Added hwmon/thermal driver for reporting core temperature. Thanks Dorian

arch/arm/mach-bcm2708/bcm2708.c

@@ -557,6 +557,14 @@ static struct platform_device bcm2708_bsc1_device = {
 	.resource = bcm2708_bsc1_resources,
 };
 
+static struct platform_device bcm2835_hwmon_device = {
+	.name = "bcm2835_hwmon",
+};
+
+static struct platform_device bcm2835_thermal_device = {
+	.name = "bcm2835_thermal",
+};
+
 int __init bcm_register_device(struct platform_device *pdev)
 {
 	int ret;
@@ -623,6 +631,9 @@ void __init bcm2708_init(void)
 	bcm_register_device(&bcm2708_bsc0_device);
 	bcm_register_device(&bcm2708_bsc1_device);
 
+	bcm_register_device(&bcm2835_hwmon_device);
+	bcm_register_device(&bcm2835_thermal_device);
+
 	for (i = 0; i < ARRAY_SIZE(amba_devs); i++) {
 		struct amba_device *d = amba_devs[i];
 		amba_device_register(d, &iomem_resource);

drivers/hwmon/Kconfig

@@ -1543,6 +1543,16 @@ config SENSORS_MC13783_ADC
         help
           Support for the A/D converter on MC13783 and MC13892 PMIC.
 
+config SENSORS_BCM2835
+	depends on THERMAL_BCM2835=n
+	tristate "Broadcom BCM2835 HWMON Driver"
+	help
+	  If you say yes here you get support for the hardware
+	  monitoring features of the BCM2835 Chip
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called bcm2835-hwmon.
+
 if ACPI
 
 comment "ACPI drivers"

drivers/hwmon/Makefile

@@ -141,6 +141,7 @@ 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
+obj-$(CONFIG_SENSORS_BCM2835)	+= bcm2835-hwmon.o
 
 obj-$(CONFIG_PMBUS)		+= pmbus/
 

drivers/hwmon/bcm2835-hwmon.c

@@ -0,0 +1,219 @@
+/*****************************************************************************
+* Copyright 2011 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+#include <mach/vcio.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+
+#define MODULE_NAME "bcm2835_hwmon"
+
+/*#define HWMON_DEBUG_ENABLE*/
+
+#ifdef HWMON_DEBUG_ENABLE
+#define print_debug(fmt,...) printk(KERN_INFO "%s:%s:%d: "fmt"\n", MODULE_NAME, __func__, __LINE__, ##__VA_ARGS__)
+#else
+#define print_debug(fmt,...)
+#endif
+#define print_err(fmt,...) printk(KERN_ERR "%s:%s:%d: "fmt"\n", MODULE_NAME, __func__,__LINE__, ##__VA_ARGS__)
+#define print_info(fmt,...) printk(KERN_INFO "%s: "fmt"\n", MODULE_NAME, ##__VA_ARGS__)
+
+#define VC_TAG_GET_TEMP 0x00030006
+#define VC_TAG_GET_MAX_TEMP 0x0003000A
+
+/* --- STRUCTS --- */
+struct bcm2835_hwmon_data {
+	struct device *hwmon_dev;
+};
+
+/* tag part of the message */
+struct vc_msg_tag {
+	uint32_t tag_id;		/* the tag ID for the temperature */
+	uint32_t buffer_size;	/* size of the buffer (should be 8) */
+	uint32_t request_code;	/* identifies message as a request (should be 0) */
+	uint32_t id;			/* extra ID field (should be 0) */
+	uint32_t val;			/* returned value of the temperature */
+};
+
+/* message structure to be sent to videocore */
+struct vc_msg {
+	uint32_t msg_size;		/* simply, sizeof(struct vc_msg) */
+	uint32_t request_code;		/* holds various information like the success and number of bytes returned (refer to mailboxes wiki) */
+	struct vc_msg_tag tag;		/* the tag structure above to make */
+	uint32_t end_tag;		/* an end identifier, should be set to NULL */
+};
+
+typedef enum {
+	TEMP,
+	MAX_TEMP,
+} temp_type;
+
+/* --- PROTOTYPES --- */
+static ssize_t bcm2835_get_temp(struct device *dev, struct device_attribute *attr, char *buf);
+static ssize_t bcm2835_get_name(struct device *dev, struct device_attribute *attr, char *buf);
+
+/* --- GLOBALS --- */
+
+static struct bcm2835_hwmon_data *bcm2835_data;
+static struct platform_driver bcm2835_hwmon_driver;
+
+static SENSOR_DEVICE_ATTR(name, S_IRUGO,bcm2835_get_name,NULL,0);
+static SENSOR_DEVICE_ATTR(temp1_input,S_IRUGO,bcm2835_get_temp,NULL,TEMP);
+static SENSOR_DEVICE_ATTR(temp1_max,S_IRUGO,bcm2835_get_temp,NULL,MAX_TEMP);
+
+static struct attribute* bcm2835_attributes[] = {
+	&sensor_dev_attr_name.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group bcm2835_attr_group = {
+	.attrs = bcm2835_attributes,
+};
+
+/* --- FUNCTIONS --- */
+
+static ssize_t bcm2835_get_name(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf,"bcm2835_hwmon\n");
+}
+
+static ssize_t bcm2835_get_temp(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct vc_msg msg;
+	int result;
+	uint temp = 0;
+	int index = ((struct sensor_device_attribute*)to_sensor_dev_attr(attr))->index;
+
+	print_debug("IN");
+
+	/* wipe all previous message data */
+	memset(&msg, 0, sizeof msg);
+
+	/* determine the message type */
+	if(index == TEMP)
+		msg.tag.tag_id = VC_TAG_GET_TEMP;
+	else if (index == MAX_TEMP)
+		msg.tag.tag_id = VC_TAG_GET_MAX_TEMP;
+	else
+	{
+		print_debug("Unknown temperature message!");
+		return -EINVAL;
+	}
+
+	msg.msg_size = sizeof msg;
+	msg.tag.buffer_size = 8;
+
+	/* send the message */
+	result = bcm_mailbox_property(&msg, sizeof msg);
+
+	/* check if it was all ok and return the rate in milli degrees C */
+	if (result == 0 && (msg.request_code & 0x80000000))
+		temp = (uint)msg.tag.val;
+	#ifdef HWMON_DEBUG_ENABLE
+	else
+		print_debug("Failed to get temperature!");
+	#endif
+	print_debug("Got temperature as %u",temp);
+	print_debug("OUT");
+	return sprintf(buf, "%u\n", temp);
+}
+
+
+static int bcm2835_hwmon_probe(struct platform_device *pdev)
+{
+	int err;
+
+	print_debug("IN");
+	print_debug("HWMON Driver has been probed!");
+
+	/* check that the device isn't null!*/
+	if(pdev == NULL)
+	{
+		print_debug("Platform device is empty!");
+		return -ENODEV;
+	}
+
+	/* allocate memory for neccessary data */
+	bcm2835_data = kzalloc(sizeof(struct bcm2835_hwmon_data),GFP_KERNEL);
+	if(!bcm2835_data)
+	{
+		print_debug("Unable to allocate memory for hwmon data!");
+		err = -ENOMEM;
+		goto kzalloc_error;
+	}
+
+	/* create the sysfs files */
+	if(sysfs_create_group(&pdev->dev.kobj, &bcm2835_attr_group))
+	{
+		print_debug("Unable to create sysfs files!");
+		err = -EFAULT;
+		goto sysfs_error;
+	}
+
+	/* register the hwmon device */
+	bcm2835_data->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(bcm2835_data->hwmon_dev))
+	{
+		err = PTR_ERR(bcm2835_data->hwmon_dev);
+		goto hwmon_error;
+	}
+	print_debug("OUT");
+	return 0;
+
+	/* error goto's */
+	hwmon_error:
+	sysfs_remove_group(&pdev->dev.kobj, &bcm2835_attr_group);
+
+	sysfs_error:
+	kfree(bcm2835_data);
+
+	kzalloc_error:
+
+	return err;
+
+}
+
+static int bcm2835_hwmon_remove(struct platform_device *pdev)
+{
+	print_debug("IN");
+	hwmon_device_unregister(bcm2835_data->hwmon_dev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &bcm2835_attr_group);
+	print_debug("OUT");
+	return 0;
+}
+
+/* Hwmon Driver */
+static struct platform_driver bcm2835_hwmon_driver = {
+	.probe = bcm2835_hwmon_probe,
+	.remove = bcm2835_hwmon_remove,
+	.driver = {
+				.name = "bcm2835_hwmon",
+				.owner = THIS_MODULE,
+			},
+};
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dorian Peake");
+MODULE_DESCRIPTION("HW Monitor driver for bcm2835 chip");
+
+module_platform_driver(bcm2835_hwmon_driver);

drivers/thermal/Kconfig

@@ -169,6 +169,12 @@ config INTEL_POWERCLAMP
 	  enforce idle time which results in more package C-state residency. The
 	  user interface is exposed via generic thermal framework.
 
+config THERMAL_BCM2835
+	tristate "BCM2835 Thermal Driver"
+	help
+	  This will enable temperature monitoring for the Broadcom BCM2835
+	  chip. If built as a module, it will be called 'bcm2835-thermal'.
+
 config X86_PKG_TEMP_THERMAL
 	tristate "X86 package temperature thermal driver"
 	depends on X86_THERMAL_VECTOR

drivers/thermal/Makefile

@@ -23,5 +23,6 @@ obj-$(CONFIG_DB8500_THERMAL)	+= db8500_thermal.o
 obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
 obj-$(CONFIG_DB8500_CPUFREQ_COOLING)	+= db8500_cpufreq_cooling.o
 obj-$(CONFIG_INTEL_POWERCLAMP)	+= intel_powerclamp.o
+obj-$(CONFIG_THERMAL_BCM2835)	+= bcm2835-thermal.o
 obj-$(CONFIG_X86_PKG_TEMP_THERMAL)	+= x86_pkg_temp_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/