From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@linaro.org (Ulf Hansson) Date: Fri, 17 Apr 2015 11:18:20 +0200 Subject: [PATCH 08/13] coresight: etm: retrieve and handle atclk In-Reply-To: <1429261140-13910-9-git-send-email-linus.walleij@linaro.org> References: <1429261140-13910-1-git-send-email-linus.walleij@linaro.org> <1429261140-13910-9-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, DDI0401C A.1.1 the ETM 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. > > Signed-off-by: Linus Walleij > --- > drivers/coresight/coresight-etm.h | 2 ++ > drivers/coresight/coresight-etm3x.c | 38 ++++++++++++++++++++++++++++++++++++- > 2 files changed, 39 insertions(+), 1 deletion(-) > > diff --git a/drivers/coresight/coresight-etm.h b/drivers/coresight/coresight-etm.h > index d1421e1f8b8a..098ffbec0a44 100644 > --- a/drivers/coresight/coresight-etm.h > +++ b/drivers/coresight/coresight-etm.h > @@ -140,6 +140,7 @@ > * struct etm_drvdata - specifics associated to an ETM component > * @base: memory mapped base address for this component. > * @dev: the device entity associated to this component. > + * @atclk: optional clock for the core parts of the ETM. > * @csdev: component vitals needed by the framework. > * @spinlock: only one at a time pls. > * @cpu: the cpu this component is affined to. > @@ -191,6 +192,7 @@ > struct etm_drvdata { > void __iomem *base; > struct device *dev; > + struct clk *atclk; > struct coresight_device *csdev; > spinlock_t spinlock; > int cpu; > diff --git a/drivers/coresight/coresight-etm3x.c b/drivers/coresight/coresight-etm3x.c > index f0be12bd79e0..25f49b84a6d2 100644 > --- a/drivers/coresight/coresight-etm3x.c > +++ b/drivers/coresight/coresight-etm3x.c > @@ -30,6 +30,7 @@ > #include > #include > #include > +#include > #include > > #include "coresight-etm.h" > @@ -1315,7 +1316,6 @@ static ssize_t seq_curr_state_show(struct device *dev, > } > > pm_runtime_get_sync(drvdata->dev); > - > spin_lock_irqsave(&drvdata->spinlock, flags); > > CS_UNLOCK(drvdata->base); > @@ -1796,6 +1796,13 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) > > spin_lock_init(&drvdata->spinlock); > > + drvdata->atclk = devm_clk_get(&adev->dev, "atclk"); /* optional */ > + if (!IS_ERR(drvdata->atclk)) { > + ret = clk_prepare_enable(drvdata->atclk); > + if (ret) > + return ret; > + } > + > drvdata->cpu = pdata ? pdata->cpu : 0; > > get_online_cpus(); > @@ -1858,6 +1865,34 @@ static int etm_remove(struct amba_device *adev) > return 0; > } > > +#ifdef CONFIG_PM > +static int etm_runtime_suspend(struct device *dev) > +{ > + struct amba_device *adev = to_amba_device(dev); > + struct etm_drvdata *drvdata = amba_get_drvdata(adev); I think you could replace the above two lines with: struct etm_drvdata *drvdata = dev_get_drvdata(dev); > + > + if (drvdata && !IS_ERR(drvdata->atclk)) > + clk_disable_unprepare(drvdata->atclk); > + > + return 0; > +} > + > +static int etm_runtime_resume(struct device *dev) > +{ > + struct amba_device *adev = to_amba_device(dev); > + struct etm_drvdata *drvdata = amba_get_drvdata(adev); I think you could replace the above two lines with: struct etm_drvdata *drvdata = dev_get_drvdata(dev) > + > + if (drvdata && !IS_ERR(drvdata->atclk)) > + clk_prepare_enable(drvdata->atclk); > + > + return 0; > +} > +#endif > + > +static const struct dev_pm_ops etm_dev_pm_ops = { > + SET_RUNTIME_PM_OPS(etm_runtime_suspend, etm_runtime_resume, NULL) > +}; > + > static struct amba_id etm_ids[] = { > { /* ETM 3.3 */ > .id = 0x0003b921, > @@ -1886,6 +1921,7 @@ static struct amba_driver etm_driver = { > .drv = { > .name = "coresight-etm3x", > .owner = THIS_MODULE, > + .pm = &etm_dev_pm_ops, > }, > .probe = etm_probe, > .remove = etm_remove, > -- > 1.9.3 > With the minor changes suggested. Reviewed-by: Ulf Hansson