linux-kernel - Re: [PATCH v3 05/11] coresight-tpdm: Add nodes to set trigger timestamp and type

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Date:   Sat, 1 Apr 2023 10:30:51 +0100
From:   Suzuki K Poulose <suzuki.poulose@....com>
To:     Tao Zhang <quic_taozha@...cinc.com>,
        Mathieu Poirier <mathieu.poirier@...aro.org>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Konrad Dybcio <konradybcio@...il.com>,
        Mike Leach <mike.leach@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
Cc:     Jinlong Mao <quic_jinlmao@...cinc.com>,
        Leo Yan <leo.yan@...aro.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        Tingwei Zhang <quic_tingweiz@...cinc.com>,
        Yuanfang Zhang <quic_yuanfang@...cinc.com>,
        Trilok Soni <quic_tsoni@...cinc.com>,
        Hao Zhang <quic_hazha@...cinc.com>,
        linux-arm-msm@...r.kernel.org, bjorn.andersson@...aro.org
Subject: Re: [PATCH v3 05/11] coresight-tpdm: Add nodes to set trigger
 timestamp and type

On 23/03/2023 06:04, Tao Zhang wrote:
> The nodes are needed to set or show the trigger timestamp and
> trigger type. This change is to add these nodes to achieve these
> function.
> 
> Signed-off-by: Tao Zhang <quic_taozha@...cinc.com>
> ---
>   .../ABI/testing/sysfs-bus-coresight-devices-tpdm   | 24 ++++++
>   drivers/hwtracing/coresight/coresight-tpdm.c       | 95 ++++++++++++++++++++++
>   2 files changed, 119 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> index 4a58e64..27ce681 100644
> --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
> @@ -11,3 +11,27 @@ Description:
>   		Accepts only one of the 2 values -  1 or 2.
>   		1 : Generate 64 bits data
>   		2 : Generate 32 bits data
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/dsb_trig_type
> +Date:		March 2023
> +KernelVersion	6.3
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@...cinc.com>, Tao Zhang (QUIC) <quic_taozha@...cinc.com>
> +Description:
> +		(Write) Set the trigger type of DSB tpdm. Read the trigger
> +		type of DSB tpdm.
> +
> +		Accepts only one of the 2 values -  0 or 1.
> +		0 : Set the DSB trigger type to false
> +		1 : Set the DSB trigger type to true
> +
> +What:		/sys/bus/coresight/devices/<tpdm-name>/dsb_trig_ts
> +Date:		March 2023
> +KernelVersion	6.3
> +Contact:	Jinlong Mao (QUIC) <quic_jinlmao@...cinc.com>, Tao Zhang (QUIC) <quic_taozha@...cinc.com>
> +Description:
> +		(Write) Set the trigger timestamp of DSB tpdm. Read the
> +		trigger timestamp of DSB tpdm.
> +
> +		Accepts only one of the 2 values -  0 or 1.
> +		0 : Set the DSB trigger type to false
> +		1 : Set the DSB trigger type to true
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 104638d..e28cf10 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -20,6 +20,19 @@
>   
>   DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");
>   
> +static umode_t tpdm_dsb_is_visible(struct kobject *kobj,
> +							struct attribute *attr, int n)

minor nit: alignment. extra tabs

> +{
> +	struct device *dev = kobj_to_dev(kobj);
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	if (drvdata)
> +		if (drvdata->datasets & TPDM_PIDR0_DS_DSB)
> +			return attr->mode;

minor nit:
	if (drvdata && drvdata->dataset & TPDM_PIDR0_DS_DSB) ?

> +
> +	return 0;
> +}
> +
>   static int tpdm_init_datasets(struct tpdm_drvdata *drvdata)
>   {
>   	if (drvdata->datasets & TPDM_PIDR0_DS_DSB) {
> @@ -237,8 +250,90 @@ static struct attribute_group tpdm_attr_grp = {
>   	.attrs = tpdm_attrs,
>   };
>   
> +static ssize_t dsb_trig_type_show(struct device *dev,
> +				     struct device_attribute *attr,
> +				     char *buf)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n",
> +			 (unsigned int)drvdata->dsb->trig_type);
> +}
> +
> +/*
> + * value 0: set trigger type as enablement
> + * value 1: set trigger type as disablement
> + */

minor nit: The above looks confusing.

   /*
    * Trigger type (boolean):
    *   false - Disable trigger type.
    *   true  - Enable trigger type.
    */

> +static ssize_t dsb_trig_type_store(struct device *dev,
> +				      struct device_attribute *attr,
> +				      const char *buf,
> +				      size_t size)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if ((kstrtoul(buf, 0, &val)) || (val & ~1UL))
> +		return -EINVAL;
> +
> +	spin_lock(&drvdata->spinlock);
> +	if (val)
> +		drvdata->dsb->trig_type = true;
> +	else
> +		drvdata->dsb->trig_type = false;
> +	spin_unlock(&drvdata->spinlock);
> +	return size;
> +}
> +static DEVICE_ATTR_RW(dsb_trig_type);
> +
> +static ssize_t dsb_trig_ts_show(struct device *dev,
> +				     struct device_attribute *attr,
> +				     char *buf)
> +{
> +	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n",
> +			 (unsigned int)drvdata->dsb->trig_ts);
> +}
> +
> +/*
> + * value 0: set trigger timestamp as enablement
> + * value 1: set trigger timestamp as disablement
> + */

Same as above.


Otherwise looks good to me

Suzuki