From mboxrd@z Thu Jan 1 00:00:00 1970 From: ulf.hansson@linaro.org (Ulf Hansson) Date: Fri, 17 Apr 2015 11:10:06 +0200 Subject: [PATCH 07/13] coresight: tmc: let runtime PM handle core clock In-Reply-To: <1429261140-13910-8-git-send-email-linus.walleij@linaro.org> References: <1429261140-13910-1-git-send-email-linus.walleij@linaro.org> <1429261140-13910-8-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: > This uses runtime PM to manage the PCLK ("amba_pclk") instead > of screwing around with the framework by going in and taking > a copy from the amba device. The amba bus core will uprepare > and disable the clock when the device is unused when > CONFIG_PM is selected, else the clock will be always on. > > Prior to this patch, as the AMBA primecell bus code enables > the PCLK, it would be left on after probe as > the clk_prepare_enable() and clk_disable_unprepare() was > called and thus just increase and decreas the refcount by > one, without it reaching zero and actually disabling the > clock. Now the runtime PM callbacks will make sure the PCLK > is properly disabled after probe. > > Signed-off-by: Linus Walleij Reviewed-by: Ulf Hansson > --- > drivers/coresight/coresight-tmc.c | 20 +++++--------------- > 1 file changed, 5 insertions(+), 15 deletions(-) > > diff --git a/drivers/coresight/coresight-tmc.c b/drivers/coresight/coresight-tmc.c > index 3ff232f9ddf7..db917c70d2b3 100644 > --- a/drivers/coresight/coresight-tmc.c > +++ b/drivers/coresight/coresight-tmc.c > @@ -23,7 +23,7 @@ > #include > #include > #include > -#include > +#include > #include > #include > #include > @@ -104,7 +104,6 @@ enum tmc_mem_intf_width { > * @dev: the device entity associated to this component. > * @csdev: component vitals needed by the framework. > * @miscdev: specifics to handle "/dev/xyz.tmc" entry. > - * @clk: the clock this component is associated to. > * @spinlock: only one at a time pls. > * @read_count: manages preparation of buffer for reading. > * @buf: area of memory where trace data get sent. > @@ -120,7 +119,6 @@ struct tmc_drvdata { > struct device *dev; > struct coresight_device *csdev; > struct miscdevice miscdev; > - struct clk *clk; > spinlock_t spinlock; > int read_count; > bool reading; > @@ -242,17 +240,14 @@ static void tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > > static int tmc_enable(struct tmc_drvdata *drvdata, enum tmc_mode mode) > { > - int ret; > unsigned long flags; > > - ret = clk_prepare_enable(drvdata->clk); > - if (ret) > - return ret; > + pm_runtime_get_sync(drvdata->dev); > > spin_lock_irqsave(&drvdata->spinlock, flags); > if (drvdata->reading) { > spin_unlock_irqrestore(&drvdata->spinlock, flags); > - clk_disable_unprepare(drvdata->clk); > + pm_runtime_put(drvdata->dev); > return -EBUSY; > } > > @@ -386,7 +381,7 @@ out: > drvdata->enable = false; > spin_unlock_irqrestore(&drvdata->spinlock, flags); > > - clk_disable_unprepare(drvdata->clk); > + pm_runtime_put(drvdata->dev); > > dev_info(drvdata->dev, "TMC disabled\n"); > } > @@ -644,11 +639,6 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) > > spin_lock_init(&drvdata->spinlock); > > - drvdata->clk = adev->pclk; > - ret = clk_prepare_enable(drvdata->clk); > - if (ret) > - return ret; > - > devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID); > drvdata->config_type = BMVAL(devid, 6, 7); > > @@ -663,7 +653,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) > drvdata->size = readl_relaxed(drvdata->base + TMC_RSZ) * 4; > } > > - clk_disable_unprepare(drvdata->clk); > + pm_runtime_put(&adev->dev); > > if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { > drvdata->vaddr = dma_alloc_coherent(dev, drvdata->size, > -- > 1.9.3 >