Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 26 Apr 2021 17:04:42 +0300 | Subject | Re: [PATCH v6 3/3] pinctrl: Add Xilinx ZynqMP pinctrl driver support |
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On Mon, Apr 26, 2021 at 4:20 PM Sai Krishna Potthuri <lakshmis@xilinx.com> wrote: > > From: Andy Shevchenko <andy.shevchenko@gmail.com> > > Sent: Friday, April 23, 2021 9:24 PM > > On Thu, Apr 22, 2021 at 11:31 AM Sai Krishna Potthuri > > <lakshmi.sai.krishna.potthuri@xilinx.com> wrote:
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> > > +config PINCTRL_ZYNQMP > > > + tristate "Pinctrl driver for Xilinx ZynqMP" > > > + depends on ZYNQMP_FIRMWARE > > > + select PINMUX > > > + select GENERIC_PINCONF > > > + default ZYNQMP_FIRMWARE > > > + help > > > + This selects the pinctrl driver for Xilinx ZynqMP platform. > > > + This driver will query the pin information from the firmware > > > + and allow configuring the pins. > > > + Configuration can include the mux function to select on those > > > + pin(s)/group(s), and various pin configuration parameters > > > + such as pull-up, slew rate, etc. > > > > Missed module name. > Is this (module name) a configuration option in Kconfig?
It's a text in a free form that sheds light on how the module will be named in case the user will choose "m".
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> > > + * Copyright (C) 2020 Xilinx, Inc. > > > > 2021? > Couple of versions for this patch series sent in 2020, hence maintaining > the same. > Is it like we maintain the year when this patch series is applied, which is > 2021?
2020, 2021 sounds okay as well.
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> > > + if (pin >= zynqmp_desc.npins) > > > + return -EOPNOTSUPP; > > > > Is it possible? > This is a safe check.
I.o.w. dead code, right?
> Pin information will get from dt files/Xilinx firmware (query pin information > for a group)/user application and there are chances of getting wrong pin.
I'm not sure I understand this. How comes that pin control core will ask for a pin higher than npins?
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> > > + ret = zynqmp_pm_pinctrl_get_config(pin, param, &arg); > > > + if (arg != PM_PINCTRL_BIAS_PULL_UP) > > > + return -EINVAL; > > > > Error code being shadowed. Instead check it here properly.
> Are you mentioning the case where ret is also a non-zero? > If yes, then I will update this check to > if (!ret && arg != PM_PINCTRL_BIAS_PULL_UP) > return -EINVAL;
No, this is wrong in the same way.
> ret non-zero case, we are handling at the end of switch case.
I meant that you need to pass the real return code to the (upper) caller. Ditto for all other cases (mentioned and not mentioned)
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> > > + ret = -EOPNOTSUPP; > > > > Isn't it ENOTSUP for all cases here? > Giving 'Operation Not Supported (EOPNOTSUPP)' error, when > driver gets a request for unsupported pin or configuration. > Can you please elaborate your question if I didn't answer properly.
The pin control subsystem along with the GPIO library are using -ENOTSUPP error code for internal operations. EOPNOTSUPP is the one that should be returned to user space. Is it the case here?
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> > > +}; > > > > > + > > > > Ditto. > I see some drivers are maintaining the extra line in above two cases. > We shouldn't maintain extra line after struct declaration?
What's the point to add more blank lines where they won't add any value?
> > > +module_platform_driver(zynqmp_pinctrl_driver);
-- With Best Regards, Andy Shevchenko
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