[PATCH v4 1/8] thermal: qcom: tsens: Add a skeletal TSENS drivers
Eduardo Valentin
edubezval at gmail.com
Mon Nov 2 12:30:23 PST 2015
Hello Rajendra,
On Fri, Oct 09, 2015 at 03:11:03PM +0530, Rajendra Nayak wrote:
<cut>
> +- #thermal-sensor-cells : Should be 1. See ./thermal.txt for a description.
> +- Refer to Documentation/devicetree/bindings/nvmem/nvmem.txt to know how to specify
> +nvmem cells
> +
> +Optional properties:
> +- qcom,sensor-id: List of sensor instances used in a given SoC. A TSENS IP can
> + have a fixed number of sensors (like 11) but a given SoC can
> + use only 5 of these and they might not always the first 5. They
> + could be sensors 0, 1, 4, 8 and 9. This property is used to
> + describe the subset of the sensors used. If this property is
> + missing they are assumed to be the first 'n' sensors numbered
> + sequentially in which case the number of sensors defaults to
> + the number of slope values.
Can you please elaborate a bit more on why you could not solve this
using the thermal sensor descriptor id?
> +
> +Example:
> +tsens: thermal-sensor at 900000 {
> + compatible = "qcom,msm8916-tsens";
> + nvmem-cells = <&tsens_caldata>, <&tsens_calsel>;
> + nvmem-cell-names = "caldata", "calsel";
> + qcom,tsens-slopes = <3200 3200 3200 3200 3200>;
This property is not documented. Please, also consider my comment on
Narendran's work: use the already existing thermal zone properties.
Have a look on the binding documentation:
Documentation/devicetree/bindings/thermal/thermal.txt
<quote>
Optional property:
- coefficients: An array of integers (one signed cell) containing
Type: array coefficients to compose a linear relation between
Elem size: one cell the sensors listed in the thermal-sensors property.
Elem type: signed Coefficients defaults to 1, in case this property
is not specified. A simple linear polynomial is used:
Z = c0 * x0 + c1 + x1 + ... + c(n-1) * x(n-1) + cn.
The coefficients are ordered and they match with sensors
by means of sensor ID. Additional coefficients are
interpreted as constant offset.
</quote>
Today the code supports only slope + offset linear coefficients. Which I am
assuming you could reuse in your case.
> + qcom,sensor-id = <0 1 2 4 5>;
> + #thermal-sensor-cells = <1>;
How about if you simply make the sensor driver expose all sensors, then in the
thermal zone descriptor, you pick which sensor to use using the thermal sensor
descriptor (quoting the binding again):
ocp {
...
/*
* A simple IC with several bandgap temperature sensors.
*/
bandgap0: bandgap at 0x0000ED00 {
...
#thermal-sensor-cells = <1>;
};
};
thermal-zones {
cpu_thermal: cpu-thermal {
polling-delay-passive = <250>; /* milliseconds */
polling-delay = <1000>; /* milliseconds */
/* sensor ID */
thermal-sensors = <&bandgap0 0>;
};
gpu_thermal: gpu-thermal {
polling-delay-passive = <120>; /* milliseconds */
polling-delay = <1000>; /* milliseconds */
/* sensor ID */
thermal-sensors = <&bandgap0 1>;
};
};
Would that simplify ?
BR,
Eduardo Valentin
> + };
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 5aabc4b..d49f2bd 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -374,4 +374,9 @@ config QCOM_SPMI_TEMP_ALARM
> real time die temperature if an ADC is present or an estimate of the
> temperature based upon the over temperature stage value.
>
> +menu "Qualcomm thermal drivers"
> +depends on ARCH_QCOM && OF
Please add compile test too.
> +source "drivers/thermal/qcom/Kconfig"
> +endmenu
> +
> endif
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 26f1608..cdaa55f 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -43,5 +43,6 @@ obj-$(CONFIG_TI_SOC_THERMAL) += ti-soc-thermal/
> obj-$(CONFIG_INT340X_THERMAL) += int340x_thermal/
> obj-$(CONFIG_INTEL_PCH_THERMAL) += intel_pch_thermal.o
> obj-$(CONFIG_ST_THERMAL) += st/
> +obj-$(CONFIG_QCOM_TSENS) += qcom/
> obj-$(CONFIG_TEGRA_SOCTHERM) += tegra_soctherm.o
> obj-$(CONFIG_HISI_THERMAL) += hisi_thermal.o
> diff --git a/drivers/thermal/qcom/Kconfig b/drivers/thermal/qcom/Kconfig
> new file mode 100644
> index 0000000..f7e8e40
> --- /dev/null
> +++ b/drivers/thermal/qcom/Kconfig
> @@ -0,0 +1,10 @@
> +config QCOM_TSENS
> + tristate "Qualcomm TSENS Temperature Alarm"
> + depends on THERMAL
> + depends on QCOM_QFPROM
Compile test..
> + help
> + This enables the thermal sysfs driver for the TSENS device. It shows
> + up in Sysfs as a thermal zone with multiple trip points. Disabling the
> + thermal zone device via the mode file results in disabling the sensor.
> + Also able to set threshold temperature for both hot and cold and update
> + when a threshold is reached.
> diff --git a/drivers/thermal/qcom/Makefile b/drivers/thermal/qcom/Makefile
> new file mode 100644
> index 0000000..401069b
> --- /dev/null
> +++ b/drivers/thermal/qcom/Makefile
> @@ -0,0 +1,2 @@
> +obj-$(CONFIG_QCOM_TSENS) += qcom_tsens.o
> +qcom_tsens-y += tsens.o
> diff --git a/drivers/thermal/qcom/tsens.c b/drivers/thermal/qcom/tsens.c
> new file mode 100644
> index 0000000..87f5215
> --- /dev/null
> +++ b/drivers/thermal/qcom/tsens.c
> @@ -0,0 +1,199 @@
> +/*
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * 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/err.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm.h>
> +#include <linux/slab.h>
> +#include <linux/thermal.h>
> +#include "tsens.h"
> +
> +static int tsens_get_temp(void *data, int *temp)
> +{
> + const struct tsens_sensor *s = data;
> + struct tsens_device *tmdev = s->tmdev;
> +
> + return tmdev->ops->get_temp(tmdev, s->id, temp);
> +}
> +
> +static int tsens_get_trend(void *data, long *temp)
> +{
> + const struct tsens_sensor *s = data;
> + struct tsens_device *tmdev = s->tmdev;
> +
> + if (tmdev->ops->get_trend)
> + return tmdev->ops->get_trend(tmdev, s->id, temp);
> +
> + return -ENOSYS;
> +}
> +
> +static int tsens_suspend(struct device *dev)
> +{
> + struct tsens_device *tmdev = dev_get_drvdata(dev);
> +
> + if (tmdev->ops && tmdev->ops->suspend)
> + return tmdev->ops->suspend(tmdev);
> +
> + return 0;
> +}
> +
> +static int tsens_resume(struct device *dev)
> +{
> + struct tsens_device *tmdev = dev_get_drvdata(dev);
> +
> + if (tmdev->ops && tmdev->ops->resume)
> + return tmdev->ops->resume(tmdev);
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(tsens_pm_ops, tsens_suspend, tsens_resume);
> +
> +static const struct of_device_id tsens_table[] = {
> + {
> + .compatible = "qcom,msm8916-tsens",
> + }, {
> + .compatible = "qcom,msm8974-tsens",
> + },
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, tsens_table);
> +
> +static const struct thermal_zone_of_device_ops tsens_of_ops = {
> + .get_temp = tsens_get_temp,
> + .get_trend = tsens_get_trend,
> +};
> +
> +static int tsens_register(struct tsens_device *tmdev)
> +{
> + int i, ret;
> + struct thermal_zone_device *tzd;
> + u32 *hw_id, n = tmdev->num_sensors;
> + struct device_node *np = tmdev->dev->of_node;
> +
> + hw_id = devm_kcalloc(tmdev->dev, n, sizeof(u32), GFP_KERNEL);
> + if (!hw_id)
> + return -ENOMEM;
> +
> + ret = of_property_read_u32_array(np, "qcom,sensor-id", hw_id, n);
> + for (i = 0; i < tmdev->num_sensors; i++) {
> + if (ret)
> + tmdev->sensor[i].hw_id = i;
> + else
> + tmdev->sensor[i].hw_id = hw_id[i];
> + tmdev->sensor[i].tmdev = tmdev;
> + tmdev->sensor[i].id = i;
> + tzd = thermal_zone_of_sensor_register(tmdev->dev, i,
> + &tmdev->sensor[i],
> + &tsens_of_ops);
> + if (IS_ERR(tzd))
> + continue;
> + tmdev->sensor[i].tzd = tzd;
> + if (tmdev->ops->enable)
> + tmdev->ops->enable(tmdev, i);
> + }
> + return 0;
> +}
> +
> +static int tsens_probe(struct platform_device *pdev)
> +{
> + int ret, i, num;
> + struct device *dev;
> + struct device_node *np;
> + struct tsens_sensor *s;
> + struct tsens_device *tmdev;
> + const struct of_device_id *id;
> +
> + dev = &pdev->dev;
> + np = dev->of_node;
> +
> + num = of_property_count_u32_elems(np, "qcom,tsens-slopes");
> + if (num <= 0) {
> + dev_err(dev, "invalid tsens slopes\n");
> + return -EINVAL;
> + }
> +
> + tmdev = devm_kzalloc(dev, sizeof(*tmdev) +
> + num * sizeof(*s), GFP_KERNEL);
> + if (!tmdev)
> + return -ENOMEM;
> +
> + tmdev->dev = dev;
> + tmdev->num_sensors = num;
> +
> + for (i = 0, s = tmdev->sensor; i < tmdev->num_sensors; i++, s++)
> + of_property_read_u32_index(np, "qcom,tsens-slopes", i,
> + &s->slope);
> +
> + id = of_match_node(tsens_table, np);
> + if (!id)
> + return -ENODEV;
> +
> + tmdev->ops = id->data;
> + if (!tmdev->ops || !tmdev->ops->init || !tmdev->ops->calibrate ||
> + !tmdev->ops->get_temp)
> + return -EINVAL;
> +
> + ret = tmdev->ops->init(tmdev);
> + if (ret < 0) {
> + dev_err(dev, "tsens init failed\n");
> + return ret;
> + }
> +
> + ret = tmdev->ops->calibrate(tmdev);
> + if (ret < 0) {
> + dev_err(dev, "tsens calibration failed\n");
> + return ret;
> + }
> +
> + ret = tsens_register(tmdev);
> +
> + platform_set_drvdata(pdev, tmdev);
> +
> + return ret;
> +}
> +
> +static int tsens_remove(struct platform_device *pdev)
> +{
> + int i;
> + struct tsens_device *tmdev = platform_get_drvdata(pdev);
> + struct thermal_zone_device *tzd;
> +
> + if (tmdev->ops->disable)
> + tmdev->ops->disable(tmdev);
> +
> + for (i = 0; i < tmdev->num_sensors; i++) {
> + tzd = tmdev->sensor[i].tzd;
> + thermal_zone_of_sensor_unregister(&pdev->dev, tzd);
> + }
> +
> + return 0;
> +}
> +
> +static struct platform_driver tsens_driver = {
> + .probe = tsens_probe,
> + .remove = tsens_remove,
> + .driver = {
> + .name = "qcom-tsens",
> + .pm = &tsens_pm_ops,
> + .of_match_table = tsens_table,
> + },
> +};
> +module_platform_driver(tsens_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("QCOM Temperature Sensor driver");
> +MODULE_ALIAS("platform:qcom-tsens");
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> new file mode 100644
> index 0000000..f0fc353
> --- /dev/null
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -0,0 +1,58 @@
> +/*
> + * Copyright (c) 2015, The Linux Foundation. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * 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.
> + */
> +#ifndef __QCOM_TSENS_H__
> +#define __QCOM_TSENS_H__
> +
> +struct tsens_device;
> +
> +struct tsens_sensor {
> + struct tsens_device *tmdev;
> + struct thermal_zone_device *tzd;
> + int offset;
> + int id;
> + int hw_id;
> + u32 slope;
> + u32 status;
> +};
> +
> +struct tsens_ops {
> + /* mandatory callbacks */
> + int (*init)(struct tsens_device *);
> + int (*calibrate)(struct tsens_device *);
> + int (*get_temp)(struct tsens_device *, int, int *);
> + /* optional callbacks */
> + int (*enable)(struct tsens_device *, int);
> + void (*disable)(struct tsens_device *);
> + int (*suspend)(struct tsens_device *);
> + int (*resume)(struct tsens_device *);
> + int (*get_trend)(struct tsens_device *, int, long *);
> +};
I know this is a set of internal data structures. But, given that you
are creating a driver that supports a family of chips, and that I
assume will be having additions on it in the future, it would
be nice if you add kernel doc entries on these, so people know
what to expect from them.
> +
> +/* Registers to be saved/restored across a context loss */
> +struct tsens_context {
> + int threshold;
> + int control;
> +};
> +
> +struct tsens_device {
> + struct device *dev;
> + u32 num_sensors;
> + struct regmap *map;
> + struct regmap_field *status_field;
> + struct tsens_context ctx;
> + bool trdy;
> + const struct tsens_ops *ops;
> + struct tsens_sensor sensor[0];
> +};
> +
> +#endif /* __QCOM_TSENS_H__ */
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>
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