On 23-08-2013 19:50, Guenter Roeck wrote:
> On Fri, Aug 23, 2013 at 07:15:44PM -0400, Eduardo Valentin wrote:
>> This patch adds to lm75 temperature sensor the possibility
>> to expose itself as thermal zone device, registered on the
>> thermal framework.
>>
>> The thermal zone is built only if a device tree node
>> describing a thermal zone for this sensor is present
>> inside the lm75 DT node. Otherwise, the driver behavior
>> will be the same.
>>
>> Cc: Jean Delvare <kh...@linux-fr.org>
>> Cc: Guenter Roeck <li...@roeck-us.net>
>> Cc: lm-sens...@lm-sensors.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Eduardo Valentin <eduardo.valen...@ti.com>
>> ---
>> drivers/hwmon/lm75.c | 31 +++++++++++++++++++++++++++++++
>> 1 file changed, 31 insertions(+)
>>
>> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
>> index c03b490..dc55908 100644
>> --- a/drivers/hwmon/lm75.c
>> +++ b/drivers/hwmon/lm75.c
>> @@ -27,6 +27,8 @@
>> #include <linux/hwmon-sysfs.h>
>> #include <linux/err.h>
>> #include <linux/mutex.h>
>> +#include <linux/thermal.h>
>> +#include <linux/of.h>
>> #include "lm75.h"
>>
>>
>> @@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = {
>> /* Each client has this additional data */
>> struct lm75_data {
>> struct device *hwmon_dev;
>> + struct thermal_zone_device *tz;
>> struct mutex update_lock;
>> u8 orig_conf;
>> u8 resolution; /* In bits, between 9 and 12 */
>> @@ -92,6 +95,19 @@ static struct lm75_data *lm75_update_device(struct device
>> *dev);
>>
>> /* sysfs attributes for hwmon */
>>
>> +static int lm75_read_temp(void *dev, unsigned long *temp)
>> +{
>> + struct lm75_data *data = lm75_update_device(dev);
>> +
>> + if (IS_ERR(data))
>> + return PTR_ERR(data);
>> +
>> + *temp = ((data->temp[0] >> (16 - data->resolution)) * 1000) >>
>> + (data->resolution - 8);
>> +
> The reported temperature can be negative, which would result in reporting a
> very
> high temperature (note this applies to the tmp102 driver patch as well).
>
Good point.
> The computation is quite complex and matches the computation done in
> show_temp().
> Given that, it would make sense to declare an inline function to convert the
> register value to the temperature. This function can take the register value
> and the resolution as argument.
Sounds reasonable. Modifying accordingly in next version.
>
> Guenter
>
>> + return 0;
>> +}
>> +
>> static ssize_t show_temp(struct device *dev, struct device_attribute *da,
>> char *buf)
>> {
>> @@ -271,11 +287,25 @@ lm75_probe(struct i2c_client *client, const struct
>> i2c_device_id *id)
>> goto exit_remove;
>> }
>>
>> + if (of_find_property(client->dev.of_node, "monitored-zones", NULL)) {
>> + data->tz = thermal_zone_of_device_register(&client->dev,
>> + 0,
>> + false, /* -hwmon */
>> + &client->dev,
>> + lm75_read_temp);
>> + if (IS_ERR(data->tz)) {
>> + status = PTR_ERR(data->tz);
>> + goto exit_hwmon;
>> + }
>> + }
>> +
>> dev_info(&client->dev, "%s: sensor '%s'\n",
>> dev_name(data->hwmon_dev), client->name);
>>
>> return 0;
>>
>> +exit_hwmon:
>> + hwmon_device_unregister(data->hwmon_dev);
>> exit_remove:
>> sysfs_remove_group(&client->dev.kobj, &lm75_group);
>> return status;
>> @@ -285,6 +315,7 @@ static int lm75_remove(struct i2c_client *client)
>> {
>> struct lm75_data *data = i2c_get_clientdata(client);
>>
>> + thermal_zone_device_unregister(data->tz);
>> hwmon_device_unregister(data->hwmon_dev);
>> sysfs_remove_group(&client->dev.kobj, &lm75_group);
>> lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
>> --
>> 1.8.2.1.342.gfa7285d
>>
>>
>
>
--
You have got to be excited about what you are doing. (L. Lamport)
Eduardo Valentin
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