Re: [PATCH v6 1/3] dt-bindings: pinctrl: renesas,rzn1-pinctrl: documentation
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2018-09-27 15:16:10
Also in:
linux-gpio, linux-renesas-soc, lkml
On Thu, Sep 27, 2018 at 3:59 PM Phil Edworthy [off-list ref] wrote:
The Renesas RZ/N1 device family PINCTRL node description. Based on a patch originally written by Michel Pollet at Renesas. Signed-off-by: Phil Edworthy <redacted> Reviewed-by: Jacopo Mondi <jacopo+renesas@jmondi.org> --- v6: - Instead of combining the pin nr and func into a single element, use a pair of 8-bit elements.
quoted hunk ↗ jump to hunk
--- /dev/null +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rzn1-pinctrl.txt
+- Pin multiplexing sub-nodes:
+ A pin multiplexing sub-node describes how to configure a set of
+ (or a single) pin in some desired alternate function mode.
+ A single sub-node may define several pin configurations.
+ Please refer to pinctrl-bindings.txt to get to know more on generic
+ pin properties usage.
+
+ The allowed generic formats for a pin multiplexing sub-node are the
+ following ones:
+
+ node-1 {
+ pinmux = /bits/ 8 <PIN_NR MUX_FUNC>, <PIN_NR MUX_FUNC>, ... ;
+ GENERIC_PINCONFIG;
+ };and
+ Example:
+ A serial communication interface with a TX output pin and an RX input pin.
+
+ &pinctrl {
+ pins_uart0: pins_uart0 {
+ pinmux = /bits/ 8 <
+ 103 RZN1_FUNC_UART0_I /* UART0_TXD */
+ 104 RZN1_FUNC_UART0_I /* UART0_RXD */
+ >;
+ };
+ };
So the above is in response to Rob's comment on v4:
| > +#define RZN1_MUX(_gpio, _func) \
| > + (((RZN1_FUNC_##_func) << 8) | (_gpio))
|
| I'm not a fan of token pasting and it also goes against kernel style.
| If every other Renesas platform is doing this, then fine. Otherwise,
| you can express it in pretty much the same (source) space:
|
| pinmux = <RZN1_MUX_UART0_I 104>;
|
| Yes, this is 2 cells instead of 1, but if you care about space, you
| can use 8 or 16 bit size.
I'm not so much impressed by the "/bits/ 8" part.
No other pinctrl bindings uses this.
We do have RZA1_PINMUX() and STM32_PINMUX() macros.
Rob: Is this really what you intended?
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
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when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds