Re: [PATCH v2 3/8] coresight-tpdm: Add CMB dataset support

[James Clark <james.clark@arm.com>]

On 25/10/2023 03:53, Tao Zhang wrote:
> CMB (continuous multi-bit) is one of TPDM's dataset type. CMB subunit
> can be enabled for data collection by writing 1 to the first bit of
> CMB_CR register. This change is to add enable/disable function for
> CMB dataset by writing CMB_CR register.
> 
> Signed-off-by: Tao Zhang <quic_taozha@quicinc.com>
> Signed-off-by: Jinlong Mao <quic_jinlmao@quicinc.com>
> ---
>  drivers/hwtracing/coresight/coresight-tpdm.c | 31 ++++++++++++++++++++++++++++
>  drivers/hwtracing/coresight/coresight-tpdm.h |  8 +++++++
>  2 files changed, 39 insertions(+)
> 

Reviewed-by: James Clark <james.clark@arm.com>

> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
> index 97654aa..c8bb388 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.c
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.c
> @@ -131,6 +131,11 @@ static bool tpdm_has_dsb_dataset(struct tpdm_drvdata *drvdata)
>  	return (drvdata->datasets & TPDM_PIDR0_DS_DSB);
>  }
>  
> +static bool tpdm_has_cmb_dataset(struct tpdm_drvdata *drvdata)
> +{
> +	return (drvdata->datasets & TPDM_PIDR0_DS_CMB);
> +}
> +
>  static umode_t tpdm_dsb_is_visible(struct kobject *kobj,
>  				   struct attribute *attr, int n)
>  {
> @@ -267,6 +272,17 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
>  	writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>  }
>  
> +static void tpdm_enable_cmb(struct tpdm_drvdata *drvdata)
> +{
> +	u32 val;
> +
> +	val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
> +	val |= TPDM_CMB_CR_ENA;
> +
> +	/* Set the enable bit of CMB control register to 1 */
> +	writel_relaxed(val, drvdata->base + TPDM_CMB_CR);
> +}
> +
>  /*
>   * TPDM enable operations
>   * The TPDM or Monitor serves as data collection component for various
> @@ -281,6 +297,8 @@ static void __tpdm_enable(struct tpdm_drvdata *drvdata)
>  
>  	if (tpdm_has_dsb_dataset(drvdata))
>  		tpdm_enable_dsb(drvdata);
> +	if (tpdm_has_cmb_dataset(drvdata))
> +		tpdm_enable_cmb(drvdata);
>  
>  	CS_LOCK(drvdata->base);
>  }
> @@ -314,6 +332,17 @@ static void tpdm_disable_dsb(struct tpdm_drvdata *drvdata)
>  	writel_relaxed(val, drvdata->base + TPDM_DSB_CR);
>  }
>  
> +static void tpdm_disable_cmb(struct tpdm_drvdata *drvdata)
> +{
> +	u32 val;
> +
> +	val = readl_relaxed(drvdata->base + TPDM_CMB_CR);
> +	val &= ~TPDM_CMB_CR_ENA;
> +
> +	/* Set the enable bit of CMB control register to 0 */
> +	writel_relaxed(val, drvdata->base + TPDM_CMB_CR);
> +}
> +
>  /* TPDM disable operations */
>  static void __tpdm_disable(struct tpdm_drvdata *drvdata)
>  {
> @@ -321,6 +350,8 @@ static void __tpdm_disable(struct tpdm_drvdata *drvdata)
>  
>  	if (tpdm_has_dsb_dataset(drvdata))
>  		tpdm_disable_dsb(drvdata);
> +	if (tpdm_has_cmb_dataset(drvdata))
> +		tpdm_disable_cmb(drvdata);
>  
>  	CS_LOCK(drvdata->base);
>  }
> diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
> index 4115b2a1..0098c58 100644
> --- a/drivers/hwtracing/coresight/coresight-tpdm.h
> +++ b/drivers/hwtracing/coresight/coresight-tpdm.h
> @@ -9,6 +9,12 @@
>  /* The max number of the datasets that TPDM supports */
>  #define TPDM_DATASETS       7
>  
> +/* CMB Subunit Registers */
> +#define TPDM_CMB_CR		(0xA00)
> +
> +/* Enable bit for CMB subunit */
> +#define TPDM_CMB_CR_ENA		BIT(0)
> +
>  /* DSB Subunit Registers */
>  #define TPDM_DSB_CR		(0x780)
>  #define TPDM_DSB_TIER		(0x784)
> @@ -79,10 +85,12 @@
>   *
>   * PERIPHIDR0[0] : Fix to 1 if ImplDef subunit present, else 0
>   * PERIPHIDR0[1] : Fix to 1 if DSB subunit present, else 0
> + * PERIPHIDR0[2] : Fix to 1 if CMB subunit present, else 0
>   */
>  
>  #define TPDM_PIDR0_DS_IMPDEF	BIT(0)
>  #define TPDM_PIDR0_DS_DSB	BIT(1)
> +#define TPDM_PIDR0_DS_CMB	BIT(2)
>  
>  #define TPDM_DSB_MAX_LINES	256
>  /* MAX number of EDCR registers */