Re: [PATCH v8 05/10] dt-bindings: i3c: Add macros to help fill I3C/I2C device's reg property

From: Joe Perches <joe@perches.com>
To: Boris Brezillon <boris.brezillon@bootlin.com>,
	Wolfram Sang <wsa@the-dreams.de>,
	linux-i2c@vger.kernel.org, Jonathan Corbet <corbet@lwn.net>,
	linux-doc@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Arnd Bergmann <arnd@arndb.de>
Cc: Przemyslaw Sroka <psroka@cadence.com>,
	Arkadiusz Golec <agolec@cadence.com>,
	Alan Douglas <adouglas@cadence.com>,
	Bartosz Folta <bfolta@cadence.com>, Damian Kos <dkos@cadence.com>,
	Alicja Jurasik-Urbaniak <alicja@cadence.com>,
	Cyprian Wronka <cwronka@cadence.com>,
	Suresh Punnoose <sureshp@cadence.com>,
	Rafal Ciepiela <rafalc@cadence.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Nishanth Menon <nm@ti.com>, Rob Herring <robh+dt@kernel.org>,
	Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Vitor Soares <Vitor.Soares@synopsys.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Linus Walleij <linus.walleij@linaro.org>,
	Xiang Lin <Xiang.Lin@synaptics.com>,
	linux-gpio@vger.kernel.org, Sekhar Nori <nsekhar@ti.com>,
	Przemyslaw Gaj <pgaj@cadence.com>, Peter Rosin <peda@axentia.se>,
	Mike Shettel <mshettel@codeaurora.org>,
	Stephen Boyd <swboyd@chromium.org>
Subject: Re: [PATCH v8 05/10] dt-bindings: i3c: Add macros to help fill I3C/I2C device's reg property
Date: Wed, 03 Oct 2018 11:37:17 -0700	[thread overview]
Message-ID: <c7b929a8c8ebaec7ce0f0e09f803e414e74f986b.camel@perches.com> (raw)
In-Reply-To: <20181003132212.12619-6-boris.brezillon@bootlin.com>

On Wed, 2018-10-03 at 15:22 +0200, Boris Brezillon wrote:
> The reg property of devices connected to an I3C bus have 3 cells, and
> filling them manually is not trivial. Provides macros to help doing
> that.

This patch logic seems excessively fragile.

> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
> Changes in v8:
> - None
> 
> Changes in v5:
> - none
> ---
>  include/dt-bindings/i3c/i3c.h | 28 ++++++++++++++++++++++++++++
>  1 file changed, 28 insertions(+)
>  create mode 100644 include/dt-bindings/i3c/i3c.h
> 
> diff --git a/include/dt-bindings/i3c/i3c.h b/include/dt-bindings/i3c/i3c.h
> new file mode 100644
> index 000000000000..97448c546649
> --- /dev/null
> +++ b/include/dt-bindings/i3c/i3c.h
> @@ -0,0 +1,28 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2017 Cadence Design Systems Inc.
> + *
> + * Author: Boris Brezillon <boris.brezillon@bootlin.com>
> + */
> +
> +#ifndef _DT_BINDINGS_I3C_I3C_H
> +#define _DT_BINDINGS_I3C_I3C_H
> +
> +#define IS_I2C_DEV		0x80000000
> +
> +#define I2C_DEV(addr, lvr)					\
> +	(addr) (IS_I2C_DEV | (lvr)) 0x0

This looks to be missing surrounding parentheses.

> +
> +#define I3C_PID(manufid, partid, instid, extrainfo)		\
> +	((manufid) << 1)					\
> +	(((partid) << 16) | ((instid) << 12) | (extrainfo))

This macro doesn't make any sense.  Missing a shift and an or?

> +
> +#define I3C_DEV_WITH_STATIC_ADDR(addr, manufid, partid,		\
> +				 instid, extrainfo)		\
> +	(addr) I3C_PID(manufid, partid, instid, extrainfo)
> +
> +#define I3C_DEV(manufid, partid, instid, extrainfo)		\
> +	I3C_DEV_WITH_STATIC_ADDR(0x0, manufid, partid,		\
> +				 instid, extrainfo)
> +
> +#endif