Subject: Re: [lm-sensors] [PATCH] hwmon: (tmp421) Add nfactor support (2nd attempt)

From: Andre Prendel <[email-masked]>
Date: Tue, 20 Jul 2010 17:09:53 +0200

On Thu, May 20, 2010 at 09:35:56PM +0200, Andre Prendel wrote:
> On Thu, May 20, 2010 at 03:07:05PM -0400, Jeff Angielski wrote:
> > In any event, here it is again:
> 
> Acked-by: Andre Prendel <[email-masked]>

Hi Jeff,

I'de suggest to resend the patch with my acked-by to the lm-sensors list and
Andrew Morton. It looks like Jean is too busy at the moment.

Regards,
Andre
 
> > 
> > >From 9acd29ff48c64e58a7f5cdb888c86e737c56281c Mon Sep 17 00:00:00 2001
> > From: Jeff Angielski <[email-masked]>
> > Date: Mon, 10 May 2010 10:26:34 -0400
> > Subject: [PATCH] hwmon: (tmp421) Add nfactor support
> > 
> > Add support for reading and writing the n-factor correction
> > registers.  This is needed to compensate for the characteristics
> > of a particular sensor hanging off of the remote channels.
> > 
> > Signed-off-by: Jeff Angielski <[email-masked]>
> > ---
> >  Documentation/hwmon/tmp421 |   19 +++++++++++++++++++
> >  drivers/hwmon/tmp421.c     |   41 +++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 60 insertions(+), 0 deletions(-)
> > 
> > diff --git a/Documentation/hwmon/tmp421 b/Documentation/hwmon/tmp421
> > index 0cf07f8..668228a 100644
> > --- a/Documentation/hwmon/tmp421
> > +++ b/Documentation/hwmon/tmp421
> > @@ -17,6 +17,7 @@ Supported chips:
> >  
> >  Authors:
> >  	Andre Prendel <[email-masked]>
> > +	Jeff Angielski <[email-masked]>
> >  
> >  Description
> >  -----------
> > @@ -34,3 +35,21 @@ the temperature values via the following sysfs files:
> >  
> >  temp[1-4]_input
> >  temp[2-4]_fault
> > +
> > +The chips allow the user to adjust the n-factor value that is used
> > +when converting the remote channel measurements to temperature. The
> > +adjustment has a range of -128 to +127 that yields an effective
> > +n-factor range of 0.706542 to 1.747977.  The power on reset value
> > +for the adjustment is 0 which results in an n-factor of 1.008.
> > +
> > +The effective n-factor is calculated according to the following
> > +equation:
> > +
> > +n_factor = (1.008 * 300) / (300 - nfactor_adjust)
> > +
> > +The driver exports the n-factor adjustment value via the following 
> > +sysfs files:
> > +
> > +temp[2-4]_n_adjust
> > +
> > +
> > diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
> > index 738c472..dfd62be 100644
> > --- a/drivers/hwmon/tmp421.c
> > +++ b/drivers/hwmon/tmp421.c
> > @@ -49,6 +49,7 @@ enum chips { tmp421, tmp422, tmp423 };
> >  
> >  static const u8 TMP421_TEMP_MSB[4]		= { 0x00, 0x01, 0x02, 0x03 };
> >  static const u8 TMP421_TEMP_LSB[4]		= { 0x10, 0x11, 0x12, 0x13 };
> > +static const u8 TMP421_N_CORRECT[3]		= { 0x21, 0x22, 0x23 };
> >  
> >  /* Flags */
> >  #define TMP421_CONFIG_SHUTDOWN			0x40
> > @@ -76,6 +77,7 @@ struct tmp421_data {
> >  	int channels;
> >  	u8 config;
> >  	s16 temp[4];
> > +	s8 n_adjust[3];
> >  };
> >  
> >  static int temp_from_s16(s16 reg)
> > @@ -115,6 +117,10 @@ static struct tmp421_data *tmp421_update_device(struct device *dev)
> >  			data->temp[i] |= i2c_smbus_read_byte_data(client,
> >  				TMP421_TEMP_LSB[i]);
> >  		}
> > +		for (i = 1; i < data->channels; i++) {
> > +			data->n_adjust[i - 1] = i2c_smbus_read_byte_data(client,
> > +				TMP421_N_CORRECT[i - 1]);
> > +		}
> >  		data->last_updated = jiffies;
> >  		data->valid = 1;
> >  	}
> > @@ -157,6 +163,32 @@ static ssize_t show_fault(struct device *dev,
> >  		return sprintf(buf, "0\n");
> >  }
> >  
> > +static ssize_t show_n_adjust(struct device *dev,
> > +			     struct device_attribute *devattr, char *buf)
> > +{
> > +	int index = to_sensor_dev_attr(devattr)->index;
> > +	struct tmp421_data *data = tmp421_update_device(dev);
> > +
> > +	return sprintf(buf, "%d\n", data->n_adjust[index - 1]);
> > +}
> > +
> > +static ssize_t set_n_adjust(struct device *dev,
> > +			    struct device_attribute *devattr,
> > +			    const char *buf, size_t count)
> > +{
> > +	struct i2c_client *client = to_i2c_client(dev);
> > +	struct tmp421_data *data = i2c_get_clientdata(client);
> > +	int index = to_sensor_dev_attr(devattr)->index;
> > +	int n_adjust = simple_strtol(buf, NULL, 10);
> > +
> > +	mutex_lock(&data->update_lock);
> > +	i2c_smbus_write_byte_data(client, TMP421_N_CORRECT[index - 1],
> > +				  SENSORS_LIMIT(n_adjust, -128, 127));
> > +	mutex_unlock(&data->update_lock);
> > +
> > +	return count;
> > +}
> > +
> >  static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
> >  				int n)
> >  {
> > @@ -177,19 +209,28 @@ static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
> >  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
> >  static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
> >  static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
> > +static SENSOR_DEVICE_ATTR(temp2_n_adjust, S_IRUSR | S_IWUSR | S_IRGRP,
> > +			  show_n_adjust, set_n_adjust, 1);
> >  static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
> >  static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
> > +static SENSOR_DEVICE_ATTR(temp3_n_adjust, S_IRUSR | S_IWUSR | S_IRGRP,
> > +			  show_n_adjust, set_n_adjust, 2);
> >  static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
> >  static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
> > +static SENSOR_DEVICE_ATTR(temp4_n_adjust, S_IRUSR | S_IWUSR | S_IRGRP,
> > +			  show_n_adjust, set_n_adjust, 3);
> >  
> >  static struct attribute *tmp421_attr[] = {
> >  	&sensor_dev_attr_temp1_input.dev_attr.attr,
> >  	&sensor_dev_attr_temp2_input.dev_attr.attr,
> >  	&sensor_dev_attr_temp2_fault.dev_attr.attr,
> > +	&sensor_dev_attr_temp2_n_adjust.dev_attr.attr,
> >  	&sensor_dev_attr_temp3_input.dev_attr.attr,
> >  	&sensor_dev_attr_temp3_fault.dev_attr.attr,
> > +	&sensor_dev_attr_temp3_n_adjust.dev_attr.attr,
> >  	&sensor_dev_attr_temp4_input.dev_attr.attr,
> >  	&sensor_dev_attr_temp4_fault.dev_attr.attr,
> > +	&sensor_dev_attr_temp4_n_adjust.dev_attr.attr,
> >  	NULL
> >  };
> >  
> > -- 
> > 1.7.0.4
> > 
> > 
> > -- 
> > Jeff Angielski
> > The PTR Group
> > www.theptrgroup.com
> > 
> > _______________________________________________
> > lm-sensors mailing list
> > [email-masked]
> > http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
> 
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