[PATCH 1/2] thermal: Add support for thermal sensor for Orion SoC

[andrew@lunn.ch (Andrew Lunn)]

From: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

Some Orion SoC has thermal sensor.
This patch adds support for 88F6282 and 88F6283.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 .../devicetree/bindings/thermal/orion-thermal.txt  |   16 +++
 drivers/thermal/Kconfig                            |    7 ++
 drivers/thermal/Makefile                           |    1 +
 drivers/thermal/orion_thermal.c                    |  133 ++++++++++++++++++++
 4 files changed, 157 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/thermal/orion-thermal.txt
 create mode 100644 drivers/thermal/orion_thermal.c

diff --git a/Documentation/devicetree/bindings/thermal/orion-thermal.txt b/Documentation/devicetree/bindings/thermal/orion-thermal.txt
new file mode 100644
index 0000000..5ce925d
--- /dev/null
+++ b/Documentation/devicetree/bindings/thermal/orion-thermal.txt
@@ -0,0 +1,16 @@
+* Orion Thermal
+
+This initial version is for Kirkwood 88F8262 & 88F6283 SoCs, however
+it is expected the driver will sometime in the future be expanded to
+also support Dove, using a different compatibility string.
+
+Required properties:
+- compatible : "marvell,kirkwood-thermal"
+- reg : Address range of the thermal registers
+
+Example:
+
+	thermal at 10078 {
+		compatible = "marvell,kirkwood";
+		reg = <0x10078 0x4>;
+	};
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index e1cb6bd..3bba13f 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -55,3 +55,10 @@ config EXYNOS_THERMAL
 	help
 	  If you say yes here you get support for TMU (Thermal Managment
 	  Unit) on SAMSUNG EXYNOS series of SoC.
+
+config ORION_THERMAL
+	tristate "Temperature sensor on Marvel Orion SoCs"
+	depends on PLAT_ORION && THERMAL
+	help
+	  Support for the Orion thermal sensor driver into the Linux thermal
+	  framework. This currently supports only 88F6282 and 88F6283.
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 885550d..2fc64aa 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_THERMAL)		+= thermal_sys.o
 obj-$(CONFIG_CPU_THERMAL)		+= cpu_cooling.o
 obj-$(CONFIG_SPEAR_THERMAL)		+= spear_thermal.o
 obj-$(CONFIG_RCAR_THERMAL)	+= rcar_thermal.o
+obj-$(CONFIG_ORION_THERMAL)         	+= orion_thermal.o
 obj-$(CONFIG_EXYNOS_THERMAL)		+= exynos_thermal.o
diff --git a/drivers/thermal/orion_thermal.c b/drivers/thermal/orion_thermal.c
new file mode 100644
index 0000000..e8a2a68
--- /dev/null
+++ b/drivers/thermal/orion_thermal.c
@@ -0,0 +1,133 @@
+/*
+ * Orion thermal sensor driver
+ *
+ * Copyright (C) 2012 Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+#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 THERMAL_VALID_OFFSET	9
+#define THERMAL_VALID_MASK	0x1
+#define THERMAL_TEMP_OFFSET	10
+#define THERMAL_TEMP_MASK	0x1FF
+
+/* Orion Thermal Sensor Dev Structure */
+struct orion_thermal_dev {
+	void __iomem *base_addr;
+};
+
+static int orion_get_temp(struct thermal_zone_device *thermal,
+			  unsigned long *temp)
+{
+	unsigned long reg;
+	struct orion_thermal_dev *thermal_dev = thermal->devdata;
+
+	reg = readl_relaxed(thermal_dev->base_addr);
+
+	/* Valid check */
+	if (!(reg >> THERMAL_VALID_OFFSET) & THERMAL_VALID_MASK) {
+		dev_info(&thermal->device,
+			 "Temperature sensor reading not valid\n");
+		return -EIO;
+	}
+
+	reg = (reg >> THERMAL_TEMP_OFFSET) & THERMAL_TEMP_MASK;
+	/* Calculate temperature. See Table 814 in 8262 hardware manual. */
+	*temp = ((322UL - reg) * 10000UL * 1000UL) / 13625UL;
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops ops = {
+	.get_temp = orion_get_temp,
+};
+
+static int orion_thermal_probe(struct platform_device *pdev)
+{
+	struct thermal_zone_device *thermal = NULL;
+	struct orion_thermal_dev *thermal_dev;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Failed to get platform resource\n");
+		return -ENODEV;
+	}
+
+	thermal_dev = devm_kzalloc(&pdev->dev, sizeof(*thermal_dev),
+				   GFP_KERNEL);
+	if (!thermal_dev) {
+		dev_err(&pdev->dev, "kzalloc fail\n");
+		return -ENOMEM;
+	}
+
+	thermal_dev->base_addr = devm_ioremap(&pdev->dev, res->start,
+					      resource_size(res));
+	if (!thermal_dev->base_addr) {
+		dev_err(&pdev->dev, "Failed to ioremap memory\n");
+		return -ENOMEM;
+	}
+
+	thermal = thermal_zone_device_register("orion_thermal", 0, 0,
+				   thermal_dev, &ops, 0, 0);
+	if (IS_ERR(thermal)) {
+		dev_err(&pdev->dev,
+			"Failed to register thermal zone device\n");
+		return  PTR_ERR(thermal);
+	}
+
+	platform_set_drvdata(pdev, thermal);
+
+	dev_info(&thermal->device,
+		 KBUILD_MODNAME ": Thermal sensor registered\n");
+
+	return 0;
+}
+
+static int orion_thermal_exit(struct platform_device *pdev)
+{
+	struct thermal_zone_device *orion_thermal = platform_get_drvdata(pdev);
+
+	thermal_zone_device_unregister(orion_thermal);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id orion_thermal_id_table[] = {
+	{ .compatible = "marvell,kirkwood-thermal" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, orion_thermal_id_table);
+
+static struct platform_driver orion_thermal_driver = {
+	.probe = orion_thermal_probe,
+	.remove = orion_thermal_exit,
+	.driver = {
+		.name = "orion_thermal",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(orion_thermal_id_table),
+	},
+};
+
+module_platform_driver(orion_thermal_driver);
+
+MODULE_AUTHOR("Nobuhiro Iwamatsu <iwamatsu@nigauri.org>");
+MODULE_DESCRIPTION("orion thermal driver");
+MODULE_LICENSE("GPL");
-- 
1.7.10.4