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Subject[PATCH V2 2/4] thermal: imx8mm: Add support for i.MX8MM thermal monitoring unit
Date
i.MX8MM has a thermal monitoring unit(TMU) inside, it ONLY has one
sensor for CPU, add support for reading immediate temperature of
this sensor.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
Changes since V1:
- Update the copyright and add the author.
---
drivers/thermal/Kconfig | 10 +++
drivers/thermal/Makefile | 1 +
drivers/thermal/imx8mm_thermal.c | 135 +++++++++++++++++++++++++++++++++++++++
3 files changed, 146 insertions(+)
create mode 100644 drivers/thermal/imx8mm_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 3502ee8..165b7d6 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -262,6 +262,16 @@ config IMX_SC_THERMAL
sensor. It supports one critical trip point and one
passive trip point for each thermal sensor.

+config IMX8MM_THERMAL
+ tristate "Temperature sensor driver for Freescale i.MX8MM SoC"
+ depends on ARCH_MXC
+ depends on OF
+ help
+ Support for Thermal Monitoring Unit (TMU) found on Freescale i.MX8MM 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 MAX77620_THERMAL
tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
depends on MFD_MAX77620
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index a11a6d8..120a05e 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
obj-$(CONFIG_TANGO_THERMAL) += tango_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_MAX77620_THERMAL) += max77620_thermal.o
obj-$(CONFIG_QORIQ_THERMAL) += qoriq_thermal.o
obj-$(CONFIG_DA9062_THERMAL) += da9062-thermal.o
diff --git a/drivers/thermal/imx8mm_thermal.c b/drivers/thermal/imx8mm_thermal.c
new file mode 100644
index 0000000..ad5dd57
--- /dev/null
+++ b/drivers/thermal/imx8mm_thermal.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 NXP.
+ *
+ * Author: Anson Huang <Anson.Huang@nxp.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#include "thermal_core.h"
+
+#define TER 0x0 /* TMU enable */
+#define TRITSR 0x20 /* TMU immediate temp */
+
+#define TER_EN BIT(31)
+#define TRITSR_VAL_MASK 0xff
+
+#define TEMP_LOW_LIMIT 10
+
+struct imx8mm_tmu {
+ struct thermal_zone_device *tzd;
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static int tmu_get_temp(void *data, int *temp)
+{
+ struct imx8mm_tmu *tmu = data;
+ u32 val;
+
+ /* the temp sensor need about 1ms to finish the measurement */
+ usleep_range(1000, 2000);
+
+ val = readl_relaxed(tmu->base + TRITSR) & TRITSR_VAL_MASK;
+ if (val < TEMP_LOW_LIMIT)
+ return -EAGAIN;
+
+ *temp = val * 1000;
+
+ return 0;
+}
+
+static struct thermal_zone_of_device_ops tmu_tz_ops = {
+ .get_temp = tmu_get_temp,
+};
+
+static int imx8mm_tmu_probe(struct platform_device *pdev)
+{
+ struct imx8mm_tmu *tmu;
+ u32 val;
+ int ret;
+
+ tmu = devm_kzalloc(&pdev->dev, sizeof(struct imx8mm_tmu), GFP_KERNEL);
+ if (!tmu)
+ return -ENOMEM;
+
+ 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)) {
+ ret = PTR_ERR(tmu->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err(&pdev->dev,
+ "failed to get tmu clock: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(tmu->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable tmu clock: %d\n", ret);
+ return ret;
+ }
+
+ tmu->tzd = devm_thermal_zone_of_sensor_register(&pdev->dev, 0,
+ tmu, &tmu_tz_ops);
+ if (IS_ERR(tmu->tzd)) {
+ dev_err(&pdev->dev,
+ "failed to register thermal zone sensor: %d\n", ret);
+ return PTR_ERR(tmu->tzd);
+ }
+
+ platform_set_drvdata(pdev, tmu);
+
+ /* enable the monitor */
+ val = readl_relaxed(tmu->base + TER);
+ val |= TER_EN;
+ writel_relaxed(val, tmu->base + TER);
+
+ return 0;
+}
+
+static int imx8mm_tmu_remove(struct platform_device *pdev)
+{
+ struct imx8mm_tmu *tmu = platform_get_drvdata(pdev);
+ u32 val;
+
+ /* disable TMU */
+ val = readl_relaxed(tmu->base + TER);
+ val &= ~TER_EN;
+ writel_relaxed(val, tmu->base + TER);
+
+ clk_disable_unprepare(tmu->clk);
+ platform_set_drvdata(pdev, NULL);
+
+ return 0;
+}
+
+static const struct of_device_id imx8mm_tmu_table[] = {
+ { .compatible = "fsl,imx8mm-tmu", },
+ { },
+};
+
+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");
--
2.7.4
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