hwmon: Versatile Express hwmon driver
authorPawel Moll <pawel.moll@arm.com>
Mon, 17 Sep 2012 17:40:09 +0000 (18:40 +0100)
committerPawel Moll <pawel.moll@arm.com>
Tue, 16 Oct 2012 16:12:35 +0000 (17:12 +0100)
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>
Documentation/devicetree/bindings/hwmon/vexpress.txt [new file with mode: 0644]
Documentation/hwmon/vexpress [new file with mode: 0644]
drivers/hwmon/Kconfig
drivers/hwmon/Makefile
drivers/hwmon/vexpress.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/hwmon/vexpress.txt b/Documentation/devicetree/bindings/hwmon/vexpress.txt
new file mode 100644 (file)
index 0000000..9c27ed6
--- /dev/null
@@ -0,0 +1,23 @@
+Versatile Express hwmon sensors
+-------------------------------
+
+Requires node properties:
+- "compatible" value : one of
+       "arm,vexpress-volt"
+       "arm,vexpress-amp"
+       "arm,vexpress-temp"
+       "arm,vexpress-power"
+       "arm,vexpress-energy"
+- "arm,vexpress-sysreg,func" when controlled via vexpress-sysreg
+  (see Documentation/devicetree/bindings/arm/vexpress-sysreg.txt
+  for more details)
+
+Optional node properties:
+- label : string describing the monitored value
+
+Example:
+       energy@0 {
+               compatible = "arm,vexpress-energy";
+               arm,vexpress-sysreg,func = <13 0>;
+               label = "A15 Jcore";
+       };
diff --git a/Documentation/hwmon/vexpress b/Documentation/hwmon/vexpress
new file mode 100644 (file)
index 0000000..557d6d5
--- /dev/null
@@ -0,0 +1,34 @@
+Kernel driver vexpress
+======================
+
+Supported systems:
+  * ARM Ltd. Versatile Express platform
+    Prefix: 'vexpress'
+    Datasheets:
+      * "Hardware Description" sections of the Technical Reference Manuals
+        for the Versatile Express boards:
+        http://infocenter.arm.com/help/topic/com.arm.doc.subset.boards.express/index.html
+      * Section "4.4.14. System Configuration registers" of the V2M-P1 TRM:
+        http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0447-/index.html
+
+Author: Pawel Moll
+
+Description
+-----------
+
+Versatile Express platform (http://www.arm.com/versatileexpress/) is a
+reference & prototyping system for ARM Ltd. processors. It can be set up
+from a wide range of boards, each of them containing (apart of the main
+chip/FPGA) a number of microcontrollers responsible for platform
+configuration and control. Theses microcontrollers can also monitor the
+board and its environment by a number of internal and external sensors,
+providing information about power lines voltages and currents, board
+temperature and power usage. Some of them also calculate consumed energy
+and provide a cumulative use counter.
+
+The configuration devices are _not_ memory mapped and must be accessed
+via a custom interface, abstracted by the "vexpress_config" API.
+
+As these devices are non-discoverable, they must be described in a Device
+Tree passed to the kernel. Details of the DT binding for them can be found
+in Documentation/devicetree/bindings/hwmon/vexpress.txt.
index c4633de..db213fe 100644 (file)
@@ -1197,6 +1197,14 @@ 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
+       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
index 8d5fcb5..aac8b7c 100644 (file)
@@ -121,6 +121,7 @@ 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 (file)
index 0000000..59fd126
--- /dev/null
@@ -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");