[PATCH v8 09/13] coresight-tpdm: Add nodes for dsb edge control

[Tao Zhang]

On 9/5/2023 5:36 PM, Suzuki K Poulose wrote:
> 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 at quicinc.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 at quicinc.com>, Tao 
>>>> Zhang (QUIC) <quic_taozha at quicinc.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 at quicinc.com>, Tao 
>>>> Zhang (QUIC) <quic_taozha at quicinc.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 at quicinc.com>, Tao 
>>>> Zhang (QUIC) <quic_taozha at quicinc.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 at quicinc.com>, Tao 
>>>> Zhang (QUIC) <quic_taozha at quicinc.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 at quicinc.com>, Tao 
>>>> Zhang (QUIC) <quic_taozha at quicinc.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;

Sure, I will update this in the next patch series.


Best,

Tao

>
> Suzuki
>