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From: Zhang Rui <rui.zhang@intel.com>
To: Shawn Guo <shawn.guo@linaro.org>
Cc: linux-pm@vger.kernel.org,
	Eduardo Valentin <eduardo.valentin@ti.com>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] thermal: add imx thermal driver support
Date: Thu, 13 Jun 2013 11:12:57 +0800
Message-ID: <1371093177.2135.24.camel@rzhang1-mobl4> (raw)
In-Reply-To: <1370330008-5982-1-git-send-email-shawn.guo@linaro.org>

On Tue, 2013-06-04 at 15:13 +0800, Shawn Guo wrote:
> This is based on the initial imx thermal work done by
> Rob Lee <rob.lee@linaro.org> (Not sure if the email address is still
> valid).  Since he is no longer interested in the work and I have
> rewritten a significant amount of the code, I just took the authorship
> over from him.
> 
> It adds the imx thermal support using Temperature Monitor (TEMPMON)
> block found on some Freescale i.MX SoCs.  The driver uses syscon regmap
> interface to access TEMPMON control registers and calibration data, and
> supports cpufreq as the cooling device.
> 
you're using the cpufrq_cooling to throttle cpus at 85C, right?
then you should register it as THERMAL_TRIP_PASSIVE instead of
THERMAL_TRIP_ACTIVE.

thanks,
rui
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
>  .../devicetree/bindings/thermal/imx-thermal.txt    |   14 +
>  drivers/thermal/Kconfig                            |    8 +
>  drivers/thermal/Makefile                           |    1 +
>  drivers/thermal/imx_thermal.c                      |  421 ++++++++++++++++++++
>  4 files changed, 444 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/thermal/imx-thermal.txt
>  create mode 100644 drivers/thermal/imx_thermal.c
> 
> diff --git a/Documentation/devicetree/bindings/thermal/imx-thermal.txt b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> new file mode 100644
> index 0000000..c606e2b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/thermal/imx-thermal.txt
> @@ -0,0 +1,14 @@
> +* Temperature Monitor (TEMPMON) on Freescale i.MX SoCs
> +
> +Required properties:
> +- compatible : "fsl,imx6q-thermal"
> +- fsl,tempmon : phandle pointer to TEMPMON control registers
> +- fsl,tempmon-data : phandle pointer to TEMPMON calibration data
> +
> +Example:
> +
> +tempmon {
> +	compatible = "fsl,imx6q-tempmon";
> +	fsl,tempmon = <&anatop>;
> +	fsl,tempmon-data = <&ocotp>;
> +};
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 5e3c025..935fcbe 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -91,6 +91,14 @@ config THERMAL_EMULATION
>  	  because userland can easily disable the thermal policy by simply
>  	  flooding this sysfs node with low temperature values.
>  
> +config IMX_THERMAL
> +	tristate "Temperature sensor driver for Freescale i.MX SoCs"
> +	depends on CPU_THERMAL
> +	depends on MFD_SYSCON
> +	depends on OF
> +	help
> +	  Support for Temperature Monitor (TEMPMON) found on Freescale i.MX SoCs.
> +
>  config SPEAR_THERMAL
>  	bool "SPEAr thermal sensor driver"
>  	depends on PLAT_SPEAR
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index c054d41..6910b2d 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_EXYNOS_THERMAL)	+= exynos_thermal.o
>  obj-$(CONFIG_DOVE_THERMAL)  	+= dove_thermal.o
>  obj-$(CONFIG_DB8500_THERMAL)	+= db8500_thermal.o
>  obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
> +obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
>  obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
>  obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
>  
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> new file mode 100644
> index 0000000..bdfcadb
> --- /dev/null
> +++ b/drivers/thermal/imx_thermal.c
> @@ -0,0 +1,421 @@
> +/*
> + * Copyright 2013 Freescale Semiconductor, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + */
> +
> +#include <linux/cpu_cooling.h>
> +#include <linux/cpufreq.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/thermal.h>
> +#include <linux/types.h>
> +
> +#define REG_SET		0x4
> +#define REG_CLR		0x8
> +#define REG_TOG		0xc
> +
> +#define MISC0				0x0150
> +#define MISC0_REFTOP_SELBIASOFF		(1 << 3)
> +
> +#define TEMPSENSE0			0x0180
> +#define TEMPSENSE0_TEMP_CNT_SHIFT	8
> +#define TEMPSENSE0_TEMP_CNT_MASK	(0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
> +#define TEMPSENSE0_FINISHED		(1 << 2)
> +#define TEMPSENSE0_MEASURE_TEMP		(1 << 1)
> +#define TEMPSENSE0_POWER_DOWN		(1 << 0)
> +
> +#define TEMPSENSE1			0x0190
> +#define TEMPSENSE1_MEASURE_FREQ		0xffff
> +
> +#define OCOTP_ANA1			0x04e0
> +
> +/* The driver supports 1 active trip point and 1 critical trip point */
> +enum imx_thermal_trip {
> +	IMX_TRIP_ACTIVE,
> +	IMX_TRIP_CRITICAL,
> +	IMX_TRIP_NUM,
> +};
> +
> +/*
> + * It defines the temperature in millicelsius for active trip point
> + * that will trigger cooling action when crossed.
> + */
> +#define IMX_TEMP_ACTIVE			85000
> +
> +/*
> + * The maximum die temperature on imx parts is 105C, let's give some cushion
> + * for noise and possible temperature rise between measurements.
> + */
> +#define IMX_TEMP_CRITICAL		100000
> +
> +#define IMX_THERMAL_POLLING_INTERVAL	1000 /* millisecond */
> +
> +struct imx_thermal_data {
> +	struct thermal_zone_device *tz;
> +	struct thermal_cooling_device *cdev;
> +	enum thermal_device_mode mode;
> +	struct regmap *tempmon;
> +	bool meas_suspended;
> +	int c1, c2; /* See forumla in imx_get_sensor_data() */
> +};
> +
> +static int imx_get_temp(struct thermal_zone_device *tz, unsigned long *temp)
> +{
> +	struct imx_thermal_data *data = tz->devdata;
> +	struct regmap *map = data->tempmon;
> +	static unsigned long last_temp;
> +	unsigned int n_meas;
> +	u32 val;
> +
> +	/*
> +	 * Every time we measure the temperature, we will power on the
> +	 * temperature sensor, enable measurements, take a reading,
> +	 * disable measurements, power off the temperature sensor.
> +	 */
> +	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
> +	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
> +
> +	/*
> +	 * According to the temp sensor designers, it may require up to ~17us
> +	 * to complete a measurement.  But this timing isn't checked on every
> +	 * part nor is it specified in the datasheet, so sleeping at least 1ms
> +	 * should provide plenty of time.  Sleeping longer than 1ms is ok so no
> +	 * need for usleep_range.
> +	 */
> +	msleep(1);
> +
> +	regmap_read(map, TEMPSENSE0, &val);
> +	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
> +	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
> +
> +	if ((val & TEMPSENSE0_FINISHED) == 0) {
> +		dev_dbg(&tz->device, "temp measurement never finished\n");
> +		return -EAGAIN;
> +	}
> +
> +	n_meas = (val & TEMPSENSE0_TEMP_CNT_MASK) >> TEMPSENSE0_TEMP_CNT_SHIFT;
> +
> +	/* See imx_get_sensor_data() for forumla derivation */
> +	*temp = data->c2 + data->c1 * n_meas;
> +
> +	if (*temp != last_temp) {
> +		dev_dbg(&tz->device, "millicelsius: %ld\n", *temp);
> +		last_temp = *temp;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imx_get_mode(struct thermal_zone_device *tz,
> +			enum thermal_device_mode *mode)
> +{
> +	struct imx_thermal_data *data = tz->devdata;
> +
> +	*mode = data->mode;
> +
> +	return 0;
> +}
> +
> +static int imx_set_mode(struct thermal_zone_device *tz,
> +			enum thermal_device_mode mode)
> +{
> +	struct imx_thermal_data *data = tz->devdata;
> +
> +	tz->polling_delay = (mode == THERMAL_DEVICE_ENABLED) ?
> +				IMX_THERMAL_POLLING_INTERVAL : 0;
> +	data->mode = mode;
> +	thermal_zone_device_update(tz);
> +
> +	return 0;
> +}
> +
> +static int imx_get_trip_type(struct thermal_zone_device *tz, int trip,
> +			     enum thermal_trip_type *type)
> +{
> +	*type = (trip == IMX_TRIP_ACTIVE) ? THERMAL_TRIP_ACTIVE :
> +					    THERMAL_TRIP_CRITICAL;
> +	return 0;
> +}
> +
> +static int imx_get_crit_temp(struct thermal_zone_device *tz,
> +			     unsigned long *temp)
> +{
> +	*temp = IMX_TEMP_CRITICAL;
> +	return 0;
> +}
> +
> +static int imx_get_trip_temp(struct thermal_zone_device *tz, int trip,
> +			     unsigned long *temp)
> +{
> +	*temp = (trip == IMX_TRIP_ACTIVE) ? IMX_TEMP_ACTIVE :
> +					    IMX_TEMP_CRITICAL;
> +	return 0;
> +}
> +
> +static int imx_bind(struct thermal_zone_device *tz,
> +		    struct thermal_cooling_device *cdev)
> +{
> +	int ret;
> +
> +	ret = thermal_zone_bind_cooling_device(tz, IMX_TRIP_ACTIVE, cdev,
> +					       THERMAL_NO_LIMIT,
> +					       THERMAL_NO_LIMIT);
> +	if (ret) {
> +		dev_err(&tz->device,
> +			"binding zone %s with cdev %s failed:%d\n",
> +			tz->type, cdev->type, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int imx_unbind(struct thermal_zone_device *tz,
> +		      struct thermal_cooling_device *cdev)
> +{
> +	int ret;
> +
> +	ret = thermal_zone_unbind_cooling_device(tz, IMX_TRIP_ACTIVE, cdev);
> +	if (ret) {
> +		dev_err(&tz->device,
> +			"unbinding zone %s with cdev %s failed:%d\n",
> +			tz->type, cdev->type, ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_device_ops imx_tz_ops = {
> +	.bind = imx_bind,
> +	.unbind = imx_unbind,
> +	.get_temp = imx_get_temp,
> +	.get_mode = imx_get_mode,
> +	.set_mode = imx_set_mode,
> +	.get_trip_type = imx_get_trip_type,
> +	.get_trip_temp = imx_get_trip_temp,
> +	.get_crit_temp = imx_get_crit_temp,
> +};
> +
> +static int imx_get_sensor_data(struct platform_device *pdev)
> +{
> +	struct imx_thermal_data *data = platform_get_drvdata(pdev);
> +	struct regmap *map;
> +	int t1, t2, n1, n2;
> +	int ret;
> +	u32 val;
> +
> +	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> +					      "fsl,tempmon-data");
> +	if (IS_ERR(map)) {
> +		ret = PTR_ERR(map);
> +		dev_err(&pdev->dev, "failed to get sensor regmap: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = regmap_read(map, OCOTP_ANA1, &val);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to read sensor data: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (val == 0 || val == ~0) {
> +		dev_err(&pdev->dev, "invalid sensor calibration data\n");
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * Sensor data layout:
> +	 *   [31:20] - sensor value @ 25C
> +	 *    [19:8] - sensor value of hot
> +	 *     [7:0] - hot temperature value
> +	 */
> +	n1 = val >> 20;
> +	n2 = (val & 0xfff00) >> 8;
> +	t2 = val & 0xff;
> +	t1 = 25; /* t1 always 25C */
> +
> +	/*
> +	 * Derived from linear interpolation,
> +	 * Tmeas = T2 + (Nmeas - N2) * (T1 - T2) / (N1 - N2)
> +	 * We want to reduce this down to the minimum computation necessary
> +	 * for each temperature read.  Also, we want Tmeas in millicelsius
> +	 * and we don't want to lose precision from integer division. So...
> +	 * milli_Tmeas = 1000 * T2 + 1000 * (Nmeas - N2) * (T1 - T2) / (N1 - N2)
> +	 * Let constant c1 = 1000 * (T1 - T2) / (N1 - N2)
> +	 * milli_Tmeas = (1000 * T2) + c1 * (Nmeas - N2)
> +	 * milli_Tmeas = (1000 * T2) + (c1 * Nmeas) - (c1 * N2)
> +	 * Let constant c2 = (1000 * T2) - (c1 * N2)
> +	 * milli_Tmeas = c2 + (c1 * Nmeas)
> +	 */
> +	data->c1 = 1000 * (t1 - t2) / (n1 - n2);
> +	data->c2 = 1000 * t2 - data->c1 * n2;
> +
> +	return 0;
> +}
> +
> +static int imx_thermal_probe(struct platform_device *pdev)
> +{
> +	struct imx_thermal_data *data;
> +	struct cpumask clip_cpus;
> +	struct regmap *map;
> +	int ret;
> +
> +	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "fsl,tempmon");
> +	if (IS_ERR(map)) {
> +		ret = PTR_ERR(map);
> +		dev_err(&pdev->dev, "failed to get tempmon regmap: %d\n", ret);
> +		return ret;
> +	}
> +	data->tempmon = map;
> +
> +	platform_set_drvdata(pdev, data);
> +
> +	ret = imx_get_sensor_data(pdev);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to get sensor data\n");
> +		return ret;
> +	}
> +
> +	/* Make sure sensor is in known good state for measurements */
> +	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
> +	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
> +	regmap_write(map, TEMPSENSE1 + REG_CLR, TEMPSENSE1_MEASURE_FREQ);
> +	regmap_write(map, MISC0 + REG_SET, MISC0_REFTOP_SELBIASOFF);
> +	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
> +
> +	cpumask_set_cpu(0, &clip_cpus);
> +	data->cdev = cpufreq_cooling_register(&clip_cpus);
> +	if (IS_ERR(data->cdev)) {
> +		ret = PTR_ERR(data->cdev);
> +		dev_err(&pdev->dev,
> +			"failed to register cpufreq cooling device: %d\n", ret);
> +		return ret;
> +	}
> +
> +	data->tz = thermal_zone_device_register("imx_thermal_zone",
> +						IMX_TRIP_NUM, 0, data,
> +						&imx_tz_ops, NULL, 0,
> +						IMX_THERMAL_POLLING_INTERVAL);
> +	if (IS_ERR(data->tz)) {
> +		ret = PTR_ERR(data->tz);
> +		dev_err(&pdev->dev,
> +			"failed to register thermal zone device %d\n", ret);
> +		cpufreq_cooling_unregister(data->cdev);
> +		return ret;
> +	}
> +
> +	data->mode = THERMAL_DEVICE_ENABLED;
> +
> +	return 0;
> +}
> +
> +static int imx_thermal_remove(struct platform_device *pdev)
> +{
> +	struct imx_thermal_data *data = platform_get_drvdata(pdev);
> +
> +	thermal_zone_device_unregister(data->tz);
> +	cpufreq_cooling_unregister(data->cdev);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int imx_thermal_suspend(struct device *dev)
> +{
> +	struct imx_thermal_data *data = dev_get_drvdata(dev);
> +	struct regmap *map = data->tempmon;
> +	u32 val;
> +
> +	regmap_read(map, TEMPSENSE0, &val);
> +
> +	/* Was a measurement taking place?  If not, nothing to do. */
> +	if (val & TEMPSENSE0_POWER_DOWN)
> +		return 0;
> +
> +	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
> +	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
> +
> +	data->meas_suspended = true;
> +
> +	return 0;
> +}
> +
> +static int imx_thermal_resume(struct device *dev)
> +{
> +	struct imx_thermal_data *data = dev_get_drvdata(dev);
> +	struct regmap *map = data->tempmon;
> +
> +	/*
> +	 * If a measurement was taking place while suspend, re-take the
> +	 * measurement.
> +	 */
> +	if (data->meas_suspended) {
> +		regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
> +		regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);
> +		/*
> +		 * According to the temp sensor designers, it may require
> +		 * up to ~17us to complete a measurement.  But this timing
> +		 * isn't checked on every part nor is it specified in the
> +		 * datasheet, so delay 50us for timing margin.
> +		 */
> +		udelay(50);
> +		data->meas_suspended = false;
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static SIMPLE_DEV_PM_OPS(imx_thermal_pm_ops,
> +			 imx_thermal_suspend, imx_thermal_resume);
> +
> +static const struct of_device_id of_imx_thermal_match[] = {
> +	{ .compatible = "fsl,imx6q-tempmon", },
> +	{ /* end */ }
> +};
> +
> +static struct platform_driver imx_thermal = {
> +	.driver = {
> +		.name	= "imx_thermal",
> +		.owner  = THIS_MODULE,
> +		.pm	= &imx_thermal_pm_ops,
> +		.of_match_table = of_imx_thermal_match,
> +	},
> +	.probe		= imx_thermal_probe,
> +	.remove		= imx_thermal_remove,
> +};
> +
> +static int __init imx_thermal_init(void)
> +{
> +	return platform_driver_register(&imx_thermal);
> +}
> +late_initcall(imx_thermal_init);
> +
> +static void __exit imx_thermal_exit(void)
> +{
> +	platform_driver_unregister(&imx_thermal);
> +}
> +module_exit(imx_thermal_exit);
> +
> +MODULE_AUTHOR("Freescale Semiconductor, Inc.");
> +MODULE_DESCRIPTION("Thermal driver for Freescale i.MX SoCs");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:imx-thermal");



  parent reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-04  7:13 Shawn Guo
2013-06-13  0:16 ` Shawn Guo
2013-06-13  3:12 ` Zhang Rui [this message]
2013-06-13  4:12   ` Shawn Guo
2013-06-13  5:14     ` Zhang Rui

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