From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754730Ab1KIMWs (ORCPT ); Wed, 9 Nov 2011 07:22:48 -0500 Received: from zone0.gcu-squad.org ([212.85.147.21]:5675 "EHLO services.gcu-squad.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751758Ab1KIMWr (ORCPT ); Wed, 9 Nov 2011 07:22:47 -0500 Date: Wed, 9 Nov 2011 13:22:38 +0100 From: Jean Delvare To: Eric Miao Cc: linux-kernel , lm-sensors Subject: Re: [lm-sensors] [PATCH] hwmon: (max1111) change sysfs interface to in[0-3]_input in millivolts Message-ID: <20111109132238.0a35ccee@endymion.delvare> In-Reply-To: <1320837303-30697-1-git-send-email-eric.y.miao@gmail.com> References: <1320837303-30697-1-git-send-email-eric.y.miao@gmail.com> X-Mailer: Claws Mail 3.7.5 (GTK+ 2.20.1; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Eric, On Wed, 9 Nov 2011 19:15:03 +0800, Eric Miao wrote: > This patch fixed the inconsistent max1111 sysfs interface as pointed > out by Jean Delvare: > > It was pointed to me that the max1111 driver doesn't implement the > standard sysfs interface for hwmon drivers (as described in > Documentation/hwmon/sysfs-interface). It exports files adc[0-3]_in, > which > aren't part of the standard interface. Presumably these should be > renamed to in[0-3]_input. Renaming them is probably not sufficient > though, as I see no scaling done in the driver. As the MAX1111 chip has > a documented full scale of 2.048V, I take it that the LSB of the ADC > has a weight of 8 mV. Exporting raw register values to user-space is > not OK. > > Reported-by: Jean Delvare > Signed-off-by: Eric Miao > --- > drivers/hwmon/max1111.c | 13 +++++++------ > 1 files changed, 7 insertions(+), 6 deletions(-) > > diff --git a/drivers/hwmon/max1111.c b/drivers/hwmon/max1111.c > index c97b78e..0e9fcfd 100644 > --- a/drivers/hwmon/max1111.c > +++ b/drivers/hwmon/max1111.c > @@ -106,11 +106,12 @@ static ssize_t show_adc(struct device *dev, > if (ret < 0) > return ret; > > - return sprintf(buf, "%d\n", ret); > + /* assume the reference voltage to be 2.048V */ > + return sprintf(buf, "%d\n", 2048 * 256 / ret); I bet you did not actually test your changes? ret == 0 would obviously crash the driver. The formula looks wrong anyway, should be 2048 * ret / 256. Or in short ret * 8, i.e. LSB weight of the ADC is 8 mV. > } > > #define MAX1111_ADC_ATTR(_id) \ > - SENSOR_DEVICE_ATTR(adc##_id##_in, S_IRUGO, show_adc, NULL, _id) > + SENSOR_DEVICE_ATTR(in##_id##_input, S_IRUGO, show_adc, NULL, _id) > > static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); > static MAX1111_ADC_ATTR(0); > @@ -120,10 +121,10 @@ static MAX1111_ADC_ATTR(3); > > static struct attribute *max1111_attributes[] = { > &dev_attr_name.attr, > - &sensor_dev_attr_adc0_in.dev_attr.attr, > - &sensor_dev_attr_adc1_in.dev_attr.attr, > - &sensor_dev_attr_adc2_in.dev_attr.attr, > - &sensor_dev_attr_adc3_in.dev_attr.attr, > + &sensor_dev_attr_in0_input.dev_attr.attr, > + &sensor_dev_attr_in1_input.dev_attr.attr, > + &sensor_dev_attr_in2_input.dev_attr.attr, > + &sensor_dev_attr_in3_input.dev_attr.attr, > NULL, > }; > The rest of the changes look good. -- Jean Delvare