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

Suzuki K Poulose
2020-11-10T10:50:46Z

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@linaro.org>
>> Cc: Mike Leach <mike.leach@linaro.org>
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> ---
>> .../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@linaro.org>
>

Thanks

Suzuki