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Groups > linux.kernel > #1632829
| From | Andy Shevchenko <andy.shevchenko@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable |
| Date | 2017-04-28 14:20 +0200 |
| Message-ID | <tBd2p-78J-3@gated-at.bofh.it> (permalink) |
| References | <tAMYh-6lN-3@gated-at.bofh.it> <tAMYi-6lN-21@gated-at.bofh.it> <tAT3I-20u-5@gated-at.bofh.it> <tB9Bw-4Ua-43@gated-at.bofh.it> <tBcSJ-75z-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, Apr 28, 2017 at 3:07 PM, Chris Brandt <Chris.Brandt@renesas.com> wrote: > On Friday, April 28, 2017, Linus Walleij wrote: >> > For me it looks like you are trying to alias open-drain + bias or >> > alike. Don't actually see the benefit of it. >> >> Andy is bringing up a valid point. And I remember asking about this before. >> >> What does "bi-directional" really mean, electrically speaking? > Take the SDHI data pins. You send AND receive data over those pins (and they are not open drain). Can you point to schematics and electrical characteristics of such buffer? (Yes, I can imagine one case where it's possible to have an "automatic" switch based on which current is bigger output of your side or remote's. But! I would like to see actual specifications to prove this or otherwise.) > The issue is that the PFC HW that enables the connections between the SDHI IP block and the I/O pad buffers can only enable one path/signal/direction to the buffer enables (in or out). So for a pin that needs both directions, the PFC enables output and the "bidirectional register" is used to enable the input buffer as well. > In the RZ/A1 HW manual you can kind of see that in 54.18 Port Control Logical Diagram (but that wasn't obvious to me at first). Please, post a link to it or copy essential parts. I'm quite skeptical that cheap hardware can implement something more costable than simplest open-source / open-drain + bias. -- With Best Regards, Andy Shevchenko
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[PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
[PATCH v5 05/10] arm: dts: dt-bindings: Add Renesas RZ/A1 pinctrl header Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 05/10] arm: dts: dt-bindings: Add Renesas RZ/A1 pinctrl header Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-27 10:40 +0200
Re: [PATCH v5 05/10] arm: dts: dt-bindings: Add Renesas RZ/A1 pinctrl header Simon Horman <horms@verge.net.au> - 2017-04-28 07:20 +0200
[PATCH v5 07/10] arm: dts: genmai: Add SCIF2 pin group Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 07/10] arm: dts: genmai: Add SCIF2 pin group Simon Horman <horms@verge.net.au> - 2017-04-28 07:30 +0200
[PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-27 12:00 +0200
RE: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-27 12:50 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Simon Horman <horms@verge.net.au> - 2017-04-28 07:30 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-28 09:20 +0200
RE: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 16:50 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Linus Walleij <linus.walleij@linaro.org> - 2017-05-05 14:10 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Geert Uytterhoeven <geert@linux-m68k.org> - 2017-05-05 14:30 +0200
RE: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Chris Brandt <Chris.Brandt@renesas.com> - 2017-05-05 14:50 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Linus Walleij <linus.walleij@linaro.org> - 2017-05-11 15:50 +0200
Re: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Linus Walleij <linus.walleij@linaro.org> - 2017-04-28 11:00 +0200
RE: [PATCH v5 10/10] arm: dts: genmai: Add ethernet pin group Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 16:00 +0200
[PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-27 17:00 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Linus Walleij <linus.walleij@linaro.org> - 2017-04-28 10:40 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-28 12:20 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Linus Walleij <linus.walleij@linaro.org> - 2017-05-07 23:50 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 14:10 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-28 14:20 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 15:20 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-28 17:00 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 17:20 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-28 17:40 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-04-28 18:50 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Linus Walleij <linus.walleij@linaro.org> - 2017-05-08 01:30 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable jmondi <jacopo@jmondi.org> - 2017-05-08 18:10 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-05-08 18:20 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-05-08 19:10 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-05-08 20:30 +0200
RE: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Chris Brandt <Chris.Brandt@renesas.com> - 2017-05-08 22:10 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable jmondi <jacopo@jmondi.org> - 2017-05-08 19:30 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-05-08 19:50 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable jmondi <jacopo@jmondi.org> - 2017-05-09 12:00 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Linus Walleij <linus.walleij@linaro.org> - 2017-05-08 23:20 +0200
Re: [PATCH v5 01/10] pinctrl: generic: Add bi-directional and output-enable Geert Uytterhoeven <geert@linux-m68k.org> - 2017-05-09 13:00 +0200
[PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-27 10:40 +0200
Re: [PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties Linus Walleij <linus.walleij@linaro.org> - 2017-04-28 10:20 +0200
Re: [PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-28 12:10 +0200
Re: [PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties jmondi <jacopo@jmondi.org> - 2017-04-28 14:50 +0200
Re: [PATCH v5 02/10] pinctrl: generic: Add macros to unpack properties Andy Shevchenko <andy.shevchenko@gmail.com> - 2017-04-28 18:30 +0200
[PATCH v5 04/10] dt-bindings: pinctrl: Add RZ/A1 bindings doc Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 04/10] dt-bindings: pinctrl: Add RZ/A1 bindings doc Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-27 10:40 +0200
Re: [PATCH v5 04/10] dt-bindings: pinctrl: Add RZ/A1 bindings doc Rob Herring <robh@kernel.org> - 2017-04-28 23:10 +0200
[PATCH v5 06/10] arm: dts: r7s72100: Add pin controller node Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
[PATCH v5 09/10] arm: dts: genmai: Add user led device nodes Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
[PATCH v5 08/10] arm: dts: genmai: Add RIIC2 pin group Jacopo Mondi <jacopo+renesas@jmondi.org> - 2017-04-27 10:30 +0200
Re: [PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-27 10:50 +0200
Re: [PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller Simon Horman <horms@verge.net.au> - 2017-04-28 07:30 +0200
Re: [PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller jmondi <jacopo@jmondi.org> - 2017-04-28 09:30 +0200
Re: [PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller Simon Horman <horms@verge.net.au> - 2017-04-28 09:40 +0200
Re: [PATCH v5 00/10] Renesas RZ/A1 pin and gpio controller Geert Uytterhoeven <geert@linux-m68k.org> - 2017-04-28 09:40 +0200
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