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Diffstat (limited to 'drivers/thermal/kirkwood_thermal.c')
-rw-r--r--drivers/thermal/kirkwood_thermal.c123
1 files changed, 123 insertions, 0 deletions
diff --git a/drivers/thermal/kirkwood_thermal.c b/drivers/thermal/kirkwood_thermal.c
new file mode 100644
index 000000000..7fb6e476c
--- /dev/null
+++ b/drivers/thermal/kirkwood_thermal.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Kirkwood thermal sensor driver
+ *
+ * Copyright (C) 2012 Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+#define KIRKWOOD_THERMAL_VALID_OFFSET 9
+#define KIRKWOOD_THERMAL_VALID_MASK 0x1
+#define KIRKWOOD_THERMAL_TEMP_OFFSET 10
+#define KIRKWOOD_THERMAL_TEMP_MASK 0x1FF
+
+/* Kirkwood Thermal Sensor Dev Structure */
+struct kirkwood_thermal_priv {
+ void __iomem *sensor;
+};
+
+static int kirkwood_get_temp(struct thermal_zone_device *thermal,
+ int *temp)
+{
+ unsigned long reg;
+ struct kirkwood_thermal_priv *priv = thermal->devdata;
+
+ reg = readl_relaxed(priv->sensor);
+
+ /* Valid check */
+ if (!((reg >> KIRKWOOD_THERMAL_VALID_OFFSET) &
+ KIRKWOOD_THERMAL_VALID_MASK)) {
+ dev_err(&thermal->device,
+ "Temperature sensor reading not valid\n");
+ return -EIO;
+ }
+
+ /*
+ * Calculate temperature. According to Marvell internal
+ * documentation the formula for this is:
+ * Celsius = (322-reg)/1.3625
+ */
+ reg = (reg >> KIRKWOOD_THERMAL_TEMP_OFFSET) &
+ KIRKWOOD_THERMAL_TEMP_MASK;
+ *temp = ((3220000000UL - (10000000UL * reg)) / 13625);
+
+ return 0;
+}
+
+static struct thermal_zone_device_ops ops = {
+ .get_temp = kirkwood_get_temp,
+};
+
+static const struct of_device_id kirkwood_thermal_id_table[] = {
+ { .compatible = "marvell,kirkwood-thermal" },
+ {}
+};
+
+static int kirkwood_thermal_probe(struct platform_device *pdev)
+{
+ struct thermal_zone_device *thermal = NULL;
+ struct kirkwood_thermal_priv *priv;
+ struct resource *res;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->sensor = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->sensor))
+ return PTR_ERR(priv->sensor);
+
+ thermal = thermal_zone_device_register("kirkwood_thermal", 0, 0,
+ priv, &ops, NULL, 0, 0);
+ if (IS_ERR(thermal)) {
+ dev_err(&pdev->dev,
+ "Failed to register thermal zone device\n");
+ return PTR_ERR(thermal);
+ }
+ ret = thermal_zone_device_enable(thermal);
+ if (ret) {
+ thermal_zone_device_unregister(thermal);
+ dev_err(&pdev->dev, "Failed to enable thermal zone device\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, thermal);
+
+ return 0;
+}
+
+static int kirkwood_thermal_exit(struct platform_device *pdev)
+{
+ struct thermal_zone_device *kirkwood_thermal =
+ platform_get_drvdata(pdev);
+
+ thermal_zone_device_unregister(kirkwood_thermal);
+
+ return 0;
+}
+
+MODULE_DEVICE_TABLE(of, kirkwood_thermal_id_table);
+
+static struct platform_driver kirkwood_thermal_driver = {
+ .probe = kirkwood_thermal_probe,
+ .remove = kirkwood_thermal_exit,
+ .driver = {
+ .name = "kirkwood_thermal",
+ .of_match_table = kirkwood_thermal_id_table,
+ },
+};
+
+module_platform_driver(kirkwood_thermal_driver);
+
+MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
+MODULE_DESCRIPTION("kirkwood thermal driver");
+MODULE_LICENSE("GPL");