// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) STMicroelectronics 2018 - All Rights Reserved * Author: David Hernandez Sanchez for * STMicroelectronics. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "../thermal_core.h" #include "../thermal_hwmon.h" /* DTS register offsets */ #define DTS_CFGR1_OFFSET 0x0 #define DTS_T0VALR1_OFFSET 0x8 #define DTS_RAMPVALR_OFFSET 0X10 #define DTS_ITR1_OFFSET 0x14 #define DTS_DR_OFFSET 0x1C #define DTS_SR_OFFSET 0x20 #define DTS_ITENR_OFFSET 0x24 #define DTS_CIFR_OFFSET 0x28 /* DTS_CFGR1 register mask definitions */ #define HSREF_CLK_DIV_MASK GENMASK(30, 24) #define TS1_SMP_TIME_MASK GENMASK(19, 16) #define TS1_INTRIG_SEL_MASK GENMASK(11, 8) /* DTS_T0VALR1 register mask definitions */ #define TS1_T0_MASK GENMASK(17, 16) #define TS1_FMT0_MASK GENMASK(15, 0) /* DTS_RAMPVALR register mask definitions */ #define TS1_RAMP_COEFF_MASK GENMASK(15, 0) /* DTS_ITR1 register mask definitions */ #define TS1_HITTHD_MASK GENMASK(31, 16) #define TS1_LITTHD_MASK GENMASK(15, 0) /* DTS_DR register mask definitions */ #define TS1_MFREQ_MASK GENMASK(15, 0) /* Less significant bit position definitions */ #define TS1_T0_POS 16 #define TS1_SMP_TIME_POS 16 #define TS1_HITTHD_POS 16 #define HSREF_CLK_DIV_POS 24 /* DTS_CFGR1 bit definitions */ #define TS1_EN BIT(0) #define TS1_START BIT(4) #define REFCLK_SEL BIT(20) #define REFCLK_LSE REFCLK_SEL #define Q_MEAS_OPT BIT(21) #define CALIBRATION_CONTROL Q_MEAS_OPT /* DTS_SR bit definitions */ #define TS_RDY BIT(15) /* Bit definitions below are common for DTS_SR, DTS_ITENR and DTS_CIFR */ #define HIGH_THRESHOLD BIT(2) #define LOW_THRESHOLD BIT(1) /* Constants */ #define ADJUST 100 #define ONE_MHZ 1000000 #define POLL_TIMEOUT 5000 #define STARTUP_TIME 40 #define TS1_T0_VAL0 30 #define TS1_T0_VAL1 130 #define NO_HW_TRIG 0 /* The Thermal Framework expects millidegrees */ #define mcelsius(temp) ((temp) * 1000) /* The Sensor expects oC degrees */ #define celsius(temp) ((temp) / 1000) struct stm_thermal_sensor { struct device *dev; struct thermal_zone_device *th_dev; enum thermal_device_mode mode; struct clk *clk; int high_temp; int low_temp; int temp_critical; int temp_passive; unsigned int low_temp_enabled; int num_trips; int irq; unsigned int irq_enabled; void __iomem *base; int t0, fmt0, ramp_coeff; }; static irqreturn_t stm_thermal_alarm_irq(int irq, void *sdata) { struct stm_thermal_sensor *sensor = sdata; disable_irq_nosync(irq); sensor->irq_enabled = false; return IRQ_WAKE_THREAD; } static irqreturn_t stm_thermal_alarm_irq_thread(int irq, void *sdata) { u32 value; struct stm_thermal_sensor *sensor = sdata; /* read IT reason in SR and clear flags */ value = readl_relaxed(sensor->base + DTS_SR_OFFSET); if ((value & LOW_THRESHOLD) == LOW_THRESHOLD) writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET); if ((value & HIGH_THRESHOLD) == HIGH_THRESHOLD) writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET); thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED); return IRQ_HANDLED; } static int stm_sensor_power_on(struct stm_thermal_sensor *sensor) { int ret; u32 value; /* Enable sensor */ value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); value |= TS1_EN; writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); /* * The DTS block can be enabled by setting TSx_EN bit in * DTS_CFGRx register. It requires a startup time of * 40μs. Use 5 ms as arbitrary timeout. */ ret = readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value, (value & TS_RDY), STARTUP_TIME, POLL_TIMEOUT); if (ret) return ret; /* Start continuous measuring */ value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); value |= TS1_START; writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); return 0; } static int stm_sensor_power_off(struct stm_thermal_sensor *sensor) { u32 value; /* Stop measuring */ value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); value &= ~TS1_START; writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); /* Ensure stop is taken into account */ usleep_range(STARTUP_TIME, POLL_TIMEOUT); /* Disable sensor */ value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); value &= ~TS1_EN; writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); /* Ensure disable is taken into account */ return readl_poll_timeout(sensor->base + DTS_SR_OFFSET, value, !(value & TS_RDY), STARTUP_TIME, POLL_TIMEOUT); } static int stm_thermal_calibration(struct stm_thermal_sensor *sensor) { u32 value, clk_freq; u32 prescaler; /* Figure out prescaler value for PCLK during calibration */ clk_freq = clk_get_rate(sensor->clk); if (!clk_freq) return -EINVAL; prescaler = 0; clk_freq /= ONE_MHZ; if (clk_freq) { while (prescaler <= clk_freq) prescaler++; } value = readl_relaxed(sensor->base + DTS_CFGR1_OFFSET); /* Clear prescaler */ value &= ~HSREF_CLK_DIV_MASK; /* Set prescaler. pclk_freq/prescaler < 1MHz */ value |= (prescaler << HSREF_CLK_DIV_POS); /* Select PCLK as reference clock */ value &= ~REFCLK_SEL; /* Set maximal sampling time for better precision */ value |= TS1_SMP_TIME_MASK; /* Measure with calibration */ value &= ~CALIBRATION_CONTROL; /* select trigger */ value &= ~TS1_INTRIG_SEL_MASK; value |= NO_HW_TRIG; writel_relaxed(value, sensor->base + DTS_CFGR1_OFFSET); return 0; } /* Fill in DTS structure with factory sensor values */ static int stm_thermal_read_factory_settings(struct stm_thermal_sensor *sensor) { /* Retrieve engineering calibration temperature */ sensor->t0 = readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) & TS1_T0_MASK; if (!sensor->t0) sensor->t0 = TS1_T0_VAL0; else sensor->t0 = TS1_T0_VAL1; /* Retrieve fmt0 and put it on Hz */ sensor->fmt0 = ADJUST * (readl_relaxed(sensor->base + DTS_T0VALR1_OFFSET) & TS1_FMT0_MASK); /* Retrieve ramp coefficient */ sensor->ramp_coeff = readl_relaxed(sensor->base + DTS_RAMPVALR_OFFSET) & TS1_RAMP_COEFF_MASK; if (!sensor->fmt0 || !sensor->ramp_coeff) { dev_err(sensor->dev, "%s: wrong setting\n", __func__); return -EINVAL; } dev_dbg(sensor->dev, "%s: T0 = %doC, FMT0 = %dHz, RAMP_COEFF = %dHz/oC", __func__, sensor->t0, sensor->fmt0, sensor->ramp_coeff); return 0; } static int stm_thermal_calculate_threshold(struct stm_thermal_sensor *sensor, int temp, u32 *th) { int freqM; u32 sampling_time; /* Retrieve the number of periods to sample */ sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) & TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS; /* Figure out the CLK_PTAT frequency for a given temperature */ freqM = ((temp - sensor->t0) * sensor->ramp_coeff) + sensor->fmt0; dev_dbg(sensor->dev, "%s: freqM for threshold = %d Hz", __func__, freqM); /* Figure out the threshold sample number */ *th = clk_get_rate(sensor->clk); if (!*th) return -EINVAL; *th = *th / freqM; *th *= sampling_time; return 0; } static int stm_thermal_set_threshold(struct stm_thermal_sensor *sensor) { u32 value, th; int ret; value = readl_relaxed(sensor->base + DTS_ITR1_OFFSET); /* Erase threshold content */ value &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK); /* Retrieve the sample threshold number th for a given temperature */ ret = stm_thermal_calculate_threshold(sensor, sensor->high_temp, &th); if (ret) return ret; value |= th & TS1_LITTHD_MASK; if (sensor->low_temp_enabled) { /* Retrieve the sample threshold */ ret = stm_thermal_calculate_threshold(sensor, sensor->low_temp, &th); if (ret) return ret; value |= (TS1_HITTHD_MASK & (th << TS1_HITTHD_POS)); } /* Write value on the Low interrupt threshold */ writel_relaxed(value, sensor->base + DTS_ITR1_OFFSET); return 0; } /* Disable temperature interrupt */ static int stm_disable_irq(struct stm_thermal_sensor *sensor) { u32 value; /* Disable IT generation for low and high thresholds */ value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); writel_relaxed(value & ~(LOW_THRESHOLD | HIGH_THRESHOLD), sensor->base + DTS_ITENR_OFFSET); dev_dbg(sensor->dev, "%s: IT disabled on sensor side", __func__); return 0; } /* Enable temperature interrupt */ static int stm_enable_irq(struct stm_thermal_sensor *sensor) { u32 value; /* * Code below enables High temperature threshold using a low threshold * sampling value */ /* Make sure LOW_THRESHOLD IT is clear before enabling */ writel_relaxed(LOW_THRESHOLD, sensor->base + DTS_CIFR_OFFSET); /* Enable IT generation for low threshold */ value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); value |= LOW_THRESHOLD; /* Enable the low temperature threshold if needed */ if (sensor->low_temp_enabled) { /* Make sure HIGH_THRESHOLD IT is clear before enabling */ writel_relaxed(HIGH_THRESHOLD, sensor->base + DTS_CIFR_OFFSET); /* Enable IT generation for high threshold */ value |= HIGH_THRESHOLD; } /* Enable thresholds */ writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET); dev_dbg(sensor->dev, "%s: IT enabled on sensor side", __func__); return 0; } static int stm_thermal_update_threshold(struct stm_thermal_sensor *sensor) { int ret; sensor->mode = THERMAL_DEVICE_DISABLED; ret = stm_sensor_power_off(sensor); if (ret) return ret; ret = stm_disable_irq(sensor); if (ret) return ret; ret = stm_thermal_set_threshold(sensor); if (ret) return ret; ret = stm_enable_irq(sensor); if (ret) return ret; ret = stm_sensor_power_on(sensor); if (ret) return ret; sensor->mode = THERMAL_DEVICE_ENABLED; return 0; } /* Callback to get temperature from HW */ static int stm_thermal_get_temp(void *data, int *temp) { struct stm_thermal_sensor *sensor = data; u32 sampling_time; int freqM, ret; if (sensor->mode != THERMAL_DEVICE_ENABLED) return -EAGAIN; /* Retrieve the number of samples */ ret = readl_poll_timeout(sensor->base + DTS_DR_OFFSET, freqM, (freqM & TS1_MFREQ_MASK), STARTUP_TIME, POLL_TIMEOUT); if (ret) return ret; if (!freqM) return -ENODATA; /* Retrieve the number of periods sampled */ sampling_time = (readl_relaxed(sensor->base + DTS_CFGR1_OFFSET) & TS1_SMP_TIME_MASK) >> TS1_SMP_TIME_POS; /* Figure out the number of samples per period */ freqM /= sampling_time; /* Figure out the CLK_PTAT frequency */ freqM = clk_get_rate(sensor->clk) / freqM; if (!freqM) return -EINVAL; dev_dbg(sensor->dev, "%s: freqM=%d\n", __func__, freqM); /* Figure out the temperature in mili celsius */ *temp = mcelsius(sensor->t0 + ((freqM - sensor->fmt0) / sensor->ramp_coeff)); dev_dbg(sensor->dev, "%s: temperature = %d millicelsius", __func__, *temp); /* Update thresholds */ if (sensor->num_trips > 1) { /* Update alarm threshold value to next higher trip point */ if (sensor->high_temp == sensor->temp_passive && celsius(*temp) >= sensor->temp_passive) { sensor->high_temp = sensor->temp_critical; sensor->low_temp = sensor->temp_passive; sensor->low_temp_enabled = true; ret = stm_thermal_update_threshold(sensor); if (ret) return ret; } if (sensor->high_temp == sensor->temp_critical && celsius(*temp) < sensor->temp_passive) { sensor->high_temp = sensor->temp_passive; sensor->low_temp_enabled = false; ret = stm_thermal_update_threshold(sensor); if (ret) return ret; } /* * Re-enable alarm IRQ if temperature below critical * temperature */ if (!sensor->irq_enabled && (celsius(*temp) < sensor->temp_critical)) { sensor->irq_enabled = true; enable_irq(sensor->irq); } } return 0; } /* Registers DTS irq to be visible by GIC */ static int stm_register_irq(struct stm_thermal_sensor *sensor) { struct device *dev = sensor->dev; struct platform_device *pdev = to_platform_device(dev); int ret; sensor->irq = platform_get_irq(pdev, 0); if (sensor->irq < 0) { dev_err(dev, "%s: Unable to find IRQ\n", __func__); return sensor->irq; } ret = devm_request_threaded_irq(dev, sensor->irq, stm_thermal_alarm_irq, stm_thermal_alarm_irq_thread, IRQF_ONESHOT, dev->driver->name, sensor); if (ret) { dev_err(dev, "%s: Failed to register IRQ %d\n", __func__, sensor->irq); return ret; } sensor->irq_enabled = true; dev_dbg(dev, "%s: thermal IRQ registered", __func__); return 0; } static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor) { int ret; ret = stm_sensor_power_off(sensor); if (ret) return ret; clk_disable_unprepare(sensor->clk); return 0; } static int stm_thermal_prepare(struct stm_thermal_sensor *sensor) { int ret; struct device *dev = sensor->dev; ret = clk_prepare_enable(sensor->clk); if (ret) return ret; ret = stm_thermal_read_factory_settings(sensor); if (ret) goto thermal_unprepare; ret = stm_thermal_calibration(sensor); if (ret) goto thermal_unprepare; /* Set threshold(s) for IRQ */ ret = stm_thermal_set_threshold(sensor); if (ret) goto thermal_unprepare; ret = stm_enable_irq(sensor); if (ret) goto thermal_unprepare; ret = stm_sensor_power_on(sensor); if (ret) { dev_err(dev, "%s: failed to power on sensor\n", __func__); goto irq_disable; } return 0; irq_disable: stm_disable_irq(sensor); thermal_unprepare: clk_disable_unprepare(sensor->clk); return ret; } #ifdef CONFIG_PM_SLEEP static int stm_thermal_suspend(struct device *dev) { int ret; struct stm_thermal_sensor *sensor = dev_get_drvdata(dev); ret = stm_thermal_sensor_off(sensor); if (ret) return ret; sensor->mode = THERMAL_DEVICE_DISABLED; return 0; } static int stm_thermal_resume(struct device *dev) { int ret; struct stm_thermal_sensor *sensor = dev_get_drvdata(dev); ret = stm_thermal_prepare(sensor); if (ret) return ret; sensor->mode = THERMAL_DEVICE_ENABLED; return 0; } #endif /* CONFIG_PM_SLEEP */ SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, stm_thermal_suspend, stm_thermal_resume); static const struct thermal_zone_of_device_ops stm_tz_ops = { .get_temp = stm_thermal_get_temp, }; static const struct of_device_id stm_thermal_of_match[] = { { .compatible = "st,stm32-thermal"}, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, stm_thermal_of_match); static int stm_thermal_probe(struct platform_device *pdev) { struct stm_thermal_sensor *sensor; struct resource *res; const struct thermal_trip *trip; void __iomem *base; int ret, i; if (!pdev->dev.of_node) { dev_err(&pdev->dev, "%s: device tree node not found\n", __func__); return -EINVAL; } sensor = devm_kzalloc(&pdev->dev, sizeof(*sensor), GFP_KERNEL); if (!sensor) return -ENOMEM; platform_set_drvdata(pdev, sensor); sensor->dev = &pdev->dev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(base)) return PTR_ERR(base); /* Populate sensor */ sensor->base = base; sensor->clk = devm_clk_get(&pdev->dev, "pclk"); if (IS_ERR(sensor->clk)) { dev_err(&pdev->dev, "%s: failed to fetch PCLK clock\n", __func__); return PTR_ERR(sensor->clk); } /* Register IRQ into GIC */ ret = stm_register_irq(sensor); if (ret) return ret; sensor->th_dev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, sensor, &stm_tz_ops); if (IS_ERR(sensor->th_dev)) { dev_err(&pdev->dev, "%s: thermal zone sensor registering KO\n", __func__); ret = PTR_ERR(sensor->th_dev); return ret; } if (!sensor->th_dev->ops->get_crit_temp) { /* Critical point must be provided */ ret = -EINVAL; goto err_tz; } ret = sensor->th_dev->ops->get_crit_temp(sensor->th_dev, &sensor->temp_critical); if (ret) { dev_err(&pdev->dev, "Not able to read critical_temp: %d\n", ret); goto err_tz; } sensor->temp_critical = celsius(sensor->temp_critical); /* Set thresholds for IRQ */ sensor->high_temp = sensor->temp_critical; trip = of_thermal_get_trip_points(sensor->th_dev); sensor->num_trips = of_thermal_get_ntrips(sensor->th_dev); /* Find out passive temperature if it exists */ for (i = (sensor->num_trips - 1); i >= 0; i--) { if (trip[i].type == THERMAL_TRIP_PASSIVE) { sensor->temp_passive = celsius(trip[i].temperature); /* Update high temperature threshold */ sensor->high_temp = sensor->temp_passive; } } /* * Ensure low_temp_enabled flag is disabled. * By disabling low_temp_enabled, low threshold IT will not be * configured neither enabled because it is not needed as high * threshold is set on the lowest temperature trip point after * probe. */ sensor->low_temp_enabled = false; /* Configure and enable HW sensor */ ret = stm_thermal_prepare(sensor); if (ret) { dev_err(&pdev->dev, "Not able to enable sensor: %d\n", ret); goto err_tz; } /* * Thermal_zone doesn't enable hwmon as default, * enable it here */ sensor->th_dev->tzp->no_hwmon = false; ret = thermal_add_hwmon_sysfs(sensor->th_dev); if (ret) goto err_tz; sensor->mode = THERMAL_DEVICE_ENABLED; dev_info(&pdev->dev, "%s: Driver initialized successfully\n", __func__); return 0; err_tz: thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev); return ret; } static int stm_thermal_remove(struct platform_device *pdev) { struct stm_thermal_sensor *sensor = platform_get_drvdata(pdev); stm_thermal_sensor_off(sensor); thermal_remove_hwmon_sysfs(sensor->th_dev); thermal_zone_of_sensor_unregister(&pdev->dev, sensor->th_dev); return 0; } static struct platform_driver stm_thermal_driver = { .driver = { .name = "stm_thermal", .pm = &stm_thermal_pm_ops, .of_match_table = stm_thermal_of_match, }, .probe = stm_thermal_probe, .remove = stm_thermal_remove, }; module_platform_driver(stm_thermal_driver); MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver"); MODULE_AUTHOR("David Hernandez Sanchez "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:stm_thermal");