On 6/20/2023 3:37 PM, Greg Kroah-Hartman wrote:
On Tue, Jun 20, 2023 at 03:32:37PM +0800, 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.
Signed-off-by: Tao Zhang quic_taozha@quicinc.com
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 32 +++++ drivers/hwtracing/coresight/coresight-tpdm.c | 143 ++++++++++++++++++++- drivers/hwtracing/coresight/coresight-tpdm.h | 22 ++++ 3 files changed, 196 insertions(+), 1 deletion(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm index 2a82cd0..34189e4a 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm @@ -60,3 +60,35 @@ 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 +Date: March 2023 +KernelVersion 6.5 +Contact: Jinlong Mao (QUIC) quic_jinlmao@quicinc.com, Tao Zhang (QUIC) quic_taozha@quicinc.com +Description:
Read/Write a set of the edge control registers of the DSB
in TPDM.
Expected format is the following:
<integer1> <integer2> <integer3>
sysfs is "one value", not 3. Please never have to parse a sysfs file.
Do you mean sysfs file can only accept "one value"?
I see that more than one value are written to the sysfs file "trigout_attach".
+static ssize_t dsb_edge_ctrl_show(struct device *dev,
struct device_attribute *attr,
char *buf)
+{
- struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
- ssize_t size = 0;
- unsigned long bytes;
- int i;
- spin_lock(&drvdata->spinlock);
- for (i = 0; i < TPDM_DSB_MAX_EDCR; i++) {
bytes = sysfs_emit_at(buf, size,
"Index:0x%x Val:0x%x\n", i,
Again, no, one value, no "string" needed to parse anything.
I also see other sysfs files can be read more than one value in other drivers.
Is this "one value" limitation the usage rule of Linux sysfs system?
Or am I misunderstanding what you mean?
Best,
Tao
greg k-h