thermal: add support for thermal sensor present on SPEAr13xx machines
Vincenzo Frascino [Wed, 21 Mar 2012 19:55:03 +0000 (12:55 -0700)]
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
drivers/thermal/Makefile
drivers/thermal/spear_thermal.c [new file with mode: 0644]
include/linux/platform_data/spear_thermal.h [new file with mode: 0644]

index f7f71b2..514a691 100644 (file)
@@ -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
index 31108a0..a9fff0b 100644 (file)
@@ -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 (file)
index 0000000..880bf28
--- /dev/null
@@ -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 (file)
index 0000000..724f2e1
--- /dev/null
@@ -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 */