// 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 "../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_ICIFR_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) /* DTS_ITENR register mask definitions */ #define ITENR_MASK (GENMASK(2, 0) | GENMASK(6, 4)) /* DTS_ICIFR register mask definitions */ #define ICIFR_MASK (GENMASK(2, 0) | GENMASK(6, 4)) /* Less significant bit position definitions */ #define TS1_T0_POS 16 #define TS1_HITTHD_POS 16 #define TS1_LITTHD_POS 0 #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 30000 /* 30 celsius */ #define TS1_T0_VAL1 130000 /* 130 celsius */ #define NO_HW_TRIG 0 #define SAMPLING_TIME 15 struct stm_thermal_sensor { struct device *dev; struct thermal_zone_device *th_dev; enum thermal_device_mode mode; struct clk *clk; unsigned int low_temp_enabled; unsigned int high_temp_enabled; int irq; void __iomem *base; int t0, fmt0, ramp_coeff; }; static int stm_enable_irq(struct stm_thermal_sensor *sensor) { u32 value; dev_dbg(sensor->dev, "low:%d high:%d\n", sensor->low_temp_enabled, sensor->high_temp_enabled); /* Disable IT generation for low and high thresholds */ value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); value &= ~(LOW_THRESHOLD | HIGH_THRESHOLD); if (sensor->low_temp_enabled) value |= HIGH_THRESHOLD; if (sensor->high_temp_enabled) value |= LOW_THRESHOLD; /* Enable interrupts */ writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET); return 0; } static irqreturn_t stm_thermal_irq_handler(int irq, void *sdata) { struct stm_thermal_sensor *sensor = sdata; dev_dbg(sensor->dev, "sr:%d\n", readl_relaxed(sensor->base + DTS_SR_OFFSET)); thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED); stm_enable_irq(sensor); /* Acknoledge all DTS irqs */ writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET); 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); sensor->mode = THERMAL_DEVICE_ENABLED; return 0; } static int stm_sensor_power_off(struct stm_thermal_sensor *sensor) { u32 value; sensor->mode = THERMAL_DEVICE_DISABLED; /* 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; /* Figure out the CLK_PTAT frequency for a given temperature */ freqM = ((temp - sensor->t0) * sensor->ramp_coeff) / 1000 + sensor->fmt0; /* Figure out the threshold sample number */ *th = clk_get_rate(sensor->clk) * SAMPLING_TIME / freqM; if (!*th) return -EINVAL; dev_dbg(sensor->dev, "freqM=%d Hz, threshold=0x%x", freqM, *th); return 0; } /* Disable temperature interrupt */ static int stm_disable_irq(struct stm_thermal_sensor *sensor) { u32 value; /* Disable IT generation */ value = readl_relaxed(sensor->base + DTS_ITENR_OFFSET); value &= ~ITENR_MASK; writel_relaxed(value, sensor->base + DTS_ITENR_OFFSET); return 0; } static int stm_thermal_set_trips(struct thermal_zone_device *tz, int low, int high) { struct stm_thermal_sensor *sensor = thermal_zone_device_priv(tz); u32 itr1, th; int ret; dev_dbg(sensor->dev, "set trips %d <--> %d\n", low, high); /* Erase threshold content */ itr1 = readl_relaxed(sensor->base + DTS_ITR1_OFFSET); itr1 &= ~(TS1_LITTHD_MASK | TS1_HITTHD_MASK); /* * Disable low-temp if "low" is too small. As per thermal framework * API, we use -INT_MAX rather than INT_MIN. */ if (low > -INT_MAX) { sensor->low_temp_enabled = 1; /* add 0.5 of hysteresis due to measurement error */ ret = stm_thermal_calculate_threshold(sensor, low - 500, &th); if (ret) return ret; itr1 |= (TS1_HITTHD_MASK & (th << TS1_HITTHD_POS)); } else { sensor->low_temp_enabled = 0; } /* Disable high-temp if "high" is too big. */ if (high < INT_MAX) { sensor->high_temp_enabled = 1; ret = stm_thermal_calculate_threshold(sensor, high, &th); if (ret) return ret; itr1 |= (TS1_LITTHD_MASK & (th << TS1_LITTHD_POS)); } else { sensor->high_temp_enabled = 0; } /* Write new threshod values*/ writel_relaxed(itr1, sensor->base + DTS_ITR1_OFFSET); return 0; } /* Callback to get temperature from HW */ static int stm_thermal_get_temp(struct thermal_zone_device *tz, int *temp) { struct stm_thermal_sensor *sensor = thermal_zone_device_priv(tz); u32 periods; int freqM, ret; if (sensor->mode != THERMAL_DEVICE_ENABLED) return -EAGAIN; /* Retrieve the number of periods sampled */ ret = readl_relaxed_poll_timeout(sensor->base + DTS_DR_OFFSET, periods, (periods & TS1_MFREQ_MASK), STARTUP_TIME, POLL_TIMEOUT); if (ret) return ret; /* Figure out the CLK_PTAT frequency */ freqM = (clk_get_rate(sensor->clk) * SAMPLING_TIME) / periods; if (!freqM) return -EINVAL; /* Figure out the temperature in mili celsius */ *temp = (freqM - sensor->fmt0) * 1000 / sensor->ramp_coeff + sensor->t0; 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) return sensor->irq; ret = devm_request_threaded_irq(dev, sensor->irq, NULL, stm_thermal_irq_handler, IRQF_ONESHOT, dev->driver->name, sensor); if (ret) { dev_err(dev, "%s: Failed to register IRQ %d\n", __func__, sensor->irq); return ret; } dev_dbg(dev, "%s: thermal IRQ registered", __func__); return 0; } static int stm_thermal_sensor_off(struct stm_thermal_sensor *sensor) { int ret; stm_disable_irq(sensor); 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; 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; return 0; thermal_unprepare: clk_disable_unprepare(sensor->clk); return ret; } static int stm_thermal_suspend(struct device *dev) { struct stm_thermal_sensor *sensor = dev_get_drvdata(dev); return stm_thermal_sensor_off(sensor); } 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; ret = stm_sensor_power_on(sensor); if (ret) return ret; thermal_zone_device_update(sensor->th_dev, THERMAL_EVENT_UNSPECIFIED); stm_enable_irq(sensor); return 0; } static DEFINE_SIMPLE_DEV_PM_OPS(stm_thermal_pm_ops, stm_thermal_suspend, stm_thermal_resume); static const struct thermal_zone_device_ops stm_tz_ops = { .get_temp = stm_thermal_get_temp, .set_trips = stm_thermal_set_trips, }; 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; void __iomem *base; int ret; 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; base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); 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); } stm_disable_irq(sensor); /* Clear irq flags */ writel_relaxed(ICIFR_MASK, sensor->base + DTS_ICIFR_OFFSET); /* Configure and enable HW sensor */ ret = stm_thermal_prepare(sensor); if (ret) { dev_err(&pdev->dev, "Error prepare sensor: %d\n", ret); return ret; } ret = stm_sensor_power_on(sensor); if (ret) { dev_err(&pdev->dev, "Error power on sensor: %d\n", ret); return ret; } sensor->th_dev = devm_thermal_of_zone_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; } /* Register IRQ into GIC */ ret = stm_register_irq(sensor); if (ret) goto err_tz; stm_enable_irq(sensor); /* * Thermal_zone doesn't enable hwmon as default, * enable it here */ ret = thermal_add_hwmon_sysfs(sensor->th_dev); if (ret) goto err_tz; dev_info(&pdev->dev, "%s: Driver initialized successfully\n", __func__); return 0; err_tz: return ret; } static void 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); } static struct platform_driver stm_thermal_driver = { .driver = { .name = "stm_thermal", .pm = pm_sleep_ptr(&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");