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Subject[PATCH 18/76] thermal: add support for thermal sensor present on SPEAr13xx machines
Date
From: Vincenzo Frascino <vincenzo.frascino@st.com>

ST's SPEAr13xx machines are based on CortexA9 ARM processors. These
machines contain a thermal sensor for junction temperature monitoring.

This patch adds support for this thermal sensor in existing thermal
framework.

[akpm@linux-foundation.org: little code cleanup]
[akpm@linux-foundation.org: print the pointer correctly]
[viresh.kumar@st.com: thermal/spear_thermal: add compilation dependency on PLAT_SPEAR]
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
---
drivers/thermal/Kconfig | 8 ++
drivers/thermal/Makefile | 1 +
drivers/thermal/spear_thermal.c | 206 +++++++++++++++++++++++++++
include/linux/platform_data/spear_thermal.h | 26 ++++
4 files changed, 241 insertions(+)
create mode 100644 drivers/thermal/spear_thermal.c
create mode 100644 include/linux/platform_data/spear_thermal.h

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index f7f71b2..514a691 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -18,3 +18,11 @@ config THERMAL_HWMON
depends on THERMAL
depends on HWMON=y || HWMON=THERMAL
default y
+
+config SPEAR_THERMAL
+ bool "SPEAr thermal sensor driver"
+ depends on THERMAL
+ depends on PLAT_SPEAR
+ help
+ Enable this to plug the SPEAr thermal sensor driver into the Linux
+ thermal framework
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 31108a0..a9fff0b 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -3,3 +3,4 @@
#

obj-$(CONFIG_THERMAL) += thermal_sys.o
+obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o
\ No newline at end of file
diff --git a/drivers/thermal/spear_thermal.c b/drivers/thermal/spear_thermal.c
new file mode 100644
index 0000000..880bf28
--- /dev/null
+++ b/drivers/thermal/spear_thermal.c
@@ -0,0 +1,206 @@
+/*
+ * SPEAr thermal driver.
+ *
+ * Copyright (C) 2011-2012 ST Microelectronics
+ * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
+ *
+ * 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/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/spear_thermal.h>
+#include <linux/thermal.h>
+
+#define MD_FACTOR 1000
+
+/* SPEAr Thermal Sensor Dev Structure */
+struct spear_thermal_dev {
+ /* pointer to base address of the thermal sensor */
+ void __iomem *thermal_base;
+ /* clk structure */
+ struct clk *clk;
+ /* pointer to thermal flags */
+ unsigned int flags;
+};
+
+static inline int thermal_get_temp(struct thermal_zone_device *thermal,
+ unsigned long *temp)
+{
+ struct spear_thermal_dev *stdev = thermal->devdata;
+
+ /*
+ * Data are ready to be read after 628 usec from POWERDOWN signal
+ * (PDN) = 1
+ */
+ *temp = (readl(stdev->thermal_base) & 0x7F) * MD_FACTOR;
+ return 0;
+}
+
+static struct thermal_zone_device_ops ops = {
+ .get_temp = thermal_get_temp,
+};
+
+#ifdef CONFIG_PM
+static int spear_thermal_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
+ struct spear_thermal_dev *stdev = spear_thermal->devdata;
+ unsigned int actual_mask = 0;
+
+ /* Disable SPEAr Thermal Sensor */
+ actual_mask = readl(stdev->thermal_base);
+ writel(actual_mask & ~stdev->flags, stdev->thermal_base);
+
+ clk_disable(stdev->clk);
+ dev_info(dev, "Suspended.\n");
+
+ return 0;
+}
+
+static int spear_thermal_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
+ struct spear_thermal_dev *stdev = spear_thermal->devdata;
+ unsigned int actual_mask = 0;
+ int ret = 0;
+
+ ret = clk_enable(stdev->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't enable clock\n");
+ return ret;
+ }
+
+ /* Enable SPEAr Thermal Sensor */
+ actual_mask = readl(stdev->thermal_base);
+ writel(actual_mask | stdev->flags, stdev->thermal_base);
+
+ dev_info(dev, "Resumed.\n");
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
+ spear_thermal_resume);
+
+static int spear_thermal_probe(struct platform_device *pdev)
+{
+ struct thermal_zone_device *spear_thermal = NULL;
+ struct spear_thermal_dev *stdev;
+ struct spear_thermal_pdata *pdata;
+ int ret = 0;
+ struct resource *stres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!stres) {
+ dev_err(&pdev->dev, "memory resource missing\n");
+ return -ENODEV;
+ }
+
+ pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform data is NULL\n");
+ return -EINVAL;
+ }
+
+ stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
+ if (!stdev) {
+ dev_err(&pdev->dev, "kzalloc fail\n");
+ return -ENOMEM;
+ }
+
+ /* Enable thermal sensor */
+ stdev->thermal_base = devm_ioremap(&pdev->dev, stres->start,
+ resource_size(stres));
+ if (!stdev->thermal_base) {
+ dev_err(&pdev->dev, "ioremap failed\n");
+ return -ENOMEM;
+ }
+
+ stdev->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(stdev->clk)) {
+ dev_err(&pdev->dev, "Can't get clock\n");
+ return PTR_ERR(stdev->clk);
+ }
+
+ ret = clk_enable(stdev->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't enable clock\n");
+ goto put_clk;
+ }
+
+ stdev->flags = pdata->thermal_flags;
+ writel(stdev->flags, stdev->thermal_base);
+
+ spear_thermal = thermal_zone_device_register("spear_thermal", 0,
+ stdev, &ops, 0, 0, 0, 0);
+ if (!spear_thermal) {
+ dev_err(&pdev->dev, "thermal zone device is NULL\n");
+ ret = -EINVAL;
+ goto disable_clk;
+ }
+
+ platform_set_drvdata(pdev, spear_thermal);
+
+ dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
+ stdev->thermal_base);
+
+ return 0;
+
+disable_clk:
+ clk_disable(stdev->clk);
+put_clk:
+ clk_put(stdev->clk);
+
+ return ret;
+}
+
+static int spear_thermal_exit(struct platform_device *pdev)
+{
+ unsigned int actual_mask = 0;
+ struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
+ struct spear_thermal_dev *stdev = spear_thermal->devdata;
+
+ thermal_zone_device_unregister(spear_thermal);
+ platform_set_drvdata(pdev, NULL);
+
+ /* Disable SPEAr Thermal Sensor */
+ actual_mask = readl(stdev->thermal_base);
+ writel(actual_mask & ~stdev->flags, stdev->thermal_base);
+
+ clk_disable(stdev->clk);
+ clk_put(stdev->clk);
+
+ return 0;
+}
+
+static struct platform_driver spear_thermal_driver = {
+ .probe = spear_thermal_probe,
+ .remove = spear_thermal_exit,
+ .driver = {
+ .name = "spear_thermal",
+ .owner = THIS_MODULE,
+ .pm = &spear_thermal_pm_ops,
+ },
+};
+
+module_platform_driver(spear_thermal_driver);
+
+MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
+MODULE_DESCRIPTION("SPEAr thermal driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/platform_data/spear_thermal.h b/include/linux/platform_data/spear_thermal.h
new file mode 100644
index 0000000..724f2e1
--- /dev/null
+++ b/include/linux/platform_data/spear_thermal.h
@@ -0,0 +1,26 @@
+/*
+ * SPEAr thermal driver platform data.
+ *
+ * Copyright (C) 2011-2012 ST Microelectronics
+ * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
+ *
+ * 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.
+ *
+ */
+#ifndef SPEAR_THERMAL_H
+#define SPEAR_THERMAL_H
+
+/* SPEAr Thermal Sensor Platform Data */
+struct spear_thermal_pdata {
+ /* flags used to enable thermal sensor */
+ unsigned int thermal_flags;
+};
+
+#endif /* SPEAR_THERMAL_H */
--
1.7.10.rc2.19.gfae9d


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