[PATCH] hwmon: Add WM835x PMIC hardware monitoring driver

From: Mark Brown
Date: Mon Jul 20 2009 - 07:44:00 EST


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@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
---

This should address all the issues Jean raised:
- Add a brief document to the hwmon directory.
- Use full constant names as arguments for template macro.
- Use DIV_ROUND_CLOSEST()
- Set driver owner.
- Fix typos.

Thanks to Jonathan and Jean for their reviews.

Documentation/hwmon/wm8350 | 26 +++++++
drivers/hwmon/Kconfig | 10 +++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/wm8350-hwmon.c | 151 +++++++++++++++++++++++++++++++++++++++
drivers/mfd/wm8350-core.c | 3 +
include/linux/mfd/wm8350/core.h | 6 ++
6 files changed, 197 insertions(+), 0 deletions(-)
create mode 100644 Documentation/hwmon/wm8350
create mode 100644 drivers/hwmon/wm8350-hwmon.c

diff --git a/Documentation/hwmon/wm8350 b/Documentation/hwmon/wm8350
new file mode 100644
index 0000000..98f923b
--- /dev/null
+++ b/Documentation/hwmon/wm8350
@@ -0,0 +1,26 @@
+Kernel driver wm8350-hwmon
+==========================
+
+Supported chips:
+ * Wolfson Microelectronics WM835x PMICs
+ Prefix: 'wm8350'
+ Datasheet:
+ http://www.wolfsonmicro.com/products/WM8350
+ http://www.wolfsonmicro.com/products/WM8351
+ http://www.wolfsonmicro.com/products/WM8352
+
+Authors: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
+
+Description
+-----------
+
+The WM835x 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
+simple access to these major supplies.
+
+Voltage Monitoring
+------------------
+
+Voltages are sampled by a 12 bit ADC. For the internal supplies the ADC
+is referenced to the system VRTC.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 2d50166..c94d708 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -920,6 +920,16 @@ config SENSORS_W83627EHF
This driver can also be built as a module. If so, the module
will be called w83627ehf.

+config SENSORS_WM8350
+ tristate "Wolfson Microelectronics WM835x"
+ depends on MFD_WM8350
+ help
+ If you say yes here you get support for the hardware
+ monitoring features of the WM835x series of PMICs.
+
+ This driver can also be built as a module. If so, the module
+ will be called wm8350-hwmon.
+
config SENSORS_ULTRA45
tristate "Sun Ultra45 PIC16F747"
depends on SPARC64
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index b793dce..c02e90e 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -89,6 +89,7 @@ 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_WM8350) += wm8350-hwmon.o

ifeq ($(CONFIG_HWMON_DEBUG_CHIP),y)
EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/hwmon/wm8350-hwmon.c b/drivers/hwmon/wm8350-hwmon.c
new file mode 100644
index 0000000..1329059
--- /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@xxxxxxxxxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("WM8350 Hardware Monitoring");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm8350-hwmon");
diff --git a/drivers/mfd/wm8350-core.c b/drivers/mfd/wm8350-core.c
index fe24079..9d662a5 100644
--- a/drivers/mfd/wm8350-core.c
+++ b/drivers/mfd/wm8350-core.c
@@ -1472,6 +1472,8 @@ int wm8350_device_init(struct wm8350 *wm8350, int irq,
&(wm8350->codec.pdev));
wm8350_client_dev_register(wm8350, "wm8350-gpio",
&(wm8350->gpio.pdev));
+ wm8350_client_dev_register(wm8350, "wm8350-hwmon",
+ &(wm8350->hwmon.pdev));
wm8350_client_dev_register(wm8350, "wm8350-power",
&(wm8350->power.pdev));
wm8350_client_dev_register(wm8350, "wm8350-rtc", &(wm8350->rtc.pdev));
@@ -1498,6 +1500,7 @@ void wm8350_device_exit(struct wm8350 *wm8350)
platform_device_unregister(wm8350->wdt.pdev);
platform_device_unregister(wm8350->rtc.pdev);
platform_device_unregister(wm8350->power.pdev);
+ platform_device_unregister(wm8350->hwmon.pdev);
platform_device_unregister(wm8350->gpio.pdev);
platform_device_unregister(wm8350->codec.pdev);

diff --git a/include/linux/mfd/wm8350/core.h b/include/linux/mfd/wm8350/core.h
index 42cca67..969b0b5 100644
--- a/include/linux/mfd/wm8350/core.h
+++ b/include/linux/mfd/wm8350/core.h
@@ -605,6 +605,11 @@ struct wm8350_irq {
void *data;
};

+struct wm8350_hwmon {
+ struct platform_device *pdev;
+ struct device *classdev;
+};
+
struct wm8350 {
struct device *dev;

@@ -629,6 +634,7 @@ struct wm8350 {
/* Client devices */
struct wm8350_codec codec;
struct wm8350_gpio gpio;
+ struct wm8350_hwmon hwmon;
struct wm8350_pmic pmic;
struct wm8350_power power;
struct wm8350_rtc rtc;
--
1.6.3.3

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