Re: [PATCH v3 25/26] coresight: etm4x: Add support for sysreg only devices

[Suzuki K Poulose]

On 11/9/20 8:46 PM, Mathieu Poirier wrote:
> On Wed, Oct 28, 2020 at 10:09:44PM +0000, Suzuki K Poulose wrote:
> > Add support for devices with system instruction access only.
> > They don't have a memory mapped interface and thus are not
> > AMBA devices.
> >
> > Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
> > Cc: Mike Leach <mike.leach@xxxxxxxxxx>
> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
> > ---
> >   .../coresight/coresight-etm4x-core.c          | 50 +++++++++++++++++--
> >   1 file changed, 45 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index 25fab5513604..50a574228866 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > @@ -26,6 +26,7 @@
> >   #include <linux/seq_file.h>
> >   #include <linux/uaccess.h>
> >   #include <linux/perf_event.h>
> > +#include <linux/platform_device.h>
> >   #include <linux/pm_runtime.h>
> >   #include <linux/property.h>
> >   #include <asm/sections.h>
> > @@ -1623,9 +1624,6 @@ static int etm4_probe(struct device *dev, void __iomem *base)
> >   			return -ENOMEM;
> >   	}
> >   
> > -	if (fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
> > -		drvdata->skip_power_up = true;
> > -
> >   	drvdata->base = base;
> >   
> >   	spin_lock_init(&drvdata->spinlock);
> > @@ -1648,6 +1646,11 @@ static int etm4_probe(struct device *dev, void __iomem *base)
> >   	if (!drvdata->arch)
> >   		return -EINVAL;
> >   
> > +	/* Skip programming TRCPDCR for system instructions. */
>
> It would be nice to mention that TRCPDCR is not available in system instruction
> mode.

Sure.

> > +	if (!desc.access.io_mem ||
> > +	    fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
> > +		drvdata->skip_power_up = true;
> > +
> >   	etm4_init_trace_id(drvdata);
> >   	etm4_set_default(&drvdata->config);
> >   
> > @@ -1706,6 +1709,20 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
> >   	return ret;
> >   }
> >   
> > +static int etm4_probe_platform_dev(struct platform_device *pdev)
> > +{
> > +	int ret;
> > +
> > +	pm_runtime_get_noresume(&pdev->dev);
> > +	pm_runtime_set_active(&pdev->dev);
> > +	pm_runtime_enable(&pdev->dev);
> > +
> > +	ret = etm4_probe(&pdev->dev, NULL);
> > +
> > +	pm_runtime_put(&pdev->dev);
> > +	return ret;
> > +}
> > +
> >   static struct amba_cs_uci_id uci_id_etm4[] = {
> >   	{
> >   		/*  ETMv4 UCI data */
> > @@ -1781,6 +1798,20 @@ static struct amba_driver etm4x_amba_driver = {
> >   	.id_table	= etm4_ids,
> >   };
> >   
> > +static const struct of_device_id etm_sysreg_match[] = {
>
> s/etm_sysreg_match/etm4_sysreg_match
>
> > +	{ .compatible	= "arm,coresight-etm-sysreg" },
>
> See my comment in the next patch.
>
> With the above:
>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

Thanks

Suzuki