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path: root/drivers/thermal/rzg2l_thermal.c
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Diffstat (limited to 'drivers/thermal/rzg2l_thermal.c')
-rw-r--r--drivers/thermal/rzg2l_thermal.c252
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");