Commit 50fdd36f authored by Baoyou Xie's avatar Baoyou Xie Committed by Eduardo Valentin
Browse files

thermal: zx2967: add thermal driver for ZTE's zx2967 family 



This patch adds thermal driver for ZTE's zx2967 family.

Signed-off-by: default avatarBaoyou Xie <baoyou.xie@linaro.org>
Reviewed-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: default avatarEduardo Valentin <edubezval@gmail.com>
parent e0fa5648

drivers/thermal/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -445,4 +445,12 @@ depends on (ARCH_QCOM && OF) || COMPILE_TEST 
source "drivers/thermal/qcom/Kconfig"

endmenu



config ZX2967_THERMAL

	tristate "Thermal sensors on zx2967 SoC"

	depends on ARCH_ZX || COMPILE_TEST

	help

	  Enable the zx2967 thermal sensors driver, which supports

	  the primitive temperature sensor embedded in zx2967 SoCs.

	  This sensor generates the real time die temperature.



endif

drivers/thermal/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -57,3 +57,4 @@ obj-$(CONFIG_TEGRA_SOCTHERM) += tegra/ 
obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o

obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o

obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o

obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o

drivers/thermal/zx2967_thermal.c

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+258 −0
Original line number Diff line number Diff line 
/*

 * ZTE's zx2967 family thermal sensor driver

 *

 * Copyright (C) 2017 ZTE Ltd.

 *

 * Author: Baoyou Xie <baoyou.xie@linaro.org>

 *

 * License terms: GNU General Public License (GPL) version 2

 */



#include <linux/clk.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/iopoll.h>

#include <linux/module.h>

#include <linux/platform_device.h>

#include <linux/thermal.h>



/* Power Mode: 0->low 1->high */

#define ZX2967_THERMAL_POWER_MODE	0

#define ZX2967_POWER_MODE_LOW		0

#define ZX2967_POWER_MODE_HIGH		1



/* DCF Control Register */

#define ZX2967_THERMAL_DCF		0x4

#define ZX2967_DCF_EN			BIT(1)

#define ZX2967_DCF_FREEZE		BIT(0)



/* Selection Register */

#define ZX2967_THERMAL_SEL		0x8



/* Control Register */

#define ZX2967_THERMAL_CTRL		0x10



#define ZX2967_THERMAL_READY		BIT(12)

#define ZX2967_THERMAL_TEMP_MASK	GENMASK(11, 0)

#define ZX2967_THERMAL_ID_MASK		0x18

#define ZX2967_THERMAL_ID		0x10



#define ZX2967_GET_TEMP_TIMEOUT_US	(100 * 1024)



/**

 * struct zx2967_thermal_priv - zx2967 thermal sensor private structure

 * @tzd: struct thermal_zone_device where the sensor is registered

 * @lock: prevents read sensor in parallel

 * @clk_topcrm: topcrm clk structure

 * @clk_apb: apb clk structure

 * @regs: pointer to base address of the thermal sensor

 */



struct zx2967_thermal_priv {

	struct thermal_zone_device	*tzd;

	struct mutex			lock;

	struct clk			*clk_topcrm;

	struct clk			*clk_apb;

	void __iomem			*regs;

	struct device			*dev;

};



static int zx2967_thermal_get_temp(void *data, int *temp)

{

	void __iomem *regs;

	struct zx2967_thermal_priv *priv = data;

	u32 val;

	int ret;



	if (!priv->tzd)

		return -EAGAIN;



	regs = priv->regs;

	mutex_lock(&priv->lock);

	writel_relaxed(ZX2967_POWER_MODE_LOW,

		       regs + ZX2967_THERMAL_POWER_MODE);

	writel_relaxed(ZX2967_DCF_EN, regs + ZX2967_THERMAL_DCF);



	val = readl_relaxed(regs + ZX2967_THERMAL_SEL);

	val &= ~ZX2967_THERMAL_ID_MASK;

	val |= ZX2967_THERMAL_ID;

	writel_relaxed(val, regs + ZX2967_THERMAL_SEL);



	/*

	 * Must wait for a while, surely it's a bit odd.

	 * otherwise temperature value we got has a few deviation, even if

	 * the THERMAL_READY bit is set.

	 */

	usleep_range(100, 300);

	ret = readx_poll_timeout(readl, regs + ZX2967_THERMAL_CTRL,

				 val, val & ZX2967_THERMAL_READY, 300,

				 ZX2967_GET_TEMP_TIMEOUT_US);

	if (ret) {

		dev_err(priv->dev, "Thermal sensor data timeout\n");

		goto unlock;

	}



	writel_relaxed(ZX2967_DCF_FREEZE | ZX2967_DCF_EN,

		       regs + ZX2967_THERMAL_DCF);

	val = readl_relaxed(regs + ZX2967_THERMAL_CTRL)

			 & ZX2967_THERMAL_TEMP_MASK;

	writel_relaxed(ZX2967_POWER_MODE_HIGH,

		       regs + ZX2967_THERMAL_POWER_MODE);



	/*

	 * Calculate temperature

	 * In dts, slope is multiplied by 1000.

	 */

	*temp = DIV_ROUND_CLOSEST(((s32)val + priv->tzd->tzp->offset) * 1000,

				  priv->tzd->tzp->slope);



unlock:

	mutex_unlock(&priv->lock);

	return ret;

}



static struct thermal_zone_of_device_ops zx2967_of_thermal_ops = {

	.get_temp = zx2967_thermal_get_temp,

};



static int zx2967_thermal_probe(struct platform_device *pdev)

{

	struct zx2967_thermal_priv *priv;

	struct resource *res;

	int ret;



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

	if (!priv)

		return -ENOMEM;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	priv->regs = devm_ioremap_resource(&pdev->dev, res);

	if (IS_ERR(priv->regs))

		return PTR_ERR(priv->regs);



	priv->clk_topcrm = devm_clk_get(&pdev->dev, "topcrm");

	if (IS_ERR(priv->clk_topcrm)) {

		ret = PTR_ERR(priv->clk_topcrm);

		dev_err(&pdev->dev, "failed to get topcrm clock: %d\n", ret);

		return ret;

	}



	ret = clk_prepare_enable(priv->clk_topcrm);

	if (ret) {

		dev_err(&pdev->dev, "failed to enable topcrm clock: %d\n",

			ret);

		return ret;

	}



	priv->clk_apb = devm_clk_get(&pdev->dev, "apb");

	if (IS_ERR(priv->clk_apb)) {

		ret = PTR_ERR(priv->clk_apb);

		dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret);

		goto disable_clk_topcrm;

	}



	ret = clk_prepare_enable(priv->clk_apb);

	if (ret) {

		dev_err(&pdev->dev, "failed to enable apb clock: %d\n",

			ret);

		goto disable_clk_topcrm;

	}



	mutex_init(&priv->lock);

	priv->tzd = thermal_zone_of_sensor_register(&pdev->dev,

					0, priv, &zx2967_of_thermal_ops);



	if (IS_ERR(priv->tzd)) {

		ret = PTR_ERR(priv->tzd);

		dev_err(&pdev->dev, "failed to register sensor: %d\n", ret);

		goto disable_clk_all;

	}



	if (priv->tzd->tzp->slope == 0) {

		thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd);

		dev_err(&pdev->dev, "coefficients of sensor is invalid\n");

		ret = -EINVAL;

		goto disable_clk_all;

	}



	priv->dev = &pdev->dev;

	platform_set_drvdata(pdev, priv);



	return 0;



disable_clk_all:

	clk_disable_unprepare(priv->clk_apb);

disable_clk_topcrm:

	clk_disable_unprepare(priv->clk_topcrm);

	return ret;

}



static int zx2967_thermal_exit(struct platform_device *pdev)

{

	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);



	thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd);

	clk_disable_unprepare(priv->clk_topcrm);

	clk_disable_unprepare(priv->clk_apb);



	return 0;

}



static const struct of_device_id zx2967_thermal_id_table[] = {

	{ .compatible = "zte,zx296718-thermal" },

	{}

};

MODULE_DEVICE_TABLE(of, zx2967_thermal_id_table);



#ifdef CONFIG_PM_SLEEP

static int zx2967_thermal_suspend(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);



	if (priv && priv->clk_topcrm)

		clk_disable_unprepare(priv->clk_topcrm);



	if (priv && priv->clk_apb)

		clk_disable_unprepare(priv->clk_apb);



	return 0;

}



static int zx2967_thermal_resume(struct device *dev)

{

	struct platform_device *pdev = to_platform_device(dev);

	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);

	int error;



	error = clk_prepare_enable(priv->clk_topcrm);

	if (error)

		return error;



	error = clk_prepare_enable(priv->clk_apb);

	if (error) {

		clk_disable_unprepare(priv->clk_topcrm);

		return error;

	}



	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops,

			 zx2967_thermal_suspend, zx2967_thermal_resume);



static struct platform_driver zx2967_thermal_driver = {

	.probe = zx2967_thermal_probe,

	.remove = zx2967_thermal_exit,

	.driver = {

		.name = "zx2967_thermal",

		.of_match_table = zx2967_thermal_id_table,

		.pm = &zx2967_thermal_pm_ops,

	},

};

module_platform_driver(zx2967_thermal_driver);



MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");

MODULE_DESCRIPTION("ZTE zx2967 thermal driver");

MODULE_LICENSE("GPL v2");