Commit 6a92c366 authored by Vincenzo Frascino's avatar Vincenzo Frascino Committed by Len Brown
Browse files

thermal: add support for thermal sensor present on SPEAr13xx machines 



ST's SPEAr13xx machines are based on CortexA9 ARM processors.  These
machines contain a thermal sensor for junction temperature monitoring.

This patch adds support for this thermal sensor in existing thermal
framework.

[akpm@linux-foundation.org: little code cleanup]
[akpm@linux-foundation.org: print the pointer correctly]
[viresh.kumar@st.com: thermal/spear_thermal: add compilation dependency on PLAT_SPEAR]
Signed-off-by: default avatarVincenzo Frascino <vincenzo.frascino@st.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@st.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent c5a01dd5

drivers/thermal/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -18,3 +18,11 @@ config THERMAL_HWMON 
	depends on THERMAL

	depends on HWMON=y || HWMON=THERMAL

	default y



config SPEAR_THERMAL

	bool "SPEAr thermal sensor driver"

	depends on THERMAL

	depends on PLAT_SPEAR

	help

	  Enable this to plug the SPEAr thermal sensor driver into the Linux

	  thermal framework

drivers/thermal/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -3,3 +3,4 @@ 
#



obj-$(CONFIG_THERMAL)		+= thermal_sys.o

obj-$(CONFIG_SPEAR_THERMAL)		+= spear_thermal.o
 
 No newline at end of file

drivers/thermal/spear_thermal.c

0 → 100644
+206 −0
Original line number Diff line number Diff line 
/*

 * SPEAr thermal driver.

 *

 * Copyright (C) 2011-2012 ST Microelectronics

 * Author: Vincenzo Frascino <vincenzo.frascino@st.com>

 *

 * 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.

 *

 */



#include <linux/clk.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/io.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/platform_data/spear_thermal.h>

#include <linux/thermal.h>



#define MD_FACTOR	1000



/* SPEAr Thermal Sensor Dev Structure */

struct spear_thermal_dev {

	/* pointer to base address of the thermal sensor */

	void __iomem *thermal_base;

	/* clk structure */

	struct clk *clk;

	/* pointer to thermal flags */

	unsigned int flags;

};



static inline int thermal_get_temp(struct thermal_zone_device *thermal,

				unsigned long *temp)

{

	struct spear_thermal_dev *stdev = thermal->devdata;



	/*

	 * Data are ready to be read after 628 usec from POWERDOWN signal

	 * (PDN) = 1

	 */

	*temp = (readl(stdev->thermal_base) & 0x7F) * MD_FACTOR;

	return 0;

}



static struct thermal_zone_device_ops ops = {

	.get_temp = thermal_get_temp,

};



#ifdef CONFIG_PM

static int spear_thermal_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);

	struct spear_thermal_dev *stdev = spear_thermal->devdata;

	unsigned int actual_mask = 0;



	/* Disable SPEAr Thermal Sensor */

	actual_mask = readl(stdev->thermal_base);

	writel(actual_mask & ~stdev->flags, stdev->thermal_base);



	clk_disable(stdev->clk);

	dev_info(dev, "Suspended.\n");



	return 0;

}



static int spear_thermal_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);

	struct spear_thermal_dev *stdev = spear_thermal->devdata;

	unsigned int actual_mask = 0;

	int ret = 0;



	ret = clk_enable(stdev->clk);

	if (ret) {

		dev_err(&pdev->dev, "Can't enable clock\n");

		return ret;

	}



	/* Enable SPEAr Thermal Sensor */

	actual_mask = readl(stdev->thermal_base);

	writel(actual_mask | stdev->flags, stdev->thermal_base);



	dev_info(dev, "Resumed.\n");



	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,

		spear_thermal_resume);



static int spear_thermal_probe(struct platform_device *pdev)

{

	struct thermal_zone_device *spear_thermal = NULL;

	struct spear_thermal_dev *stdev;

	struct spear_thermal_pdata *pdata;

	int ret = 0;

	struct resource *stres = platform_get_resource(pdev, IORESOURCE_MEM, 0);



	if (!stres) {

		dev_err(&pdev->dev, "memory resource missing\n");

		return -ENODEV;

	}



	pdata = dev_get_platdata(&pdev->dev);

	if (!pdata) {

		dev_err(&pdev->dev, "platform data is NULL\n");

		return -EINVAL;

	}



	stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);

	if (!stdev) {

		dev_err(&pdev->dev, "kzalloc fail\n");

		return -ENOMEM;

	}



	/* Enable thermal sensor */

	stdev->thermal_base = devm_ioremap(&pdev->dev, stres->start,

			resource_size(stres));

	if (!stdev->thermal_base) {

		dev_err(&pdev->dev, "ioremap failed\n");

		return -ENOMEM;

	}



	stdev->clk = clk_get(&pdev->dev, NULL);

	if (IS_ERR(stdev->clk)) {

		dev_err(&pdev->dev, "Can't get clock\n");

		return PTR_ERR(stdev->clk);

	}



	ret = clk_enable(stdev->clk);

	if (ret) {

		dev_err(&pdev->dev, "Can't enable clock\n");

		goto put_clk;

	}



	stdev->flags = pdata->thermal_flags;

	writel(stdev->flags, stdev->thermal_base);



	spear_thermal = thermal_zone_device_register("spear_thermal", 0,

				stdev, &ops, 0, 0, 0, 0);

	if (!spear_thermal) {

		dev_err(&pdev->dev, "thermal zone device is NULL\n");

		ret = -EINVAL;

		goto disable_clk;

	}



	platform_set_drvdata(pdev, spear_thermal);



	dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",

			stdev->thermal_base);



	return 0;



disable_clk:

	clk_disable(stdev->clk);

put_clk:

	clk_put(stdev->clk);



	return ret;

}



static int spear_thermal_exit(struct platform_device *pdev)

{

	unsigned int actual_mask = 0;

	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);

	struct spear_thermal_dev *stdev = spear_thermal->devdata;



	thermal_zone_device_unregister(spear_thermal);

	platform_set_drvdata(pdev, NULL);



	/* Disable SPEAr Thermal Sensor */

	actual_mask = readl(stdev->thermal_base);

	writel(actual_mask & ~stdev->flags, stdev->thermal_base);



	clk_disable(stdev->clk);

	clk_put(stdev->clk);



	return 0;

}



static struct platform_driver spear_thermal_driver = {

	.probe = spear_thermal_probe,

	.remove = spear_thermal_exit,

	.driver = {

		.name = "spear_thermal",

		.owner = THIS_MODULE,

		.pm = &spear_thermal_pm_ops,

	},

};



module_platform_driver(spear_thermal_driver);



MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");

MODULE_DESCRIPTION("SPEAr thermal driver");

MODULE_LICENSE("GPL");

include/linux/platform_data/spear_thermal.h

0 → 100644
+26 −0
Original line number Diff line number Diff line 
/*

 * SPEAr thermal driver platform data.

 *

 * Copyright (C) 2011-2012 ST Microelectronics

 * Author: Vincenzo Frascino <vincenzo.frascino@st.com>

 *

 * 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 SPEAR_THERMAL_H

#define SPEAR_THERMAL_H



/* SPEAr Thermal Sensor Platform Data */

struct spear_thermal_pdata {

	/* flags used to enable thermal sensor */

	unsigned int thermal_flags;

};



#endif /* SPEAR_THERMAL_H */

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