Re: [PATCH v2 6/9] coresight-tpdm: Add node to set dsb programming mode

On 19/01/2023 07:41, Tao Zhang wrote:

Add node to set and show programming mode for TPDM DSB subunit. Once the DSB programming mode is set, it will be written to the register DSB_CR. Bit[10:9] of the DSB_CR register is used to set the DSB test mode.

Signed-off-by: Tao Zhang quic_taozha@quicinc.com Signed-off-by: Tao Zhang taozha@qti.qualcomm.com

---

drivers/hwtracing/coresight/coresight-tpdm.c | 45 +++++++++++++++++++++++++++- drivers/hwtracing/coresight/coresight-tpdm.h | 12 ++++++++ 2 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c index 1dbb6c4..9126a37 100644 --- a/drivers/hwtracing/coresight/coresight-tpdm.c +++ b/drivers/hwtracing/coresight/coresight-tpdm.c @@ -4,6 +4,7 @@ */ #include <linux/amba/bus.h> +#include <linux/bitfield.h> #include <linux/bitmap.h> #include <linux/coresight.h> #include <linux/coresight-pmu.h> @@ -38,7 +39,7 @@ static umode_t tpdm_dsb_is_visible(struct kobject *kobj, static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata) {

• u32 val;

• u32 val, mode;

val = readl_relaxed(drvdata->base + TPDM_DSB_TIER); /* Set trigger timestamp */ @@ -58,6 +59,19 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata) /* Set the enable bit of DSB control register to 1 */ val = readl_relaxed(drvdata->base + TPDM_DSB_CR);

• /* Set the cycle accurate mode */
• mode = TPDM_DSB_MODE_CYCACC(drvdata->dsb->mode);
• val &= ~TPDM_DSB_TEST_MODE;
• val |= FIELD_PREP(TPDM_DSB_TEST_MODE, mode);
• /* Set the byte lane for high-performance mode */
• mode = TPDM_DSB_MODE_HPBYTESEL(drvdata->dsb->mode);
• val &= ~TPDM_DSB_HPSEL;
• val |= FIELD_PREP(TPDM_DSB_HPSEL, mode);
• /* Set the performance mode */
• if (drvdata->dsb->mode & TPDM_DSB_MODE_PERF)

• val |= TPDM_DSB_MODE;
  

• else

• val &= ~TPDM_DSB_MODE;
  

This looks a bit tricky to me. Please could you add documentation of the values supported under Documentation/ABI/testing/sysfs-....-

Couldn't we provide separate handles for these "mode bits" ?

cycacc perf hpsel

Suzuki

val |= TPDM_DSB_CR_ENA; writel_relaxed(val, drvdata->base + TPDM_DSB_CR); } @@ -257,6 +271,34 @@ static struct attribute_group tpdm_attr_grp = { .attrs = tpdm_attrs, }; +static ssize_t dsb_mode_show(struct device *dev,

• 		  struct device_attribute *attr,
  

• 		  char *buf)
  

+{

• struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
• return sysfs_emit(buf, "%lx\n",

• 	 (unsigned long)drvdata->dsb->mode);
  

+}

+static ssize_t dsb_mode_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 < 0)

• return -EINVAL;
  

• spin_lock(&drvdata->spinlock);
• drvdata->dsb->mode = val & TPDM_MODE_ALL;
• spin_unlock(&drvdata->spinlock);
• return size;

+} +static DEVICE_ATTR_RW(dsb_mode);

• static ssize_t dsb_trig_type_show(struct device *dev, struct device_attribute *attr, char *buf)

@@ -327,6 +369,7 @@ static ssize_t dsb_trig_ts_store(struct device *dev, } static DEVICE_ATTR_RW(dsb_trig_ts); static struct attribute *tpdm_dsb_attrs[] = {

• &dev_attr_dsb_mode.attr, &dev_attr_dsb_trig_ts.attr, &dev_attr_dsb_trig_type.attr, NULL,

diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h index 3ad1be5..b3ecb9f 100644 --- a/drivers/hwtracing/coresight/coresight-tpdm.h +++ b/drivers/hwtracing/coresight/coresight-tpdm.h @@ -19,6 +19,16 @@ #define TPDM_DSB_XTRIG_TSENAB BIT(1) /* Enable bit for DSB subunit trigger type */ #define TPDM_DSB_TRIG_TYPE BIT(12) +/* Enable bit for DSB subunit perfmance mode */ +#define TPDM_DSB_MODE BIT(1)

+/* DSB programming modes */ +#define TPDM_DSB_MODE_CYCACC(val) (val & GENMASK(2, 0)) +#define TPDM_DSB_MODE_PERF BIT(3) +#define TPDM_DSB_MODE_HPBYTESEL(val) (val & GENMASK(8, 4)) +#define TPDM_MODE_ALL (0xFFFFFFF) +#define TPDM_DSB_TEST_MODE GENMASK(11, 9) +#define TPDM_DSB_HPSEL GENMASK(6, 2) /* TPDM integration test registers */ #define TPDM_ITATBCNTRL (0xEF0) @@ -48,10 +58,12 @@ /**

• struct dsb_dataset - specifics associated to dsb dataset

• • @mode: DSB programming mode
  • @trig_ts: Enable/Disable trigger timestamp.
  • @trig_type: Enable/Disable trigger type.
  */ struct dsb_dataset {
• u32 mode; bool trig_ts; bool trig_type; };