From: Lars-Peter Clausen <lars@metafoo.de>
To: Mark Brown <broonie@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>,
Guenter Roeck <linux@roeck-us.net>,
Jonathan Cameron <jic23@kernel.org>,
lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org,
linux-iio@vger.kernel.org, linux-spi@vger.kernel.org
Subject: Re: [PATCH 1/3] spi: Add a spi_w8r16be() helper
Date: Fri, 27 Sep 2013 20:46:56 +0200 [thread overview]
Message-ID: <5245D2A0.4090909@metafoo.de> (raw)
In-Reply-To: <20130927183456.GM19304@sirena.org.uk>
On 09/27/2013 08:34 PM, Mark Brown wrote:
> On Fri, Sep 27, 2013 at 04:34:27PM +0200, Lars-Peter Clausen wrote:
>> This patch adds a new spi_w8r16be() helper, which is similar to spi_w8r16()
>> except that it converts the read data word from big endian to native endianness
>> before returning it. The reason for introducing this new helper is that for SPI
>
> This actually feels like a bug in spi_w8r16() - I'd expect it to be
> returning native endian in the first place since in SPI a word is by
> default big endian so I'd expect this to have more of a register I/O
> model. It certainly seems to match what almost all of the users are
> doing.
According to the documentation of spi_w8r16() it is a feature.
* The number is returned in wire-order, which is at least sometimes
* big-endian.
There seem to be at least two users though which assume that the result is
in native endianness drivers/hwmon/ads7871.c and drivers/mfd/stmpe-spi.c
>
> That said I'm not sure this is worth fixing in which case the new API
> makes sense. Or converting the users to regmap I guess.
>
regmap is always my first choice, but the users are all devices having
varying register sizes, so regmap is not working that nicely.
- Lars
next prev parent reply other threads:[~2013-09-27 18:46 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-27 14:34 [PATCH 1/3] spi: Add a spi_w8r16be() helper Lars-Peter Clausen
2013-09-27 14:34 ` [PATCH 2/3] hwmon: (adt7310) Use spi_w8r16be() instead spi_w8r16() Lars-Peter Clausen
2013-09-27 16:12 ` Guenter Roeck
2013-10-03 12:53 ` Mark Brown
2013-09-27 14:34 ` [PATCH 3/3] staging:iio:ade7753/ade7754/ade7759: Use spi_w8r16be() instead of spi_w8r16() Lars-Peter Clausen
2013-09-28 10:42 ` Jonathan Cameron
2013-09-27 18:34 ` [PATCH 1/3] spi: Add a spi_w8r16be() helper Mark Brown
2013-09-27 18:46 ` Lars-Peter Clausen [this message]
2013-09-27 19:22 ` Mark Brown
2013-09-27 20:01 ` Lars-Peter Clausen
2013-09-29 12:30 ` Mark Brown
2013-10-03 10:39 ` Lars-Peter Clausen
2013-10-03 10:59 ` Mark Brown
2013-09-27 20:42 ` Guenter Roeck
2013-10-03 12:52 ` Mark Brown
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