diff mbox

[V3,8/9] thermal: da9062/61: Thermal junction temperature monitoring driver

Message ID 52d74c72cc445d2bc911014f38b79c1f10426878.1477929725.git.stwiss.opensource@diasemi.com (mailing list archive)
State New, archived
Headers show

Commit Message

Steve Twiss Oct. 31, 2016, 4:02 p.m. UTC
From: Steve Twiss <stwiss.opensource@diasemi.com>

Add junction temperature monitoring supervisor device driver, compatible
with the DA9062 and DA9061 PMICs. A MODULE_DEVICE_TABLE() macro is added.

If the PMIC's internal junction temperature rises above TEMP_WARN (125
degC) an interrupt is issued. This TEMP_WARN level is defined as the
THERMAL_TRIP_HOT trip-wire inside the device driver.

The thermal triggering mechanism is interrupt based and happens when the
temperature rises above a given threshold level. The component cannot
return an exact temperature, it only has knowledge if the temperature is
above or below a given threshold value. A status bit must be polled to
detect when the temperature falls below that threshold level again. A
kernel work queue is configured to repeatedly poll and detect when the
temperature falls below this trip-wire, between 1 and 10 second intervals
(defaulting at 3 seconds).

This first level of temperature supervision is intended for non-invasive
temperature control, where the necessary measures for cooling the system
down are left to the host software.

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>

---
This patch applies against linux-next and v4.8

v2 -> v3
 - Patch renamed from [PATCH V2 09/10] to [PATCH V3 8/9]
 - Addition of MODULE_DEVICE_TABLE macro to allow modinfo additions

v1 -> v2
 - Patch renamed from [PATCH V1 05/10] to [PATCH V2 09/10] -- these
   changes were made to fix checkpatch warnings caused by the patch
   set dependency order
 - List the header files in alphabetical order
 - Remove "GPL v2" and replace with MODULE_LICENSE("GPL") to match the
   copyright "GNU Public License v2 or later" option in the header
   comment for this file. See the allowed identifiers in the file
   include/linux/module.h +170
 - Remove notify function "da9062_thermal_notify" function.
 - MODULE_AUTHOR() macros removes Company Name and just gives Name in
   accordance with include/linux/module.h +200
 - Remove the compatible "dlg,da9061-thermal" option in the of_device_id
   struct table. This patch now assumes the use of a DA9062 fallback
   compatible string in the DTS when using the DA9061 thermal component
   of the DA9061 device.
 - Re-ordered some assignments earlier in the probe() for thermal->hw,
   thermal->polling_period, thermal->mode, thermal->dev
 - Added further information in the patch description to explain the use
   of the device driver's built-in work-queue.

Regards,
Steve Twiss, Dialog Semiconductor Ltd.


 drivers/thermal/Kconfig          |  10 ++
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/da9062-thermal.c | 291 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 302 insertions(+)
 create mode 100644 drivers/thermal/da9062-thermal.c

Comments

Lukasz Luba Nov. 2, 2016, 1:28 p.m. UTC | #1
Hi Steve,

Please find my comments below.

Apart from these 2 comments, 10sec is not to long
(waiting for the temperature change)?

On 31/10/16 16:02, Steve Twiss wrote:
> From: Steve Twiss <stwiss.opensource@diasemi.com>
>
> Add junction temperature monitoring supervisor device driver, compatible
> with the DA9062 and DA9061 PMICs. A MODULE_DEVICE_TABLE() macro is added.
>
> If the PMIC's internal junction temperature rises above TEMP_WARN (125
> degC) an interrupt is issued. This TEMP_WARN level is defined as the
> THERMAL_TRIP_HOT trip-wire inside the device driver.
>
> The thermal triggering mechanism is interrupt based and happens when the
> temperature rises above a given threshold level. The component cannot
> return an exact temperature, it only has knowledge if the temperature is
> above or below a given threshold value. A status bit must be polled to
> detect when the temperature falls below that threshold level again. A
> kernel work queue is configured to repeatedly poll and detect when the
> temperature falls below this trip-wire, between 1 and 10 second intervals
> (defaulting at 3 seconds).
>
> This first level of temperature supervision is intended for non-invasive
> temperature control, where the necessary measures for cooling the system
> down are left to the host software.
>
> Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
>
> ---
> This patch applies against linux-next and v4.8
>
> v2 -> v3
>  - Patch renamed from [PATCH V2 09/10] to [PATCH V3 8/9]
>  - Addition of MODULE_DEVICE_TABLE macro to allow modinfo additions
>
> v1 -> v2
>  - Patch renamed from [PATCH V1 05/10] to [PATCH V2 09/10] -- these
>    changes were made to fix checkpatch warnings caused by the patch
>    set dependency order
>  - List the header files in alphabetical order
>  - Remove "GPL v2" and replace with MODULE_LICENSE("GPL") to match the
>    copyright "GNU Public License v2 or later" option in the header
>    comment for this file. See the allowed identifiers in the file
>    include/linux/module.h +170
>  - Remove notify function "da9062_thermal_notify" function.
>  - MODULE_AUTHOR() macros removes Company Name and just gives Name in
>    accordance with include/linux/module.h +200
>  - Remove the compatible "dlg,da9061-thermal" option in the of_device_id
>    struct table. This patch now assumes the use of a DA9062 fallback
>    compatible string in the DTS when using the DA9061 thermal component
>    of the DA9061 device.
>  - Re-ordered some assignments earlier in the probe() for thermal->hw,
>    thermal->polling_period, thermal->mode, thermal->dev
>  - Added further information in the patch description to explain the use
>    of the device driver's built-in work-queue.
>
> Regards,
> Steve Twiss, Dialog Semiconductor Ltd.
>
>
>  drivers/thermal/Kconfig          |  10 ++
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/da9062-thermal.c | 291 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 302 insertions(+)
>  create mode 100644 drivers/thermal/da9062-thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 2d702ca..da58e54 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -272,6 +272,16 @@ config DB8500_CPUFREQ_COOLING
>  	  bound cpufreq cooling device turns active to set CPU frequency low to
>  	  cool down the CPU.
>
> +config DA9062_THERMAL
> +	tristate "DA9062/DA9061 Dialog Semiconductor thermal driver"
> +	depends on MFD_DA9062
> +	depends on OF
> +	help
> +	  Enable this for the Dialog Semiconductor thermal sensor driver.
> +	  This will report PMIC junction over-temperature for one thermal trip
> +	  zone.
> +	  Compatible with the DA9062 and DA9061 PMICs.
> +
>  config INTEL_POWERCLAMP
>  	tristate "Intel PowerClamp idle injection driver"
>  	depends on THERMAL
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 10b07c1..0a2b3f2 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -38,6 +38,7 @@ obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
>  obj-$(CONFIG_TANGO_THERMAL)	+= tango_thermal.o
>  obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
>  obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
> +obj-$(CONFIG_DA9062_THERMAL)	+= da9062-thermal.o
>  obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
>  obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
>  obj-$(CONFIG_INTEL_SOC_DTS_IOSF_CORE)	+= intel_soc_dts_iosf.o
> diff --git a/drivers/thermal/da9062-thermal.c b/drivers/thermal/da9062-thermal.c
> new file mode 100644
> index 0000000..1f0af22
> --- /dev/null
> +++ b/drivers/thermal/da9062-thermal.c
> @@ -0,0 +1,291 @@
> +/*
> + * Thermal device driver for DA9062 and DA9061
> + * Copyright (C) 2016  Dialog Semiconductor Ltd.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version 2
> + * of the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/thermal.h>
> +#include <linux/workqueue.h>
> +
> +#include <linux/mfd/da9062/core.h>
> +#include <linux/mfd/da9062/registers.h>
> +
> +#define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
> +#define DA9062_MAX_POLLING_MS_PERIOD		10000
> +#define DA9062_MIN_POLLING_MS_PERIOD		1000
> +
> +#define DA9062_MILLI_CELSIUS(t)			((t)*1000)
> +
> +struct da9062_thermal_config {
> +	const char *name;
> +};
> +
> +struct da9062_thermal {
> +	struct da9062 *hw;
> +	struct delayed_work work;
> +	struct thermal_zone_device *zone;
> +	enum thermal_device_mode mode;
> +	unsigned int polling_period;
> +	struct mutex lock;
> +	int temperature;
> +	int irq;
> +	const struct da9062_thermal_config *config;
> +	struct device *dev;
> +};
> +
> +static void da9062_thermal_poll_on(struct work_struct *work)
> +{
> +	struct da9062_thermal *thermal = container_of(work,
> +						struct da9062_thermal,
> +						work.work);
> +	unsigned int val;
> +	int ret;
> +
> +	/* clear E_TEMP */
> +	ret = regmap_write(thermal->hw->regmap,
> +				DA9062AA_EVENT_B,
> +				DA9062AA_E_TEMP_MASK);
> +	if (ret < 0) {
> +		dev_err(thermal->dev,
> +			"Cannot clear the TJUNC temperature status\n");
> +		goto err_enable_irq;
> +	}
> +
> +	/* Now read E_TEMP again: it is acting like a status bit.
> +	 * If over-temperature, then this status will be true.
> +	 * If not over-temperature, this status will be false.
> +	 */
> +	ret = regmap_read(thermal->hw->regmap,
> +			  DA9062AA_EVENT_B,
> +			  &val);
> +	if (ret < 0) {
> +		dev_err(thermal->dev,
> +			"Cannot check the TJUNC temperature status\n");
> +		goto err_enable_irq;
> +	} else {
> +		if (val & DA9062AA_E_TEMP_MASK) {
> +			mutex_lock(&thermal->lock);
> +			thermal->temperature = DA9062_MILLI_CELSIUS(125);
> +			mutex_unlock(&thermal->lock);
> +			thermal_zone_device_update(thermal->zone);
> +
> +			schedule_delayed_work(&thermal->work,
> +				msecs_to_jiffies(thermal->polling_period));
> +			return;
> +		} else {
> +			mutex_lock(&thermal->lock);
> +			thermal->temperature = DA9062_MILLI_CELSIUS(0);
> +			mutex_unlock(&thermal->lock);
> +			thermal_zone_device_update(thermal->zone);
> +		}
> +	}
> +
> +err_enable_irq:
> +	enable_irq(thermal->irq);
> +}
> +
> +static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
> +{
> +	struct da9062_thermal *thermal = data;
> +
> +	disable_irq_nosync(thermal->irq);
> +	schedule_delayed_work(&thermal->work, 0);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int da9062_thermal_get_mode(struct thermal_zone_device *z,
> +				   enum thermal_device_mode *mode)
> +{
> +	struct da9062_thermal *thermal = z->devdata;
> +	*mode = thermal->mode;
> +	return 0;
> +}
> +
> +static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
> +				int trip,
> +				enum thermal_trip_type *type)
> +{
> +	struct da9062_thermal *thermal = z->devdata;
> +
> +	switch (trip) {
> +	case 0:
> +		*type = THERMAL_TRIP_HOT;
> +		break;
> +	default:
> +		dev_err(thermal->dev,
> +			"Driver does not support more than 1 trip-wire\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
> +					int trip,
> +					int *temp)
> +{
> +	struct da9062_thermal *thermal = z->devdata;
> +
> +	switch (trip) {
> +	case 0:
> +		*temp = DA9062_MILLI_CELSIUS(125);
> +		break;
> +	default:
> +		dev_err(thermal->dev,
> +			"Driver does not support more than 1 trip-wire\n");
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int da9062_thermal_get_temp(struct thermal_zone_device *z,
> +				   int *temp)
> +{
> +	struct da9062_thermal *thermal = z->devdata;
> +
> +	mutex_lock(&thermal->lock);
> +	*temp = thermal->temperature;
> +	mutex_unlock(&thermal->lock);
> +
> +	return 0;
> +}
> +
> +static struct thermal_zone_device_ops da9062_thermal_ops = {
> +	.get_temp	= da9062_thermal_get_temp,
> +	.get_mode	= da9062_thermal_get_mode,
> +	.get_trip_type	= da9062_thermal_get_trip_type,
> +	.get_trip_temp	= da9062_thermal_get_trip_temp,
> +};
> +
> +static const struct da9062_thermal_config da9062_config = {
> +	.name = "da9062-thermal",
> +};
> +
> +static const struct of_device_id da9062_compatible_reg_id_table[] = {
> +	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
> +
> +static int da9062_thermal_probe(struct platform_device *pdev)
> +{
> +	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
> +	struct da9062_thermal *thermal;
> +	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
> +	const struct of_device_id *match;
> +	int ret = 0;
> +
> +	match = of_match_node(da9062_compatible_reg_id_table,
> +			      pdev->dev.of_node);
> +	if (!match)
> +		return -ENXIO;
> +
> +	if (pdev->dev.of_node) {
> +		if (!of_property_read_u32(pdev->dev.of_node,
> +					"dlg,tjunc-temp-polling-period-ms",
> +					&pp_tmp)) {
> +			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
> +				pp_tmp > DA9062_MAX_POLLING_MS_PERIOD)
> +				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
Maybe it's worth to add some print here just to mention about
the DT value out of range. When you saw a dmesg with
this print on some bug report, you would know about wrong DT entry
(even if debug was not set).
> +		}
> +
> +		dev_dbg(&pdev->dev,
> +			 "TJUNC temp polling period set at %d ms\n",
> +			 pp_tmp);
> +	}
> +
> +	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
> +			     GFP_KERNEL);
> +	if (!thermal) {
> +		ret = -ENOMEM;
> +		goto err;
> +	}
> +
> +	thermal->config = match->data;
> +	thermal->hw = chip;
> +	thermal->polling_period = pp_tmp;
> +	thermal->mode = THERMAL_DEVICE_ENABLED;
> +	thermal->dev = &pdev->dev;
> +
> +	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
> +	mutex_init(&thermal->lock);
> +
> +	thermal->zone = thermal_zone_device_register(thermal->config->name,
> +					1, 0, thermal,
> +					&da9062_thermal_ops, NULL, 0,
> +					0);
> +	if (IS_ERR(thermal->zone)) {
> +		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
> +		ret = PTR_ERR(thermal->zone);
> +		goto err;
> +	}
> +
> +	ret = platform_get_irq_byname(pdev, "THERMAL");
> +	if (ret < 0) {
> +		dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
> +		goto err_zone;
> +	}
> +	thermal->irq = ret;
> +
> +	ret = request_threaded_irq(thermal->irq, NULL,
> +				   da9062_thermal_irq_handler,
> +				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +				   "THERMAL", thermal);
> +	if (ret) {
> +		dev_err(&pdev->dev,
> +			"Failed to request thermal device IRQ.\n");
> +		goto err_zone;
> +	}
> +
> +	platform_set_drvdata(pdev, thermal);
> +	return 0;
> +
> +err_zone:
> +	thermal_zone_device_unregister(thermal->zone);
> +err:
> +	return ret;
> +}
> +
> +static int da9062_thermal_remove(struct platform_device *pdev)
> +{
> +	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
> +
> +	free_irq(thermal->irq, thermal);
> +	thermal_zone_device_unregister(thermal->zone);
> +	cancel_delayed_work_sync(&thermal->work);
You should change the order for these two functions
and cancel the work before unregistering thermal zone device.

> +	return 0;
> +}
> +
> +static struct platform_driver da9062_thermal_driver = {
> +	.probe	= da9062_thermal_probe,
> +	.remove	= da9062_thermal_remove,
> +	.driver	= {
> +		.name	= "da9062-thermal",
> +		.of_match_table = da9062_compatible_reg_id_table,
> +	},
> +};
> +
> +module_platform_driver(da9062_thermal_driver);
> +
> +MODULE_AUTHOR("Steve Twiss");
> +MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:da9062-thermal");
>

Regards,
Lukasz Luba
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Steve Twiss Nov. 9, 2016, 6:20 p.m. UTC | #2
On 02 November 2016 13:29, Lukasz Luba wrote:
[...]

> Apart from these 2 comments, 10sec is not to long
> (waiting for the temperature change)?

Hi Lukasz,

Are you saying the maximum polling time is too long or too short if it
is fixed in the driver at 10 seconds?

Certainly 10 seconds can be seen as either too long or too short a time
when waiting for the temperature to fall-back below a threshold.
But, this maximum polling time will be application dependent I think.

However, this is a repeated polling event notifying of a warning
over-temperature condition, so, it is already known that the
temperature is above the threshold and action should already be
in progress to reduce the temperature.

#define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
#define DA9062_MAX_POLLING_MS_PERIOD		10000
#define DA9062_MIN_POLLING_MS_PERIOD		1000

The TEMP_WARN first level temperature supervision is intended for
non-invasive temperature controlling measures for cooling the system
and are left to the host software. This first level temperature
TEMP_WARN (125 degC) is only +15degC off the next TEMP_CRIT
(140 degC) temperature threshold. And this TEMP_CRIT is where
the hardware will automatically shutdown.

I suppose it all depends on how fast the temperature is expected to
rise and fall.

In any case, this 10 second polling maximum value was provided as part
of guidance from a specific solution with this hardware. It would be expected
that any final implementation will also include a notify() function and any
of these settings could be altered to match the application where
appropriate.

I've added a comment above these defined variables for the next code
patch.

> On 31/10/16 16:02, Steve Twiss wrote:
> > From: Steve Twiss <stwiss.opensource@diasemi.com>
> >
> > +static int da9062_thermal_probe(struct platform_device *pdev)
> > +{
> > +	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
> > +	struct da9062_thermal *thermal;
> > +	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
> > +	const struct of_device_id *match;
> > +	int ret = 0;
> > +
> > +	match = of_match_node(da9062_compatible_reg_id_table,
> > +			      pdev->dev.of_node);
> > +	if (!match)
> > +		return -ENXIO;
> > +
> > +	if (pdev->dev.of_node) {
> > +		if (!of_property_read_u32(pdev->dev.of_node,
> > +					"dlg,tjunc-temp-polling-period-ms",
> > +					&pp_tmp)) {
> > +			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
> > +				pp_tmp > DA9062_MAX_POLLING_MS_PERIOD)
> > +				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
>
> Maybe it's worth to add some print here just to mention about
> the DT value out of range. When you saw a dmesg with
> this print on some bug report, you would know about wrong DT entry
> (even if debug was not set).

I can add a dev_warn() here explaining the invalid configuration.

[...]

> > +static int da9062_thermal_remove(struct platform_device *pdev)
> > +{
> > +	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
> > +
> > +	free_irq(thermal->irq, thermal);
> > +	thermal_zone_device_unregister(thermal->zone);
> > +	cancel_delayed_work_sync(&thermal->work);
>
> You should change the order for these two functions
> and cancel the work before unregistering thermal zone device.

ok

Regards,
Steve
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Lukasz Luba Nov. 11, 2016, 9:57 a.m. UTC | #3
Hi Steve,

On 09/11/16 18:20, Steve Twiss wrote:
> On 02 November 2016 13:29, Lukasz Luba wrote:
> [...]
>
>> Apart from these 2 comments, 10sec is not to long
>> (waiting for the temperature change)?
>
> Hi Lukasz,
>
> Are you saying the maximum polling time is too long or too short if it
> is fixed in the driver at 10 seconds?
In my opinion 10s is too long.
>
> Certainly 10 seconds can be seen as either too long or too short a time
> when waiting for the temperature to fall-back below a threshold.
> But, this maximum polling time will be application dependent I think.
>
> However, this is a repeated polling event notifying of a warning
> over-temperature condition, so, it is already known that the
> temperature is above the threshold and action should already be
> in progress to reduce the temperature.
In this case we have precise start time when we should e.g. throttle
the CPU, because this interrupt will be fired by the hardware just
after the real temperature change. We do not have precise end time
for the throttling process, though. The function .get_temp
may return stale data which was read out some time ago
(< 3s or max 10s).
The hole system performance may suffer for too long (because the
temperature could drop to i.e. 100degC).

On the other hand, when we consider that this is just a binary flag
reacting on 125degC threshold then maybe there is a point of cooling
down the PMIC for longer time.
You are right it is application and system specific (i.e. how many
other temperature sensors is registered in the system and what
decisions we can make based on them i.e. in IPA).
>
> #define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
> #define DA9062_MAX_POLLING_MS_PERIOD		10000
> #define DA9062_MIN_POLLING_MS_PERIOD		1000
>
> The TEMP_WARN first level temperature supervision is intended for
> non-invasive temperature controlling measures for cooling the system
> and are left to the host software. This first level temperature
> TEMP_WARN (125 degC) is only +15degC off the next TEMP_CRIT
> (140 degC) temperature threshold. And this TEMP_CRIT is where
> the hardware will automatically shutdown.
>
> I suppose it all depends on how fast the temperature is expected to
> rise and fall.
>
> In any case, this 10 second polling maximum value was provided as part
> of guidance from a specific solution with this hardware. It would be expected
> that any final implementation will also include a notify() function and any
> of these settings could be altered to match the application where
> appropriate.
>
> I've added a comment above these defined variables for the next code
> patch.
Fair enough. You can mention about the throttling side effect so that
engineers working on bring-up will be aware of this particular knob
during the experiments.

Best Regards,
Lukasz


>
>> On 31/10/16 16:02, Steve Twiss wrote:
>>> From: Steve Twiss <stwiss.opensource@diasemi.com>
>>>
>>> +static int da9062_thermal_probe(struct platform_device *pdev)
>>> +{
>>> +	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
>>> +	struct da9062_thermal *thermal;
>>> +	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
>>> +	const struct of_device_id *match;
>>> +	int ret = 0;
>>> +
>>> +	match = of_match_node(da9062_compatible_reg_id_table,
>>> +			      pdev->dev.of_node);
>>> +	if (!match)
>>> +		return -ENXIO;
>>> +
>>> +	if (pdev->dev.of_node) {
>>> +		if (!of_property_read_u32(pdev->dev.of_node,
>>> +					"dlg,tjunc-temp-polling-period-ms",
>>> +					&pp_tmp)) {
>>> +			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
>>> +				pp_tmp > DA9062_MAX_POLLING_MS_PERIOD)
>>> +				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
>>
>> Maybe it's worth to add some print here just to mention about
>> the DT value out of range. When you saw a dmesg with
>> this print on some bug report, you would know about wrong DT entry
>> (even if debug was not set).
>
> I can add a dev_warn() here explaining the invalid configuration.
>
> [...]
>
>>> +static int da9062_thermal_remove(struct platform_device *pdev)
>>> +{
>>> +	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
>>> +
>>> +	free_irq(thermal->irq, thermal);
>>> +	thermal_zone_device_unregister(thermal->zone);
>>> +	cancel_delayed_work_sync(&thermal->work);
>>
>> You should change the order for these two functions
>> and cancel the work before unregistering thermal zone device.
>
> ok
>
> Regards,
> Steve
>
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diff mbox

Patch

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 2d702ca..da58e54 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -272,6 +272,16 @@  config DB8500_CPUFREQ_COOLING
 	  bound cpufreq cooling device turns active to set CPU frequency low to
 	  cool down the CPU.
 
+config DA9062_THERMAL
+	tristate "DA9062/DA9061 Dialog Semiconductor thermal driver"
+	depends on MFD_DA9062
+	depends on OF
+	help
+	  Enable this for the Dialog Semiconductor thermal sensor driver.
+	  This will report PMIC junction over-temperature for one thermal trip
+	  zone.
+	  Compatible with the DA9062 and DA9061 PMICs.
+
 config INTEL_POWERCLAMP
 	tristate "Intel PowerClamp idle injection driver"
 	depends on THERMAL
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 10b07c1..0a2b3f2 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -38,6 +38,7 @@  obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
 obj-$(CONFIG_TANGO_THERMAL)	+= tango_thermal.o
 obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
 obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
+obj-$(CONFIG_DA9062_THERMAL)	+= da9062-thermal.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
 obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
 obj-$(CONFIG_INTEL_SOC_DTS_IOSF_CORE)	+= intel_soc_dts_iosf.o
diff --git a/drivers/thermal/da9062-thermal.c b/drivers/thermal/da9062-thermal.c
new file mode 100644
index 0000000..1f0af22
--- /dev/null
+++ b/drivers/thermal/da9062-thermal.c
@@ -0,0 +1,291 @@ 
+/*
+ * Thermal device driver for DA9062 and DA9061
+ * Copyright (C) 2016  Dialog Semiconductor Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/da9062/core.h>
+#include <linux/mfd/da9062/registers.h>
+
+#define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
+#define DA9062_MAX_POLLING_MS_PERIOD		10000
+#define DA9062_MIN_POLLING_MS_PERIOD		1000
+
+#define DA9062_MILLI_CELSIUS(t)			((t)*1000)
+
+struct da9062_thermal_config {
+	const char *name;
+};
+
+struct da9062_thermal {
+	struct da9062 *hw;
+	struct delayed_work work;
+	struct thermal_zone_device *zone;
+	enum thermal_device_mode mode;
+	unsigned int polling_period;
+	struct mutex lock;
+	int temperature;
+	int irq;
+	const struct da9062_thermal_config *config;
+	struct device *dev;
+};
+
+static void da9062_thermal_poll_on(struct work_struct *work)
+{
+	struct da9062_thermal *thermal = container_of(work,
+						struct da9062_thermal,
+						work.work);
+	unsigned int val;
+	int ret;
+
+	/* clear E_TEMP */
+	ret = regmap_write(thermal->hw->regmap,
+				DA9062AA_EVENT_B,
+				DA9062AA_E_TEMP_MASK);
+	if (ret < 0) {
+		dev_err(thermal->dev,
+			"Cannot clear the TJUNC temperature status\n");
+		goto err_enable_irq;
+	}
+
+	/* Now read E_TEMP again: it is acting like a status bit.
+	 * If over-temperature, then this status will be true.
+	 * If not over-temperature, this status will be false.
+	 */
+	ret = regmap_read(thermal->hw->regmap,
+			  DA9062AA_EVENT_B,
+			  &val);
+	if (ret < 0) {
+		dev_err(thermal->dev,
+			"Cannot check the TJUNC temperature status\n");
+		goto err_enable_irq;
+	} else {
+		if (val & DA9062AA_E_TEMP_MASK) {
+			mutex_lock(&thermal->lock);
+			thermal->temperature = DA9062_MILLI_CELSIUS(125);
+			mutex_unlock(&thermal->lock);
+			thermal_zone_device_update(thermal->zone);
+
+			schedule_delayed_work(&thermal->work,
+				msecs_to_jiffies(thermal->polling_period));
+			return;
+		} else {
+			mutex_lock(&thermal->lock);
+			thermal->temperature = DA9062_MILLI_CELSIUS(0);
+			mutex_unlock(&thermal->lock);
+			thermal_zone_device_update(thermal->zone);
+		}
+	}
+
+err_enable_irq:
+	enable_irq(thermal->irq);
+}
+
+static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
+{
+	struct da9062_thermal *thermal = data;
+
+	disable_irq_nosync(thermal->irq);
+	schedule_delayed_work(&thermal->work, 0);
+
+	return IRQ_HANDLED;
+}
+
+static int da9062_thermal_get_mode(struct thermal_zone_device *z,
+				   enum thermal_device_mode *mode)
+{
+	struct da9062_thermal *thermal = z->devdata;
+	*mode = thermal->mode;
+	return 0;
+}
+
+static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
+				int trip,
+				enum thermal_trip_type *type)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	switch (trip) {
+	case 0:
+		*type = THERMAL_TRIP_HOT;
+		break;
+	default:
+		dev_err(thermal->dev,
+			"Driver does not support more than 1 trip-wire\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
+					int trip,
+					int *temp)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	switch (trip) {
+	case 0:
+		*temp = DA9062_MILLI_CELSIUS(125);
+		break;
+	default:
+		dev_err(thermal->dev,
+			"Driver does not support more than 1 trip-wire\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int da9062_thermal_get_temp(struct thermal_zone_device *z,
+				   int *temp)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	mutex_lock(&thermal->lock);
+	*temp = thermal->temperature;
+	mutex_unlock(&thermal->lock);
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops da9062_thermal_ops = {
+	.get_temp	= da9062_thermal_get_temp,
+	.get_mode	= da9062_thermal_get_mode,
+	.get_trip_type	= da9062_thermal_get_trip_type,
+	.get_trip_temp	= da9062_thermal_get_trip_temp,
+};
+
+static const struct da9062_thermal_config da9062_config = {
+	.name = "da9062-thermal",
+};
+
+static const struct of_device_id da9062_compatible_reg_id_table[] = {
+	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
+
+static int da9062_thermal_probe(struct platform_device *pdev)
+{
+	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
+	struct da9062_thermal *thermal;
+	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+	const struct of_device_id *match;
+	int ret = 0;
+
+	match = of_match_node(da9062_compatible_reg_id_table,
+			      pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
+
+	if (pdev->dev.of_node) {
+		if (!of_property_read_u32(pdev->dev.of_node,
+					"dlg,tjunc-temp-polling-period-ms",
+					&pp_tmp)) {
+			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
+				pp_tmp > DA9062_MAX_POLLING_MS_PERIOD)
+				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+		}
+
+		dev_dbg(&pdev->dev,
+			 "TJUNC temp polling period set at %d ms\n",
+			 pp_tmp);
+	}
+
+	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
+			     GFP_KERNEL);
+	if (!thermal) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	thermal->config = match->data;
+	thermal->hw = chip;
+	thermal->polling_period = pp_tmp;
+	thermal->mode = THERMAL_DEVICE_ENABLED;
+	thermal->dev = &pdev->dev;
+
+	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
+	mutex_init(&thermal->lock);
+
+	thermal->zone = thermal_zone_device_register(thermal->config->name,
+					1, 0, thermal,
+					&da9062_thermal_ops, NULL, 0,
+					0);
+	if (IS_ERR(thermal->zone)) {
+		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
+		ret = PTR_ERR(thermal->zone);
+		goto err;
+	}
+
+	ret = platform_get_irq_byname(pdev, "THERMAL");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
+		goto err_zone;
+	}
+	thermal->irq = ret;
+
+	ret = request_threaded_irq(thermal->irq, NULL,
+				   da9062_thermal_irq_handler,
+				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				   "THERMAL", thermal);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to request thermal device IRQ.\n");
+		goto err_zone;
+	}
+
+	platform_set_drvdata(pdev, thermal);
+	return 0;
+
+err_zone:
+	thermal_zone_device_unregister(thermal->zone);
+err:
+	return ret;
+}
+
+static int da9062_thermal_remove(struct platform_device *pdev)
+{
+	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
+
+	free_irq(thermal->irq, thermal);
+	thermal_zone_device_unregister(thermal->zone);
+	cancel_delayed_work_sync(&thermal->work);
+	return 0;
+}
+
+static struct platform_driver da9062_thermal_driver = {
+	.probe	= da9062_thermal_probe,
+	.remove	= da9062_thermal_remove,
+	.driver	= {
+		.name	= "da9062-thermal",
+		.of_match_table = da9062_compatible_reg_id_table,
+	},
+};
+
+module_platform_driver(da9062_thermal_driver);
+
+MODULE_AUTHOR("Steve Twiss");
+MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9062-thermal");