Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sun, 2 Sep 2018 21:31:29 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     Janusz Krzysztofik <jmkrzyszt@gmail.com>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>,
        Peter Korsgaard <peter.korsgaard@barco.com>,
        Peter Rosin <peda@axentia.se>,
        Ulf Hansson <ulf.hansson@linaro.org>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Dominik Brodowski <linux@dominikbrodowski.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Michael Hennerich <Michael.Hennerich@analog.com>,
        Jonathan Cameron <jic23@kernel.org>,
        Hartmut Knaack <knaack.h@gmx.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        Jiri Slaby <jslaby@suse.com>, Willy Tarreau <w@1wt.eu>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        linux-doc@vger.kernel.org, linux-i2c@vger.kernel.org,
        linux-mmc@vger.kernel.org, netdev@vger.kernel.org,
        linux-iio@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-serial@vger.kernel.org, linux-gpio@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Sebastien Bourdelin <sebastien.bourdelin@savoirfairelinux.com>,
        Lukas Wunner <lukas@wunner.de>,
        Rojhalat Ibrahim <imr@rtschenk.de>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Tony Lindgren <tony@atomide.com>,
        Yegor Yefremov <yegorslists@googlemail.com>,
        Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= 
        <u.kleine-koenig@pengutronix.de>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v7 1/4] gpiolib: Pass bitmaps, not integer arrays, to
 get/set array
Message-ID: <20180903043129.GA17856@bombadil.infradead.org>
References: <20180831225616.29221-1-jmkrzyszt@gmail.com>
 <20180902120144.6855-1-jmkrzyszt@gmail.com>
 <20180902120144.6855-2-jmkrzyszt@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20180902120144.6855-2-jmkrzyszt@gmail.com>
User-Agent: Mutt/1.9.2 (2017-12-15)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

> +++ b/drivers/auxdisplay/hd44780.c
> @@ -62,17 +62,12 @@ static void hd44780_strobe_gpio(struct hd44780 *hd)
>  /* write to an LCD panel register in 8 bit GPIO mode */
>  static void hd44780_write_gpio8(struct hd44780 *hd, u8 val, unsigned int rs)
>  {
> -	int values[10];	/* for DATA[0-7], RS, RW */
> -	unsigned int i, n;
> -
> -	for (i = 0; i < 8; i++)
> -		values[PIN_DATA0 + i] = !!(val & BIT(i));
> -	values[PIN_CTRL_RS] = rs;
> -	n = 9;
> -	if (hd->pins[PIN_CTRL_RW]) {
> -		values[PIN_CTRL_RW] = 0;
> -		n++;
> -	}
> +	DECLARE_BITMAP(values, 10); /* for DATA[0-7], RS, RW */
> +	unsigned int n;
> +
> +	*values = val;
> +	__assign_bit(8, values, rs);
> +	n = hd->pins[PIN_CTRL_RW] ? 10 : 9;

Doesn't this assume little endian bitmaps?  Has anyone tested this on
big-endian machines?