Message-Id: <20241216-imx91tmu-v4-2-75caef7481b8@nxp.com>
Date: Mon, 16 Dec 2024 14:25:15 -0500
From: Frank Li <Frank.Li@....com>
To: "Rafael J. Wysocki" <rafael@...nel.org>, 
 Daniel Lezcano <daniel.lezcano@...aro.org>, Zhang Rui <rui.zhang@...el.com>, 
 Lukasz Luba <lukasz.luba@....com>, Rob Herring <robh@...nel.org>, 
 Krzysztof Kozlowski <krzk+dt@...nel.org>, 
 Conor Dooley <conor+dt@...nel.org>, Shawn Guo <shawnguo@...nel.org>, 
 Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, Pengfei Li <pengfei.li_1@....com>, 
 Marco Felsch <m.felsch@...gutronix.de>
Cc: linux-pm@...r.kernel.org, devicetree@...r.kernel.org, 
 imx@...ts.linux.dev, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, Frank Li <Frank.Li@....com>, 
 Peng Fan <peng.fan@....com>
Subject: [PATCH v4 2/2] thermal: imx91: Add support for i.MX91 thermal
 monitoring unit

From: Pengfei Li <pengfei.li_1@....com>

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@....com>
Signed-off-by: Peng Fan <peng.fan@....com>
Reviewed-by: Marco Felsch <m.felsch@...gutronix.de>
Signed-off-by: Frank Li <Frank.Li@....com>
---
Change from v3 to v4
- Add Macro's review tag
- Use devm_add_action()
- Move pm_runtim_put before thermal_of_zone_register()

change from v2 to v3
- add IMX91_TMU_ prefix for register define
- remove unused register define
- fix missed pm_runtime_put() at error path in imx91_tmu_get_temp()
- use dev variable in probe function
- use pm_runtime_set_active() in probe
- move START to imx91_tmu_get_temp()
- use DEFINE_RUNTIME_DEV_PM_OPS()
- keep set reset value because there are not sw "reset" bit in controller,
uboot may change and enable tmu.

change from v1 to v2
- use low case for hexvalue
- combine struct imx91_tmu and tmu_sensor
- simplify imx91_tmu_start() and imx91_tmu_enable()
- use s16 for imx91_tmu_get_temp(), which may negative value
- use reverse christmas tree style
- use run time pm
- use oneshot to sample temp
- register thermal zone after hardware init
---
 drivers/thermal/Kconfig         |  10 ++
 drivers/thermal/Makefile        |   1 +
 drivers/thermal/imx91_thermal.c | 263 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 274 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..ef5e8e181dd0f
--- /dev/null
+++ b/drivers/thermal/imx91_thermal.c
@@ -0,0 +1,263 @@
+// 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/pm_runtime.h>
+#include <linux/thermal.h>
+
+#define IMX91_TMU_STAT0				0x10
+#define IMX91_TMU_STAT0_DRDY0_IF_MASK		BIT(16)
+
+#define IMX91_TMU_DATA0				0x20
+
+#define IMX91_TMU_CTRL1_SET			0x204
+#define IMX91_TMU_CTRL1_CLR			0x208
+#define IMX91_TMU_CTRL1_EN			BIT(31)
+#define IMX91_TMU_CTRL1_START			BIT(30)
+#define IMX91_TMU_CTRL1_STOP			BIT(29)
+#define IMX91_TMU_CTRL1_RES_MASK		GENMASK(19, 18)
+#define IMX91_TMU_CTRL1_MEAS_MODE_MASK		GENMASK(25, 24)
+#define   IMX91_TMU_CTRL1_MEAS_MODE_SINGLE	0
+#define   IMX91_TMU_CTRL1_MEAS_MODE_CONTINUES	1
+#define   IMX91_TMU_CTRL1_MEAS_MODE_PERIODIC	2
+
+#define IMX91_TMU_REF_DIV			0x280
+#define IMX91_TMU_DIV_EN			BIT(31)
+#define IMX91_TMU_DIV_MASK			GENMASK(23, 16)
+#define IMX91_TMU_DIV_MAX			255
+
+#define IMX91_TMU_PUD_ST_CTRL			0x2b0
+#define IMX91_TMU_PUDL_MASK			GENMASK(23, 16)
+
+#define IMX91_TMU_TRIM1				0x2e0
+#define IMX91_TMU_TRIM2				0x2f0
+
+#define IMX91_TMU_TEMP_LOW_LIMIT		-40000
+#define IMX91_TMU_TEMP_HIGH_LIMIT		125000
+
+#define IMX91_TMU_DEFAULT_TRIM1_CONFIG		0xb561bc2d
+#define IMX91_TMU_DEFAULT_TRIM2_CONFIG		0x65d4
+
+struct imx91_tmu {
+	void __iomem *base;
+	struct clk *clk;
+	struct device *dev;
+	struct thermal_zone_device *tzd;
+};
+
+static void imx91_tmu_start(struct imx91_tmu *tmu, bool start)
+{
+	u32 val = start ? IMX91_TMU_CTRL1_START : IMX91_TMU_CTRL1_STOP;
+
+	writel_relaxed(val, tmu->base + IMX91_TMU_CTRL1_SET);
+}
+
+static void imx91_tmu_enable(struct imx91_tmu *tmu, bool enable)
+{
+	u32 reg = enable ? IMX91_TMU_CTRL1_SET : IMX91_TMU_CTRL1_CLR;
+
+	writel_relaxed(IMX91_TMU_CTRL1_EN, tmu->base + reg);
+}
+
+static int imx91_tmu_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct imx91_tmu *tmu = thermal_zone_device_priv(tz);
+	s16 data;
+	int ret;
+	u32 val;
+
+	ret = pm_runtime_resume_and_get(tmu->dev);
+	if (ret < 0)
+		return ret;
+
+	imx91_tmu_start(tmu, true);
+
+	ret = readl_relaxed_poll_timeout(tmu->base + IMX91_TMU_STAT0, val,
+					 val & IMX91_TMU_STAT0_DRDY0_IF_MASK, 1000, 40000);
+	if (ret) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	/* DATA0 is 16bit signed number */
+	data = readw_relaxed(tmu->base + IMX91_TMU_DATA0);
+	*temp = data * 1000 / 64;
+	if (*temp < IMX91_TMU_TEMP_LOW_LIMIT || *temp > IMX91_TMU_TEMP_HIGH_LIMIT)
+		ret = -EAGAIN;
+
+out:
+	pm_runtime_put(tmu->dev);
+
+	return ret;
+}
+
+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;
+	u32 trim1, trim2;
+	int ret;
+
+	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 + IMX91_TMU_TRIM1);
+	writel_relaxed(trim2, tmu->base + IMX91_TMU_TRIM2);
+
+	return 0;
+}
+
+static void imx91_tmu_action_remove(void *data)
+{
+	struct imx91_tmu *tmu = data;
+
+	/* disable tmu */
+	imx91_tmu_enable(tmu, false);
+}
+
+static int imx91_tmu_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct imx91_tmu *tmu;
+	unsigned long rate;
+	u32 div;
+	int ret;
+
+	tmu = devm_kzalloc(dev, sizeof(struct imx91_tmu), GFP_KERNEL);
+	if (!tmu)
+		return -ENOMEM;
+
+	tmu->dev = dev;
+
+	tmu->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(tmu->base))
+		return dev_err_probe(dev, PTR_ERR(tmu->base), "failed to get io resource");
+
+	tmu->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(tmu->clk))
+		return dev_err_probe(dev, PTR_ERR(tmu->clk), "failed to get tmu clock\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(IMX91_TMU_DEFAULT_TRIM1_CONFIG, tmu->base + IMX91_TMU_TRIM1);
+		writel_relaxed(IMX91_TMU_DEFAULT_TRIM2_CONFIG, tmu->base + IMX91_TMU_TRIM2);
+	}
+
+	/* The typical conv clk is 4MHz, the output freq is 'rate / (div + 1)' */
+	rate = clk_get_rate(tmu->clk);
+	div = (rate / 4000000) - 1;
+	if (div > IMX91_TMU_DIV_MAX)
+		return dev_err_probe(dev, -EINVAL, "clock divider exceed hardware limitation");
+
+	/* Set divider value and enable divider */
+	writel_relaxed(IMX91_TMU_DIV_EN | FIELD_PREP(IMX91_TMU_DIV_MASK, div),
+		       tmu->base + IMX91_TMU_REF_DIV);
+
+	/* Set max power up delay: 'Tpud(ms) = 0xFF * 1000 / 4000000' */
+	writel_relaxed(FIELD_PREP(IMX91_TMU_PUDL_MASK, 100U), tmu->base + IMX91_TMU_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(IMX91_TMU_CTRL1_RES_MASK, 0x3), tmu->base + IMX91_TMU_CTRL1_CLR);
+	writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL1_RES_MASK, 0x1), tmu->base + IMX91_TMU_CTRL1_SET);
+
+	writel_relaxed(IMX91_TMU_CTRL1_MEAS_MODE_MASK, tmu->base + IMX91_TMU_CTRL1_CLR);
+	writel_relaxed(FIELD_PREP(IMX91_TMU_CTRL1_MEAS_MODE_MASK, IMX91_TMU_CTRL1_MEAS_MODE_SINGLE),
+		       tmu->base + IMX91_TMU_CTRL1_SET);
+
+	pm_runtime_set_active(dev);
+	devm_pm_runtime_enable(dev);
+	pm_runtime_put(dev);
+
+	tmu->tzd = devm_thermal_of_zone_register(dev, 0, tmu, &tmu_tz_ops);
+	if (IS_ERR(tmu->tzd))
+		return dev_err_probe(dev, PTR_ERR(tmu->tzd),
+				     "failed to register thermal zone sensor\n");
+
+	ret = devm_add_action(dev, imx91_tmu_action_remove, tmu);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failure to add action imx91_tmu_action_remove()\n");
+
+	return 0;
+}
+
+static int imx91_tmu_runtime_suspend(struct device *dev)
+{
+	struct imx91_tmu *tmu = dev_get_drvdata(dev);
+
+	/* disable tmu */
+	imx91_tmu_enable(tmu, false);
+
+	clk_disable_unprepare(tmu->clk);
+
+	return 0;
+}
+
+static int imx91_tmu_runtime_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);
+
+	return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(imx91_tmu_pm_ops, imx91_tmu_runtime_suspend,
+				 imx91_tmu_runtime_resume, NULL);
+
+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	= "imx91_thermal",
+		.pm	= pm_ptr(&imx91_tmu_pm_ops),
+		.of_match_table = imx91_tmu_table,
+	},
+	.probe = imx91_tmu_probe,
+};
+module_platform_driver(imx91_tmu);
+
+MODULE_AUTHOR("Peng Fan <peng.fan@....com>");
+MODULE_DESCRIPTION("i.MX91 Thermal Monitor Unit driver");
+MODULE_LICENSE("GPL");

-- 
2.34.1

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