RE: [PATCH] ARM: dts: imx6sx: Add missing uart mux function

[Anson Huang]

Hi, Uwe

> Subject: Re: [PATCH] ARM: dts: imx6sx: Add missing uart mux function
> 
> On Thu, Feb 13, 2020 at 02:43:09PM +0800, Anson Huang wrote:
> > From: Anson Huang <b20788@xxxxxxxxxxxxx>
> >
> > Update i.MX6SX pinfunc header to add uart mux function.
> 
> I'm aware you add the macros in a consistent way to the already existing
> stuff. Still I think there is something to improve here. We now have
> definitions like:
> 
> 	MX6SX_PAD_GPIO1_IO06__UART1_RTS_B
> 	MX6SX_PAD_GPIO1_IO06__UART1_CTS_B
> 
> 	MX6SX_PAD_GPIO1_IO07__UART1_CTS_B
> 	MX6SX_PAD_GPIO1_IO07__UART1_RTS_B
> 
> where (ignoring other pins that could be used) only the following
> combinations are valid:
> 
> 	MX6SX_PAD_GPIO1_IO04__UART1_TX
> 	MX6SX_PAD_GPIO1_IO05__UART1_RX
> 	MX6SX_PAD_GPIO1_IO06__UART1_RTS_B
> 	MX6SX_PAD_GPIO1_IO07__UART1_CTS_B
> 
> (in DCE mode) and
> 
> 	MX6SX_PAD_GPIO1_IO04__UART1_RX
> 	MX6SX_PAD_GPIO1_IO05__UART1_TX
> 	MX6SX_PAD_GPIO1_IO06__UART1_CTS_B
> 	MX6SX_PAD_GPIO1_IO07__UART1_RTS_B
> 
> (in DTE mode).

Is it possible the using below combination, if possible, then I think the prefix "DTE/DCE" are
NOT impacting real functions, they are just different names for better identification:

MX6SX_PAD_GPIO1_IO04__UART1_TX
MX6SX_PAD_GPIO1_IO05__UART1_RX
MX6SX_PAD_GPIO1_IO06__UART1_CTS_B
MX6SX_PAD_GPIO1_IO07__UART1_RTS_B

> 
> For i.MX6SLL, i.MX6UL, imx6ULL and i.MX7 the naming convention is saner, a
> typical definition there is:
> 
> 	MX7D_PAD_LPSR_GPIO1_IO04__UART5_DTE_RTS
> 
> where the name includes DTE and where is it (more) obvious that this cannot
> be combined with
> 
> 	MX7D_PAD_LPSR_GPIO1_IO07__UART5_DCE_TX
> 
> .
> 
> I suggest to adapt the latter naming convention also for the other i.MX
> pinfunc headers, probably with introducing defines for not breaking existing
> dts files.

If to improve the name, just change the existing dts files which use them should be OK,
as this header file ONLY used by DT and should be no compatible issues. So should I
change the dts files together?

Thanks,
Anson