1 files changed, 252 insertions, 0 deletions
diff --git a/drivers/thermal/rzg2l_thermal.c b/drivers/thermal/rzg2l_thermal.c
new file mode 100644
index 000000000..2e0649f38
--- /dev/null
+++ b/drivers/thermal/rzg2l_thermal.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L TSU Thermal Sensor Driver
+ *
+ * Copyright (C) 2021 Renesas Electronics Corporation
+ */
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/thermal.h>
+#include <linux/units.h>
+
+#include "thermal_hwmon.h"
+
+#define CTEMP_MASK	0xFFF
+
+/* default calibration values, if FUSE values are missing */
+#define SW_CALIB0_VAL	3148
+#define SW_CALIB1_VAL	503
+
+/* Register offsets */
+#define TSU_SM		0x00
+#define TSU_ST		0x04
+#define TSU_SAD		0x0C
+#define TSU_SS		0x10
+
+#define OTPTSUTRIM_REG(n)	(0x18 + ((n) * 0x4))
+#define OTPTSUTRIM_EN_MASK	BIT(31)
+#define OTPTSUTRIM_MASK		GENMASK(11, 0)
+
+/* Sensor Mode Register(TSU_SM) */
+#define TSU_SM_EN_TS		BIT(0)
+#define TSU_SM_ADC_EN_TS	BIT(1)
+#define TSU_SM_NORMAL_MODE	(TSU_SM_EN_TS | TSU_SM_ADC_EN_TS)
+
+/* TSU_ST bits */
+#define TSU_ST_START		BIT(0)
+
+#define TSU_SS_CONV_RUNNING	BIT(0)
+
+#define TS_CODE_AVE_SCALE(x)	((x) * 1000000)
+#define MCELSIUS(temp)		((temp) * MILLIDEGREE_PER_DEGREE)
+#define TS_CODE_CAP_TIMES	8	/* Total number of ADC data samples */
+
+#define RZG2L_THERMAL_GRAN	500	/* milli Celsius */
+#define RZG2L_TSU_SS_TIMEOUT_US	1000
+
+#define CURVATURE_CORRECTION_CONST	13
+
+struct rzg2l_thermal_priv {
+	struct device *dev;
+	void __iomem *base;
+	struct thermal_zone_device *zone;
+	struct reset_control *rstc;
+	u32 calib0, calib1;
+};
+
+static inline u32 rzg2l_thermal_read(struct rzg2l_thermal_priv *priv, u32 reg)
+{
+	return ioread32(priv->base + reg);
+}
+
+static inline void rzg2l_thermal_write(struct rzg2l_thermal_priv *priv, u32 reg,
+				       u32 data)
+{
+	iowrite32(data, priv->base + reg);
+}
+
+static int rzg2l_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct rzg2l_thermal_priv *priv = tz->devdata;
+	u32 result = 0, dsensor, ts_code_ave;
+	int val, i;
+
+	for (i = 0; i < TS_CODE_CAP_TIMES ; i++) {
+		/*
+		 * TSU repeats measurement at 20 microseconds intervals and
+		 * automatically updates the results of measurement. As per
+		 * the HW manual for measuring temperature we need to read 8
+		 * values consecutively and then take the average.
+		 * ts_code_ave = (ts_code[0] + ⋯ + ts_code[7]) / 8
+		 */
+		result += rzg2l_thermal_read(priv, TSU_SAD) & CTEMP_MASK;
+		usleep_range(20, 30);
+	}
+
+	ts_code_ave = result / TS_CODE_CAP_TIMES;
+
+	/*
+	 * Calculate actual sensor value by applying curvature correction formula
+	 * dsensor = ts_code_ave / (1 + ts_code_ave * 0.000013). Here we are doing
+	 * integer calculation by scaling all the values by 1000000.
+	 */
+	dsensor = TS_CODE_AVE_SCALE(ts_code_ave) /
+		(TS_CODE_AVE_SCALE(1) + (ts_code_ave * CURVATURE_CORRECTION_CONST));
+
+	/*
+	 * The temperature Tj is calculated by the formula
+	 * Tj = (dsensor − calib1) * 165/ (calib0 − calib1) − 40
+	 * where calib0 and calib1 are the calibration values.
+	 */
+	val = ((dsensor - priv->calib1) * (MCELSIUS(165) /
+		(priv->calib0 - priv->calib1))) - MCELSIUS(40);
+
+	*temp = roundup(val, RZG2L_THERMAL_GRAN);
+
+	return 0;
+}
+
+static const struct thermal_zone_device_ops rzg2l_tz_of_ops = {
+	.get_temp = rzg2l_thermal_get_temp,
+};
+
+static int rzg2l_thermal_init(struct rzg2l_thermal_priv *priv)
+{
+	u32 reg_val;
+
+	rzg2l_thermal_write(priv, TSU_SM, TSU_SM_NORMAL_MODE);
+	rzg2l_thermal_write(priv, TSU_ST, 0);
+
+	/*
+	 * Before setting the START bit, TSU should be in normal operating
+	 * mode. As per the HW manual, it will take 60 µs to place the TSU
+	 * into normal operating mode.
+	 */
+	usleep_range(60, 80);
+
+	reg_val = rzg2l_thermal_read(priv, TSU_ST);
+	reg_val |= TSU_ST_START;
+	rzg2l_thermal_write(priv, TSU_ST, reg_val);
+
+	return readl_poll_timeout(priv->base + TSU_SS, reg_val,
+				  reg_val == TSU_SS_CONV_RUNNING, 50,
+				  RZG2L_TSU_SS_TIMEOUT_US);
+}
+
+static void rzg2l_thermal_reset_assert_pm_disable_put(struct platform_device *pdev)
+{
+	struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	reset_control_assert(priv->rstc);
+}
+
+static int rzg2l_thermal_remove(struct platform_device *pdev)
+{
+	struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
+
+	thermal_remove_hwmon_sysfs(priv->zone);
+	rzg2l_thermal_reset_assert_pm_disable_put(pdev);
+
+	return 0;
+}
+
+static int rzg2l_thermal_probe(struct platform_device *pdev)
+{
+	struct thermal_zone_device *zone;
+	struct rzg2l_thermal_priv *priv;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	priv->dev = dev;
+	priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(priv->rstc))
+		return dev_err_probe(dev, PTR_ERR(priv->rstc),
+				     "failed to get cpg reset");
+
+	ret = reset_control_deassert(priv->rstc);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to deassert");
+
+	pm_runtime_enable(dev);
+	pm_runtime_get_sync(dev);
+
+	priv->calib0 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0));
+	if (priv->calib0 & OTPTSUTRIM_EN_MASK)
+		priv->calib0 &= OTPTSUTRIM_MASK;
+	else
+		priv->calib0 = SW_CALIB0_VAL;
+
+	priv->calib1 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(1));
+	if (priv->calib1 & OTPTSUTRIM_EN_MASK)
+		priv->calib1 &= OTPTSUTRIM_MASK;
+	else
+		priv->calib1 = SW_CALIB1_VAL;
+
+	platform_set_drvdata(pdev, priv);
+	ret = rzg2l_thermal_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to start TSU");
+		goto err;
+	}
+
+	zone = devm_thermal_of_zone_register(dev, 0, priv,
+					     &rzg2l_tz_of_ops);
+	if (IS_ERR(zone)) {
+		dev_err(dev, "Can't register thermal zone");
+		ret = PTR_ERR(zone);
+		goto err;
+	}
+
+	priv->zone = zone;
+	priv->zone->tzp->no_hwmon = false;
+	ret = thermal_add_hwmon_sysfs(priv->zone);
+	if (ret)
+		goto err;
+
+	dev_dbg(dev, "TSU probed with %s calibration values",
+		rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)) ?  "hw" : "sw");
+
+	return 0;
+
+err:
+	rzg2l_thermal_reset_assert_pm_disable_put(pdev);
+	return ret;
+}
+
+static const struct of_device_id rzg2l_thermal_dt_ids[] = {
+	{ .compatible = "renesas,rzg2l-tsu", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzg2l_thermal_dt_ids);
+
+static struct platform_driver rzg2l_thermal_driver = {
+	.driver = {
+		.name = "rzg2l_thermal",
+		.of_match_table = rzg2l_thermal_dt_ids,
+	},
+	.probe = rzg2l_thermal_probe,
+	.remove = rzg2l_thermal_remove,
+};
+module_platform_driver(rzg2l_thermal_driver);
+
+MODULE_DESCRIPTION("Renesas RZ/G2L TSU Thermal Sensor Driver");
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_LICENSE("GPL v2");