diff options
Diffstat (limited to 'drivers/thermal/thermal_hwmon.c')
| -rw-r--r-- | drivers/thermal/thermal_hwmon.c | 250 |
1 files changed, 250 insertions, 0 deletions
diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c new file mode 100644 index 000000000..dd5d8ee37 --- /dev/null +++ b/drivers/thermal/thermal_hwmon.c @@ -0,0 +1,250 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * thermal_hwmon.c - Generic Thermal Management hwmon support. + * + * Code based on Intel thermal_core.c. Copyrights of the original code: + * Copyright (C) 2008 Intel Corp + * Copyright (C) 2008 Zhang Rui <rui.zhang@intel.com> + * Copyright (C) 2008 Sujith Thomas <sujith.thomas@intel.com> + * + * Copyright (C) 2013 Texas Instruments + * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.com> + */ +#include <linux/hwmon.h> +#include <linux/thermal.h> +#include <linux/slab.h> +#include <linux/err.h> +#include "thermal_hwmon.h" + +/* hwmon sys I/F */ +/* thermal zone devices with the same type share one hwmon device */ +struct thermal_hwmon_device { + char type[THERMAL_NAME_LENGTH]; + struct device *device; + int count; + struct list_head tz_list; + struct list_head node; +}; + +struct thermal_hwmon_attr { + struct device_attribute attr; + char name[16]; +}; + +/* one temperature input for each thermal zone */ +struct thermal_hwmon_temp { + struct list_head hwmon_node; + struct thermal_zone_device *tz; + struct thermal_hwmon_attr temp_input; /* hwmon sys attr */ + struct thermal_hwmon_attr temp_crit; /* hwmon sys attr */ +}; + +static LIST_HEAD(thermal_hwmon_list); + +static DEFINE_MUTEX(thermal_hwmon_list_lock); + +static ssize_t +temp_input_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + int temperature; + int ret; + struct thermal_hwmon_attr *hwmon_attr + = container_of(attr, struct thermal_hwmon_attr, attr); + struct thermal_hwmon_temp *temp + = container_of(hwmon_attr, struct thermal_hwmon_temp, + temp_input); + struct thermal_zone_device *tz = temp->tz; + + ret = thermal_zone_get_temp(tz, &temperature); + + if (ret) + return ret; + + return sprintf(buf, "%d\n", temperature); +} + +static ssize_t +temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct thermal_hwmon_attr *hwmon_attr + = container_of(attr, struct thermal_hwmon_attr, attr); + struct thermal_hwmon_temp *temp + = container_of(hwmon_attr, struct thermal_hwmon_temp, + temp_crit); + struct thermal_zone_device *tz = temp->tz; + int temperature; + int ret; + + ret = tz->ops->get_crit_temp(tz, &temperature); + if (ret) + return ret; + + return sprintf(buf, "%d\n", temperature); +} + + +static struct thermal_hwmon_device * +thermal_hwmon_lookup_by_type(const struct thermal_zone_device *tz) +{ + struct thermal_hwmon_device *hwmon; + char type[THERMAL_NAME_LENGTH]; + + mutex_lock(&thermal_hwmon_list_lock); + list_for_each_entry(hwmon, &thermal_hwmon_list, node) { + strcpy(type, tz->type); + strreplace(type, '-', '_'); + if (!strcmp(hwmon->type, type)) { + mutex_unlock(&thermal_hwmon_list_lock); + return hwmon; + } + } + mutex_unlock(&thermal_hwmon_list_lock); + + return NULL; +} + +/* Find the temperature input matching a given thermal zone */ +static struct thermal_hwmon_temp * +thermal_hwmon_lookup_temp(const struct thermal_hwmon_device *hwmon, + const struct thermal_zone_device *tz) +{ + struct thermal_hwmon_temp *temp; + + mutex_lock(&thermal_hwmon_list_lock); + list_for_each_entry(temp, &hwmon->tz_list, hwmon_node) + if (temp->tz == tz) { + mutex_unlock(&thermal_hwmon_list_lock); + return temp; + } + mutex_unlock(&thermal_hwmon_list_lock); + + return NULL; +} + +static bool thermal_zone_crit_temp_valid(struct thermal_zone_device *tz) +{ + int temp; + return tz->ops->get_crit_temp && !tz->ops->get_crit_temp(tz, &temp); +} + +int thermal_add_hwmon_sysfs(struct thermal_zone_device *tz) +{ + struct thermal_hwmon_device *hwmon; + struct thermal_hwmon_temp *temp; + int new_hwmon_device = 1; + int result; + + hwmon = thermal_hwmon_lookup_by_type(tz); + if (hwmon) { + new_hwmon_device = 0; + goto register_sys_interface; + } + + hwmon = kzalloc(sizeof(*hwmon), GFP_KERNEL); + if (!hwmon) + return -ENOMEM; + + INIT_LIST_HEAD(&hwmon->tz_list); + strlcpy(hwmon->type, tz->type, THERMAL_NAME_LENGTH); + strreplace(hwmon->type, '-', '_'); + hwmon->device = hwmon_device_register_with_info(&tz->device, hwmon->type, + hwmon, NULL, NULL); + if (IS_ERR(hwmon->device)) { + result = PTR_ERR(hwmon->device); + goto free_mem; + } + + register_sys_interface: + temp = kzalloc(sizeof(*temp), GFP_KERNEL); + if (!temp) { + result = -ENOMEM; + goto unregister_name; + } + + temp->tz = tz; + hwmon->count++; + + snprintf(temp->temp_input.name, sizeof(temp->temp_input.name), + "temp%d_input", hwmon->count); + temp->temp_input.attr.attr.name = temp->temp_input.name; + temp->temp_input.attr.attr.mode = 0444; + temp->temp_input.attr.show = temp_input_show; + sysfs_attr_init(&temp->temp_input.attr.attr); + result = device_create_file(hwmon->device, &temp->temp_input.attr); + if (result) + goto free_temp_mem; + + if (thermal_zone_crit_temp_valid(tz)) { + snprintf(temp->temp_crit.name, + sizeof(temp->temp_crit.name), + "temp%d_crit", hwmon->count); + temp->temp_crit.attr.attr.name = temp->temp_crit.name; + temp->temp_crit.attr.attr.mode = 0444; + temp->temp_crit.attr.show = temp_crit_show; + sysfs_attr_init(&temp->temp_crit.attr.attr); + result = device_create_file(hwmon->device, + &temp->temp_crit.attr); + if (result) + goto unregister_input; + } + + mutex_lock(&thermal_hwmon_list_lock); + if (new_hwmon_device) + list_add_tail(&hwmon->node, &thermal_hwmon_list); + list_add_tail(&temp->hwmon_node, &hwmon->tz_list); + mutex_unlock(&thermal_hwmon_list_lock); + + return 0; + + unregister_input: + device_remove_file(hwmon->device, &temp->temp_input.attr); + free_temp_mem: + kfree(temp); + unregister_name: + if (new_hwmon_device) + hwmon_device_unregister(hwmon->device); + free_mem: + if (new_hwmon_device) + kfree(hwmon); + + return result; +} +EXPORT_SYMBOL_GPL(thermal_add_hwmon_sysfs); + +void thermal_remove_hwmon_sysfs(struct thermal_zone_device *tz) +{ + struct thermal_hwmon_device *hwmon; + struct thermal_hwmon_temp *temp; + + hwmon = thermal_hwmon_lookup_by_type(tz); + if (unlikely(!hwmon)) { + /* Should never happen... */ + dev_dbg(&tz->device, "hwmon device lookup failed!\n"); + return; + } + + temp = thermal_hwmon_lookup_temp(hwmon, tz); + if (unlikely(!temp)) { + /* Should never happen... */ + dev_dbg(&tz->device, "temperature input lookup failed!\n"); + return; + } + + device_remove_file(hwmon->device, &temp->temp_input.attr); + if (thermal_zone_crit_temp_valid(tz)) + device_remove_file(hwmon->device, &temp->temp_crit.attr); + + mutex_lock(&thermal_hwmon_list_lock); + list_del(&temp->hwmon_node); + kfree(temp); + if (!list_empty(&hwmon->tz_list)) { + mutex_unlock(&thermal_hwmon_list_lock); + return; + } + list_del(&hwmon->node); + mutex_unlock(&thermal_hwmon_list_lock); + + hwmon_device_unregister(hwmon->device); + kfree(hwmon); +} +EXPORT_SYMBOL_GPL(thermal_remove_hwmon_sysfs); |