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

BCM270x: Move thermal sensor to Device Tree

Add Device Tree support to bcm2835-thermal driver.
Add thermal sensor device to Device Tree.
Don't add platform device when booting in DT mode.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

arch/arm/mach-bcm2708/bcm2708.c

@@ -505,6 +505,10 @@ static struct platform_device bcm2708_alsa_devices[] = {
 	       },
 };
 
+static struct platform_device bcm2835_thermal_device = {
+	.name = "bcm2835_thermal",
+};
+
 int __init bcm_register_device(struct platform_device *pdev)
 {
 	int ret;
@@ -651,6 +655,8 @@ void __init bcm2708_init(void)
 	for (i = 0; i < ARRAY_SIZE(bcm2708_alsa_devices); i++)
 		bcm_register_device_dt(&bcm2708_alsa_devices[i]);
 
+	bcm_register_device_dt(&bcm2835_thermal_device);
+
 	if (!use_dt) {
 		for (i = 0; i < ARRAY_SIZE(amba_devs); i++) {
 			struct amba_device *d = amba_devs[i];

arch/arm/mach-bcm2709/bcm2709.c

@@ -525,6 +525,10 @@ static struct platform_device bcm2708_alsa_devices[] = {
 	       },
 };
 
+static struct platform_device bcm2835_thermal_device = {
+	.name = "bcm2835_thermal",
+};
+
 int __init bcm_register_device(struct platform_device *pdev)
 {
 	int ret;
@@ -671,6 +675,8 @@ void __init bcm2709_init(void)
 	for (i = 0; i < ARRAY_SIZE(bcm2708_alsa_devices); i++)
 		bcm_register_device_dt(&bcm2708_alsa_devices[i]);
 
+	bcm_register_device_dt(&bcm2835_thermal_device);
+
 	if (!use_dt) {
 		for (i = 0; i < ARRAY_SIZE(amba_devs); i++) {
 			struct amba_device *d = amba_devs[i];

drivers/thermal/Kconfig

@@ -238,6 +238,13 @@ 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
+	depends on BCM2708_MBOX
+	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

@@ -33,6 +33,7 @@ obj-$(CONFIG_ARMADA_THERMAL)	+= armada_thermal.o
 obj-$(CONFIG_IMX_THERMAL)	+= imx_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-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
 obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/

drivers/thermal/bcm2835-thermal.c

@@ -0,0 +1,190 @@
+/*****************************************************************************
+* 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/platform_data/mailbox-bcm2708.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/thermal.h>
+
+
+/* --- DEFINITIONS --- */
+#define MODULE_NAME "bcm2835_thermal"
+
+/*#define THERMAL_DEBUG_ENABLE*/
+
+#ifdef THERMAL_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 VC_TAG_GET_TEMP 0x00030006
+#define VC_TAG_GET_MAX_TEMP 0x0003000A
+
+typedef enum {
+	TEMP,
+	MAX_TEMP,
+} temp_type;
+
+/* --- STRUCTS --- */
+/* 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 */
+};
+
+struct bcm2835_thermal_data {
+	struct thermal_zone_device *thermal_dev;
+	struct vc_msg msg;
+};
+
+/* --- GLOBALS --- */
+static struct bcm2835_thermal_data bcm2835_data;
+
+/* Thermal Device Operations */
+static struct thermal_zone_device_ops ops;
+
+/* --- FUNCTIONS --- */
+
+static int bcm2835_get_temp_or_max(struct thermal_zone_device *thermal_dev, unsigned long *temp, unsigned tag_id)
+{
+	int result = -1, retry = 3;
+	print_debug("IN");
+
+	*temp = 0;
+	while (result != 0 && retry-- > 0) {
+		/* wipe all previous message data */
+		memset(&bcm2835_data.msg, 0, sizeof bcm2835_data.msg);
+
+		/* prepare message */
+		bcm2835_data.msg.msg_size = sizeof bcm2835_data.msg;
+		bcm2835_data.msg.tag.buffer_size = 8;
+		bcm2835_data.msg.tag.tag_id = tag_id;
+
+		/* send the message */
+		result = bcm_mailbox_property(&bcm2835_data.msg, sizeof bcm2835_data.msg);
+		print_debug("Got %stemperature as %u (%d,%x)\n", tag_id==VC_TAG_GET_MAX_TEMP ? "max ":"", (uint)bcm2835_data.msg.tag.val, result, bcm2835_data.msg.request_code);
+		if (!(bcm2835_data.msg.request_code & 0x80000000))
+			result = -1;
+	}
+
+	/* check if it was all ok and return the rate in milli degrees C */
+	if (result == 0)
+		*temp = (uint)bcm2835_data.msg.tag.val;
+	else
+		print_err("Failed to get temperature! (%x:%d)\n", tag_id, result);
+	print_debug("OUT");
+	return result;
+}
+
+static int bcm2835_get_temp(struct thermal_zone_device *thermal_dev, unsigned long *temp)
+{
+	return bcm2835_get_temp_or_max(thermal_dev, temp, VC_TAG_GET_TEMP);
+}
+
+static int bcm2835_get_max_temp(struct thermal_zone_device *thermal_dev, int trip_num, unsigned long *temp)
+{
+	return bcm2835_get_temp_or_max(thermal_dev, temp, VC_TAG_GET_MAX_TEMP);
+}
+
+static int bcm2835_get_trip_type(struct thermal_zone_device * thermal_dev, int trip_num, enum thermal_trip_type *trip_type)
+{
+	*trip_type = THERMAL_TRIP_HOT;
+	return 0;
+}
+
+
+static int bcm2835_get_mode(struct thermal_zone_device *thermal_dev, enum thermal_device_mode *dev_mode)
+{
+	*dev_mode = THERMAL_DEVICE_ENABLED;
+	return 0;
+}
+
+
+static int bcm2835_thermal_probe(struct platform_device *pdev)
+{
+	print_debug("IN");
+	print_debug("THERMAL Driver has been probed!");
+
+	/* check that the device isn't null!*/
+	if(pdev == NULL)
+	{
+		print_debug("Platform device is empty!");
+		return -ENODEV;
+	}
+
+	if(!(bcm2835_data.thermal_dev = thermal_zone_device_register("bcm2835_thermal",  1, 0, NULL, &ops, NULL, 0, 0)))
+	{
+		print_debug("Unable to register the thermal device!");
+		return -EFAULT;
+	}
+	return 0;
+}
+
+
+static int bcm2835_thermal_remove(struct platform_device *pdev)
+{
+	print_debug("IN");
+
+	thermal_zone_device_unregister(bcm2835_data.thermal_dev);
+
+	print_debug("OUT");
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops ops  = {
+	.get_temp = bcm2835_get_temp,
+	.get_trip_temp = bcm2835_get_max_temp,
+	.get_trip_type = bcm2835_get_trip_type,
+	.get_mode = bcm2835_get_mode,
+};
+
+static const struct of_device_id bcm2835_thermal_of_match_table[] = {
+	{ .compatible = "brcm,bcm2835-thermal", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
+
+static struct platform_driver bcm2835_thermal_driver = {
+	.probe = bcm2835_thermal_probe,
+	.remove = bcm2835_thermal_remove,
+	.driver = {
+				.name = "bcm2835_thermal",
+				.owner = THIS_MODULE,
+				.of_match_table = bcm2835_thermal_of_match_table,
+			},
+};
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dorian Peake");
+MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
+
+module_platform_driver(bcm2835_thermal_driver);