// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
* Author: David Hernandez Sanchez <[email protected]> for
* STMicroelectronics.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/thermal.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_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;
}
#ifdef CONFIG_PM_SLEEP
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;
}
#endif /* CONFIG_PM_SLEEP */
static 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 = &stm_thermal_pm_ops,
.of_match_table = stm_thermal_of_match,
},
.probe = stm_thermal_probe,
.remove_new = stm_thermal_remove,
};
module_platform_driver(stm_thermal_driver);
MODULE_DESCRIPTION("STMicroelectronics STM32 Thermal Sensor Driver");
MODULE_AUTHOR("David Hernandez Sanchez <[email protected]>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:stm_thermal");
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