--- /dev/null
+/*
+ * 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");
projects / platform / kernel / linux-starfive.git / commitdiff