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Message-ID: <4370a34d-e36f-421c-aa02-48dd96c0af77@arm.com>
Date: Tue, 5 Sep 2023 10:36:06 +0100
From: Suzuki K Poulose <suzuki.poulose@....com>
To: Tao Zhang <quic_taozha@...cinc.com>,
Mathieu Poirier <mathieu.poirier@...aro.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Konrad Dybcio <konradybcio@...il.com>,
Mike Leach <mike.leach@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>
Cc: Jinlong Mao <quic_jinlmao@...cinc.com>,
Leo Yan <leo.yan@...aro.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
Tingwei Zhang <quic_tingweiz@...cinc.com>,
Yuanfang Zhang <quic_yuanfang@...cinc.com>,
Trilok Soni <quic_tsoni@...cinc.com>,
Hao Zhang <quic_hazha@...cinc.com>,
linux-arm-msm@...r.kernel.org, andersson@...nel.org
Subject: Re: [PATCH v8 09/13] coresight-tpdm: Add nodes for dsb edge control
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@...cinc.com>
>>> ---
>>> .../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@...cinc.com>, Tao Zhang
>>> (QUIC) <quic_taozha@...cinc.com>
>>> +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@...cinc.com>, Tao Zhang
>>> (QUIC) <quic_taozha@...cinc.com>
>>> +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@...cinc.com>, Tao Zhang
>>> (QUIC) <quic_taozha@...cinc.com>
>>> +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@...cinc.com>, Tao Zhang
>>> (QUIC) <quic_taozha@...cinc.com>
>>> +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@...cinc.com>, Tao Zhang
>>> (QUIC) <quic_taozha@...cinc.com>
>>> +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
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