On Wed, Jun 28, 2023 at 11:11:29AM +0800, Tao Zhang wrote: > > On 6/20/2023 4:49 PM, Greg Kroah-Hartman wrote: > > On Tue, Jun 20, 2023 at 04:31:59PM +0800, Tao Zhang wrote: > > > 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@xxxxxxxxxxx> > > > > > --- > > > > > .../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@xxxxxxxxxxx>, Tao Zhang (QUIC)<quic_taozha@xxxxxxxxxxx> > > > > > +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"? > > Yes. > > Hi Greg, > > > I‘d like to clarify the usage of this sysfs file again. > > In the current design, three integers will be written to "dsb_edge_ctrl" to > configure DSB edge detection. > > Integer #1: The start number of edge detection which needs to be configured. > > Integer #2: The end number of edge detection which needs to be configured. > > Integer #3: The type of the edge detection needs to be configured. All of this is wrong. Again, sysfs is "one value per file" > Below is an example. > > echo 0x3 0x25 0x1 > dsb_edge_ctrl > > It will configure edge detection #3 to #37 as "falling edge detection". > > Since these three integers are interrelated and written to achieve the same > function, can we use these three integers as "one tuple" here? Nope! sorry, greg k-h
