From 673c68bd48390dad01f7d17670de3e33b60860ac Mon Sep 17 00:00:00 2001 From: Biju Das Date: Tue, 30 Nov 2021 15:57:57 +0000 Subject: thermal/drivers: Add TSU driver for RZ/G2L MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The RZ/G2L SoC incorporates a thermal sensor unit (TSU) that measures the temperature inside the LSI. The thermal sensor in this unit measures temperatures in the range from −40 degree Celsius to 125 degree Celsius with an accuracy of ±3°C. The TSU repeats measurement at 20 microseconds intervals and automatically updates the results of measurement. The TSU has no interrupts as well as no external pins. This patch adds Thermal Sensor Unit(TSU) driver for RZ/G2L SoC. Signed-off-by: Biju Das Reviewed-by: Lad Prabhakar Link: https://lore.kernel.org/r/20211130155757.17837-3-biju.das.jz@bp.renesas.com Signed-off-by: Daniel Lezcano --- drivers/thermal/rzg2l_thermal.c | 240 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 drivers/thermal/rzg2l_thermal.c (limited to 'drivers/thermal/rzg2l_thermal.c') diff --git a/drivers/thermal/rzg2l_thermal.c b/drivers/thermal/rzg2l_thermal.c new file mode 100644 index 000000000000..d47d4a30cd6c --- /dev/null +++ b/drivers/thermal/rzg2l_thermal.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/G2L TSU Thermal Sensor Driver + * + * Copyright (C) 2021 Renesas Electronics Corporation + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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)) + +/* 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 /* Capture times */ + +#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(void *devdata, int *temp) +{ + struct rzg2l_thermal_priv *priv = 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 caliberation 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_of_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(&pdev->dev, NULL); + if (IS_ERR(priv->rstc)) + return dev_err_probe(dev, PTR_ERR(priv->rstc), + "failed to get cpg reset"); + + reset_control_deassert(priv->rstc); + + pm_runtime_enable(dev); + pm_runtime_get_sync(dev); + + priv->calib0 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)); + if (!priv->calib0) + priv->calib0 = SW_CALIB0_VAL; + + priv->calib1 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(1)); + if (!priv->calib1) + 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_zone_of_sensor_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 caliberation 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 "); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3