On Tue, Mar 12, 2013 at 03:45:43PM +0100, Jean Delvare wrote:
> 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: Jean Delvare <khali@xxxxxxxxxxxx>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> drivers/hwmon/lm75.c | 31 ++++++++++++++++++++++++++-----
> 1 file changed, 26 insertions(+), 5 deletions(-)
>
> --- linux-3.9-rc2.orig/drivers/hwmon/lm75.c 2013-03-12 13:37:45.206041683 +0100
> +++ linux-3.9-rc2/drivers/hwmon/lm75.c 2013-03-12 13:58:09.676334428 +0100
> @@ -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 *
> {
> 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 *d
> 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, co
> 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_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");
>
> --
> Jean Delvare
>
> _______________________________________________
> lm-sensors mailing list
> lm-sensors@xxxxxxxxxxxxxx
> http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
>
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