From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@linaro.org (Ulf Hansson) Date: Fri, 17 Apr 2015 11:31:09 +0200 Subject: [PATCH 12/13] coresight: replicator: retrieve and handle atclk In-Reply-To: <1429261140-13910-13-git-send-email-linus.walleij@linaro.org> References: <1429261140-13910-1-git-send-email-linus.walleij@linaro.org> <1429261140-13910-13-git-send-email-linus.walleij@linaro.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 17 April 2015 at 10:58, Linus Walleij wrote: > As can be seen from the datasheet of the CoreSight > Components, DDI0314 table A-4 the funnel has a clock signal > apart from the AHB interconnect ("amba_pclk", that we're > already handling) called ATCLK, ARM Trace Clock, that SoC > implementers may provide from an entirely different clock > source. So to model this correctly create an optional > path for handling ATCLK alongside the PCLK so we don't > break old platforms that only define PCLK ("amba_pclk") but > still makes it possible for SoCs that have both clock signals > (such as the DB8500) to fetch and prepare/enable/disable/ > unprepare both clocks. > > The ATCLK is enabled and disabled using the runtime PM > callbacks. As the replicator is a platform device, the > code is a bit different from the other CoreSight components > and the bus core does not activate runtime PM by default, > so we need a few extra calls. > > Signed-off-by: Linus Walleij > --- > drivers/coresight/coresight-replicator.c | 43 ++++++++++++++++++++++++++++++++ > 1 file changed, 43 insertions(+) > > diff --git a/drivers/coresight/coresight-replicator.c b/drivers/coresight/coresight-replicator.c > index cdf05537d574..126ae1f731d7 100644 > --- a/drivers/coresight/coresight-replicator.c > +++ b/drivers/coresight/coresight-replicator.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -27,10 +28,12 @@ > /** > * struct replicator_drvdata - specifics associated to a replicator component > * @dev: the device entity associated with this component > + * @atclk: optional clock for the core parts of the replicator. > * @csdev: component vitals needed by the framework > */ > struct replicator_drvdata { > struct device *dev; > + struct clk *atclk; > struct coresight_device *csdev; > }; > > @@ -39,6 +42,7 @@ static int replicator_enable(struct coresight_device *csdev, int inport, > { > struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > > + pm_runtime_get_sync(drvdata->dev); > dev_info(drvdata->dev, "REPLICATOR enabled\n"); > return 0; > } > @@ -48,6 +52,7 @@ static void replicator_disable(struct coresight_device *csdev, int inport, > { > struct replicator_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > > + pm_runtime_put(drvdata->dev); > dev_info(drvdata->dev, "REPLICATOR disabled\n"); > } > > @@ -62,6 +67,7 @@ static const struct coresight_ops replicator_cs_ops = { > > static int replicator_probe(struct platform_device *pdev) > { > + int ret; > struct device *dev = &pdev->dev; > struct coresight_platform_data *pdata = NULL; > struct replicator_drvdata *drvdata; > @@ -80,7 +86,16 @@ static int replicator_probe(struct platform_device *pdev) > return -ENOMEM; > > drvdata->dev = &pdev->dev; > + drvdata->atclk = devm_clk_get(&pdev->dev, "atclk"); /* optional */ > + if (!IS_ERR(drvdata->atclk)) { > + ret = clk_prepare_enable(drvdata->atclk); > + if (ret) > + return ret; > + } > platform_set_drvdata(pdev, drvdata); > + pm_runtime_set_active(&pdev->dev); > + pm_runtime_enable(&pdev->dev); > + pm_runtime_put(&pdev->dev); > Move the pm_runtime_put() to the end of the ->probe(). Add a pm_runtime_get_noresume() prior the pm_runtime_set_active() call. The you also need to add error handling. Taking care of gating the clock, decreasing the runtime PM reference count and disabling runtime PM. > desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL); > if (!desc) > @@ -107,6 +122,33 @@ static int replicator_remove(struct platform_device *pdev) > return 0; > } > > +#ifdef CONFIG_PM > +static int replicator_runtime_suspend(struct device *dev) > +{ > + struct replicator_drvdata *drvdata = dev_get_drvdata(dev); > + > + if (drvdata && !IS_ERR(drvdata->atclk)) > + clk_disable_unprepare(drvdata->atclk); > + > + return 0; > +} > + > +static int replicator_runtime_resume(struct device *dev) > +{ > +struct replicator_drvdata *drvdata = dev_get_drvdata(dev); Tab? > + > + if (drvdata && !IS_ERR(drvdata->atclk)) > + clk_prepare_enable(drvdata->atclk); > + > + return 0; > +} > +#endif > + > +static const struct dev_pm_ops replicator_dev_pm_ops = { > + SET_RUNTIME_PM_OPS(replicator_runtime_suspend, > + replicator_runtime_resume, NULL) > +}; > + > static struct of_device_id replicator_match[] = { > {.compatible = "arm,coresight-replicator"}, > {} > @@ -118,6 +160,7 @@ static struct platform_driver replicator_driver = { > .driver = { > .name = "coresight-replicator", > .of_match_table = replicator_match, > + .pm = &replicator_dev_pm_ops, > }, > }; > > -- > 1.9.3 > Kind regards Uffe