[PATCH 08/11] hwmon: Versatile Express hwmon driver
Pawel Moll
pawel.moll at arm.com
Mon Sep 3 12:25:28 EDT 2012
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 at arm.com>
---
drivers/hwmon/Kconfig | 8 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/vexpress.c | 275 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 284 insertions(+)
create mode 100644 drivers/hwmon/vexpress.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index b0a2e4c..3915794 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1187,6 +1187,14 @@ config SENSORS_TWL4030_MADC
This driver can also be built as a module. If so it will be called
twl4030-madc-hwmon.
+config SENSORS_VEXPRESS
+ tristate "Versatile Express"
+ depends on VEXPRESS_CONFIG_BUS
+ help
+ This driver provides support for hardware sensors available on
+ the ARM Ltd's Versatile Express platform. It can provide wide
+ range of information like temperature, power, energy.
+
config SENSORS_VIA_CPUTEMP
tristate "VIA CPU temperature sensor"
depends on X86
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 7aa9811..e719a7d 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -120,6 +120,7 @@ obj-$(CONFIG_SENSORS_TMP102) += tmp102.o
obj-$(CONFIG_SENSORS_TMP401) += tmp401.o
obj-$(CONFIG_SENSORS_TMP421) += tmp421.o
obj-$(CONFIG_SENSORS_TWL4030_MADC)+= twl4030-madc-hwmon.o
+obj-$(CONFIG_SENSORS_VEXPRESS) += vexpress.o
obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
obj-$(CONFIG_SENSORS_VIA686A) += via686a.o
obj-$(CONFIG_SENSORS_VT1211) += vt1211.o
diff --git a/drivers/hwmon/vexpress.c b/drivers/hwmon/vexpress.c
new file mode 100644
index 0000000..7ada171
--- /dev/null
+++ b/drivers/hwmon/vexpress.c
@@ -0,0 +1,275 @@
+/*
+ * 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/module.h>
+#include <linux/of_device.h>
+#include <linux/vexpress.h>
+
+static struct device *vexpress_hwmon_dev;
+static int vexpress_hwmon_dev_refcount;
+static DEFINE_SPINLOCK(vexpress_hwmon_dev_lock);
+
+static ssize_t vexpress_hwmon_name_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ return sprintf(buffer, "%s\n", DRVNAME);
+}
+
+static struct device_attribute vexpress_hwmon_name_attr =
+ __ATTR(name, 0444, vexpress_hwmon_name_show, NULL);
+
+struct vexpress_hwmon_attrs {
+ struct vexpress_config_device *vecdev;
+ const char *label;
+ struct device_attribute label_attr;
+ char label_name[16];
+ struct device_attribute input_attr;
+ char input_name[16];
+ u32 divisor;
+};
+
+static ssize_t vexpress_hwmon_label_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ struct vexpress_hwmon_attrs *attrs = container_of(dev_attr,
+ struct vexpress_hwmon_attrs, label_attr);
+
+ return snprintf(buffer, PAGE_SIZE, "%s\n", attrs->label);
+}
+
+static ssize_t vexpress_hwmon_u32_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ struct vexpress_hwmon_attrs *attrs = container_of(dev_attr,
+ struct vexpress_hwmon_attrs, input_attr);
+ int err;
+ u32 value;
+
+ err = vexpress_config_read(attrs->vecdev, 0, &value);
+ if (err)
+ return err;
+
+ return snprintf(buffer, PAGE_SIZE, "%u\n", value / attrs->divisor);
+}
+
+static ssize_t vexpress_hwmon_u64_show(struct device *dev,
+ struct device_attribute *dev_attr, char *buffer)
+{
+ struct vexpress_hwmon_attrs *attrs = container_of(dev_attr,
+ struct vexpress_hwmon_attrs, input_attr);
+ int err;
+ u32 value_hi, value_lo;
+
+ err = vexpress_config_read(attrs->vecdev, 0, &value_lo);
+ if (err)
+ return err;
+
+ err = vexpress_config_read(attrs->vecdev, 1, &value_hi);
+ if (err)
+ return err;
+
+ return snprintf(buffer, PAGE_SIZE, "%llu\n",
+ div_u64(((u64)value_hi << 32) | value_lo,
+ attrs->divisor));
+}
+
+static struct device *vexpress_hwmon_dev_get(void)
+{
+ struct device *result;
+
+ spin_lock(&vexpress_hwmon_dev_lock);
+
+ if (vexpress_hwmon_dev) {
+ result = vexpress_hwmon_dev;
+ } else {
+ int err;
+
+ result = hwmon_device_register(NULL);
+ if (IS_ERR(result))
+ goto out;
+
+ err = device_create_file(result, &vexpress_hwmon_name_attr);
+ if (err) {
+ result = ERR_PTR(err);
+ hwmon_device_unregister(result);
+ goto out;
+ }
+
+ vexpress_hwmon_dev = result;
+ }
+
+ vexpress_hwmon_dev_refcount++;
+
+out:
+ spin_unlock(&vexpress_hwmon_dev_lock);
+
+ return result;
+}
+
+static void vexpress_hwmon_dev_put(void)
+{
+ spin_lock(&vexpress_hwmon_dev_lock);
+
+ if (--vexpress_hwmon_dev_refcount == 0) {
+ vexpress_hwmon_dev = NULL;
+ hwmon_device_unregister(vexpress_hwmon_dev);
+ }
+
+ WARN_ON(vexpress_hwmon_dev_refcount < 0);
+
+ spin_unlock(&vexpress_hwmon_dev_lock);
+}
+
+static struct {
+ const char *name;
+ u32 divisor;
+ atomic_t index;
+} vexpress_hwmon_func_list[] = {
+ [VEXPRESS_CONFIG_FUNC_VOLT] = { .name = "in", .divisor = 1000, },
+ [VEXPRESS_CONFIG_FUNC_AMP] = { .name = "curr", .divisor = 1000, },
+ [VEXPRESS_CONFIG_FUNC_TEMP] = { .name = "temp", .divisor = 1000, },
+ [VEXPRESS_CONFIG_FUNC_POWER] = { .name = "power", .divisor = 1, },
+ [VEXPRESS_CONFIG_FUNC_ENERGY] = { .name = "energy", .divisor = 1, },
+};
+
+static int vexpress_hwmon_probe(struct vexpress_config_device *vecdev)
+{
+ int err;
+ struct device *hwmon_dev;
+ unsigned func = vecdev->func;
+ struct vexpress_hwmon_attrs *attrs;
+ const char *attr_name;
+ int attr_index;
+
+ hwmon_dev = vexpress_hwmon_dev_get();
+ if (IS_ERR(hwmon_dev)) {
+ err = PTR_ERR(hwmon_dev);
+ goto error_hwmon_dev_get;
+ }
+
+ attrs = devm_kzalloc(&vecdev->dev, sizeof(*attrs), GFP_KERNEL);
+ if (!attrs) {
+ err = -ENOMEM;
+ goto error_kzalloc;
+ }
+ attrs->vecdev = vecdev;
+
+ err = sysfs_create_link(&vecdev->dev.kobj, &hwmon_dev->kobj, "hwmon");
+ if (err)
+ goto error_create_link;
+
+ attr_index = atomic_inc_return(&vexpress_hwmon_func_list[func].index);
+ attr_name = vexpress_hwmon_func_list[func].name;
+
+ snprintf(attrs->input_name, sizeof(attrs->input_name),
+ "%s%d_input", attr_name, attr_index);
+ attrs->input_attr.attr.name = attrs->input_name;
+ attrs->input_attr.attr.mode = 0444;
+ if (func == VEXPRESS_CONFIG_FUNC_ENERGY)
+ attrs->input_attr.show = vexpress_hwmon_u64_show;
+ else
+ attrs->input_attr.show = vexpress_hwmon_u32_show;
+ sysfs_attr_init(&attrs->input_attr.attr);
+ err = device_create_file(hwmon_dev, &attrs->input_attr);
+ if (err)
+ goto error_create_input;
+
+ attrs->label = of_get_property(vecdev->dev.of_node, "label", NULL);
+ if (attrs->label) {
+ snprintf(attrs->label_name, sizeof(attrs->label_name),
+ "%s%d_label", attr_name, attr_index);
+ attrs->label_attr.attr.name = attrs->label_name;
+ attrs->label_attr.attr.mode = 0444;
+ attrs->label_attr.show = vexpress_hwmon_label_show;
+ sysfs_attr_init(&attrs->label_attr.attr);
+ err = device_create_file(hwmon_dev, &attrs->label_attr);
+ if (err)
+ goto error_create_label;
+ }
+
+ attrs->divisor = vexpress_hwmon_func_list[func].divisor;
+
+ vexpress_config_set_drvdata(vecdev, attrs);
+
+ return 0;
+
+error_create_label:
+ device_remove_file(hwmon_dev, &attrs->input_attr);
+error_create_input:
+ sysfs_remove_link(&vecdev->dev.kobj, "hwmon");
+error_create_link:
+error_kzalloc:
+ vexpress_hwmon_dev_put();
+error_hwmon_dev_get:
+ return err;
+}
+
+static int __devexit vexpress_hwmon_remove(struct vexpress_config_device
+ *vecdev)
+{
+ struct vexpress_hwmon_attrs *attrs =
+ vexpress_config_get_drvdata(vecdev);
+
+ if (attrs->label)
+ device_remove_file(vexpress_hwmon_dev, &attrs->label_attr);
+ device_remove_file(vexpress_hwmon_dev, &attrs->input_attr);
+ atomic_dec(&vexpress_hwmon_func_list[vecdev->func].index);
+ sysfs_remove_link(&vecdev->dev.kobj, "hwmon");
+ vexpress_hwmon_dev_put();
+
+ return 0;
+}
+
+static const unsigned vexpress_hwmon_funcs[] = {
+#if !defined(CONFIG_REGULATOR_VEXPRESS)
+ VEXPRESS_CONFIG_FUNC_VOLT,
+#endif
+ VEXPRESS_CONFIG_FUNC_AMP,
+ VEXPRESS_CONFIG_FUNC_TEMP,
+ VEXPRESS_CONFIG_FUNC_POWER,
+ VEXPRESS_CONFIG_FUNC_ENERGY,
+ 0,
+};
+
+static struct vexpress_config_driver vexpress_hwmon_driver = {
+ .funcs = vexpress_hwmon_funcs,
+ .probe = vexpress_hwmon_probe,
+ .remove = __devexit_p(vexpress_hwmon_remove),
+ .driver = {
+ .name = DRVNAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init vexpress_hwmon_init(void)
+{
+ return vexpress_config_driver_register(&vexpress_hwmon_driver);
+}
+
+static void __exit vexpress_hwmon_exit(void)
+{
+ vexpress_config_driver_unregister(&vexpress_hwmon_driver);
+}
+
+MODULE_AUTHOR("Pawel Moll <pawel.moll at arm.com>");
+MODULE_DESCRIPTION("Versatile Express hwmon");
+MODULE_LICENSE("GPL");
+
+module_init(vexpress_hwmon_init);
+module_exit(vexpress_hwmon_exit);
--
1.7.9.5
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