hwmon: Versatile Express hwmon driver
hwmon framework driver for Versatile Express sensors, providing
information about board level voltage (only when regulator driver
is not configured), currents, temperature and power/energy usage.
Labels for the values can be defined as DT properties.
Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
diff --git a/drivers/hwmon/vexpress.c b/drivers/hwmon/vexpress.c
new file mode 100644
index 0000000..59fd126
--- /dev/null
+++ b/drivers/hwmon/vexpress.c
@@ -0,0 +1,229 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 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.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#define DRVNAME "vexpress-hwmon"
+#define pr_fmt(fmt) DRVNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/vexpress.h>
+
+struct vexpress_hwmon_data {
+ struct device *hwmon_dev;
+ struct vexpress_config_func *func;
+};
+
+static ssize_t vexpress_hwmon_name_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ const char *compatible = of_get_property(dev->of_node, "compatible",
+ NULL);
+
+ return sprintf(buffer, "%s\n", compatible);
+}
+
+static ssize_t vexpress_hwmon_label_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ const char *label = of_get_property(dev->of_node, "label", NULL);
+
+ if (!label)
+ return -ENOENT;
+
+ return snprintf(buffer, PAGE_SIZE, "%s\n", label);
+}
+
+static ssize_t vexpress_hwmon_u32_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
+ int err;
+ u32 value;
+
+ err = vexpress_config_read(data->func, 0, &value);
+ if (err)
+ return err;
+
+ return snprintf(buffer, PAGE_SIZE, "%u\n", value /
+ to_sensor_dev_attr(dev_attr)->index);
+}
+
+static ssize_t vexpress_hwmon_u64_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ struct vexpress_hwmon_data *data = dev_get_drvdata(dev);
+ int err;
+ u32 value_hi, value_lo;
+
+ err = vexpress_config_read(data->func, 0, &value_lo);
+ if (err)
+ return err;
+
+ err = vexpress_config_read(data->func, 1, &value_hi);
+ if (err)
+ return err;
+
+ return snprintf(buffer, PAGE_SIZE, "%llu\n",
+ div_u64(((u64)value_hi << 32) | value_lo,
+ to_sensor_dev_attr(dev_attr)->index));
+}
+
+static DEVICE_ATTR(name, S_IRUGO, vexpress_hwmon_name_show, NULL);
+
+#define VEXPRESS_HWMON_ATTRS(_name, _label_attr, _input_attr) \
+struct attribute *vexpress_hwmon_attrs_##_name[] = { \
+ &dev_attr_name.attr, \
+ &dev_attr_##_label_attr.attr, \
+ &sensor_dev_attr_##_input_attr.dev_attr.attr, \
+ NULL \
+}
+
+#if !defined(CONFIG_REGULATOR_VEXPRESS)
+static DEVICE_ATTR(in1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, vexpress_hwmon_u32_show,
+ NULL, 1000);
+static VEXPRESS_HWMON_ATTRS(volt, in1_label, in1_input);
+static struct attribute_group vexpress_hwmon_group_volt = {
+ .attrs = vexpress_hwmon_attrs_volt,
+};
+#endif
+
+static DEVICE_ATTR(curr1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, vexpress_hwmon_u32_show,
+ NULL, 1000);
+static VEXPRESS_HWMON_ATTRS(amp, curr1_label, curr1_input);
+static struct attribute_group vexpress_hwmon_group_amp = {
+ .attrs = vexpress_hwmon_attrs_amp,
+};
+
+static DEVICE_ATTR(temp1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, vexpress_hwmon_u32_show,
+ NULL, 1000);
+static VEXPRESS_HWMON_ATTRS(temp, temp1_label, temp1_input);
+static struct attribute_group vexpress_hwmon_group_temp = {
+ .attrs = vexpress_hwmon_attrs_temp,
+};
+
+static DEVICE_ATTR(power1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, vexpress_hwmon_u32_show,
+ NULL, 1);
+static VEXPRESS_HWMON_ATTRS(power, power1_label, power1_input);
+static struct attribute_group vexpress_hwmon_group_power = {
+ .attrs = vexpress_hwmon_attrs_power,
+};
+
+static DEVICE_ATTR(energy1_label, S_IRUGO, vexpress_hwmon_label_show, NULL);
+static SENSOR_DEVICE_ATTR(energy1_input, S_IRUGO, vexpress_hwmon_u64_show,
+ NULL, 1);
+static VEXPRESS_HWMON_ATTRS(energy, energy1_label, energy1_input);
+static struct attribute_group vexpress_hwmon_group_energy = {
+ .attrs = vexpress_hwmon_attrs_energy,
+};
+
+static struct of_device_id vexpress_hwmon_of_match[] = {
+#if !defined(CONFIG_REGULATOR_VEXPRESS)
+ {
+ .compatible = "arm,vexpress-volt",
+ .data = &vexpress_hwmon_group_volt,
+ },
+#endif
+ {
+ .compatible = "arm,vexpress-amp",
+ .data = &vexpress_hwmon_group_amp,
+ }, {
+ .compatible = "arm,vexpress-temp",
+ .data = &vexpress_hwmon_group_temp,
+ }, {
+ .compatible = "arm,vexpress-power",
+ .data = &vexpress_hwmon_group_power,
+ }, {
+ .compatible = "arm,vexpress-energy",
+ .data = &vexpress_hwmon_group_energy,
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(of, vexpress_hwmon_of_match);
+
+static int vexpress_hwmon_probe(struct platform_device *pdev)
+{
+ int err;
+ const struct of_device_id *match;
+ struct vexpress_hwmon_data *data;
+
+ data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, data);
+
+ match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
+ if (!match)
+ return -ENODEV;
+
+ data->func = vexpress_config_func_get_by_dev(&pdev->dev);
+ if (!data->func)
+ return -ENODEV;
+
+ err = sysfs_create_group(&pdev->dev.kobj, match->data);
+ if (err)
+ goto error;
+
+ data->hwmon_dev = hwmon_device_register(&pdev->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ err = PTR_ERR(data->hwmon_dev);
+ goto error;
+ }
+
+ return 0;
+
+error:
+ sysfs_remove_group(&pdev->dev.kobj, match->data);
+ vexpress_config_func_put(data->func);
+ return err;
+}
+
+static int __devexit vexpress_hwmon_remove(struct platform_device *pdev)
+{
+ struct vexpress_hwmon_data *data = platform_get_drvdata(pdev);
+ const struct of_device_id *match;
+
+ hwmon_device_unregister(data->hwmon_dev);
+
+ match = of_match_device(vexpress_hwmon_of_match, &pdev->dev);
+ sysfs_remove_group(&pdev->dev.kobj, match->data);
+
+ vexpress_config_func_put(data->func);
+
+ return 0;
+}
+
+static struct platform_driver vexpress_hwmon_driver = {
+ .probe = vexpress_hwmon_probe,
+ .remove = __devexit_p(vexpress_hwmon_remove),
+ .driver = {
+ .name = DRVNAME,
+ .owner = THIS_MODULE,
+ .of_match_table = vexpress_hwmon_of_match,
+ },
+};
+
+module_platform_driver(vexpress_hwmon_driver);
+
+MODULE_AUTHOR("Pawel Moll <pawel.moll@arm.com>");
+MODULE_DESCRIPTION("Versatile Express hwmon sensors driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:vexpress-hwmon");