Re: [PATCH v2 1/3] coresight: tpda: add sysfs nodes for tpda cross-trigger configuration

[James Clark <james.clark@xxxxxxxxxx>]

On 27/08/2025 5:20 am, Jie Gan wrote:
> From: Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>
>
> Introduce sysfs nodes to configure cross-trigger parameters for TPDA.
> These registers define the characteristics of cross-trigger packets,
> including generation frequency and flag values.
>
> Signed-off-by: Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>
> Co-developed-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> Signed-off-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> ---
>   .../testing/sysfs-bus-coresight-devices-tpda  |  43 ++++
>   drivers/hwtracing/coresight/coresight-tpda.c  | 227 ++++++++++++++++++
>   drivers/hwtracing/coresight/coresight-tpda.h  |  27 ++-
>   3 files changed, 296 insertions(+), 1 deletion(-)
>   create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
> new file mode 100644
> index 000000000000..fb651aebeb31
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
> @@ -0,0 +1,43 @@
> +What:		/sys/bus/coresight/devices/<tpda-name>/trig_async_enable
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Enable/disable cross trigger synchronization sequence interface.
> +
> +What:		/sys/bus/coresight/devices/<tpda-name>/trig_flag_ts_enable
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Enable/disable cross trigger FLAG packet request interface.
> +
> +What:		/sys/bus/coresight/devices/<tpda-name>/trig_freq_enable
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Enable/disable cross trigger FREQ packet request interface.
> +
> +What:		/sys/bus/coresight/devices/<tpda-name>/freq_ts_enable
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Enable/disable the timestamp for all FREQ packets.
> +
> +What:		/sys/bus/coresight/devices/<tpda-name>/global_flush_req
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Set global (all ports) flush request bit. The bit remains set until a
> +		global flush request sequence completes.
> +
> +What:		/sys/bus/coresight/devices/<tpda-name>/cmbchan_mode
> +Date:		August 2025
> +KernelVersion:	6.17
> +Contact:	Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
> +Description:
> +		(RW) Configure the CMB/MCMB channel mode for all enabled ports.
> +		Value 0 means raw channel mapping mode. Value 1 means channel pair marking mode.
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
> index 4e93fa5bace4..647ab49a98d7 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -156,9 +156,37 @@ static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
>   	u32 val;
>   
>   	val = readl_relaxed(drvdata->base + TPDA_CR);
> +	val &= ~TPDA_CR_MID;
>   	val &= ~TPDA_CR_ATID;
>   	val |= FIELD_PREP(TPDA_CR_ATID, drvdata->atid);
> +	if (drvdata->trig_async)
> +		val |= TPDA_CR_SRIE;
> +	else
> +		val &= ~TPDA_CR_SRIE;
> +	if (drvdata->trig_flag_ts)
> +		val |= TPDA_CR_FLRIE;
> +	else
> +		val &= ~TPDA_CR_FLRIE;
> +	if (drvdata->trig_freq)
> +		val |= TPDA_CR_FRIE;
> +	else
> +		val &= ~TPDA_CR_FRIE;
> +	if (drvdata->freq_ts)
> +		val |= TPDA_CR_FREQTS;
> +	else
> +		val &= ~TPDA_CR_FREQTS;
> +	if (drvdata->cmbchan_mode)
> +		val |= TPDA_CR_CMBCHANMODE;
> +	else
> +		val &= ~TPDA_CR_CMBCHANMODE;
>   	writel_relaxed(val, drvdata->base + TPDA_CR);
> +
> +	/*
> +	 * If FLRIE bit is set, set the master and channel
> +	 * id as zero
> +	 */
> +	if (drvdata->trig_flag_ts)
> +		writel_relaxed(0x0, drvdata->base + TPDA_FPID_CR);
>   }
>   
>   static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
> @@ -274,6 +302,203 @@ static const struct coresight_ops tpda_cs_ops = {
>   	.link_ops	= &tpda_link_ops,
>   };
>   
> +static ssize_t trig_async_enable_show(struct device *dev,
> +				      struct device_attribute *attr,
> +				      char *buf)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n", (unsigned int)drvdata->trig_async);
> +}
> +
> +static ssize_t trig_async_enable_store(struct device *dev,
> +				       struct device_attribute *attr,
> +				       const char *buf,
> +				       size_t size)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (kstrtoul(buf, 0, &val))
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	drvdata->trig_async = !!val;
> +
> +	return size;
> +}
> +static DEVICE_ATTR_RW(trig_async_enable);
> +
> +static ssize_t trig_flag_ts_enable_show(struct device *dev,
> +					struct device_attribute *attr,
> +					char *buf)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n", (unsigned int)drvdata->trig_flag_ts);
> +}
> +
> +static ssize_t trig_flag_ts_enable_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf,
> +					 size_t size)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (kstrtoul(buf, 0, &val))
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	drvdata->trig_flag_ts = !!val;
> +
> +	return size;
> +}
> +static DEVICE_ATTR_RW(trig_flag_ts_enable);
> +
> +static ssize_t trig_freq_enable_show(struct device *dev,
> +				     struct device_attribute *attr,
> +				     char *buf)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n", (unsigned int)drvdata->trig_freq);
> +}
> +
> +static ssize_t trig_freq_enable_store(struct device *dev,
> +				      struct device_attribute *attr,
> +				      const char *buf,
> +				      size_t size)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (kstrtoul(buf, 0, &val))
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	drvdata->trig_freq = !!val;
> +
> +	return size;
> +}
> +static DEVICE_ATTR_RW(trig_freq_enable);
> +
> +static ssize_t freq_ts_enable_show(struct device *dev,
> +				   struct device_attribute *attr,
> +				   char *buf)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +
> +	return sysfs_emit(buf, "%u\n", (unsigned int)drvdata->freq_ts);
> +}
> +
> +static ssize_t freq_ts_enable_store(struct device *dev,
> +				    struct device_attribute *attr,
> +				    const char *buf,
> +				    size_t size)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (kstrtoul(buf, 0, &val))
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	drvdata->freq_ts = !!val;
> +
> +	return size;
> +}
> +static DEVICE_ATTR_RW(freq_ts_enable);
> +
> +static ssize_t global_flush_req_show(struct device *dev,
> +				     struct device_attribute *attr,
> +				     char *buf)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (!drvdata->csdev->refcnt)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	CS_UNLOCK(drvdata->base);
> +	val = readl_relaxed(drvdata->base + TPDA_CR);
> +	CS_LOCK(drvdata->base);
> +
> +	return sysfs_emit(buf, "%lx\n", val);

I know in practice it's probably only either 0 or 1, but this should 
either be decimal or have the 0x prefix otherwise it looks like a mistake.

> +}
> +
> +static ssize_t global_flush_req_store(struct device *dev,
> +				      struct device_attribute *attr,
> +				      const char *buf,
> +				      size_t size)
> +{
> +	struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	unsigned long val;
> +
> +	if (kstrtoul(buf, 0, &val))
> +		return -EINVAL;
> +
> +	if (!drvdata->csdev->refcnt || !val)
> +		return -EINVAL;
> +
> +	guard(spinlock)(&drvdata->spinlock);
> +	CS_UNLOCK(drvdata->base);
> +	val = readl_relaxed(drvdata->base + TPDA_CR);
> +	val |= BIT(0);

If you only set bit 0 do you only want to show bit 0 in 
global_flush_req_show() above? The sysfs files should be divided up by 
function rather than dumping the whole register, otherwise tools need 
their own copy of the fields to interperet them.