Re: [PATCH v7 08/13] coresight-tpdm: Add node to set dsb programming mode
From: Suzuki K Poulose
Date: Mon Aug 07 2023 - 06:00:38 EST
On 25/07/2023 08:15, 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.
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 15 ++++++
drivers/hwtracing/coresight/coresight-tpdm.c | 62 ++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-tpdm.h | 16 ++++++
3 files changed, 93 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 0b7b4ad..2a82cd0 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -45,3 +45,18 @@ 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 6.5
+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.
(RW) ...
+
+ Accepts the value needs to be greater than 0. What data
+ bits do is listed below.
+ Bit[0:1] : Test mode control bit for choosing the inputs.
+ Bit[3] : Set to 0 for low performance mode.
+ Set to 1 for high performance mode.
+ Bit[4:8] : Select byte lane for high performance mode.
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 62efc18..c38760b 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>
@@ -42,6 +43,32 @@ static void tpdm_reset_datasets(struct tpdm_drvdata *drvdata)
}
}
+static void set_dsb_test_mode(struct tpdm_drvdata *drvdata, u32 *val)
+{
+ u32 mode;
+
+ mode = TPDM_DSB_MODE_TEST(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 tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
{
u32 val;
@@ -55,6 +82,12 @@ 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 test accurate mode */
+ set_dsb_test_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);
Couldn't all of them be combined to a single function, as they
operate on a single value to be written ?
set_dsb_mode(drvdata, &val);
/* Set trigger type */
if (drvdata->dsb->trig_type)
val |= TPDM_DSB_CR_TRIG_TYPE;
@@ -241,6 +274,34 @@ 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);
It is u32 anyways, hence why not :
(buf, "%x\n", 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;
+
Is it not an error :
if (val & ~TPDM_DSB_MODE_MASK) ?
+ spin_lock(&drvdata->spinlock);
+ drvdata->dsb->mode = val & TPDM_DSB_MODE_MASK;
+ 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)
{
@@ -312,6 +373,7 @@ 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 92c34cd..49fffb1 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -15,11 +15,25 @@
/* 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 */
+/* Test mode control bit*/
+#define TPDM_DSB_MODE_TEST(val) (val & GENMASK(1, 0))
What is the difference between MODE_TEST ^ and the TEST_MODE ( below ).
Please could we have clear naming conventions ?
+/* Performance mode */
+#define TPDM_DSB_MODE_PERF BIT(3)
+/* High performance mode */
+#define TPDM_DSB_MODE_HPBYTESEL(val) (val & GENMASK(8, 4))
+#define TPDM_DSB_MODE_MASK GENMASK(8, 0)
+#define TPDM_DSB_TEST_MODE GENMASK(10, 9)
+#define TPDM_DSB_HPSEL GENMASK(6, 2)
Ah, I read it again and these two are really TPDM_DSB_CR_x and
1) Must be defined as such (to avoid any confusion as above)
2) And defined closer to the other value defintions for the registers ?
Suzuki
+
/* TPDM integration test registers */
#define TPDM_ITATBCNTRL (0xEF0)
#define TPDM_ITCNTRL (0xF00)
@@ -48,10 +62,12 @@
/**
* 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;
};