[PATCH v1 11/20] dt-bindings: pinctrl: Add starfive,jhb100-per1-pinctrl

[Changhuang Liang]

Hi, linus

> On Tue, Apr 28, 2026 at 8:51 PM Conor Dooley <conor at kernel.org> wrote:
> > On Tue, Apr 28, 2026 at 01:28:05AM +0000, Changhuang Liang wrote:
> 
> > > We think that implementing this in the pinmux will be relatively
> > > simple. It avoids the need to create a large number of mapping
> > > relationships in the driver, which simplifies our driver
> > > implementation. I'm not sure if you'll find this explanation acceptable.
> >
> > I don't really see how pins + functions would require lots of "mapping
> > relationships". Instead of having
> > +/* pinctrl_sys2 pad function selection */
> > +#define FUNC_SYS2_UART_CTS                             1
> > +#define FUNC_SYS2_UART_RTS                             1
> > +#define FUNC_SYS2_UART_DCD                             1
> > +#define FUNC_SYS2_UART_DSR                             1
> > +#define FUNC_SYS2_UART_DTR                             1
> > +#define FUNC_SYS2_UART_RI                              1
> > +#define FUNC_SYS2_UART0_TX                             1
> > +#define FUNC_SYS2_UART0_RX                             1
> > +#define FUNC_SYS2_UART1_TX                             1
> > +#define FUNC_SYS2_UART1_RX                             1
> > +#define FUNC_SYS2_UART2_TX                             1
> > +#define FUNC_SYS2_UART2_RX                             1
> > +#define FUNC_SYS2_UART3_TX                             1
> > +#define FUNC_SYS2_UART3_RX                             1
> > +#define FUNC_SYS2_UART4_TX                             1
> > +#define FUNC_SYS2_UART4_RX                             1
> > +#define FUNC_SYS2_UART5_TX                             1
> > +#define FUNC_SYS2_UART5_RX                             1
> > +#define FUNC_SYS2_UART6_TX                             1
> > +#define FUNC_SYS2_UART6_RX                             1
> > +#define FUNC_SYS2_UART7_TX                             1
> > +#define FUNC_SYS2_UART7_RX                             1
> > +#define FUNC_SYS2_UART8_TX                             1
> > +#define FUNC_SYS2_UART8_RX                             1
> > +#define FUNC_SYS2_UART9_TX                             1
> > +#define FUNC_SYS2_UART9_RX                             1
> > +#define FUNC_SYS2_UART10_TX                            1
> > +#define FUNC_SYS2_UART10_RX                            1
> > +#define FUNC_SYS2_UART11_TX                            1
> > +#define FUNC_SYS2_UART11_RX                            1
> > +#define FUNC_SYS2_UART12_TX                            1
> > +#define FUNC_SYS2_UART12_RX                            1
> > +#define FUNC_SYS2_UART13_TX                            1
> > +#define FUNC_SYS2_UART13_RX                            1
> > +#define FUNC_SYS2_UART14_TX                            1
> > +#define FUNC_SYS2_UART14_RX                            1
> > you just define a function called "uart" and have a simple map of that
> > string to the number 1. You end up with a single array with the
> > relationships, not lots.
> >
> > Frankly, pinmux just does not seem appropriate to me when it looks
> > like 90%+ of the pin mappings for a peripheral share the same function
> value.
> > There appears only to be a rare number of cases where that doesn't
> > apply, but that could be handled by having them represented by a
> > different group/pins node with a different function.
> 
> I share Conors view on the muxing here. Using functions + groups as strings
> looks easier for this hardware, and the driver needs many changes anyway so
> I would say just get to it.
> 
> A common problem among upstream contributors is pushback that seems to
> mask the fact that your organization has already decided to use this scheme
> before discussing things with the community (based on previous work and
> assumptions usually), and I'm not happy about such situations, so please take
> this time for an internal discussion about community work if this is the case.

Thanks for the criticism. I'm now reworking the binding to use the simpler 
string-based functions+groups as Conor suggested, instead of overcomplicating 
pinmux. Will send a new version soon.

Best Regards,
Changhuang