--- /dev/null +++ b/drivers/thermal/bcm2835-thermal.c @@ -0,0 +1,184 @@ +/***************************************************************************** +* 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 +#include +#include +#include +#include +#include +#include +#include + + +/* --- 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, +}; + +/* Thermal Driver */ +static struct platform_driver bcm2835_thermal_driver = { + .probe = bcm2835_thermal_probe, + .remove = bcm2835_thermal_remove, + .driver = { + .name = "bcm2835_thermal", + .owner = THIS_MODULE, + }, +}; + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Dorian Peake"); +MODULE_DESCRIPTION("Thermal driver for bcm2835 chip"); + +module_platform_driver(bcm2835_thermal_driver); --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -169,4 +169,11 @@ 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'. + endif + --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -23,4 +23,5 @@ obj-$(CONFIG_DB8500_THERMAL) += db8500_t obj-$(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