[lm-sensors] [PATCH] hwmon: (tmp421) Add nfactor support (2nd attempt)
Andre Prendel
andre.prendel at gmx.de
Fri May 21 05:35:56 EST 2010
On Thu, May 20, 2010 at 03:07:05PM -0400, Jeff Angielski wrote:
> On 05/20/2010 02:50 PM, Andre Prendel wrote:
> > You made a careless mistake, see below. Please fix this and resend the patch
> > again. Then I added my Acked-by and I think Jean will schedule the patch for
> > 2.6.35 (after another review of course :))
>
> You sir, would be correct... *sigh* I tried using the scripts/Lindent on it to
> be sure there were no coding style issues but that messed up even your original
> code.
/scripts/checkpatch.pl is the key ;)
> In any event, here it is again:
Acked-by: Andre Prendel <andre.prendel at gmx.de>
>
> >From 9acd29ff48c64e58a7f5cdb888c86e737c56281c Mon Sep 17 00:00:00 2001
> From: Jeff Angielski <jeff at theptrgroup.com>
> 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 <jeff at theptrgroup.com>
> ---
> 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 <andre.prendel at gmx.de>
> + Jeff Angielski <jeff at theptrgroup.com>
>
> 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
> lm-sensors at lm-sensors.org
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