Re: [PATCH 3/4] thermal: qcom: Add RPMHPD cooling device driver.

[Thara Gopinath <thara.gopinath@linaro.org>]

On 08/28/2019 08:23 AM, Zhang Rui wrote:
> On Fri, 2019-08-09 at 20:58 -0400, Thara Gopinath wrote:
>> The MX power domain in RPMH can be used to warm the
>> the SoC in SDM845. To support this feature, introduce
>> a RPMH power domain cooling device driver that can be
>> plugged into the thermal framework.(The thermal framework
>> itself requires further modifiction to support a warming
>> device in place of a cooling device. Those extensions are
>> not introduced in this patch series).
> 
> I'm wondering how this device is used, as well as the thermal extension
> changes needed. To me, it's better to see this patch together with the
> thermal extension changes.
Hello Rui,

I somehow missed this email. I am sorry about that.

IMHO, the thermal extensions, needed would be
1. Extend the dt-bindings either in the thermal-zone or in the trip
description to indicate whether a zone/trip is being monitored for
rising/falling temperature
2. Changes in thermal-core and the governors(starting with step-wise) to
monitor falling temperature as well.

There are comments for this patch series like fixing the genpd
extensions I have proposed and making the warming device more generic.
So I will post a v2 for this anyways.

I have some proto-type for the above mentioned extensions. I will post
them out asap.

Again, apologies for missing this email

Regards
Thara

> 
> thanks,
> rui
>>
>> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
>> ---
>>  drivers/thermal/qcom/Kconfig            |   7 ++
>>  drivers/thermal/qcom/Makefile           |   1 +
>>  drivers/thermal/qcom/qcom-rpmhpd-cdev.c | 141
>> ++++++++++++++++++++++++++++++++
>>  3 files changed, 149 insertions(+)
>>  create mode 100644 drivers/thermal/qcom/qcom-rpmhpd-cdev.c
>>
>> diff --git a/drivers/thermal/qcom/Kconfig
>> b/drivers/thermal/qcom/Kconfig
>> index aa9c1d8..a540130 100644
>> --- a/drivers/thermal/qcom/Kconfig
>> +++ b/drivers/thermal/qcom/Kconfig
>> @@ -20,3 +20,10 @@ config QCOM_SPMI_TEMP_ALARM
>>  	  trip points. The temperature reported by the thermal sensor
>> reflects the
>>  	  real time die temperature if an ADC is present or an estimate
>> of the
>>  	  temperature based upon the over temperature stage value.
>> +
>> +config CONFIG_QCOM_RPMHPD_CDEV
>> +	tristate "Qualcomm RPMHPD based cooling device"
>> +	depends on QCOM_RPMHPD
>> +	help
>> +	  This enables RPMHPD based cooling devices. On SDM845, this is
>> +	  MX power domain.
>> diff --git a/drivers/thermal/qcom/Makefile
>> b/drivers/thermal/qcom/Makefile
>> index 7c8dc6e..e4eb520 100644
>> --- a/drivers/thermal/qcom/Makefile
>> +++ b/drivers/thermal/qcom/Makefile
>> @@ -4,3 +4,4 @@ obj-$(CONFIG_QCOM_TSENS)	+= qcom_tsens.o
>>  qcom_tsens-y			+= tsens.o tsens-common.o tsens-v0_1.o
>> \
>>  				   tsens-8960.o tsens-v2.o tsens-v1.o
>>  obj-$(CONFIG_QCOM_SPMI_TEMP_ALARM)	+= qcom-spmi-temp-alarm.o
>> +obj-$(CONFIG_QCOM_RPMHPD_CDEV)		+= qcom-rpmhpd-cdev.o
>> diff --git a/drivers/thermal/qcom/qcom-rpmhpd-cdev.c
>> b/drivers/thermal/qcom/qcom-rpmhpd-cdev.c
>> new file mode 100644
>> index 0000000..265523b
>> --- /dev/null
>> +++ b/drivers/thermal/qcom/qcom-rpmhpd-cdev.c
>> @@ -0,0 +1,141 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2019, Linaro Ltd
>> + */
>> +#include <linux/err.h>
>> +#include <linux/kernel.h>
>> +#include <linux/init.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/module.h>
>> +#include <linux/pm_domain.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/thermal.h>
>> +
>> +struct rpmhpd_cooling_device {
>> +	struct thermal_cooling_device *cdev;
>> +	struct device *pwr_domain;
>> +	int max_state;
>> +	int cur_state;
>> +	bool is_pwr_domain_on;
>> +};
>> +
>> +static const char sdm845_rpmhpd_cdev_name[] = "mx";
>> +
>> +static const struct of_device_id rpmhpd_cdev_match_table[] = {
>> +	{ .compatible = "qcom,sdm845-rpmhpd-cdev", .data =
>> &sdm845_rpmhpd_cdev_name },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, rpmhpd_cdev_match_table);
>> +
>> +static int rpmhpd_cdev_get_max_state(struct thermal_cooling_device
>> *cdev,
>> +				     unsigned long *state)
>> +{
>> +	struct rpmhpd_cooling_device *rpmhpd_cdev = cdev->devdata;
>> +
>> +	*state = rpmhpd_cdev->max_state;
>> +	return 0;
>> +}
>> +
>> +static int rpmhpd_cdev_get_cur_state(struct thermal_cooling_device
>> *cdev,
>> +				     unsigned long *state)
>> +{
>> +	struct rpmhpd_cooling_device *rpmhpd_cdev = cdev->devdata;
>> +	int perf_state;
>> +
>> +	dev_pm_genpd_get_performance_state(rpmhpd_cdev->pwr_domain,
>> +					   &perf_state);
>> +	*state = perf_state;
>> +	return 0;
>> +}
>> +
>> +static int rpmhpd_cdev_set_cur_state(struct thermal_cooling_device
>> *cdev,
>> +				     unsigned long state)
>> +{
>> +	struct rpmhpd_cooling_device *rpmhpd_cdev = cdev->devdata;
>> +	struct device *pwr_domain = rpmhpd_cdev->pwr_domain;
>> +	int ret;
>> +
>> +	ret = dev_pm_genpd_set_performance_state(pwr_domain, state);
>> +
>> +	if (ret)
>> +		return ret;
>> +
>> +	if (state && !rpmhpd_cdev->is_pwr_domain_on) {
>> +		ret = pm_runtime_get_sync(pwr_domain);
>> +		rpmhpd_cdev->is_pwr_domain_on = true;
>> +	} else if (!state && rpmhpd_cdev->is_pwr_domain_on) {
>> +		ret = pm_runtime_put(pwr_domain);
>> +		rpmhpd_cdev->is_pwr_domain_on = false;
>> +	}
>> +
>> +	return ret;
>> +}
>> +
>> +static struct thermal_cooling_device_ops rpmhpd_cooling_device_ops =
>> {
>> +	.get_max_state = rpmhpd_cdev_get_max_state,
>> +	.get_cur_state = rpmhpd_cdev_get_cur_state,
>> +	.set_cur_state = rpmhpd_cdev_set_cur_state,
>> +};
>> +
>> +static int rpmhpd_cdev_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev, *pd_dev;
>> +	struct rpmhpd_cooling_device *rpmhpd_cdev;
>> +	const char *rpmhpd_cdev_name = of_device_get_match_data(dev);
>> +	unsigned int count;
>> +	int ret;
>> +
>> +	if (!dev->pm_domain) {
>> +		pd_dev = dev_pm_domain_attach_by_name(dev,
>> rpmhpd_cdev_name);
>> +		if (IS_ERR(pd_dev))
>> +			return PTR_ERR(pd_dev);
>> +	} else {
>> +		pd_dev = dev;
>> +	}
>> +
>> +	rpmhpd_cdev = devm_kzalloc(dev, sizeof(*rpmhpd_cdev),
>> GFP_KERNEL);
>> +	if (!rpmhpd_cdev) {
>> +		ret = -ENOMEM;
>> +		goto detach_pd;
>> +	}
>> +
>> +	ret = dev_pm_genpd_performance_state_count(pd_dev, &count);
>> +	if (ret)
>> +		goto detach_pd;
>> +
>> +	rpmhpd_cdev->pwr_domain = pd_dev;
>> +	rpmhpd_cdev->max_state = count - 1;
>> +	rpmhpd_cdev->is_pwr_domain_on = false;
>> +
>> +	pm_runtime_enable(pd_dev);
>> +
>> +	rpmhpd_cdev->cdev = thermal_of_cooling_device_register
>> +					(dev->of_node,
>> rpmhpd_cdev_name,
>> +					 rpmhpd_cdev,
>> +					 &rpmhpd_cooling_device_ops);
>> +	if (IS_ERR(rpmhpd_cdev->cdev)) {
>> +		dev_err(dev, "unable to register %s cooling device\n",
>> +			rpmhpd_cdev_name);
>> +		ret = PTR_ERR(rpmhpd_cdev->cdev);
>> +		goto detach_pd;
>> +	}
>> +
>> +	return 0;
>> +
>> +detach_pd:
>> +	dev_pm_domain_detach(pd_dev, false);
>> +	return ret;
>> +}
>> +
>> +static struct platform_driver rpmhpd_cdev_driver = {
>> +	.driver = {
>> +		.name = "qcom-rpmhpd-cdev",
>> +		.of_match_table = rpmhpd_cdev_match_table,
>> +	},
>> +	.probe = rpmhpd_cdev_probe,
>> +};
>> +module_platform_driver(rpmhpd_cdev_driver);
>> +
>> +MODULE_DESCRIPTION("Qualcomm RPMHPD cooling device driver");
>> +MODULE_LICENSE("GPL v2");
> 


-- 
Regards
Thara