter function. > + */ > +int of_pm_clk_add_clks(struct device *dev, > + bool (*of_pm_clk_filter)(struct of_phandle_args *args)) > +{ > + struct of_phandle_args clkspec; > + struct clk **clks; > + unsigned int i, count, added = 0; > + int ret; > + > + if (!dev || !dev->of_node) > + return -EINVAL; > + > + count = of_count_phandle_with_args(dev->of_node, "clocks", > + "#clock-cells"); > + if (count == 0) > + return -ENODEV; > + > + clks = kcalloc(count, sizeof(*clks), GFP_KERNEL); > + if (!clks) > + return -ENOMEM; > + > + for (i = 0; i < count; i++) { > + if (of_parse_phandle_with_args(dev->of_node, "clocks", > + "#clock-cells", i, &clkspec)) > + goto error; > + > + if (of_pm_clk_filter && !of_pm_clk_filter(&clkspec)) { > + of_node_put(clkspec.np); > + continue; > + } > + > + clks[added] = of_clk_get_from_provider(&clkspec); > + of_node_put(clkspec.np); > + > + if (IS_ERR(clks[added])) { > + ret = PTR_ERR(clks[added]); > + goto error; > + } > + > + ret = pm_clk_add_clk(dev, clks[added]); > + if (ret) { > + clk_put(clks[added]); > + goto error; > + } > + > + added++; > + } > + > + kfree(clks); > + > + return added ? 0 : -ENODEV; > + > +error: > + while (added--) > + pm_clk_remove_clk(dev, clks[added]); > + > + kfree(clks); > + > + return ret; > +} > +#endif /* CONFIG_OF && CONFIG_COMMON_CLK */ > + > /** > * __pm_clk_remove - Destroy PM clock entry. > * @ce: PM clock entry to destroy. > @@ -198,6 +274,39 @@ void pm_clk_remove(struct device *dev, const char *con_id) > } > > /** > + * pm_clk_remove_clk - Stop using a device clock for power management. > + * @dev: Device whose clock should not be used for PM any more. > + * @clk: Clock pointer > + * > + * Remove the clock pointed to by @clk from the list of clocks used for > + * the power management of @dev. > + */ > +void pm_clk_remove_clk(struct device *dev, struct clk *clk) > +{ > + struct pm_subsys_data *psd = dev_to_psd(dev); > + struct pm_clock_entry *ce; > + > + if (!psd || !clk) > + return; > + > + spin_lock_irq(&psd->lock); > + > + list_for_each_entry(ce, &psd->clock_list, node) { > + if (clk == ce->clk) > + goto remove; > + } > + > + spin_unlock_irq(&psd->lock); > + return; > + > + remove: > + list_del(&ce->node); > + spin_unlock_irq(&psd->lock); > + > + __pm_clk_remove(ce); > +} > + > +/** > * pm_clk_init - Initialize a device's list of power management clocks. > * @dev: Device to initialize the list of PM clocks for. > * > diff --git a/include/linux/pm_clock.h b/include/linux/pm_clock.h > index 25266c600021..3aa5ad57067a 100644 > --- a/include/linux/pm_clock.h > +++ b/include/linux/pm_clock.h > @@ -11,6 +11,7 @@ > > #include > #include > +#include > > struct pm_clk_notifier_block { > struct notifier_block nb; > @@ -43,6 +44,7 @@ extern void pm_clk_destroy(struct device *dev); > extern int pm_clk_add(struct device *dev, const char *con_id); > extern int pm_clk_add_clk(struct device *dev, struct clk *clk); > extern void pm_clk_remove(struct device *dev, const char *con_id); > +extern void pm_clk_remove_clk(struct device *dev, struct clk *clk); > extern int pm_clk_suspend(struct device *dev); > extern int pm_clk_resume(struct device *dev); > #else > @@ -74,6 +76,9 @@ static inline void pm_clk_remove(struct device *dev, const char *con_id) > } > #define pm_clk_suspend NULL > #define pm_clk_resume NULL > +static inline void pm_clk_remove_clk(struct device *dev, struct clk *clk) > +{ > +} > #endif > > #ifdef CONFIG_HAVE_CLK > @@ -86,4 +91,15 @@ static inline void pm_clk_add_notifier(struct bus_type *bus, > } > #endif > > +#if defined(CONFIG_PM_CLK) && defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) > +extern int of_pm_clk_add_clks(struct device *dev, > + bool (*of_pm_clk_filter)(struct of_phandle_args *args)); > +#else > +static inline int of_pm_clk_add_clks(struct device *dev, > + bool (*of_pm_clk_filter)(struct of_phandle_args *args)) > +{ > + return -EINVAL; > +} > +#endif > + > #endif > -- > 2.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html