From: Linus Walleij <linus.walleij@linaro.org> To: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Lee Jones <lee.jones@linaro.org>, Alexandre Courbot <gnurou@gmail.com>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Frank Rowand <frowand.list@gmail.com>, Wolfram Sang <wsa@the-dreams.de>, Richard Purdie <rpurdie@rpsys.net>, Jacek Anaszewski <j.anaszewski@samsung.com>, Jean Delvare <jdelvare@suse.com>, Peter Rosin <peda@axentia.se>, Avirup Banerjee <abanerjee@juniper.net>, Georgi Vlaev <gvlaev@juniper.net>, Guenter Roeck <linux@roeck-us.net>, JawaharBalaji Thirumalaisamy <jawaharb@juniper.net>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>, "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>, "linux-leds@vger.kernel.org" <linux-leds@vger.kernel.org>, linux-hwmon@vger.kernel.org Subject: Re: [PATCH 06/10] gpio: gpio-i2cs: Document bindings of I2CS FPGA GPIO block Date: Fri, 21 Oct 2016 10:59:25 +0200 [thread overview] Message-ID: <CACRpkdZ=mWYJpBV_WmxYcAwA5TdHM4qv9k17Jb6TnoOL4YAPHA@mail.gmail.com> (raw) In-Reply-To: <1475853669-22480-7-git-send-email-pantelis.antoniou@konsulko.com> On Fri, Oct 7, 2016 at 5:21 PM, Pantelis Antoniou <pantelis.antoniou@konsulko.com> wrote: > +This is virtual gpio driver, that maps each bit of the I2CS FPGA to > +a gpio. It's used as a compatibility replacement for FRUs that use > +I2CS FPGA to report presence, control and report power status in > +the Juniper's driver infra that uses gpios. Compatible with any I2CS. What does "virtual" mean? I regularly NACK patches that try to shoehorn stuff into GPIO not because they are actually GPIO hardware drivers or general purpose at all, but because it is convenient. Don't do this. > +- i2c-gpio-map: Map of "I2CS register" and "direction". The registers > + are 8 bit wide, each bit of the register is mapped to either > + input or output depending on the bits of the "direction". If > + the bit in the direction is 1, then that bit from the I2CS > + register is mapped to gpio input, otherwise to gpio output. Does this mean that the hardware is synthesized so that some lines are hardwired as input and some hardwired as output? That again does not sound like "general purpose" at all. I think this happens in other hardware and should be a generic binding like gpio-lines-input-only = <0>, <4>; gpio-lines-output-only = <7>, <8>; And no bitmasking, use the local offset, parse and construct the mask. Yours, Linus Walleij
WARNING: multiple messages have this Message-ID (diff)
From: Linus Walleij <linus.walleij@linaro.org> To: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Lee Jones <lee.jones@linaro.org>, Alexandre Courbot <gnurou@gmail.com>, Rob Herring <robh+dt@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Frank Rowand <frowand.list@gmail.com>, Wolfram Sang <wsa@the-dreams.de>, Richard Purdie <rpurdie@rpsys.net>, Jacek Anaszewski <j.anaszewski@samsung.com>, Jean Delvare <jdelvare@suse.com>, Peter Rosin <peda@axentia.se>, Avirup Banerjee <abanerjee@juniper.net>, Georgi Vlaev <gvlaev@juniper.net>, Guenter Roeck <linux@roeck-us.net>, JawaharBalaji Thirumalaisamy <jawaharb@juniper.net>, "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>, "linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.o> Subject: Re: [PATCH 06/10] gpio: gpio-i2cs: Document bindings of I2CS FPGA GPIO block Date: Fri, 21 Oct 2016 10:59:25 +0200 [thread overview] Message-ID: <CACRpkdZ=mWYJpBV_WmxYcAwA5TdHM4qv9k17Jb6TnoOL4YAPHA@mail.gmail.com> (raw) In-Reply-To: <1475853669-22480-7-git-send-email-pantelis.antoniou@konsulko.com> On Fri, Oct 7, 2016 at 5:21 PM, Pantelis Antoniou <pantelis.antoniou@konsulko.com> wrote: > +This is virtual gpio driver, that maps each bit of the I2CS FPGA to > +a gpio. It's used as a compatibility replacement for FRUs that use > +I2CS FPGA to report presence, control and report power status in > +the Juniper's driver infra that uses gpios. Compatible with any I2CS. What does "virtual" mean? I regularly NACK patches that try to shoehorn stuff into GPIO not because they are actually GPIO hardware drivers or general purpose at all, but because it is convenient. Don't do this. > +- i2c-gpio-map: Map of "I2CS register" and "direction". The registers > + are 8 bit wide, each bit of the register is mapped to either > + input or output depending on the bits of the "direction". If > + the bit in the direction is 1, then that bit from the I2CS > + register is mapped to gpio input, otherwise to gpio output. Does this mean that the hardware is synthesized so that some lines are hardwired as input and some hardwired as output? That again does not sound like "general purpose" at all. I think this happens in other hardware and should be a generic binding like gpio-lines-input-only = <0>, <4>; gpio-lines-output-only = <7>, <8>; And no bitmasking, use the local offset, parse and construct the mask. Yours, Linus Walleij
next prev parent reply other threads:[~2016-10-21 8:59 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-10-07 15:20 [PATCH 00/10] Introduce Juniper I2CS FPGA driver Pantelis Antoniou 2016-10-07 15:21 ` [PATCH 01/10] mfd: Add Juniper I2CS MFD driver Pantelis Antoniou 2016-10-07 15:21 ` Pantelis Antoniou 2016-10-07 15:21 ` [PATCH 02/10] mfd: dt-bindings: Add bindings for the Juniper I2CS MFD Pantelis Antoniou 2016-10-10 20:23 ` Rob Herring 2016-10-17 19:10 ` Pantelis Antoniou 2016-10-07 15:21 ` [PATCH 03/10] i2c/muxes: Juniper I2CS RE mux Pantelis Antoniou 2016-10-07 15:21 ` Pantelis Antoniou 2016-10-10 15:29 ` Peter Rosin 2016-10-10 15:29 ` Peter Rosin 2016-10-07 15:21 ` [PATCH 04/10] i2c: i2c-mux-i2cs: Add device tree bindings Pantelis Antoniou 2016-10-10 15:48 ` Peter Rosin 2016-10-10 15:48 ` Peter Rosin 2016-10-17 19:11 ` Pantelis Antoniou 2016-10-10 20:25 ` Rob Herring 2016-10-07 15:21 ` [PATCH 05/10] gpio: i2cs: Juniper I2CS to GPIO pin mapping driver Pantelis Antoniou 2016-10-21 8:41 ` Linus Walleij 2016-10-21 8:41 ` Linus Walleij 2016-10-07 15:21 ` [PATCH 06/10] gpio: gpio-i2cs: Document bindings of I2CS FPGA GPIO block Pantelis Antoniou 2016-10-21 8:59 ` Linus Walleij [this message] 2016-10-21 8:59 ` Linus Walleij 2016-10-07 15:21 ` [PATCH 07/10] leds: i2cs: Add I2CS FPGA leds driver Pantelis Antoniou 2016-10-10 9:41 ` Jacek Anaszewski 2016-10-07 15:21 ` [PATCH 08/10] leds: Add binding for Juniper's I2CS FPGA Pantelis Antoniou 2016-10-07 15:21 ` Pantelis Antoniou 2016-10-10 9:41 ` Jacek Anaszewski 2016-10-07 15:21 ` [PATCH 09/10] hwmon: Add driver for Fan Tray on Juniper I2CS FGPA Pantelis Antoniou 2016-10-07 15:21 ` [PATCH 10/10] hwmon: i2cs-fan: Add hwmon dts binding documentation Pantelis Antoniou 2016-10-10 20:29 ` Rob Herring 2016-10-17 19:12 ` Pantelis Antoniou
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