Re: [PATCH v8 09/13] coresight-tpdm: Add nodes for dsb edge control
From: Suzuki K Poulose
Date: Tue Sep 05 2023 - 12:26:11 EST
On 01/09/2023 17:01, Tao Zhang wrote:
On 9/1/2023 10:07 PM, Suzuki K Poulose wrote:
On 22/08/2023 06:26, Tao Zhang wrote:
Add the nodes to set value for DSB edge control and DSB edge
control mask. Each DSB subunit TPDM has maximum of n(n<16) EDCR
resgisters to configure edge control. DSB edge detection control
00: Rising edge detection
01: Falling edge detection
10: Rising and falling edge detection (toggle detection)
And each DSB subunit TPDM has maximum of m(m<8) ECDMR registers to
configure mask. Eight 32 bit registers providing DSB interface
edge detection mask control.
Add the nodes to configure DSB edge control and DSB edge control
mask. Each DSB subunit TPDM maximum of 256 edge detections can be
configured. The index and value sysfs files need to be paired and
written to order. The index sysfs file is to set the index number
of the edge detection which needs to be configured. And the value
sysfs file is to set the control or mask for the edge detection.
DSB edge detection control should be set as the following values.
00: Rising edge detection
01: Falling edge detection
10: Rising and falling edge detection (toggle detection)
And DSB edge mask should be set as 0 or 1.
Each DSB subunit TPDM has maximum of n(n<16) EDCR resgisters to
configure edge control. And each DSB subunit TPDM has maximum of
m(m<8) ECDMR registers to configure mask.
Add the nodes to read a set of the edge control value and mask
of the DSB in TPDM.
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 51 ++++++
drivers/hwtracing/coresight/coresight-tpdm.c | 177
++++++++++++++++++++-
drivers/hwtracing/coresight/coresight-tpdm.h | 63 ++++++++
3 files changed, 288 insertions(+), 3 deletions(-)
diff --git
a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index e17d1b4..097fdc4 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -57,3 +57,54 @@ Description:
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.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge/ctrl_idx
+Date: March 2023
+KernelVersion 6.5
s/6.5/6.7
Sure, I will update this in the next patch series.
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ (RW) Set/Get the index number of the edge detection for the DSB
+ subunit TPDM. Since there are at most 256 edge detections, this
+ value ranges from 0 to 255.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge/ctrl_val
+Date: March 2023
+KernelVersion 6.5
same as above
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Write a data to control the edge detection corresponding to
+ the index number. Before writing data to this sysfs file,
+ "ctrl_idx" should be written first to configure the index
+ number of the edge detection which needs to be controlled.
+
+ Accepts only one of the following values.
+ 0 - Rising edge detection
+ 1 - Falling edge detection
+ 2 - Rising and falling edge detection (toggle detection)
+
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge/ctrl_mask
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Write a data to mask the edge detection corresponding to the
index
+ number. Before writing data to this sysfs file, "ctrl_idx"
should
+ be written first to configure the index number of the edge
detection
+ which needs to be masked.
+
+ Accepts only one of the 2 values - 0 or 1.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge/edcr[0:15]
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Read a set of the edge control value of the DSB in TPDM.
Read edge control register n for edcr<n>.
In fact, we don't read the register directly through this sysfs file,
but read the value
we set to be written to the registers. Do I still need to modify it here?
thats fine.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge/edcmr[0:7]
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang
(QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Read a set of the edge control mask of the DSB in TPDM.
\ No newline at end of file
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c
b/drivers/hwtracing/coresight/coresight-tpdm.c
index 2424eb7..ba61e6a 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -21,6 +21,29 @@
DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");
+/* Read dataset array member with the index number */
+static ssize_t tpdm_simple_dataset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ struct tpdm_dataset_attribute *tpdm_attr =
+ container_of(attr, struct tpdm_dataset_attribute, attr);
+
+ if (tpdm_attr->idx >= tpdm_attr->max)
minor nit: See my comment on max below. We could skip max.
I will update this in the next patch series.
+ return -EINVAL;
+
+ switch (tpdm_attr->mem) {
+ case DSB_EDGE_CTRL:
if (tmp_attr->idx > TPDM_DSB_MAX_EDCR)
break;
+ return sysfs_emit(buf, "0x%x\n",
+ drvdata->dsb->edge_ctrl[tpdm_attr->idx]);
+ case DSB_EDGE_CTRL_MASK:
if (tmp_attr->idx > TPDM_DSB_MAX_EDCMR)
break;
+ return sysfs_emit(buf, "0x%x\n",
+ drvdata->dsb->edge_ctrl_mask[tpdm_attr->idx]);
}
return -EINVAL;
Why do we need to return this error code here?
The whole block would look like :
switch (tpdm->attr->mem) {
case DSB_EDGE_CTRL:
if (tmp_attr->idx > TPDM_DSB_MAX_EDCR)
break;
return sysfs_...
case DSB_EDGE_CTRL_MASK:
if (tmp_attr->idx > TPDM_DSB_MAX_EDCMR)
break;
return sysfs_...
}
return -EINVAL;
Suzuki