Re: [PATCH v5 2/3] coresight: tpda: add logic to configure TPDA_SYNCR register

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 19/12/2025 10:04, Jie Gan wrote:
> From: Tao Zhang <tao.zhang@oss.qualcomm.com>
> 
> The TPDA_SYNC counter tracks the number of bytes transferred from the
> aggregator. When this count reaches the value programmed in the
> TPDA_SYNCR register, an ASYNC request is triggered, allowing userspace
> tools to accurately parse each valid packet.
> 
> Signed-off-by: Tao Zhang <tao.zhang@oss.qualcomm.com>
> Reviewed-by: James Clark <james.clark@linaro.org>
> Co-developed-by: Jie Gan <jie.gan@oss.qualcomm.com>
> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
> ---
>   drivers/hwtracing/coresight/coresight-tpda.c | 7 +++++++
>   drivers/hwtracing/coresight/coresight-tpda.h | 5 +++++
>   2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
> index d25a8bcfb3d4..d378ff8ad77d 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -163,6 +163,13 @@ static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
>   	 */
>   	if (drvdata->trig_flag_ts)
>   		writel_relaxed(0x0, drvdata->base + TPDA_FPID_CR);
> +
> +	val = readl_relaxed(drvdata->base + TPDA_SYNCR);
> +	/* Reset the mode ctrl */
> +	val &= ~TPDA_SYNCR_MODE_CTRL;
> +	/* Program the counter value for TPDA_SYNCR */
> +	val |= TPDA_SYNCR_COUNTER_MASK;

Do we plan to change this value via sysfs ? If not whats the point of
clearing the field. Why not simply set it (as it is all 1s anyways).

> +	writel_relaxed(val, drvdata->base + TPDA_SYNCR);
>   }
>   
>   static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h
> index 8a075cfbc3cc..97e2729c15c9 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.h
> +++ b/drivers/hwtracing/coresight/coresight-tpda.h
> @@ -9,6 +9,7 @@
>   #define TPDA_CR			(0x000)
>   #define TPDA_Pn_CR(n)		(0x004 + (n * 4))
>   #define TPDA_FPID_CR		(0x084)
> +#define TPDA_SYNCR		(0x08C)
>   
>   /* Cross trigger Global (all ports) flush request bit */
>   #define TPDA_CR_FLREQ		BIT(0)
> @@ -38,6 +39,10 @@
>   #define TPDA_Pn_CR_CMBSIZE		GENMASK(7, 6)
>   /* Aggregator port DSB data set element size bit */
>   #define TPDA_Pn_CR_DSBSIZE		BIT(8)

Newline to separate the defintions of different registers, please.

> +/* TPDA_SYNCR mode control bit */
> +#define TPDA_SYNCR_MODE_CTRL		BIT(12)
> +/* TPDA_SYNCR counter mask */
> +#define TPDA_SYNCR_COUNTER_MASK		GENMASK(11, 0)
>   
>   #define TPDA_MAX_INPORTS	32
>   

Suzuki


>