[PATCH 2/2] thermal: imx91: Add support for i.MX91 thermal monitoring unit

[Frank Li]

From: Pengfei Li <pengfei.li_1@xxxxxxx>

Introduce support for the i.MX91 thermal monitoring unit, which features a
single sensor for the CPU. The register layout differs from other chips,
necessitating the creation of a dedicated file for this.

Signed-off-by: Pengfei Li <pengfei.li_1@xxxxxxx>
Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
 drivers/thermal/Kconfig         |  10 ++
 drivers/thermal/Makefile        |   1 +
 drivers/thermal/imx91_thermal.c | 281 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 292 insertions(+)

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index d3f9686e26e71..da403ed86aeb1 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -296,6 +296,16 @@ config IMX8MM_THERMAL
 	  cpufreq is used as the cooling device to throttle CPUs when the passive
 	  trip is crossed.
 
+config IMX91_THERMAL
+	tristate "Temperature sensor driver for NXP i.MX91 SoC"
+	depends on ARCH_MXC || COMPILE_TEST
+	depends on OF
+	help
+	  Support for Temperature sensor found on NXP i.MX91 SoC.
+	  It supports one critical trip point and one passive trip point. The
+	  cpufreq is used as the cooling device to throttle CPUs when the passive
+	  trip is crossed.
+
 config K3_THERMAL
 	tristate "Texas Instruments K3 thermal support"
 	depends on ARCH_K3 || COMPILE_TEST
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 9abf43a74f2bb..08da241e6a598 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
 obj-$(CONFIG_IMX_THERMAL)	+= imx_thermal.o
 obj-$(CONFIG_IMX_SC_THERMAL)	+= imx_sc_thermal.o
 obj-$(CONFIG_IMX8MM_THERMAL)	+= imx8mm_thermal.o
+obj-$(CONFIG_IMX91_THERMAL)	+= imx91_thermal.o
 obj-$(CONFIG_MAX77620_THERMAL)	+= max77620_thermal.o
 obj-$(CONFIG_QORIQ_THERMAL)	+= qoriq_thermal.o
 obj-$(CONFIG_DA9062_THERMAL)	+= da9062-thermal.o
diff --git a/drivers/thermal/imx91_thermal.c b/drivers/thermal/imx91_thermal.c
new file mode 100644
index 0000000000000..19c4dafe9c7a9
--- /dev/null
+++ b/drivers/thermal/imx91_thermal.c
@@ -0,0 +1,281 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2024 NXP.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/iopoll.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#define CTRL0			0x0
+
+#define STAT0			0x10
+#define STAT0_DRDY0_IF_MASK	BIT(16)
+
+#define DATA0			0x20
+#define DATA_INT_MASK		GENMASK(14, 7)
+#define DATA_FRAC_MASK		GENMASK(6, 0)
+
+#define THR_CTRL01		0x30
+#define THR_CTRL23		0x40
+
+#define CTRL1			0x200
+#define CTRL1_SET		0x204
+#define CTRL1_CLR		0x208
+#define CTRL1_EN		BIT(31)
+#define CTRL1_START		BIT(30)
+#define CTRL1_STOP		BIT(29)
+#define CTRL1_RES_MASK		GENMASK(19, 18)
+#define CTRL1_MEAS_MODE_MASK	GENMASK(25, 24)
+
+#define PERIOD_CTRL		0x270
+#define MEAS_FREQ_MASK		GENMASK(23, 0)
+
+#define REF_DIV			0x280
+#define DIV_EN			BIT(31)
+#define DIV_MASK		GENMASK(23, 16)
+
+#define PUD_ST_CTRL		0x2B0
+#define PUDL_MASK		GENMASK(23, 16)
+
+#define TRIM1			0x2E0
+#define TRIM2			0x2F0
+
+#define TMU_TEMP_LOW_LIMIT	-40000
+#define TMU_TEMP_HIGH_LIMIT	125000
+
+#define DEFAULT_TRIM1_CONFIG 0xB561BC2DU
+#define DEFAULT_TRIM2_CONFIG 0x65D4U
+
+struct tmu_sensor {
+	struct imx91_tmu *priv;
+	struct thermal_zone_device *tzd;
+};
+
+struct imx91_tmu {
+	void __iomem *base;
+	struct clk *clk;
+	struct device *dev;
+	struct tmu_sensor sensors;
+};
+
+static void imx91_tmu_start(struct imx91_tmu *tmu, bool start)
+{
+	if (start)
+		writel_relaxed(CTRL1_START, tmu->base + CTRL1_SET);
+	else
+		writel_relaxed(CTRL1_STOP, tmu->base + CTRL1_SET);
+}
+
+static void imx91_tmu_enable(struct imx91_tmu *tmu, bool enable)
+{
+	if (enable)
+		writel_relaxed(CTRL1_EN, tmu->base + CTRL1_SET);
+	else
+		writel_relaxed(CTRL1_EN, tmu->base + CTRL1_CLR);
+}
+
+static int imx91_tmu_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct tmu_sensor *sensor = thermal_zone_device_priv(tz);
+	struct imx91_tmu *tmu = sensor->priv;
+	int val;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout(tmu->base + STAT0, val,
+					 val & STAT0_DRDY0_IF_MASK, 1000,
+					 40000);
+	if (ret)
+		return -EAGAIN;
+
+	val = readl_relaxed(tmu->base + DATA0) & 0xffffU;
+	*temp = val * 1000L / 64L;
+	if (*temp < TMU_TEMP_LOW_LIMIT || *temp > TMU_TEMP_HIGH_LIMIT)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops tmu_tz_ops = {
+	.get_temp = imx91_tmu_get_temp,
+};
+
+static int imx91_init_from_nvmem_cells(struct imx91_tmu *tmu)
+{
+	struct device *dev = tmu->dev;
+	int ret;
+	u32 trim1, trim2;
+
+	ret = nvmem_cell_read_u32(dev, "trim1", &trim1);
+	if (ret)
+		return ret;
+
+	ret = nvmem_cell_read_u32(dev, "trim2", &trim2);
+	if (ret)
+		return ret;
+
+	if (trim1 == 0 || trim2 == 0)
+		return -EINVAL;
+
+	writel_relaxed(trim1, tmu->base + TRIM1);
+	writel_relaxed(trim2, tmu->base + TRIM2);
+
+	return 0;
+}
+
+static int imx91_tmu_probe(struct platform_device *pdev)
+{
+	struct imx91_tmu *tmu;
+	unsigned long rate;
+	u32 div;
+	int ret;
+	int i = 0;
+
+	tmu = devm_kzalloc(&pdev->dev, sizeof(struct imx91_tmu), GFP_KERNEL);
+	if (!tmu)
+		return -ENOMEM;
+
+	tmu->dev = &pdev->dev;
+
+	tmu->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(tmu->base))
+		return PTR_ERR(tmu->base);
+
+	tmu->clk = devm_clk_get_prepared(&pdev->dev, NULL);
+	if (IS_ERR(tmu->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(tmu->clk), "failed to get tmu clock\n");
+
+	tmu->sensors.priv = tmu;
+	tmu->sensors.tzd = devm_thermal_of_zone_register(&pdev->dev, i, &tmu->sensors, &tmu_tz_ops);
+	if (IS_ERR(tmu->sensors.tzd))
+		return dev_err_probe(&pdev->dev, PTR_ERR(tmu->sensors.tzd),
+				     "failed to register thermal zone sensor\n");
+
+	platform_set_drvdata(pdev, tmu);
+
+	/* disable the monitor during initialization */
+	imx91_tmu_enable(tmu, false);
+	imx91_tmu_start(tmu, false);
+
+	ret = imx91_init_from_nvmem_cells(tmu);
+	if (ret) {
+		writel_relaxed(DEFAULT_TRIM1_CONFIG, tmu->base + TRIM1);
+		writel_relaxed(DEFAULT_TRIM2_CONFIG, tmu->base + TRIM2);
+	}
+
+	/* The typical conv clk is 4MHz, the output freq is 'rate / (div + 1)' */
+	rate = clk_get_rate(tmu->clk);
+	div = (rate / 4000000) - 1;
+
+	/* Set divider value and enable divider */
+	writel_relaxed(DIV_EN | FIELD_PREP(DIV_MASK, div), tmu->base + REF_DIV);
+
+	/* Set max power up delay: 'Tpud(ms) = 0xFF * 1000 / 4000000' */
+	writel_relaxed(FIELD_PREP(PUDL_MASK, 100U), tmu->base + PUD_ST_CTRL);
+
+	/*
+	 * Set resolution mode
+	 * 00b - Conversion time = 0.59325 ms
+	 * 01b - Conversion time = 1.10525 ms
+	 * 10b - Conversion time = 2.12925 ms
+	 * 11b - Conversion time = 4.17725 ms
+	 */
+	writel_relaxed(FIELD_PREP(CTRL1_RES_MASK, 0x3), tmu->base + CTRL1_CLR);
+	writel_relaxed(FIELD_PREP(CTRL1_RES_MASK, 0x1), tmu->base + CTRL1_SET);
+
+	/*
+	 * Set measure mode
+	 * 00b - Single oneshot measurement
+	 * 01b - Continuous measurement
+	 * 10b - Periodic oneshot measurement
+	 */
+	writel_relaxed(FIELD_PREP(CTRL1_MEAS_MODE_MASK, 0x3), tmu->base + CTRL1_CLR);
+	writel_relaxed(FIELD_PREP(CTRL1_MEAS_MODE_MASK, 0x1), tmu->base + CTRL1_SET);
+
+	/*
+	 * Set Periodic Measurement Frequency to 25Hz:
+	 * tMEAS_FREQ = tCONV_CLK * PERIOD_CTRL[MEAS_FREQ]. ->
+	 * PERIOD_CTRL(MEAS_FREQ) = (1000 / 25) / (1000 / 4000000);
+	 * Where tMEAS_FREQ = Measurement period and tCONV_CLK = 1/fCONV_CLK.
+	 * This field should have value greater than count corresponds
+	 * to time greater than summation of conversion time, power up
+	 * delay, and six times of conversion clock time.
+	 * tMEAS_FREQ > (tCONV + tPUD + 6 * tCONV_CLK).
+	 * tCONV is conversion time determined by CTRL1[RESOLUTION].
+	 */
+	writel_relaxed(FIELD_PREP(MEAS_FREQ_MASK, 0x27100), tmu->base + PERIOD_CTRL);
+
+	/* enable the monitor */
+	imx91_tmu_enable(tmu, true);
+	imx91_tmu_start(tmu, true);
+
+	return 0;
+}
+
+static void imx91_tmu_remove(struct platform_device *pdev)
+{
+	struct imx91_tmu *tmu = platform_get_drvdata(pdev);
+
+	/* disable tmu */
+	imx91_tmu_start(tmu, false);
+	imx91_tmu_enable(tmu, false);
+}
+
+static int __maybe_unused imx91_tmu_suspend(struct device *dev)
+{
+	struct imx91_tmu *tmu = dev_get_drvdata(dev);
+
+	/* disable tmu */
+	imx91_tmu_start(tmu, false);
+	imx91_tmu_enable(tmu, false);
+
+	clk_disable_unprepare(tmu->clk);
+
+	return 0;
+}
+
+static int __maybe_unused imx91_tmu_resume(struct device *dev)
+{
+	struct imx91_tmu *tmu = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(tmu->clk);
+	if (ret)
+		return ret;
+
+	imx91_tmu_enable(tmu, true);
+	imx91_tmu_start(tmu, true);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(imx91_tmu_pm_ops,
+			 imx91_tmu_suspend, imx91_tmu_resume);
+
+static const struct of_device_id imx91_tmu_table[] = {
+	{ .compatible = "fsl,imx91-tmu", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, imx91_tmu_table);
+
+static struct platform_driver imx91_tmu = {
+	.driver = {
+		.name	= "i.MX91_thermal",
+		.pm	= pm_ptr(&imx91_tmu_pm_ops),
+		.of_match_table = imx91_tmu_table,
+	},
+	.probe = imx91_tmu_probe,
+	.remove = imx91_tmu_remove,
+};
+module_platform_driver(imx91_tmu);
+
+MODULE_AUTHOR("Peng Fan <peng.fan@xxxxxxx>");
+MODULE_DESCRIPTION("i.MX91 Thermal Monitor Unit driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1