From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH 05/16] hwmon: lm75: expose to thermal fw via DT nodes Date: Sun, 15 Sep 2013 16:22:06 -0700 Message-ID: <5236411E.6040204@roeck-us.net> References: <1379282563-14650-1-git-send-email-eduardo.valentin@ti.com> <1379282563-14650-6-git-send-email-eduardo.valentin@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1379282563-14650-6-git-send-email-eduardo.valentin-l0cyMroinI0@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Eduardo Valentin Cc: swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ian.campbell-Sxgqhf6Nn4DQT0dZR+AlfA@public.gmane.org, rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org, rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, wni-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, durgadoss.r-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jean Delvare List-Id: linux-pm@vger.kernel.org On 09/15/2013 03:02 PM, 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 > Cc: Guenter Roeck > Cc: lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org > Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > Signed-off-by: Eduardo Valentin > --- > drivers/hwmon/lm75.c | 46 +++++++++++++++++++++++++++++++++++++++++----- > 1 file changed, 41 insertions(+), 5 deletions(-) > > diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c > index c03b490..2ba09ef 100644 > --- a/drivers/hwmon/lm75.c > +++ b/drivers/hwmon/lm75.c > @@ -27,6 +27,8 @@ > #include > #include > #include > +#include > +#include > #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 */ > @@ -90,22 +93,42 @@ static struct lm75_data *lm75_update_device(struct device *dev); > > /*-----------------------------------------------------------------------*/ > > +static inline long lm75_reg_to_mc(s16 temp, u8 resolution) > +{ > + return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8); > +} > + > /* sysfs attributes for hwmon */ > > +static int lm75_read_temp(void *dev, long *temp) > +{ > + struct lm75_data *data = lm75_update_device(dev); > + long temperature; > + > + if (IS_ERR(data)) > + return PTR_ERR(data); > + > + temperature = lm75_reg_to_mc(data->temp[0], data->resolution); > + if (temperature < 0) > + dev_warn(data->hwmon_dev, > + "operating in negative temp: %ld\n", temperature); Please drop this warning. It is not the responsibility of the chip driver to declare valid operational conditions, much less an arbitrary one like zero degrees C. Guenter > + > + *temp = temperature; > + > + return 0; > +} > + > static ssize_t show_temp(struct device *dev, struct device_attribute *da, > char *buf) > { > 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); > > - temp = ((data->temp[attr->index] >> (16 - data->resolution)) * 1000) > - >> (data->resolution - 8); > - > - return sprintf(buf, "%ld\n", temp); > + return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index], > + data->resolution)); > } > > static ssize_t set_temp(struct device *dev, struct device_attribute *da, > @@ -271,6 +294,17 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) > goto exit_remove; > } > > + data->tz = thermal_zone_of_sensor_register(&client->dev, > + 0, > + &client->dev, > + lm75_read_temp, NULL); > + if (IS_ERR(data->tz)) { > + dev_warn(&client->dev, > + "Could not parse thermal data in device tree: %ld\n", > + PTR_ERR(data->tz)); > + data->tz = NULL; > + } > + > dev_info(&client->dev, "%s: sensor '%s'\n", > dev_name(data->hwmon_dev), client->name); > > @@ -285,6 +319,8 @@ static int lm75_remove(struct i2c_client *client) > { > struct lm75_data *data = i2c_get_clientdata(client); > > + /* thermal zone life cycle is not our responsibility */ > + thermal_zone_of_sensor_unregister(&client->dev, 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); > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html