[PATCH v3 2/3] thermal: spacemit: k1: Add thermal sensor support

Shuwei Wu
2026-01-19T02:42:42Z

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 <shuweiwoo@163.com>
---
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..fbfd22f8fcd3
--- /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 ARCH_SPACEMIT || COMPILE_TEST
+ 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..4788ab47a086
--- /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 <shuweiwoo@163.com>
+ */
+#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;
+ 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);
+
+ 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);
+ }
+
+ 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 <shuweiwoo@163.com>");
+MODULE_LICENSE("GPL");

--
2.52.0