hwmon: Add WM835x PMIC hardware monitoring driver

This driver provides reporting of the status supply voltage rails
of the WM835x series of PMICs via the hwmon API.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 151 insertions, 0 deletions

diff --git a/drivers/hwmon/wm8350-hwmon.c b/drivers/hwmon/wm8350-hwmon.c
new file mode 100644
index 000000000000..13290595ca86
--- /dev/null
+++ b/drivers/hwmon/wm8350-hwmon.c
@@ -0,0 +1,151 @@
+/*
+ * drivers/hwmon/wm8350-hwmon.c - Wolfson Microelectronics WM8350 PMIC
+ *                                  hardware monitoring features.
+ *
+ * Copyright (C) 2009 Wolfson Microelectronics plc
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License v2 as published by the
+ * Free Software Foundation.
+ *
+ * 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.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/mfd/wm8350/core.h>
+#include <linux/mfd/wm8350/comparator.h>
+
+static ssize_t show_name(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "wm8350\n");
+}
+
+static const char *input_names[] = {
+	[WM8350_AUXADC_USB]  = "USB",
+	[WM8350_AUXADC_LINE] = "Line",
+	[WM8350_AUXADC_BATT] = "Battery",
+};
+
+
+static ssize_t show_voltage(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct wm8350 *wm8350 = dev_get_drvdata(dev);
+	int channel = to_sensor_dev_attr(attr)->index;
+	int val;
+
+	val = wm8350_read_auxadc(wm8350, channel, 0, 0) * WM8350_AUX_COEFF;
+	val = DIV_ROUND_CLOSEST(val, 1000);
+
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t show_label(struct device *dev,
+			  struct device_attribute *attr, char *buf)
+{
+	int channel = to_sensor_dev_attr(attr)->index;
+
+	return sprintf(buf, "%s\n", input_names[channel]);
+}
+
+#define WM8350_NAMED_VOLTAGE(id, name) \
+	static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage,\
+				  NULL, name);		\
+	static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,	\
+				  NULL, name)
+
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+WM8350_NAMED_VOLTAGE(0, WM8350_AUXADC_USB);
+WM8350_NAMED_VOLTAGE(1, WM8350_AUXADC_BATT);
+WM8350_NAMED_VOLTAGE(2, WM8350_AUXADC_LINE);
+
+static struct attribute *wm8350_attributes[] = {
+	&dev_attr_name.attr,
+
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in0_label.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_label.dev_attr.attr,
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in2_label.dev_attr.attr,
+
+	NULL,
+};
+
+static const struct attribute_group wm8350_attr_group = {
+	.attrs	= wm8350_attributes,
+};
+
+static int __devinit wm8350_hwmon_probe(struct platform_device *pdev)
+{
+	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &wm8350_attr_group);
+	if (ret)
+		goto err;
+
+	wm8350->hwmon.classdev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(wm8350->hwmon.classdev)) {
+		ret = PTR_ERR(wm8350->hwmon.classdev);
+		goto err_group;
+	}
+
+	return 0;
+
+err_group:
+	sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
+err:
+	return ret;
+}
+
+static int __devexit wm8350_hwmon_remove(struct platform_device *pdev)
+{
+	struct wm8350 *wm8350 = platform_get_drvdata(pdev);
+
+	hwmon_device_unregister(wm8350->hwmon.classdev);
+	sysfs_remove_group(&pdev->dev.kobj, &wm8350_attr_group);
+
+	return 0;
+}
+
+static struct platform_driver wm8350_hwmon_driver = {
+	.probe = wm8350_hwmon_probe,
+	.remove = __devexit_p(wm8350_hwmon_remove),
+	.driver = {
+		.name = "wm8350-hwmon",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init wm8350_hwmon_init(void)
+{
+	return platform_driver_register(&wm8350_hwmon_driver);
+}
+module_init(wm8350_hwmon_init);
+
+static void __exit wm8350_hwmon_exit(void)
+{
+	platform_driver_unregister(&wm8350_hwmon_driver);
+}
+module_exit(wm8350_hwmon_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM8350 Hardware Monitoring");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8350-hwmon");