[PATCH v8 08/13] coresight-tpdm: Add node to set dsb programming mode

[Tao Zhang]

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   | 14 ++++++
 drivers/hwtracing/coresight/coresight-tpdm.c       | 53 ++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpdm.h       | 19 ++++++++
 3 files changed, 86 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 9e26e30..e17d1b4 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -43,3 +43,17 @@ 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:
+		(RW) Set/Get the programming mode of the DSB for tpdm.
+
+		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 8e11c9b..2424eb7 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>
@@ -47,6 +48,27 @@ static void tpdm_reset_datasets(struct tpdm_drvdata *drvdata)
 	}
 }
 
+static void set_dsb_mode(struct tpdm_drvdata *drvdata, u32 *val)
+{
+	u32 mode;
+
+	/* Set the test accurate mode */
+	mode = TPDM_DSB_MODE_TEST(drvdata->dsb->mode);
+	*val &= ~TPDM_DSB_CR_TEST_MODE;
+	*val |= FIELD_PREP(TPDM_DSB_CR_TEST_MODE, mode);
+
+	/* Set the byte lane for high-performance mode */
+	mode = TPDM_DSB_MODE_HPBYTESEL(drvdata->dsb->mode);
+	*val &= ~TPDM_DSB_CR_HPSEL;
+	*val |= FIELD_PREP(TPDM_DSB_CR_HPSEL, mode);
+
+	/* Set the performance mode */
+	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;
@@ -60,6 +82,8 @@ 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 mode of DSB dataset */
+	set_dsb_mode(drvdata, &val);
 	/* Set trigger type */
 	if (drvdata->dsb->trig_type)
 		val |= TPDM_DSB_CR_TRIG_TYPE;
@@ -244,6 +268,34 @@ 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, "%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) ||
+			(val & ~TPDM_DSB_MODE_MASK))
+		return -EINVAL;
+
+	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)
 {
@@ -316,6 +368,7 @@ 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 f59e751..f57c9fe 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -15,11 +15,28 @@
 
 /* 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)
+/* Data bits for DSB high performace mode */
+#define TPDM_DSB_CR_HPSEL		GENMASK(6, 2)
+/* Data bits for DSB test mode */
+#define TPDM_DSB_CR_TEST_MODE		GENMASK(10, 9)
+
 /* Enable bit for DSB subunit trigger timestamp */
 #define TPDM_DSB_TIER_XTRIG_TSENAB		BIT(1)
 
+/* DSB programming modes */
+/* DSB mode bits mask */
+#define TPDM_DSB_MODE_MASK			GENMASK(8, 0)
+/* Test mode control bit*/
+#define TPDM_DSB_MODE_TEST(val)	(val & GENMASK(1, 0))
+/* Performance mode */
+#define TPDM_DSB_MODE_PERF		BIT(3)
+/* High performance mode */
+#define TPDM_DSB_MODE_HPBYTESEL(val)	(val & GENMASK(8, 4))
+
 /* TPDM integration test registers */
 #define TPDM_ITATBCNTRL		(0xEF0)
 #define TPDM_ITCNTRL		(0xF00)
@@ -48,10 +65,12 @@
 
 /**
  * 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;
 };
-- 
2.7.4