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Commit 87d0621a authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare
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hwmon: (lm75) Prepare to support per-chip resolution and sample time 



Prepare the lm75 driver to support per-chip resolution and sample
time. For now we only make the code generic enough to support it, but
we still use the same, unchanged resolution (9-bit) and sample time
(1.5 s) for all chips.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 8a5c5cc6

drivers/hwmon/lm75.c

+26 −5
Original line number Diff line number Diff line
@@ -71,9 +71,12 @@ struct lm75_data { 
	struct device		*hwmon_dev;

	struct mutex		update_lock;

	u8			orig_conf;

	u8			resolution;	/* In bits, between 9 and 12 */

	u8			resolution_limits;

	char			valid;		/* !=0 if registers are valid */

	unsigned long		last_updated;	/* In jiffies */

	u16			temp[3];	/* Register values,

	unsigned long		sample_time;	/* In jiffies */

	s16			temp[3];	/* Register values,

						   0 = input

						   1 = max

						   2 = hyst */
@@ -93,12 +96,15 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da, 
{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

	struct lm75_data *data = lm75_update_device(dev);

	long temp;



	if (IS_ERR(data))

		return PTR_ERR(data);



	return sprintf(buf, "%d\n",

		       LM75_TEMP_FROM_REG(data->temp[attr->index]));

	temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000)

	       >> (data->resolution - 8);



	return sprintf(buf, "%ld\n", temp);

}



static ssize_t set_temp(struct device *dev, struct device_attribute *da,
@@ -110,13 +116,25 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *da, 
	int nr = attr->index;

	long temp;

	int error;

	u8 resolution;



	error = kstrtol(buf, 10, &temp);

	if (error)

		return error;



	/*

	 * Resolution of limit registers is assumed to be the same as the

	 * temperature input register resolution unless given explicitly.

	 */

	if (attr->index && data->resolution_limits)

		resolution = data->resolution_limits;

	else

		resolution = data->resolution;



	mutex_lock(&data->update_lock);

	data->temp[nr] = LM75_TEMP_TO_REG(temp);

	temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);

	data->temp[nr] = DIV_ROUND_CLOSEST(temp  << (resolution - 8),

					   1000) << (16 - resolution);

	lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);

	mutex_unlock(&data->update_lock);

	return count;
@@ -190,6 +208,9 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) 
		break;

	}



	data->resolution = 9;

	data->sample_time = HZ + HZ / 2;



	/* configure as specified */

	status = lm75_read_value(client, LM75_REG_CONF);

	if (status < 0) {
@@ -427,7 +448,7 @@ static struct lm75_data *lm75_update_device(struct device *dev) 


	mutex_lock(&data->update_lock);



	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)

	if (time_after(jiffies, data->last_updated + data->sample_time)

	    || !data->valid) {

		int i;

		dev_dbg(&client->dev, "Starting lm75 update\n");