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/*
* 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 const 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 zx2967_thermal_priv *priv = dev_get_drvdata(dev);
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 zx2967_thermal_priv *priv = dev_get_drvdata(dev);
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");
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