[PATCH v5 13/13] coresight-tpdm: Add nodes for dsb msr support

[Tao Zhang]

Add the nodes for DSB subunit MSR(mux select register) support.
The TPDM MSR (mux select register) interface is an optional
interface and associated bank of registers per TPDM subunit.
The intent of mux select registers is to control muxing structures
driving the TPDM’s’ various subunit interfaces.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
 .../ABI/testing/sysfs-bus-coresight-devices-tpdm   | 14 +++++
 drivers/hwtracing/coresight/coresight-tpdm.c       | 71 ++++++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tpdm.h       |  5 ++
 3 files changed, 90 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 6e1b246..aaf02a6 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -166,3 +166,17 @@ Description:
 		Accepts only one of the 2 values -  0 or 1.
 		0 : Set the DSB pattern type to value.
 		1 : Set the DSB pattern type to toggle.
+
+What:		/sys/bus/coresight/devices/<tpdm-name>/dsb_msr
+Date:		March 2023
+KernelVersion	6.5
+Contact:	Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+		(Write) Set the MSR(mux select register) of DSB tpdm. Read
+		the MSR(mux select register) of DSB tpdm.
+
+		Expected format is the following:
+		<integer1> <integer2>
+
+		Where:
+		<integer1> : Index number of MSR register, the range is 0 to 31
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 1aff244..9c5782f 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -90,6 +90,18 @@ static void set_dsb_tier(struct tpdm_drvdata *drvdata, u32 *val)
 
 }
 
+static void set_dsb_msr(struct tpdm_drvdata *drvdata)
+{
+	int i;
+
+	if (drvdata->dsb->msr_num == 0)
+		return;
+
+	for (i = 0; i < drvdata->dsb->msr_num; i++)
+		writel_relaxed(drvdata->dsb->msr[i],
+			   drvdata->base + TPDM_DSB_MSR(i));
+}
+
 static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
 {
 	u32 val, i;
@@ -116,6 +128,8 @@ static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
 	set_dsb_tier(drvdata, &val);
 	writel_relaxed(val, drvdata->base + TPDM_DSB_TIER);
 
+	set_dsb_msr(drvdata);
+
 	val = readl_relaxed(drvdata->base + TPDM_DSB_CR);
 	/* Set the test accurate mode */
 	set_dsb_test_mode(drvdata, &val);
@@ -234,6 +248,14 @@ static int tpdm_datasets_setup(struct tpdm_drvdata *drvdata)
 			if (!drvdata->dsb)
 				return -ENOMEM;
 		}
+		if (!of_property_read_u32(drvdata->dev->of_node,
+			   "qcom,dsb_msr_num", &drvdata->dsb->msr_num)) {
+			drvdata->dsb->msr = devm_kzalloc(drvdata->dev,
+				   (drvdata->dsb->msr_num * sizeof(*drvdata->dsb->msr)),
+				   GFP_KERNEL);
+			if (!drvdata->dsb->msr)
+				return -ENOMEM;
+		}
 	}
 
 	return 0;
@@ -775,6 +797,54 @@ static ssize_t dsb_trig_ts_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(dsb_trig_ts);
 
+static ssize_t dsb_msr_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned int i;
+	unsigned long bytes;
+	ssize_t size = 0;
+
+	if (drvdata->dsb->msr_num == 0)
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	for (i = 0; i < drvdata->dsb->msr_num; i++) {
+		bytes = sysfs_emit_at(buf, size,
+				  "%u 0x%x\n", i, drvdata->dsb->msr[i]);
+		if (bytes <= 0)
+			break;
+		size += bytes;
+	}
+	spin_unlock(&drvdata->spinlock);
+
+	return size;
+}
+
+static ssize_t dsb_msr_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf,
+				  size_t size)
+{
+	struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	unsigned int num, val;
+	int nval;
+
+	if (drvdata->dsb->msr_num == 0)
+		return -EINVAL;
+
+	nval = sscanf(buf, "%u %x", &num, &val);
+	if ((nval != 2) || (num >= drvdata->dsb->msr_num))
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->dsb->msr[num] = val;
+	spin_unlock(&drvdata->spinlock);
+	return size;
+}
+static DEVICE_ATTR_RW(dsb_msr);
+
 static struct attribute *tpdm_dsb_attrs[] = {
 	&dev_attr_dsb_mode.attr,
 	&dev_attr_dsb_edge_ctrl.attr,
@@ -787,6 +857,7 @@ static struct attribute *tpdm_dsb_attrs[] = {
 	&dev_attr_dsb_trig_patt_mask.attr,
 	&dev_attr_dsb_trig_ts.attr,
 	&dev_attr_dsb_trig_type.attr,
+	&dev_attr_dsb_msr.attr,
 	NULL,
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
index 3169fb5..5372093 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -18,6 +18,7 @@
 #define TPDM_DSB_XPMR(n)	(0x7E8 + (n * 4))
 #define TPDM_DSB_EDCR(n)	(0x808 + (n * 4))
 #define TPDM_DSB_EDCMR(n)	(0x848 + (n * 4))
+#define TPDM_DSB_MSR(n)		(0x980 + (n * 4))
 
 /* Enable bit for DSB subunit */
 #define TPDM_DSB_CR_ENA		BIT(0)
@@ -97,6 +98,8 @@
  * @patt_mask:        Save value for pattern mask
  * @trig_patt_val:    Save value for trigger pattern
  * @trig_patt_mask:   Save value for trigger pattern mask
+ * @msr_num           Number of MSR supported by DSB TPDM
+ * @msr               Save value for MSR
  * @patt_ts:          Enable/Disable pattern timestamp
  * @patt_type:        Set pattern type
  * @trig_ts:          Enable/Disable trigger timestamp.
@@ -110,6 +113,8 @@ struct dsb_dataset {
 	u32				patt_mask[TPDM_DSB_MAX_PATT];
 	u32				trig_patt_val[TPDM_DSB_MAX_PATT];
 	u32				trig_patt_mask[TPDM_DSB_MAX_PATT];
+	u32				msr_num;
+	u32				*msr;
 	bool			patt_ts;
 	bool			patt_type;
 	bool			trig_ts;
-- 
2.7.4