diff options
Diffstat (limited to 'drivers/thermal/rzg2l_thermal.c')
| -rw-r--r-- | drivers/thermal/rzg2l_thermal.c | 252 |
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"); |