Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / hwmon / jz4740-hwmon.c

diff --git a/kernel/drivers/hwmon/jz4740-hwmon.c b/kernel/drivers/hwmon/jz4740-hwmon.c
new file mode 100644 (file)
index 0000000..df9b344
--- /dev/null
+++ b/kernel/drivers/hwmon/jz4740-hwmon.c
@@ -0,0 +1,183 @@
+/*
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ * JZ4740 SoC HWMON driver
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under  the terms of the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include <linux/completion.h>
+#include <linux/mfd/core.h>
+
+#include <linux/hwmon.h>
+
+struct jz4740_hwmon {
+       void __iomem *base;
+
+       int irq;
+
+       const struct mfd_cell *cell;
+       struct device *hwmon;
+
+       struct completion read_completion;
+
+       struct mutex lock;
+};
+
+static ssize_t jz4740_hwmon_show_name(struct device *dev,
+       struct device_attribute *dev_attr, char *buf)
+{
+       return sprintf(buf, "jz4740\n");
+}
+
+static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
+{
+       struct jz4740_hwmon *hwmon = data;
+
+       complete(&hwmon->read_completion);
+       return IRQ_HANDLED;
+}
+
+static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
+       struct device_attribute *dev_attr, char *buf)
+{
+       struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
+       struct completion *completion = &hwmon->read_completion;
+       long t;
+       unsigned long val;
+       int ret;
+
+       mutex_lock(&hwmon->lock);
+
+       reinit_completion(completion);
+
+       enable_irq(hwmon->irq);
+       hwmon->cell->enable(to_platform_device(dev));
+
+       t = wait_for_completion_interruptible_timeout(completion, HZ);
+
+       if (t > 0) {
+               val = readw(hwmon->base) & 0xfff;
+               val = (val * 3300) >> 12;
+               ret = sprintf(buf, "%lu\n", val);
+       } else {
+               ret = t ? t : -ETIMEDOUT;
+       }
+
+       hwmon->cell->disable(to_platform_device(dev));
+       disable_irq(hwmon->irq);
+
+       mutex_unlock(&hwmon->lock);
+
+       return ret;
+}
+
+static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
+static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);
+
+static struct attribute *jz4740_hwmon_attributes[] = {
+       &dev_attr_name.attr,
+       &dev_attr_in0_input.attr,
+       NULL
+};
+
+static const struct attribute_group jz4740_hwmon_attr_group = {
+       .attrs = jz4740_hwmon_attributes,
+};
+
+static int jz4740_hwmon_probe(struct platform_device *pdev)
+{
+       int ret;
+       struct jz4740_hwmon *hwmon;
+       struct resource *mem;
+
+       hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
+       if (!hwmon)
+               return -ENOMEM;
+
+       hwmon->cell = mfd_get_cell(pdev);
+
+       hwmon->irq = platform_get_irq(pdev, 0);
+       if (hwmon->irq < 0) {
+               dev_err(&pdev->dev, "Failed to get platform irq: %d\n",
+                       hwmon->irq);
+               return hwmon->irq;
+       }
+
+       mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       hwmon->base = devm_ioremap_resource(&pdev->dev, mem);
+       if (IS_ERR(hwmon->base))
+               return PTR_ERR(hwmon->base);
+
+       init_completion(&hwmon->read_completion);
+       mutex_init(&hwmon->lock);
+
+       platform_set_drvdata(pdev, hwmon);
+
+       ret = devm_request_irq(&pdev->dev, hwmon->irq, jz4740_hwmon_irq, 0,
+                              pdev->name, hwmon);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
+               return ret;
+       }
+       disable_irq(hwmon->irq);
+
+       ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+       if (ret) {
+               dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
+               return ret;
+       }
+
+       hwmon->hwmon = hwmon_device_register(&pdev->dev);
+       if (IS_ERR(hwmon->hwmon)) {
+               ret = PTR_ERR(hwmon->hwmon);
+               goto err_remove_file;
+       }
+
+       return 0;
+
+err_remove_file:
+       sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+       return ret;
+}
+
+static int jz4740_hwmon_remove(struct platform_device *pdev)
+{
+       struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
+
+       hwmon_device_unregister(hwmon->hwmon);
+       sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+
+       return 0;
+}
+
+static struct platform_driver jz4740_hwmon_driver = {
+       .probe  = jz4740_hwmon_probe,
+       .remove = jz4740_hwmon_remove,
+       .driver = {
+               .name = "jz4740-hwmon",
+       },
+};
+
+module_platform_driver(jz4740_hwmon_driver);
+
+MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:jz4740-hwmon");