Re: [PATCH v2 1/5] pinctrl: qcom: Add ipq8074 pinctrl driver

[Varadarajan Narayanan <varada-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On 5/18/2017 1:17 AM, Bjorn Andersson wrote:
> On Mon 15 May 04:24 PDT 2017, Varadarajan Narayanan wrote:
> 
>>
>>
>> On 5/15/2017 2:35 PM, Varadarajan Narayanan wrote:
>>> On 5/14/2017 9:53 AM, Bjorn Andersson wrote:
>>>> On Thu 11 May 03:33 PDT 2017, Varadarajan Narayanan wrote:
>>>>
>>>>> On 5/11/2017 4:13 AM, Bjorn Andersson wrote:
>>>>>> On Thu 04 May 04:53 PDT 2017, Varadarajan Narayanan wrote:
>>>>>>
>>>> [..]
>>>>>>> +enum ipq8074_functions {
>>>>>>
>>>>>> Please keep these sorted alphabetically.
>>>>>
>>>>> Ok
>>>>>
>>>>>>> +    msm_mux_gpio,
>>>>>>> +    msm_mux_qpic_pad,
>>>>>>> +    msm_mux_blsp5_i2c,
>>>>>>> +    msm_mux_blsp5_spi,
>>>>>>> +    msm_mux_wci20,
>>>>>>
>>>>>> What does "20" mean here?
>>>>>
>>>>> This is for Wireless Coex Interface. The same functionality can
>>>>> be muxed on
>>>>> to different GPIOs. WCI2, is the 2nd edition of the WCI standard
>>>>> and 0, 1
>>>>> are for the muxing to different GPIOs (alternate muxes).
>>>>>
>>>>
>>>> In other Qualcomm platforms the alternative muxes are denoted by letters
>>>> (a,b,c...). Would you mind picking up this naming scheme, or do you see
>>>> any problems with that? (E.g. wci2a in this case)
>>>
>>> Ok
>>>
>>>> Btw, do you need any additional configuration for selecting alternative
>>>> muxing or is that automagical these days?
>>>
>>> No additional configuration is needed.
>>>
>>>>>>> +    msm_mux_blsp3_spi3,
>>>>>>> +    msm_mux_burn0,
>>>>>>> +    msm_mux_pcm_zsi0,
>>>>>>> +    msm_mux_blsp5_uart,
>>>>>>> +    msm_mux_mac12,
>>>>>>
>>>>>> What does "12" mean here?
>>>>>
>>>>> The SoC has three MAC cores. Each core has two pins for the
>>>>> smart antenna
>>>>> feature. macXY indicates the function select for MAC no. X and
>>>>> smart antenna
>>>>> no. Y.
>>>>>
>>>>
>>>> Ok
>>>>
>>>>>>> +    msm_mux_blsp3_spi0,
>>>>>>> +    msm_mux_burn1,
>>>>>>> +    msm_mux_mac01,
>>>>>>> +    msm_mux_qdss_cti_trig_out_b0,
>>>>>>> +    msm_mux_qdss_cti_trig_in_b0,
>>>>>>> +    msm_mux_qpic_pad4,
>>>>>>
>>>>>> What are qpic_pad and qpic_pad0 through qpic_pad8? Different functions,
>>>>>> alternative muxings...?
>>>>>
>>>>> This is for the NAND and LCD display. The pins listed are the 9
>>>>> data pins.
>>>>>
>>>>
>>>> Then you can describe them all as "qpic_pad" (or simply "qpic"?). (It's
>>>> possible to reference a partial group in the DTS, if that's necessary)
>>>
>>> There are two sets of 9 pins, either of which can go to NAND or LCD.
>>> Will rename qpic_pad as qpic_a and qpic_pad[0-8] as qpic_b.
>>> Is that ok?
>>>
>>>>>>> +    msm_mux_blsp4_uart0,
>>>>>>> +    msm_mux_blsp4_i2c0,
>>>>>>> +    msm_mux_blsp4_spi0,
>>>>>>> +    msm_mux_mac21,
>>>>>>> +    msm_mux_qdss_cti_trig_out_b1,
>>>>>>> +    msm_mux_qpic_pad5,
>>>>>>> +    msm_mux_qdss_cti_trig_in_b1,
>>>>>>> +    msm_mux_qpic_pad6,
>>>>>>> +    msm_mux_qpic_pad7,
>>>>>>> +    msm_mux_cxc0,
>>>>>>> +    msm_mux_mac13,
>>>>>>> +    msm_mux_qdss_cti_trig_in_a1,
>>>>>>> +    msm_mux_qdss_cti_trig_out_a1,
>>>>>>> +    msm_mux_wci22,
>>>>>>> +    msm_mux_qdss_cti_trig_in_a0,
>>>>>>> +    msm_mux_qpic_pad1,
>>>>>>> +    msm_mux_qdss_cti_trig_out_a0,
>>>>>>> +    msm_mux_qpic_pad2,
>>>>>>> +    msm_mux_qpic_pad3,
>>>>>>> +    msm_mux_qdss_traceclk_b,
>>>>>>> +    msm_mux_qpic_pad0,
>>>>>>> +    msm_mux_qdss_tracectl_b,
>>>>>>> +    msm_mux_qpic_pad8,
>>>>>>> +    msm_mux_pcm_zsi1,
>>>>>>> +    msm_mux_qdss_tracedata_b,
>>>>>>> +    msm_mux_led0,
>>>>>>> +    msm_mux_pwm04,
>>>>>>
>>>>>> What does "04" mean here?
>>>>>
>>>>> There are 4 Pulse Width Modulation channels, pwmXY is pwm
>>>>> channel X and pin
>>>>> Y.
>>>>
>>>> So Y is alternative mux? Can we use letters for this as well?
>>>
>>> Ok
>>
>> Sorry, actually they are not alternative muxes. There are 4 different PWM
>> instances. Each PWM instance can handle 'n' different GPIOs (for example,
>> that can be connected to LED etc.).
>>
> 
> So we have 4 PWMs and the output from a single PWM can muxed to drive
> the output of 4 pins?
> 
> Then skip the last digit and just go pwm0, ... pwm3 and include all four
> pins that can be part of each instance. As the pingroup configuration is
> per pin in the TLMM it's possible to configure subsets of the pins in a
> group.

Ok

Thanks
Varada

> Regards,
> Bjorn
> 

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