Re: [PATCH v3 1/9] dt-bindings: reset: Add a binding for the RPi Firmware reset controller

From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
To: Philipp Zabel <p.zabel@pengutronix.de>,
	f.fainelli@gmail.com, gregkh@linuxfoundation.org,
	wahrenst@gmx.net, linux-kernel@vger.kernel.org,
	Ray Jui <rjui@broadcom.com>,
	Scott Branden <sbranden@broadcom.com>,
	bcm-kernel-feedback-list@broadcom.com,
	Eric Anholt <eric@anholt.net>
Cc: linux-usb@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, tim.gover@raspberrypi.org,
	linux-pci@vger.kernel.org, helgaas@kernel.org,
	andy.shevchenko@gmail.com, mathias.nyman@linux.intel.com,
	lorenzo.pieralisi@arm.com, Rob Herring <robh+dt@kernel.org>,
	devicetree@vger.kernel.org
Subject: Re: [PATCH v3 1/9] dt-bindings: reset: Add a binding for the RPi Firmware reset controller
Date: Wed, 17 Jun 2020 12:22:10 +0200	[thread overview]
Message-ID: <2b435e7fcf2c4600cf1618132f107a49d826d375.camel@suse.de> (raw)
In-Reply-To: <babff895a0b5e2cd63082bd38f087bd1bc345671.camel@pengutronix.de>

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Hi,

On Wed, 2020-06-17 at 11:55 +0200, Philipp Zabel wrote:
> Hi Nicolas,
> 
> On Fri, 2020-06-12 at 19:13 +0200, Nicolas Saenz Julienne wrote:
> > The firmware running on the RPi VideoCore can be used to reset and
> > initialize HW controlled by the firmware.
> > 
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
> > 
> > ---
> > Changes since v2:
> >  - Add include file for reset IDs
> > 
> > Changes since v1:
> >  - Correct cells binding as per Florian's comment
> >  - Change compatible string to be more generic
> > 
> >  .../arm/bcm/raspberrypi,bcm2835-firmware.yaml | 21 +++++++++++++++++++
> >  .../reset/raspberrypi,firmware-reset.h        | 13 ++++++++++++
> >  2 files changed, 34 insertions(+)
> >  create mode 100644 include/dt-bindings/reset/raspberrypi,firmware-reset.h
> > 
> > diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-
> > firmware.yaml
> > b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-
> > firmware.yaml
> > index b48ed875eb8e..23a885af3a28 100644
> > --- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-
> > firmware.yaml
> > +++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-
> > firmware.yaml
> > @@ -39,6 +39,22 @@ properties:
> >        - compatible
> >        - "#clock-cells"
> >  
> > +  reset:
> > +    type: object
> > +
> > +    properties:
> > +      compatible:
> > +        const: raspberrypi,firmware-reset
> > +
> > +      "#reset-cells":
> > +        const: 1
> > +        description: >
> > +          The argument is the ID of the firmware reset line to affect.
> > +
> > +    required:
> > +      - compatible
> > +      - "#reset-cells"
> > +
> >      additionalProperties: false
> >  
> >  required:
> > @@ -55,5 +71,10 @@ examples:
> >              compatible = "raspberrypi,firmware-clocks";
> >              #clock-cells = <1>;
> >          };
> > +
> > +        reset: reset {
> > +            compatible = "raspberrypi,firmware-reset";
> > +            #reset-cells = <1>;
> > +        };
> >      };
> >  ...
> > diff --git a/include/dt-bindings/reset/raspberrypi,firmware-reset.h
> > b/include/dt-bindings/reset/raspberrypi,firmware-reset.h
> > new file mode 100644
> > index 000000000000..1a4f4c792723
> > --- /dev/null
> > +++ b/include/dt-bindings/reset/raspberrypi,firmware-reset.h
> > @@ -0,0 +1,13 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +/*
> > + * Copyright (c) 2020 Nicolas Saenz Julienne
> > + * Author: Nicolas Saenz Julienne <nsaenzjulienne@suse.com>
> > + */
> > +
> > +#ifndef _DT_BINDINGS_RASPBERRYPI_FIRMWARE_RESET_H
> > +#define _DT_BINDINGS_RASPBERRYPI_FIRMWARE_RESET_H
> > +
> > +#define RASPBERRYPI_FIRMWARE_RESET_ID_USB	0
> > +#define RASPBERRYPI_FIRMWARE_RESET_NUM_IDS	1
> > +
> > +#endif
> 
> Are there going to be any more firmware controlled resets in the future?

There are not right now, but it's likely some will show up in the future. I
have some contenders in mind, which I'll request once we settle on a design
here, but it ultimately depends on what the RPi people decide to implement.

Regards,
Nicolas

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