[PATCH v4 2/3] thermal: spacemit: k1: Add thermal sensor support
Shuwei Wu
shuwei.wu at mailbox.org
Fri Apr 10 18:56:32 PDT 2026
On Fri Apr 10, 2026 at 4:25 PM CST, Jie Gan wrote:
>
>
> On 4/10/2026 11:31 AM, Shuwei Wu wrote:
>> The thermal sensor on K1 supports monitoring five temperature zones.
>> The driver registers these sensors with the thermal framework
>> and supports standard operations:
>> - Reading temperature (millidegree Celsius)
>> - Setting high/low thresholds for interrupts
>>
>> Signed-off-by: Shuwei Wu <shuwei.wu at mailbox.org>
>> Reviewed-by: Anand Moon <linux.amoon at gmail.com>
>> Tested-by: Anand Moon <linux.amoon at gmail.com>
>> Reviewed-by: Troy Mitchell <troy.mitchell at linux.spacemit.com>
>> Reviewed-by: Yao Zi <me at ziyao.cc>
>> Tested-by: Vincent Legoll <legoll at online.fr> # OrangePi-RV2
>> Tested-by: Gong Shuai <gsh517025 at gmail.com>
>>
>> ---
>> Changes in v4:
>> - Add 'depends on THERMAL_OF' in drivers/thermal/spacemit/Kconfig
>>
>> Changes in v3:
>> - Align multi-line assignments as suggested by reviewer
>> - Remove unnecessary variable definitions
>>
>> Changes in v2:
>> - Rename k1_thermal.c to k1_tsensor.c for better hardware alignment
>> - Move driver to drivers/thermal/spacemit/
>> - Add Kconfig/Makefile for spacemit and update top-level build files
>> - Refactor names, style, code alignment, and comments
>> - Simplify probe and error handling
>> ---
>> drivers/thermal/Kconfig | 2 +
>> drivers/thermal/Makefile | 1 +
>> drivers/thermal/spacemit/Kconfig | 19 +++
>> drivers/thermal/spacemit/Makefile | 3 +
>> drivers/thermal/spacemit/k1_tsensor.c | 281 ++++++++++++++++++++++++++++++++++
>> 5 files changed, 306 insertions(+)
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index b10080d61860..1c4a5cd5a23e 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -472,6 +472,8 @@ endmenu
>>
>> source "drivers/thermal/renesas/Kconfig"
>>
>> +source "drivers/thermal/spacemit/Kconfig"
>> +
>> source "drivers/thermal/tegra/Kconfig"
>>
>> config GENERIC_ADC_THERMAL
>> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
>> index bb21e7ea7fc6..3b249195c088 100644
>> --- a/drivers/thermal/Makefile
>> +++ b/drivers/thermal/Makefile
>> @@ -65,6 +65,7 @@ obj-y += mediatek/
>> obj-$(CONFIG_GENERIC_ADC_THERMAL) += thermal-generic-adc.o
>> obj-$(CONFIG_UNIPHIER_THERMAL) += uniphier_thermal.o
>> obj-$(CONFIG_AMLOGIC_THERMAL) += amlogic_thermal.o
>> +obj-y += spacemit/
>> obj-$(CONFIG_SPRD_THERMAL) += sprd_thermal.o
>> obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL) += khadas_mcu_fan.o
>> obj-$(CONFIG_LOONGSON2_THERMAL) += loongson2_thermal.o
>> diff --git a/drivers/thermal/spacemit/Kconfig b/drivers/thermal/spacemit/Kconfig
>> new file mode 100644
>> index 000000000000..de7b5ece5af2
>> --- /dev/null
>> +++ b/drivers/thermal/spacemit/Kconfig
>> @@ -0,0 +1,19 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +menu "SpacemiT thermal drivers"
>> +depends on ARCH_SPACEMIT || COMPILE_TEST
>> +
>> +config SPACEMIT_K1_TSENSOR
>> + tristate "SpacemiT K1 thermal sensor driver"
>> + depends on THERMAL_OF
>> + help
>> + This driver provides support for the thermal sensor
>> + integrated in the SpacemiT K1 SoC.
>> +
>> + The thermal sensor monitors temperatures for five thermal zones:
>> + soc, package, gpu, cluster0, and cluster1. It supports reporting
>> + temperature values and handling high/low threshold interrupts.
>> +
>> + Say Y here if you want to enable thermal monitoring on SpacemiT K1.
>> + If compiled as a module, it will be called k1_tsensor.
>> +
>> +endmenu
>> diff --git a/drivers/thermal/spacemit/Makefile b/drivers/thermal/spacemit/Makefile
>> new file mode 100644
>> index 000000000000..82b30741e4ec
>> --- /dev/null
>> +++ b/drivers/thermal/spacemit/Makefile
>> @@ -0,0 +1,3 @@
>> +# SPDX-License-Identifier: GPL-2.0-only
>> +
>> +obj-$(CONFIG_SPACEMIT_K1_TSENSOR) += k1_tsensor.o
>> diff --git a/drivers/thermal/spacemit/k1_tsensor.c b/drivers/thermal/spacemit/k1_tsensor.c
>> new file mode 100644
>> index 000000000000..b742739e9019
>> --- /dev/null
>> +++ b/drivers/thermal/spacemit/k1_tsensor.c
>> @@ -0,0 +1,281 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Thermal sensor driver for SpacemiT K1 SoC
>> + *
>> + * Copyright (C) 2026 Shuwei Wu <shuwei.wu at mailbox.org>
>> + */
>> +#include <linux/bitfield.h>
>> +#include <linux/clk.h>
>> +#include <linux/err.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/reset.h>
>> +#include <linux/slab.h>
>> +#include <linux/thermal.h>
>> +
>> +#include "../thermal_hwmon.h"
>> +
>> +#define K1_TSENSOR_PCTRL_REG 0x00
>> +#define K1_TSENSOR_PCTRL_ENABLE BIT(0)
>> +#define K1_TSENSOR_PCTRL_TEMP_MODE BIT(3)
>> +#define K1_TSENSOR_PCTRL_RAW_SEL BIT(7)
>> +
>> +#define K1_TSENSOR_PCTRL_CTUNE GENMASK(11, 8)
>> +#define K1_TSENSOR_PCTRL_SW_CTRL GENMASK(21, 18)
>> +#define K1_TSENSOR_PCTRL_HW_AUTO_MODE BIT(23)
>> +
>> +#define K1_TSENSOR_EN_REG 0x08
>> +#define K1_TSENSOR_EN_ALL GENMASK(MAX_SENSOR_NUMBER - 1, 0)
>> +
>> +#define K1_TSENSOR_TIME_REG 0x0C
>> +#define K1_TSENSOR_TIME_WAIT_REF_CNT GENMASK(3, 0)
>> +#define K1_TSENSOR_TIME_ADC_CNT_RST GENMASK(7, 4)
>> +#define K1_TSENSOR_TIME_FILTER_PERIOD GENMASK(21, 20)
>> +#define K1_TSENSOR_TIME_MASK GENMASK(23, 0)
>> +
>> +#define K1_TSENSOR_INT_CLR_REG 0x10
>> +#define K1_TSENSOR_INT_EN_REG 0x14
>> +#define K1_TSENSOR_INT_STA_REG 0x18
>> +
>> +#define K1_TSENSOR_INT_EN_MASK BIT(0)
>> +#define K1_TSENSOR_INT_MASK(x) (GENMASK(2, 1) << ((x) * 2))
>> +
>> +#define K1_TSENSOR_DATA_BASE_REG 0x20
>> +#define K1_TSENSOR_DATA_REG(x) (K1_TSENSOR_DATA_BASE_REG + ((x) / 2) * 4)
>> +#define K1_TSENSOR_DATA_LOW_MASK GENMASK(15, 0)
>> +#define K1_TSENSOR_DATA_HIGH_MASK GENMASK(31, 16)
>> +
>> +#define K1_TSENSOR_THRSH_BASE_REG 0x40
>> +#define K1_TSENSOR_THRSH_REG(x) (K1_TSENSOR_THRSH_BASE_REG + ((x) * 4))
>> +#define K1_TSENSOR_THRSH_LOW_MASK GENMASK(15, 0)
>> +#define K1_TSENSOR_THRSH_HIGH_MASK GENMASK(31, 16)
>> +
>> +#define MAX_SENSOR_NUMBER 5
>> +
>> +/* Hardware offset value required for temperature calculation */
>> +#define TEMPERATURE_OFFSET 278
>> +
>> +struct k1_tsensor_channel {
>> + struct k1_tsensor *ts;
>> + struct thermal_zone_device *tzd;
>> + int id;
>> +};
>> +
>> +struct k1_tsensor {
>> + void __iomem *base;
>> + struct k1_tsensor_channel ch[MAX_SENSOR_NUMBER];
>> +};
>> +
>> +static void k1_tsensor_init(struct k1_tsensor *ts)
>> +{
>> + u32 val;
>> +
>> + /* Disable all the interrupts */
>> + writel(0xffffffff, ts->base + K1_TSENSOR_INT_EN_REG);
>> +
>> + /* Configure ADC sampling time and filter period */
>> + val = readl(ts->base + K1_TSENSOR_TIME_REG);
>> + val &= ~K1_TSENSOR_TIME_MASK;
>> + val |= K1_TSENSOR_TIME_FILTER_PERIOD |
>> + K1_TSENSOR_TIME_ADC_CNT_RST |
>> + K1_TSENSOR_TIME_WAIT_REF_CNT;
>> + writel(val, ts->base + K1_TSENSOR_TIME_REG);
>> +
>> + /*
>> + * Enable all sensors' auto mode, enable dither control,
>> + * consecutive mode, and power up sensor.
>> + */
>> + val = readl(ts->base + K1_TSENSOR_PCTRL_REG);
>> + val &= ~K1_TSENSOR_PCTRL_SW_CTRL;
>> + val &= ~K1_TSENSOR_PCTRL_CTUNE;
>> + val |= K1_TSENSOR_PCTRL_RAW_SEL |
>> + K1_TSENSOR_PCTRL_TEMP_MODE |
>> + K1_TSENSOR_PCTRL_HW_AUTO_MODE |
>> + K1_TSENSOR_PCTRL_ENABLE;
>> + writel(val, ts->base + K1_TSENSOR_PCTRL_REG);
>> +
>> + /* Enable thermal interrupt */
>> + val = readl(ts->base + K1_TSENSOR_INT_EN_REG);
>> + val |= K1_TSENSOR_INT_EN_MASK;
>> + writel(val, ts->base + K1_TSENSOR_INT_EN_REG);
>> +
>> + /* Enable each sensor */
>> + val = readl(ts->base + K1_TSENSOR_EN_REG);
>> + val |= K1_TSENSOR_EN_ALL;
>> + writel(val, ts->base + K1_TSENSOR_EN_REG);
>> +}
>> +
>> +static void k1_tsensor_enable_irq(struct k1_tsensor_channel *ch)
>> +{
>> + struct k1_tsensor *ts = ch->ts;
>> + u32 val;
>> +
>> + val = readl(ts->base + K1_TSENSOR_INT_CLR_REG);
>> + val |= K1_TSENSOR_INT_MASK(ch->id);
>> + writel(val, ts->base + K1_TSENSOR_INT_CLR_REG);
>> +
>> + val = readl(ts->base + K1_TSENSOR_INT_EN_REG);
>> + val &= ~K1_TSENSOR_INT_MASK(ch->id);
>> + writel(val, ts->base + K1_TSENSOR_INT_EN_REG);
>> +}
>> +
>> +/*
>> + * The conversion formula used is:
>> + * T(m°C) = (((raw_value & mask) >> shift) - TEMPERATURE_OFFSET) * 1000
>> + */
>> +static int k1_tsensor_get_temp(struct thermal_zone_device *tz, int *temp)
>> +{
>> + struct k1_tsensor_channel *ch = thermal_zone_device_priv(tz);
>> + struct k1_tsensor *ts = ch->ts;
>> + u32 val;
>> +
>> + val = readl(ts->base + K1_TSENSOR_DATA_REG(ch->id));
>> + if (ch->id % 2)
>> + *temp = FIELD_GET(K1_TSENSOR_DATA_HIGH_MASK, val);
>> + else
>> + *temp = FIELD_GET(K1_TSENSOR_DATA_LOW_MASK, val);
>> +
>> + *temp -= TEMPERATURE_OFFSET;
>> + *temp *= 1000;
>> +
>> + return 0;
>> +}
>> +
>> +/*
>> + * For each sensor, the hardware threshold register is 32 bits:
>> + * - Lower 16 bits [15:0] configure the low threshold temperature.
>> + * - Upper 16 bits [31:16] configure the high threshold temperature.
>> + */
>> +static int k1_tsensor_set_trips(struct thermal_zone_device *tz, int low, int high)
>> +{
>> + struct k1_tsensor_channel *ch = thermal_zone_device_priv(tz);
>> + struct k1_tsensor *ts = ch->ts;
>> + u32 val;
>> +
>> + if (low >= high)
>> + return -EINVAL;
>> +
>> + if (low < 0)
>> + low = 0;
>> +
>> + high = high / 1000 + TEMPERATURE_OFFSET;
>
> Consider passes high = INT_MAX here:
>
> high = INT/1000 + TEMPERATURE_OFFSET == 2147761;
>
>> + low = low / 1000 + TEMPERATURE_OFFSET;
>> +
>> + val = readl(ts->base + K1_TSENSOR_THRSH_REG(ch->id));
>> + val &= ~K1_TSENSOR_THRSH_HIGH_MASK;
>> + val |= FIELD_PREP(K1_TSENSOR_THRSH_HIGH_MASK, high);
>
> K1_TSENSOR_THRSH_HIGH_MASK is a 16-bit MASK:
> FIELD_PREP(K1_TSENSOR_THRSH_HIGH_MASK, 2147761); <- overflow happened
>
> the maximum value here will be changed to 50609 from 65536.
>
> We should add a check here and limit the 'high' value here to avoid
> overflow:
>
> if (high > (int)((0xFFFF - TEMPERATURE_OFFSET) * 1000))
> high = (0Xffff - TEMPERATURE_OFFSET) * 1000;
>
> high = high / 1000 + TEMPERATURE_OFFSET;
>
> ...
Got it. I'll add a check to handle the overflow.
>
>> +
>> + val &= ~K1_TSENSOR_THRSH_LOW_MASK;
>> + val |= FIELD_PREP(K1_TSENSOR_THRSH_LOW_MASK, low);
>> + writel(val, ts->base + K1_TSENSOR_THRSH_REG(ch->id));
>> +
>> + return 0;
>> +}
>> +
>> +static const struct thermal_zone_device_ops k1_tsensor_ops = {
>> + .get_temp = k1_tsensor_get_temp,
>> + .set_trips = k1_tsensor_set_trips,
>> +};
>> +
>> +static irqreturn_t k1_tsensor_irq_thread(int irq, void *data)
>> +{
>> + struct k1_tsensor *ts = (struct k1_tsensor *)data;
>> + int mask, status, i;
>> +
>> + status = readl(ts->base + K1_TSENSOR_INT_STA_REG);
>> +
>> + for (i = 0; i < MAX_SENSOR_NUMBER; i++) {
>> + if (status & K1_TSENSOR_INT_MASK(i)) {
>> + mask = readl(ts->base + K1_TSENSOR_INT_CLR_REG);
>> + mask |= K1_TSENSOR_INT_MASK(i);
>> + writel(mask, ts->base + K1_TSENSOR_INT_CLR_REG);
>> + thermal_zone_device_update(ts->ch[i].tzd, THERMAL_EVENT_UNSPECIFIED);
>> + }
>> + }
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static int k1_tsensor_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct k1_tsensor *ts;
>> + struct reset_control *reset;
>> + struct clk *clk;
>> + int i, irq, ret;
>> +
>> + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
>> + if (!ts)
>> + return -ENOMEM;
>> +
>> + ts->base = devm_platform_ioremap_resource(pdev, 0);
>> + if (IS_ERR(ts->base))
>> + return dev_err_probe(dev, PTR_ERR(ts->base), "Failed to get reg\n");
>> +
>> + reset = devm_reset_control_get_exclusive_deasserted(dev, NULL);
>> + if (IS_ERR(reset))
>> + return dev_err_probe(dev, PTR_ERR(reset), "Failed to get/deassert reset control\n");
>> +
>> + clk = devm_clk_get_enabled(dev, "core");
>> + if (IS_ERR(clk))
>> + return dev_err_probe(dev, PTR_ERR(clk), "Failed to get core clock\n");
>> +
>> + clk = devm_clk_get_enabled(dev, "bus");
>> + if (IS_ERR(clk))
>> + return dev_err_probe(dev, PTR_ERR(clk), "Failed to get bus clock\n");
>> +
>> + k1_tsensor_init(ts);
>> +
>> + for (i = 0; i < MAX_SENSOR_NUMBER; ++i) {
>> + ts->ch[i].id = i;
>> + ts->ch[i].ts = ts;
>> + ts->ch[i].tzd = devm_thermal_of_zone_register(dev, i, ts->ch + i, &k1_tsensor_ops);
>> + if (IS_ERR(ts->ch[i].tzd))
>> + return PTR_ERR(ts->ch[i].tzd);
>> +
>> + /* Attach sysfs hwmon attributes for userspace monitoring */
>> + ret = devm_thermal_add_hwmon_sysfs(dev, ts->ch[i].tzd);
>> + if (ret)
>> + dev_warn(dev, "Failed to add hwmon sysfs attributes\n");
>> +
>> + k1_tsensor_enable_irq(ts->ch + i);
>
> should call after the devm_request_threaded_irq succeeds;
I'll reorder this in v5.
Thanks for catching that.
>
> Thanks,
> Jie
>
>> + }
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0)
>> + return irq;
>> +
>> + ret = devm_request_threaded_irq(dev, irq, NULL,
>> + k1_tsensor_irq_thread,
>> + IRQF_ONESHOT, "k1_tsensor", ts);
>> + if (ret < 0)
>> + return ret;
>> +
>> + platform_set_drvdata(pdev, ts);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id k1_tsensor_dt_ids[] = {
>> + { .compatible = "spacemit,k1-tsensor" },
>> + { /* sentinel */ }
>> +};
>> +
>> +MODULE_DEVICE_TABLE(of, k1_tsensor_dt_ids);
>> +
>> +static struct platform_driver k1_tsensor_driver = {
>> + .driver = {
>> + .name = "k1_tsensor",
>> + .of_match_table = k1_tsensor_dt_ids,
>> + },
>> + .probe = k1_tsensor_probe,
>> +};
>> +module_platform_driver(k1_tsensor_driver);
>> +
>> +MODULE_DESCRIPTION("SpacemiT K1 Thermal Sensor Driver");
>> +MODULE_AUTHOR("Shuwei Wu <shuwei.wu at mailbox.org>");
>> +MODULE_LICENSE("GPL");
>>
--
Best regards,
Shuwei Wu
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