imx8mm_thermal.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2020 NXP.
 *
 * Author: Anson Huang <Anson.Huang@nxp.com>
 */

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/thermal.h>

#include "thermal_core.h"

#define TER			0x0	/* TMU enable */
#define TPS			0x4
#define TRITSR			0x20	/* TMU immediate temp */

#define TER_EN			BIT(31)
#define TRITSR_TEMP0_VAL_MASK	0xff
#define TRITSR_TEMP1_VAL_MASK	0xff0000

#define PROBE_SEL_ALL		GENMASK(31, 30)

#define probe_status_offset(x)	(30 + x)
#define SIGN_BIT		BIT(7)
#define TEMP_VAL_MASK		GENMASK(6, 0)

#define VER1_TEMP_LOW_LIMIT	10000
#define VER2_TEMP_LOW_LIMIT	-40000
#define VER2_TEMP_HIGH_LIMIT	125000

#define TMU_VER1		0x1
#define TMU_VER2		0x2

struct thermal_soc_data {
	u32 num_sensors;
	u32 version;
	int (*get_temp)(void *, int *);
};

struct tmu_sensor {
	struct imx8mm_tmu *priv;
	u32 hw_id;
	struct thermal_zone_device *tzd;
};

struct imx8mm_tmu {
	void __iomem *base;
	struct clk *clk;
	const struct thermal_soc_data *socdata;
	struct tmu_sensor sensors[];
};

static int imx8mm_tmu_get_temp(void *data, int *temp)
{
	struct tmu_sensor *sensor = data;
	struct imx8mm_tmu *tmu = sensor->priv;
	u32 val;

	val = readl_relaxed(tmu->base + TRITSR) & TRITSR_TEMP0_VAL_MASK;
	*temp = val * 1000;
	if (*temp < VER1_TEMP_LOW_LIMIT)
		return -EAGAIN;

	return 0;
}

static int imx8mp_tmu_get_temp(void *data, int *temp)
{
	struct tmu_sensor *sensor = data;
	struct imx8mm_tmu *tmu = sensor->priv;
	unsigned long val;
	bool ready;

	val = readl_relaxed(tmu->base + TRITSR);
	ready = test_bit(probe_status_offset(sensor->hw_id), &val);
	if (!ready)
		return -EAGAIN;

	val = sensor->hw_id ? FIELD_GET(TRITSR_TEMP1_VAL_MASK, val) :
	      FIELD_GET(TRITSR_TEMP0_VAL_MASK, val);
	if (val & SIGN_BIT) /* negative */
		val = (~(val & TEMP_VAL_MASK) + 1);

	*temp = val * 1000;
	if (*temp < VER2_TEMP_LOW_LIMIT || *temp > VER2_TEMP_HIGH_LIMIT)
		return -EAGAIN;

	return 0;
}

static int tmu_get_temp(void *data, int *temp)
{
	struct tmu_sensor *sensor = data;
	struct imx8mm_tmu *tmu = sensor->priv;

	return tmu->socdata->get_temp(data, temp);
}

static struct thermal_zone_of_device_ops tmu_tz_ops = {
	.get_temp = tmu_get_temp,
};

static void imx8mm_tmu_enable(struct imx8mm_tmu *tmu, bool enable)
{
	u32 val;

	val = readl_relaxed(tmu->base + TER);
	val = enable ? (val | TER_EN) : (val & ~TER_EN);
	writel_relaxed(val, tmu->base + TER);
}

static void imx8mm_tmu_probe_sel_all(struct imx8mm_tmu *tmu)
{
	u32 val;

	val = readl_relaxed(tmu->base + TPS);
	val |= PROBE_SEL_ALL;
	writel_relaxed(val, tmu->base + TPS);
}

static int imx8mm_tmu_probe(struct platform_device *pdev)
{
	const struct thermal_soc_data *data;
	struct imx8mm_tmu *tmu;
	int ret;
	int i;

	data = of_device_get_match_data(&pdev->dev);

	tmu = devm_kzalloc(&pdev->dev, struct_size(tmu, sensors,
			   data->num_sensors), GFP_KERNEL);
	if (!tmu)
		return -ENOMEM;

	tmu->socdata = data;

	tmu->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(tmu->base))
		return PTR_ERR(tmu->base);

	tmu->clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(tmu->clk))
		return dev_err_probe(&pdev->dev, PTR_ERR(tmu->clk),
				     "failed to get tmu clock\n");

	ret = clk_prepare_enable(tmu->clk);
	if (ret) {
		dev_err(&pdev->dev, "failed to enable tmu clock: %d\n", ret);
		return ret;
	}

	/* disable the monitor during initialization */
	imx8mm_tmu_enable(tmu, false);

	for (i = 0; i < data->num_sensors; i++) {
		tmu->sensors[i].priv = tmu;
		tmu->sensors[i].tzd =
			devm_thermal_zone_of_sensor_register(&pdev->dev, i,
							     &tmu->sensors[i],
							     &tmu_tz_ops);
		if (IS_ERR(tmu->sensors[i].tzd)) {
			dev_err(&pdev->dev,
				"failed to register thermal zone sensor[%d]: %d\n",
				i, ret);
			return PTR_ERR(tmu->sensors[i].tzd);
		}
		tmu->sensors[i].hw_id = i;
	}

	platform_set_drvdata(pdev, tmu);

	/* enable all the probes for V2 TMU */
	if (tmu->socdata->version == TMU_VER2)
		imx8mm_tmu_probe_sel_all(tmu);

	/* enable the monitor */
	imx8mm_tmu_enable(tmu, true);

	return 0;
}

static int imx8mm_tmu_remove(struct platform_device *pdev)
{
	struct imx8mm_tmu *tmu = platform_get_drvdata(pdev);

	/* disable TMU */
	imx8mm_tmu_enable(tmu, false);

	clk_disable_unprepare(tmu->clk);
	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct thermal_soc_data imx8mm_tmu_data = {
	.num_sensors = 1,
	.version = TMU_VER1,
	.get_temp = imx8mm_tmu_get_temp,
};

static struct thermal_soc_data imx8mp_tmu_data = {
	.num_sensors = 2,
	.version = TMU_VER2,
	.get_temp = imx8mp_tmu_get_temp,
};

static const struct of_device_id imx8mm_tmu_table[] = {
	{ .compatible = "fsl,imx8mm-tmu", .data = &imx8mm_tmu_data, },
	{ .compatible = "fsl,imx8mp-tmu", .data = &imx8mp_tmu_data, },
	{ },
};
MODULE_DEVICE_TABLE(of, imx8mm_tmu_table);

static struct platform_driver imx8mm_tmu = {
	.driver = {
		.name	= "i.mx8mm_thermal",
		.of_match_table = imx8mm_tmu_table,
	},
	.probe = imx8mm_tmu_probe,
	.remove = imx8mm_tmu_remove,
};
module_platform_driver(imx8mm_tmu);

MODULE_AUTHOR("Anson Huang <Anson.Huang@nxp.com>");
MODULE_DESCRIPTION("i.MX8MM Thermal Monitor Unit driver");
MODULE_LICENSE("GPL v2");