thermal: imx8mm: Add support for i.MX8MM thermal monitoring unit

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>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1582947862-11073-2-git-send-email-Anson.Huang@nxp.com

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index bb7b010..770e0bd 100644 (file)
--- 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 4d1b4e7..8c8ed7b 100644 (file)
--- 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 (file)
index 0000000..d597ceb
--- /dev/null
+++ b/drivers/thermal/imx8mm_thermal.c
@@ -0,0 +1,131 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2020 NXP.
+ *
+ * Author: Anson Huang <Anson.Huang@nxp.com>
+ */
+
+#include <linux/clk.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;
+
+       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");