Date: Wed, 2 Mar 2016 22:48:59 +0100
From: Andrew Lunn <andrew@lunn.ch>
To: Vladimir Zapolskiy <vz@mleia.com>
Cc: GregKH <greg@kroah.com>, srinivas.kandagatla@linaro.org,
        maxime.ripard@free-electrons.com, wsa@the-dreams.de,
        broonie@kernel.org, linux-kernel@vger.kernel.org,
        pantelis.antoniou@konsulko.com, bgolaszewski@baylibre.com
Subject: Re: [PATCHv7 3/7] eeprom: at24: extend driver to plug into the NVMEM
 framework
Message-ID: <20160302214859.GA15541@lunn.ch>
References: <1456516764-1456-1-git-send-email-andrew@lunn.ch>
 <1456516764-1456-4-git-send-email-andrew@lunn.ch>
 <56D75F3F.5000806@mleia.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <56D75F3F.5000806@mleia.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1064
Lines: 37

On Wed, Mar 02, 2016 at 11:46:39PM +0200, Vladimir Zapolskiy wrote:
> Hi Andrew,
> 
> On 26.02.2016 21:59, Andrew Lunn wrote:
> > Add a regmap for accessing the EEPROM, and then use that with the
> > NVMEM framework. Set the NVMEM config structure to enable backward, so
> > that the 'eeprom' file in sys is provided by the framework.
> > 
> > Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> > Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > ---
> 
> [snip]
> 
> > +static int at24_regmap_read(void *context, const void *reg, size_t reg_size,
> > +			    void *val, size_t val_size)
> > +{
> > +	struct at24_data *at24 = context;
> > +	off_t offset = *(u32 *)reg;
> > +	int err;
> > +
> > +	err = at24_read(at24, val, offset, val_size);
> > +	if (err)
> > +		return err;
> > +	return 0;
> 
> return at24_read(at24, val, offset, val_size);
> 
> Minus 5 LoC.

And everything breaks :-(

regmap expects either an error code, or 0. Return a positive value and
it is not happy.

   Andrew