Re: [PATCH v3 06/11] coresight-tpdm: Add node to set dsb programming mode
From: Suzuki K Poulose
Date: Thu Mar 23 2023 - 10:56:04 EST
On 23/03/2023 06:04, 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@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 10 ++++
drivers/hwtracing/coresight/coresight-tpdm.c | 62 ++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tpdm.h | 13 +++++
3 files changed, 85 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 27ce681..f13e282 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -35,3 +35,13 @@ Description:
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_mode
+Date: March 2023
+KernelVersion 6.3
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ (Write) Set the mode of DSB tpdm. Read the mode of DSB
+ tpdm.
+
+ Accepts the value needs to be greater than 0.
Please could you document the values ?
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index e28cf10..8cd822f 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>
@@ -51,6 +52,32 @@ static int tpdm_init_datasets(struct tpdm_drvdata *drvdata)
return 0;
}
+static void set_dsb_cycacc_mode(struct tpdm_drvdata *drvdata, u32 *val)
+{
+ u32 mode;
+
+ mode = TPDM_DSB_MODE_CYCACC(drvdata->dsb->mode);
+ *val &= ~TPDM_DSB_TEST_MODE;
+ *val |= FIELD_PREP(TPDM_DSB_TEST_MODE, mode);
+}
+
+static void set_dsb_hpsel_mode(struct tpdm_drvdata *drvdata, u32 *val)
+{
+ u32 mode;
+
+ mode = TPDM_DSB_MODE_HPBYTESEL(drvdata->dsb->mode);
+ *val &= ~TPDM_DSB_HPSEL;
+ *val |= FIELD_PREP(TPDM_DSB_HPSEL, mode);
+}
+
+static void set_dsb_perf_mode(struct tpdm_drvdata *drvdata, u32 *val)
+{
+ if (drvdata->dsb->mode & TPDM_DSB_MODE_PERF)
+ *val |= TPDM_DSB_CR_MODE;
+ else
+ *val &= ~TPDM_DSB_CR_MODE;
+}
+
static void set_trigger_type(struct tpdm_drvdata *drvdata, u32 *val)
{
if (drvdata->dsb->trig_type)
@@ -72,6 +99,12 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
writel_relaxed(val, drvdata->base + TPDM_DSB_TIER);
val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
+ /* Set the cycle accurate mode */
+ set_dsb_cycacc_mode(drvdata, &val);
+ /* Set the byte lane for high-performance mode */
+ set_dsb_hpsel_mode(drvdata, &val);
+ /* Set the performance mode */
+ set_dsb_perf_mode(drvdata, &val);
/* Set trigger type */
set_trigger_type(drvdata, &val);
/* Set the enable bit of DSB control register to 1 */
@@ -250,6 +283,34 @@ 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)
@@ -321,6 +382,7 @@ 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 68f33bd..8fee562 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -15,11 +15,22 @@
/* Enable bit for DSB subunit */
#define TPDM_DSB_CR_ENA BIT(0)
+/* Enable bit for DSB subunit perfmance mode */
+#define TPDM_DSB_CR_MODE BIT(1)
/* Enable bit for DSB subunit trigger type */
#define TPDM_DSB_CR_TRIG_TYPE BIT(12)
+
/* Enable bit for DSB subunit trigger timestamp */
#define TPDM_DSB_TIER_XTRIG_TSENAB BIT(1)
+/* DSB programming modes */
+#define TPDM_DSB_MODE_CYCACC(val) (val & GENMASK(2, 0))
What do the values for the CYCACC mode mean ?
+#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)
Again what do the values mean ? Even if the kernel doesn't use them
it would be good to document it.
Suzuki
+
/* TPDM integration test registers */
#define TPDM_ITATBCNTRL (0xEF0)
#define TPDM_ITCNTRL (0xF00)
@@ -48,10 +59,12 @@
/**
* 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;
};