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authorpopcornmix <popcornmix@gmail.com>2013-03-26 19:24:24 +0000
committerpopcornmix <popcornmix@gmail.com>2015-05-18 14:10:32 +0100
commitbc0639ef79636e12ede0da9be5725072e2745830 (patch)
treedb49d7fa753b3a0b18bfa58e76f137eecc856425 /drivers/hwmon/bcm2835-hwmon.c
parent0ab0bffea9f10d7ed1c5e886452f14a7daa0a423 (diff)
downloadlinux-bc0639ef79636e12ede0da9be5725072e2745830.tar.gz
Added hwmon/thermal driver for reporting core temperature. Thanks Dorian
Diffstat (limited to 'drivers/hwmon/bcm2835-hwmon.c')
-rw-r--r--drivers/hwmon/bcm2835-hwmon.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/drivers/hwmon/bcm2835-hwmon.c b/drivers/hwmon/bcm2835-hwmon.c
new file mode 100644
index 000000000000..5bbed450100a
--- /dev/null
+++ b/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);