4 files changed, 275 insertions, 0 deletions

diff --git a/Documentation/hwmon/wm831x b/Documentation/hwmon/wm831x
new file mode 100644
index 000000000000..24f47d8f6a42
--- /dev/null
+++ b/Documentation/hwmon/wm831x
@@ -0,0 +1,37 @@
+Kernel driver wm831x-hwmon
+==========================
+
+Supported chips:
+  * Wolfson Microelectronics WM831x PMICs
+    Prefix: 'wm831x'
+    Datasheet:
+        http://www.wolfsonmicro.com/products/WM8310
+        http://www.wolfsonmicro.com/products/WM8311
+        http://www.wolfsonmicro.com/products/WM8312
+
+Authors: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+Description
+-----------
+
+The WM831x series of PMICs include an AUXADC which can be used to
+monitor a range of system operating parameters, including the voltages
+of the major supplies within the system.  Currently the driver provides
+reporting of all the input values but does not provide any alarms.
+
+Voltage Monitoring
+------------------
+
+Voltages are sampled by a 12 bit ADC.  Voltages in milivolts are 1.465
+times the ADC value.
+
+Temperature Monitoring
+----------------------
+
+Temperatures are sampled by a 12 bit ADC.  Chip and battery temperatures
+are available.  The chip temperature is calculated as:
+
+        Degrees celsius = (512.18 - data) / 1.0983
+
+while the battery temperature calculation will depend on the NTC
+thermistor component.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 120085ce651a..83e07e55a78e 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -937,6 +937,17 @@ config SENSORS_W83627EHF
           This driver can also be built as a module.  If so, the module
           will be called w83627ehf.
 
+config SENSORS_WM831X
+        tristate "WM831x PMICs"
+        depends on MFD_WM831X
+        help
+          If you say yes here you get support for the hardware
+          monitoring functionality of the Wolfson Microelectronics
+          WM831x series of PMICs.
+
+          This driver can also be built as a module.  If so, the module
+          will be called wm831x-hwmon.
+
 config SENSORS_WM8350
         tristate "Wolfson Microelectronics WM835x"
         depends on MFD_WM8350
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index ed5f1781b8c4..c5effd609abc 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -90,6 +90,7 @@ obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o
 obj-$(CONFIG_SENSORS_W83627EHF) += w83627ehf.o
 obj-$(CONFIG_SENSORS_W83L785TS) += w83l785ts.o
 obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
+obj-$(CONFIG_SENSORS_WM831X)    += wm831x-hwmon.o
 obj-$(CONFIG_SENSORS_WM8350)    += wm8350-hwmon.o
 
 ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
diff --git a/drivers/hwmon/wm831x-hwmon.c b/drivers/hwmon/wm831x-hwmon.c
new file mode 100644
index 000000000000..c16e9e74c356
--- /dev/null
+++ b/drivers/hwmon/wm831x-hwmon.c
@@ -0,0 +1,226 @@
+/*
+ * drivers/hwmon/wm831x-hwmon.c - Wolfson Microelectronics WM831x 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/platform_device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/auxadc.h>
+
+struct wm831x_hwmon {
+        struct wm831x *wm831x;
+        struct device *classdev;
+};
+
+static ssize_t show_name(struct device *dev,
+                         struct device_attribute *attr, char *buf)
+{
+        return sprintf(buf, "wm831x\n");
+}
+
+static const char *input_names[] = {
+        [WM831X_AUX_SYSVDD]    = "SYSVDD",
+        [WM831X_AUX_USB]       = "USB",
+        [WM831X_AUX_BKUP_BATT] = "Backup battery",
+        [WM831X_AUX_BATT]      = "Battery",
+        [WM831X_AUX_WALL]      = "WALL",
+        [WM831X_AUX_CHIP_TEMP] = "PMIC",
+        [WM831X_AUX_BATT_TEMP] = "Battery",
+};
+
+
+static ssize_t show_voltage(struct device *dev,
+                            struct device_attribute *attr, char *buf)
+{
+        struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
+        int channel = to_sensor_dev_attr(attr)->index;
+        int ret;
+
+        ret = wm831x_auxadc_read_uv(hwmon->wm831x, channel);
+        if (ret < 0)
+                return ret;
+
+        return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(ret, 1000));
+}
+
+static ssize_t show_chip_temp(struct device *dev,
+                              struct device_attribute *attr, char *buf)
+{
+        struct wm831x_hwmon *hwmon = dev_get_drvdata(dev);
+        int channel = to_sensor_dev_attr(attr)->index;
+        int ret;
+
+        ret = wm831x_auxadc_read(hwmon->wm831x, channel);
+        if (ret < 0)
+                return ret;
+
+        /* Degrees celsius = (512.18-ret) / 1.0983 */
+        ret = 512180 - (ret * 1000);
+        ret = DIV_ROUND_CLOSEST(ret * 10000, 10983);
+
+        return sprintf(buf, "%d\n", ret);
+}
+
+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 WM831X_VOLTAGE(id, name) \
+        static SENSOR_DEVICE_ATTR(in##id##_input, S_IRUGO, show_voltage, \
+                                  NULL, name)
+
+#define WM831X_NAMED_VOLTAGE(id, name) \
+        WM831X_VOLTAGE(id, name); \
+        static SENSOR_DEVICE_ATTR(in##id##_label, S_IRUGO, show_label,  \
+                                  NULL, name)
+
+static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+WM831X_VOLTAGE(0, WM831X_AUX_AUX1);
+WM831X_VOLTAGE(1, WM831X_AUX_AUX2);
+WM831X_VOLTAGE(2, WM831X_AUX_AUX3);
+WM831X_VOLTAGE(3, WM831X_AUX_AUX4);
+
+WM831X_NAMED_VOLTAGE(4, WM831X_AUX_SYSVDD);
+WM831X_NAMED_VOLTAGE(5, WM831X_AUX_USB);
+WM831X_NAMED_VOLTAGE(6, WM831X_AUX_BATT);
+WM831X_NAMED_VOLTAGE(7, WM831X_AUX_WALL);
+WM831X_NAMED_VOLTAGE(8, WM831X_AUX_BKUP_BATT);
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_chip_temp, NULL,
+                          WM831X_AUX_CHIP_TEMP);
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
+                          WM831X_AUX_CHIP_TEMP);
+/* Report as a voltage since conversion depends on external components
+ * and that's what the ABI wants. */
+static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_voltage, NULL,
+                          WM831X_AUX_BATT_TEMP);
+static SENSOR_DEVICE_ATTR(temp2_label, S_IRUGO, show_label, NULL,
+                          WM831X_AUX_BATT_TEMP);
+
+static struct attribute *wm831x_attributes[] = {
+        &dev_attr_name.attr,
+
+        &sensor_dev_attr_in0_input.dev_attr.attr,
+        &sensor_dev_attr_in1_input.dev_attr.attr,
+        &sensor_dev_attr_in2_input.dev_attr.attr,
+        &sensor_dev_attr_in3_input.dev_attr.attr,
+
+        &sensor_dev_attr_in4_input.dev_attr.attr,
+        &sensor_dev_attr_in4_label.dev_attr.attr,
+        &sensor_dev_attr_in5_input.dev_attr.attr,
+        &sensor_dev_attr_in5_label.dev_attr.attr,
+        &sensor_dev_attr_in6_input.dev_attr.attr,
+        &sensor_dev_attr_in6_label.dev_attr.attr,
+        &sensor_dev_attr_in7_input.dev_attr.attr,
+        &sensor_dev_attr_in7_label.dev_attr.attr,
+        &sensor_dev_attr_in8_input.dev_attr.attr,
+        &sensor_dev_attr_in8_label.dev_attr.attr,
+
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_temp1_label.dev_attr.attr,
+        &sensor_dev_attr_temp2_input.dev_attr.attr,
+        &sensor_dev_attr_temp2_label.dev_attr.attr,
+
+        NULL
+};
+
+static const struct attribute_group wm831x_attr_group = {
+        .attrs  = wm831x_attributes,
+};
+
+static int __devinit wm831x_hwmon_probe(struct platform_device *pdev)
+{
+        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+        struct wm831x_hwmon *hwmon;
+        int ret;
+
+        hwmon = kzalloc(sizeof(struct wm831x_hwmon), GFP_KERNEL);
+        if (!hwmon)
+                return -ENOMEM;
+
+        hwmon->wm831x = wm831x;
+
+        ret = sysfs_create_group(&pdev->dev.kobj, &wm831x_attr_group);
+        if (ret)
+                goto err;
+
+        hwmon->classdev = hwmon_device_register(&pdev->dev);
+        if (IS_ERR(hwmon->classdev)) {
+                ret = PTR_ERR(hwmon->classdev);
+                goto err_sysfs;
+        }
+
+        platform_set_drvdata(pdev, hwmon);
+
+        return 0;
+
+err_sysfs:
+        sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
+err:
+        kfree(hwmon);
+        return ret;
+}
+
+static int __devexit wm831x_hwmon_remove(struct platform_device *pdev)
+{
+        struct wm831x_hwmon *hwmon = platform_get_drvdata(pdev);
+
+        hwmon_device_unregister(hwmon->classdev);
+        sysfs_remove_group(&pdev->dev.kobj, &wm831x_attr_group);
+        platform_set_drvdata(pdev, NULL);
+        kfree(hwmon);
+
+        return 0;
+}
+
+static struct platform_driver wm831x_hwmon_driver = {
+        .probe = wm831x_hwmon_probe,
+        .remove = __devexit_p(wm831x_hwmon_remove),
+        .driver = {
+                .name = "wm831x-hwmon",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init wm831x_hwmon_init(void)
+{
+        return platform_driver_register(&wm831x_hwmon_driver);
+}
+module_init(wm831x_hwmon_init);
+
+static void __exit wm831x_hwmon_exit(void)
+{
+        platform_driver_unregister(&wm831x_hwmon_driver);
+}
+module_exit(wm831x_hwmon_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM831x Hardware Monitoring");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-hwmon");