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

[Bjorn Andersson]

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)


Btw, do you need any additional configuration for selecting alternative
muxing or is that automagical these days?

> > > +	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)

> > > +	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?

> > 
> > > +	msm_mux_led1,
> > > +	msm_mux_pwm14,
> > > +	msm_mux_led2,
> > > +	msm_mux_pwm24,
> > > +	msm_mux_pwm00,
> > > +	msm_mux_blsp4_uart1,
> > 
> > Are uart0 vs uart1 alternative muxes?
> 
> These are two different uarts available at two independent pins.
> 

Ok, then I'm happy with the naming of this :)

Thanks,
Bjorn