kernel/linux.git/drivers/hwmon/tmp102.c, branch v4.4.171

hwmon: (tmp102) Force wait for conversion time for the first valid data

2015-12-10T16:14:22+00:00

TMP102 works based on conversions done periodically. However, as per the TMP102 data sheet[1] the first conversion is triggered immediately after we program the configuration register. The temperature data registers do not reflect proper data until the first conversion is complete (in our case HZ/4). The driver currently sets the last_update to be jiffies - HZ, just after the configuration is complete. When TMP102 driver registers with the thermal framework, it immediately tries to read the sensor temperature data. This takes place even before the conversion on the TMP102 is complete and results in an invalid temperature read. Depending on the value read, this may cause thermal framework to assume that a critical temperature event has occurred and attempts to shutdown the system. Instead of causing an invalid mid-conversion value to be read erroneously, we mark the last_update to be in-line with the current jiffies. This allows the tmp102_update_device function to skip update until the required conversion time is complete. Further, we ensure to return -EAGAIN result instead of returning spurious temperature (such as 0C) values to the caller to prevent any wrong decisions made with such values. NOTE: this allows the read functions not to be blocking and allows the callers to make the decision if they would like to block or try again later. At least the current user(thermal) seems to handle this by retrying later. A simpler alternative approach could be to sleep in the probe for the duration required, but that will result in latency that is undesirable and delay boot sequence un-necessarily. [1] http://www.ti.com/lit/ds/symlink/tmp102.pdf Cc: Eduardo Valentin Reported-by: Aparna Balasubramanian Reported-by: Elvita Lobo Reported-by: Yan Liu Signed-off-by: Nishanth Menon Signed-off-by: Guenter Roeck

thermal: consistently use int for temperatures

2015-08-03T15:15:50+00:00

The thermal code uses int, long and unsigned long for temperatures in different places. Using an unsigned type limits the thermal framework to positive temperatures without need. Also several drivers currently will report temperatures near UINT_MAX for temperatures below 0°C. This will probably immediately shut the machine down due to overtemperature if started below 0°C. 'long' is 64bit on several architectures. This is not needed since INT_MAX °mC is above the melting point of all known materials. Consistently use a plain 'int' for temperatures throughout the thermal code and the drivers. This only changes the places in the drivers where the temperature is passed around as pointer, when drivers internally use another type this is not changed. Signed-off-by: Sascha Hauer Acked-by: Geert Uytterhoeven Reviewed-by: Jean Delvare Reviewed-by: Lukasz Majewski Reviewed-by: Darren Hart Reviewed-by: Heiko Stuebner Reviewed-by: Peter Feuerer Cc: Punit Agrawal Cc: Zhang Rui Cc: Eduardo Valentin Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: Jean Delvare Cc: Peter Feuerer Cc: Heiko Stuebner Cc: Lukasz Majewski Cc: Stephen Warren Cc: Thierry Reding Cc: linux-acpi@vger.kernel.org Cc: platform-driver-x86@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-omap@vger.kernel.org Cc: linux-samsung-soc@vger.kernel.org Cc: Guenter Roeck Cc: Rafael J. Wysocki Cc: Maxime Ripard Cc: Darren Hart Cc: lm-sensors@lm-sensors.org Signed-off-by: Zhang Rui

hwmon: (tmp102) add hibernation callbacks

2015-02-03T20:17:12+00:00

Setting a dev_pm_ops suspend/resume pair but not a set of hibernation functions means those pm functions will not be called upon hibernation. Fix this by using SIMPLE_DEV_PM_OPS, which appropriately assigns the suspend and hibernation handlers and move mp102_suspend/tmp102_resume under CONFIG_PM_SLEEP to avoid build warnings. Signed-off-by: Grygorii Strashko [groeck: Declare tmp102_dev_pm_ops as static variable] Signed-off-by: Guenter Roeck

thermal: of: improve of-thermal sensor registration API

2014-11-20T14:44:54+00:00

Different drivers request API extensions in of-thermal. For this reason, additional callbacks are required to fit the new drivers needs. The current API implementation expects the registering sensor driver to provide a get_temp and get_trend callbacks as function parameters. As the amount of callbacks is growing, this patch changes the existing implementation to use a .ops field to hold all the of thermal callbacks to sensor drivers. This patch also changes the existing of-thermal users to fit the new API design. No functional change is introduced in this patch. Cc: Alexandre Courbot Cc: devicetree@vger.kernel.org Cc: Grant Likely Cc: Guenter Roeck Cc: Jean Delvare Cc: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-tegra@vger.kernel.org Cc: lm-sensors@lm-sensors.org Cc: Rob Herring Cc: Stephen Warren Cc: Thierry Reding Cc: Zhang Rui Acked-by: Guenter Roeck Tested-by: Mikko Perttunen Reviewed-by: Mikko Perttunen Reviewed-by: Alexandre Courbot Reviewed-by: Lukasz Majewski Signed-off-by: Eduardo Valentin

hwmon: (tmp102) Convert to use hwmon_device_register_with_groups

2014-05-21T23:02:20+00:00

Simplify code, reduce code size, and attach sysfs attributes to hwmon device. Reviewed-by: Jean Delvare Signed-off-by: Guenter Roeck

hwmon: (tmp102) Introduce dev variable in probe function

2014-05-21T23:02:20+00:00

The pointer to client->dev is used several times in the probe function. Simplify code by introducing a separate variable for it. Reviewed-by: Jean Delvare Signed-off-by: Guenter Roeck

hwmon: tmp102: expose to thermal fw via DT nodes

2013-12-04T13:34:25+00:00

This patch adds to tmp102 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 tmp102 DT node. Otherwise, the driver behavior will be the same. Note: This patch has also been reviewed by Jean D. He has requested to perform a wider inspection of possible users of thermal and hwmon interaction API. On the other hand, the change on this patch is acceptable on first step of overall code change. Cc: Jean Delvare Cc: lm-sensors@lm-sensors.org Cc: linux-kernel@vger.kernel.org Acked-by: Guenter Roeck Signed-off-by: Eduardo Valentin

hwmon: Fix checkpatch warning 'quoted string split across lines'

2013-04-08T04:16:40+00:00

Cc: Corentin Labbe Cc: Mark M. Hoffman Cc: Fenghua Yu Cc: Juerg Haefliger Cc: Andreas Herrmann Cc: Rudolf Marek Cc: Jim Cromie Cc: Roger Lucas Cc: Marc Hulsman Signed-off-by: Guenter Roeck

hwmon: Replace SENSORS_LIMIT with clamp_val

2013-01-26T05:03:54+00:00

SENSORS_LIMIT and the generic clamp_val have the same functionality, and clamp_val is more efficient. This patch reduces text size by 9052 bytes and bss size by 11624 bytes for x86_64 builds. Signed-off-by: Guenter Roeck Acked-by: George Joseph Acked-by: Jean Delvare

hwmon: remove use of __devexit

2012-11-28T19:50:34+00:00

CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton Cc: Hans de Goede Cc: Jean Delvare Cc: Alistair John Strachan Cc: Fenghua Yu Cc: Juerg Haefliger Cc: Andreas Herrmann Cc: Clemens Ladisch Cc: Rudolf Marek Cc: Jim Cromie Cc: "Mark M. Hoffman" Cc: Roger Lucas Acked-by: Guenter Roeck Acked-by: Mark Brown Signed-off-by: Greg Kroah-Hartman