[linux-6.6.y] hwmon: Add support for Zhaoxin core temperature monitoring

drivers/hwmon/Kconfig

@@ -2170,6 +2170,15 @@ config SENSORS_VIA_CPUTEMP
 	  sensor inside your CPU. Supported are all known variants of
 	  the VIA C7 and Nano.
 
+config SENSORS_ZHAOXIN_CPUTEMP
+	tristate "Zhaoxin CPU temperature sensor"
+	depends on X86
+	select HWMON_VID
+	help
+	  If you say yes here you get support for the temperature
+	  sensor inside your CPU. Supported are all known variants of
+	  the Zhaoxin processors.
+
 config SENSORS_VIA686A
 	tristate "VIA686A"
 	depends on PCI

drivers/hwmon/Makefile

@@ -212,6 +212,7 @@ obj-$(CONFIG_SENSORS_TMP464)	+= tmp464.o
 obj-$(CONFIG_SENSORS_TMP513)	+= tmp513.o
 obj-$(CONFIG_SENSORS_VEXPRESS)	+= vexpress-hwmon.o
 obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
+obj-$(CONFIG_SENSORS_ZHAOXIN_CPUTEMP)    += zhaoxin-cputemp.o
 obj-$(CONFIG_SENSORS_VIA686A)	+= via686a.o
 obj-$(CONFIG_SENSORS_VT1211)	+= vt1211.o
 obj-$(CONFIG_SENSORS_VT8231)	+= vt8231.o

drivers/hwmon/via-cputemp.c

@@ -273,7 +273,6 @@ static const struct x86_cpu_id __initconst cputemp_ids[] = {
 	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_C7_A,	NULL),
 	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_C7_D,	NULL),
 	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 6, X86_CENTAUR_FAM6_NANO,	NULL),
-	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 7, X86_MODEL_ANY,		NULL),
 	{}
 };
 MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);

drivers/hwmon/zhaoxin-cputemp.c

@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * zhaoxin-cputemp.c - Driver for Zhaoxin CPU core temperature monitoring
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/hwmon.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/list.h>
+#include <linux/platform_device.h>
+#include <linux/cpu.h>
+#include <asm/msr.h>
+#include <asm/processor.h>
+#include <asm/cpu_device_id.h>
+
+#define DRVNAME "zhaoxin_cputemp"
+
+enum { SHOW_TEMP, SHOW_LABEL, SHOW_NAME, SHOW_CRIT, SHOW_MAX };
+
+/* Functions declaration */
+
+struct zhaoxin_cputemp_data {
+	struct device *hwmon_dev;
+	const char *name;
+	u32 id;
+	u32 msr_temp;
+	u32 msr_crit;
+	u32 msr_max;
+	u32 msr_index;
+};
+
+/* Sysfs stuff */
+
+static ssize_t name_show(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	int ret;
+	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+	struct zhaoxin_cputemp_data *data = dev_get_drvdata(dev);
+
+	if (attr->index == SHOW_NAME)
+		ret = sprintf(buf, "%s\n", data->name);
+	else    /* show label */
+		ret = sprintf(buf, "Core %d\n", data->id);
+	return ret;
+}
+
+static int temperature_access(struct zhaoxin_cputemp_data *data, u32 *l, u32 *h);
+static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct zhaoxin_cputemp_data *data = dev_get_drvdata(dev);
+	u32 eax, edx;
+	int err;
+
+	err = rdmsr_safe_on_cpu(data->id, data->msr_temp, &eax, &edx);
+	if (err)
+		return -EAGAIN;
+
+	return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xffffff) * 1000);
+}
+
+static ssize_t crit_show(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct zhaoxin_cputemp_data *data = dev_get_drvdata(dev);
+	u32 eax, edx;
+	int err;
+
+	err = rdmsr_safe_on_cpu(data->id, data->msr_crit, &eax, &edx);
+	if (err)
+		return -EAGAIN;
+
+	return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xff) * 1000);
+}
+
+static ssize_t max_show(struct device *dev, struct device_attribute *devattr, char *buf)
+{
+	struct zhaoxin_cputemp_data *data = dev_get_drvdata(dev);
+	u32 eax, edx;
+	int err;
+
+	err = rdmsr_safe_on_cpu(data->id, data->msr_max, &eax, &edx);
+	if (err)
+		return -EAGAIN;
+
+	return sprintf(buf, "%lu\n", ((unsigned long)eax & 0xff) * 1000);
+}
+
+static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, SHOW_TEMP);
+static SENSOR_DEVICE_ATTR_RO(temp1_label, name, SHOW_LABEL);
+static SENSOR_DEVICE_ATTR_RO(name, name, SHOW_NAME);
+static SENSOR_DEVICE_ATTR_RO(temp1_crit, crit, SHOW_CRIT);
+static SENSOR_DEVICE_ATTR_RO(temp1_max, max, SHOW_MAX);
+
+static struct attribute *zhaoxin_cputemp_attributes[] = {
+	&sensor_dev_attr_name.dev_attr.attr,
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_crit.dev_attr.attr,
+	&sensor_dev_attr_temp1_max.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group zhaoxin_cputemp_group = {
+	.attrs = zhaoxin_cputemp_attributes,
+};
+
+static int temperature_access(struct zhaoxin_cputemp_data *data, u32 *l, u32 *h)
+{
+	int err;
+	*l = 0x19;
+
+	if (data->msr_index) {
+		err = wrmsr_safe_on_cpu(data->id, data->msr_index, *l, *h);
+		if (err) {
+			pr_info("Unable to write TEMPERATURE INDEX MSR\n");
+			return err;
+		}
+	}
+
+	*l = 0;
+	err = rdmsr_safe_on_cpu(data->id, data->msr_temp, l, h);
+	if (err) {
+		pr_info("Unable to read TEMPERATURE DATA MSR\n");
+		return err;
+	}
+	return 0;
+}
+
+static int zhaoxin_cputemp_probe(struct platform_device *pdev)
+{
+	struct zhaoxin_cputemp_data *data;
+	int err;
+	u32 eax, edx;
+	struct cpuinfo_x86 *c = &cpu_data(pdev->id);
+
+	data = devm_kzalloc(&pdev->dev, sizeof(struct zhaoxin_cputemp_data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->id = pdev->id;
+	data->name = "zhaoxin_cputemp";
+	if (c->x86_model == 0x6b) {
+		data->msr_index = 0x174c;
+		data->msr_temp  = 0x174d;
+		data->msr_crit  = 0x175b;
+		data->msr_max   = 0x175a;
+	} else {
+		data->msr_index = 0;
+		data->msr_temp = 0x1423;
+		data->msr_crit = 0x1416;
+		data->msr_max = 0x1415;
+	}
+
+	/* test if we can access the TEMPERATURE MSR */
+	err = temperature_access(data, &eax, &edx);
+	if (err) {
+		dev_err(&pdev->dev, "Unable to access TEMPERATURE MSR, giving up\n");
+		return err;
+	}
+
+	platform_set_drvdata(pdev, data);
+
+	err = sysfs_create_group(&pdev->dev.kobj, &zhaoxin_cputemp_group);
+	if (err)
+		return err;
+
+	data->hwmon_dev = hwmon_device_register_for_thermal(&pdev->dev, data->name, data);
+	if (IS_ERR(data->hwmon_dev)) {
+		err = PTR_ERR(data->hwmon_dev);
+		dev_err(&pdev->dev, "Class registration failed (%d)\n", err);
+		goto exit_remove;
+	}
+
+	return 0;
+
+exit_remove:
+	sysfs_remove_group(&pdev->dev.kobj, &zhaoxin_cputemp_group);
+	return err;
+}
+
+static int zhaoxin_cputemp_remove(struct platform_device *pdev)
+{
+	struct zhaoxin_cputemp_data *data = platform_get_drvdata(pdev);
+
+	hwmon_device_unregister(data->hwmon_dev);
+	sysfs_remove_group(&pdev->dev.kobj, &zhaoxin_cputemp_group);
+	return 0;
+}
+
+static struct platform_driver zhaoxin_cputemp_driver = {
+	.driver = {
+		.name = DRVNAME,
+	},
+	.probe = zhaoxin_cputemp_probe,
+	.remove = zhaoxin_cputemp_remove,
+};
+
+struct pdev_entry {
+	struct list_head list;
+	struct platform_device *pdev;
+	unsigned int cpu;
+};
+
+static LIST_HEAD(pdev_list);
+static DEFINE_MUTEX(pdev_list_mutex);
+
+static int zhaoxin_cputemp_online(unsigned int cpu)
+{
+	int err;
+	struct platform_device *pdev;
+	struct pdev_entry *pdev_entry;
+
+	pdev = platform_device_alloc(DRVNAME, cpu);
+	if (!pdev) {
+		err = -ENOMEM;
+		pr_err("Device allocation failed\n");
+		goto exit;
+	}
+
+	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
+	if (!pdev_entry) {
+		err = -ENOMEM;
+		goto exit_device_put;
+	}
+
+	err = platform_device_add(pdev);
+	if (err) {
+		pr_err("Device addition failed (%d)\n", err);
+		goto exit_device_free;
+	}
+
+	pdev_entry->pdev = pdev;
+	pdev_entry->cpu = cpu;
+	mutex_lock(&pdev_list_mutex);
+	list_add_tail(&pdev_entry->list, &pdev_list);
+	mutex_unlock(&pdev_list_mutex);
+
+	return 0;
+
+exit_device_free:
+	kfree(pdev_entry);
+exit_device_put:
+	platform_device_put(pdev);
+exit:
+	return err;
+}
+
+static int zhaoxin_cputemp_down_prep(unsigned int cpu)
+{
+	struct pdev_entry *p;
+
+	mutex_lock(&pdev_list_mutex);
+	list_for_each_entry(p, &pdev_list, list) {
+		if (p->cpu == cpu) {
+			platform_device_unregister(p->pdev);
+			list_del(&p->list);
+			mutex_unlock(&pdev_list_mutex);
+			kfree(p);
+			return 0;
+		}
+	}
+	mutex_unlock(&pdev_list_mutex);
+	return 0;
+}
+
+static const struct x86_cpu_id __initconst cputemp_ids[] = {
+	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 7, 0x3b, NULL),
+	X86_MATCH_VENDOR_FAM_MODEL(ZHAOXIN, 7, 0x3b, NULL),
+	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 7, 0x5b, NULL),
+	X86_MATCH_VENDOR_FAM_MODEL(ZHAOXIN, 7, 0x5b, NULL),
+	X86_MATCH_VENDOR_FAM_MODEL(CENTAUR, 7, 0x6b, NULL),
+	X86_MATCH_VENDOR_FAM_MODEL(ZHAOXIN, 7, 0x6b, NULL),
+	{}
+};
+MODULE_DEVICE_TABLE(x86cpu, cputemp_ids);
+
+static enum cpuhp_state zhaoxin_temp_online;
+
+static int __init zhaoxin_cputemp_init(void)
+{
+	int err;
+
+	if (!x86_match_cpu(cputemp_ids))
+		return -ENODEV;
+
+	err = platform_driver_register(&zhaoxin_cputemp_driver);
+	if (err)
+		goto exit;
+
+	err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hwmon/zhaoxin:online",
+			zhaoxin_cputemp_online, zhaoxin_cputemp_down_prep);
+	if (err < 0)
+		goto exit_driver_unreg;
+
+	zhaoxin_temp_online = err;
+
+#ifndef CONFIG_HOTPLUG_CPU
+	if (list_empty(&pdev_list)) {
+		err = -ENODEV;
+		goto exit_hp_unreg;
+	}
+#endif
+	return 0;
+
+#ifndef CONFIG_HOTPLUG_CPU
+exit_hp_unreg:
+	cpuhp_remove_state_nocalls(zhaoxin_temp_online);
+#endif
+exit_driver_unreg:
+	platform_driver_unregister(&zhaoxin_cputemp_driver);
+exit:
+	return err;
+}
+
+static void __exit zhaoxin_cputemp_exit(void)
+{
+	cpuhp_remove_state(zhaoxin_temp_online);
+	platform_driver_unregister(&zhaoxin_cputemp_driver);
+}
+
+MODULE_DESCRIPTION("Zhaoxin CPU temperature monitor");
+MODULE_LICENSE("GPL");
+
+module_init(zhaoxin_cputemp_init)
+module_exit(zhaoxin_cputemp_exit)