Re: [PATCH 1/2] platform/x86: dell-ddv: Add hwmon support

From: Hans de Goede
Date: Mon Feb 06 2023 - 09:15:17 EST

Next message: Hans de Goede: "Re: [PATCH 2/2] platform/x86: dell-ddv: Prefer asynchronous probing"
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In reply to: Armin Wolf: "[PATCH 1/2] platform/x86: dell-ddv: Add hwmon support"
Next in thread: Guenter Roeck: "Re: [PATCH 1/2] platform/x86: dell-ddv: Add hwmon support"
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Hi Armin,

On 2/5/23 21:54, Armin Wolf wrote:
> Thanks to bugreport 216655 on bugzilla triggered by the
> dell-smm-hwmon driver, the contents of the sensor buffers
> could be almost completely decoded.
> Add an hwmon interface for exposing the fan and thermal
> sensor values. Since the WMI interface can be quite slow
> on some machines, the sensor buffers are cached for 1 second
> to lessen the performance impact.
> The debugfs interface remains in place to aid in reverse-engineering
> of unknown sensor types and the thermal buffer.
>
> Tested-by: Antonín Skala <skala.antonin@xxxxxxxxx>
> Tested-by: Gustavo Walbon <gustavowalbon@xxxxxxxxx>
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>

This looks nice and clean to me, thank you:

Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>

I'm going to wait a bit with merging this to see if Guenter
has any remarks. If there are no remarks by next Monday then
I'll merge this for the 6.3 merge window.

Regards,

Hans

> ---
> drivers/platform/x86/dell/Kconfig | 8 +-
> drivers/platform/x86/dell/dell-wmi-ddv.c | 492 ++++++++++++++++++++++-
> 2 files changed, 495 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/platform/x86/dell/Kconfig b/drivers/platform/x86/dell/Kconfig
> index d319de8f2132..bdd78076b1d7 100644
> --- a/drivers/platform/x86/dell/Kconfig
> +++ b/drivers/platform/x86/dell/Kconfig
> @@ -192,12 +192,12 @@ config DELL_WMI_DESCRIPTOR
> config DELL_WMI_DDV
> tristate "Dell WMI sensors Support"
> default m
> - depends on ACPI_BATTERY
> depends on ACPI_WMI
> + depends on ACPI_BATTERY || HWMON
> help
> - This option adds support for WMI-based sensors like
> - battery temperature sensors found on some Dell notebooks.
> - It also supports reading of the battery ePPID.
> + This option adds support for WMI-based fan and thermal sensors
> + found on some Dell notebooks. It also supports various WMI-based battery
> + extras like reading of the battery temperature and ePPID.
>
> To compile this drivers as a module, choose M here: the module will
> be called dell-wmi-ddv.
> diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
> index 9695bf493ea6..b7ac483eff12 100644
> --- a/drivers/platform/x86/dell/dell-wmi-ddv.c
> +++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
> @@ -12,19 +12,26 @@
> #include <linux/device.h>
> #include <linux/dev_printk.h>
> #include <linux/errno.h>
> +#include <linux/kconfig.h>
> #include <linux/kernel.h>
> +#include <linux/hwmon.h>
> #include <linux/kstrtox.h>
> #include <linux/math.h>
> +#include <linux/math64.h>
> #include <linux/module.h>
> +#include <linux/mutex.h>
> #include <linux/limits.h>
> #include <linux/power_supply.h>
> #include <linux/printk.h>
> #include <linux/seq_file.h>
> #include <linux/sysfs.h>
> +#include <linux/types.h>
> #include <linux/wmi.h>
>
> #include <acpi/battery.h>
>
> +#include <asm/unaligned.h>
> +
> #define DRIVER_NAME "dell-wmi-ddv"
>
> #define DELL_DDV_SUPPORTED_VERSION_MIN 2
> @@ -63,13 +70,63 @@ enum dell_ddv_method {
> DELL_DDV_THERMAL_SENSOR_INFORMATION = 0x22,
> };
>
> +struct fan_sensor_entry {
> + u8 type;
> + __le16 rpm;
> +} __packed;
> +
> +struct thermal_sensor_entry {
> + u8 type;
> + s8 now;
> + s8 min;
> + s8 max;
> + u8 unknown;
> +} __packed;
> +
> +struct combined_channel_info {
> + struct hwmon_channel_info info;
> + u32 config[];
> +};
> +
> +struct combined_chip_info {
> + struct hwmon_chip_info chip;
> + const struct hwmon_channel_info *info[];
> +};
> +
> +struct dell_wmi_ddv_sensors {
> + struct mutex lock; /* protect caching */
> + unsigned long timestamp;
> + union acpi_object *obj;
> + u64 entries;
> +};
> +
> struct dell_wmi_ddv_data {
> struct acpi_battery_hook hook;
> struct device_attribute temp_attr;
> struct device_attribute eppid_attr;
> + struct dell_wmi_ddv_sensors fans;
> + struct dell_wmi_ddv_sensors temps;
> struct wmi_device *wdev;
> };
>
> +static const char * const fan_labels[] = {
> + "CPU Fan",
> + "Chassis Motherboard Fan",
> + "Video Fan",
> + "Power Supply Fan",
> + "Chipset Fan",
> + "Memory Fan",
> + "PCI Fan",
> + "HDD Fan",
> +};
> +
> +static const char * const fan_dock_labels[] = {
> + "Docking Chassis/Motherboard Fan",
> + "Docking Video Fan",
> + "Docking Power Supply Fan",
> + "Docking Chipset Fan",
> +};
> +
> static int dell_wmi_ddv_query_type(struct wmi_device *wdev, enum dell_ddv_method method, u32 arg,
> union acpi_object **result, acpi_object_type type)
> {
> @@ -171,6 +228,427 @@ static int dell_wmi_ddv_query_string(struct wmi_device *wdev, enum dell_ddv_meth
> return dell_wmi_ddv_query_type(wdev, method, arg, result, ACPI_TYPE_STRING);
> }
>
> +/*
> + * Needs to be called with lock held, except during initialization.
> + */
> +static int dell_wmi_ddv_update_sensors(struct wmi_device *wdev, enum dell_ddv_method method,
> + struct dell_wmi_ddv_sensors *sensors, size_t entry_size)
> +{
> + u64 buffer_size, rem, entries;
> + union acpi_object *obj;
> + u8 *buffer;
> + int ret;
> +
> + if (sensors->obj) {
> + if (time_before(jiffies, sensors->timestamp + HZ))
> + return 0;
> +
> + kfree(sensors->obj);
> + sensors->obj = NULL;
> + }
> +
> + ret = dell_wmi_ddv_query_buffer(wdev, method, 0, &obj);
> + if (ret < 0)
> + return ret;
> +
> + /* buffer format sanity check */
> + buffer_size = obj->package.elements[0].integer.value;
> + buffer = obj->package.elements[1].buffer.pointer;
> + entries = div64_u64_rem(buffer_size, entry_size, &rem);
> + if (rem != 1 || buffer[buffer_size - 1] != 0xff) {
> + ret = -ENOMSG;
> +
> + goto err_free;
> + }
> +
> + if (!entries) {
> + ret = -ENODATA;
> +
> + goto err_free;
> + }
> +
> + sensors->obj = obj;
> + sensors->entries = entries;
> + sensors->timestamp = jiffies;
> +
> + return 0;
> +
> +err_free:
> + kfree(obj);
> +
> + return ret;
> +}
> +
> +static umode_t dell_wmi_ddv_is_visible(const void *drvdata, enum hwmon_sensor_types type, u32 attr,
> + int channel)
> +{
> + return 0444;
> +}
> +
> +static int dell_wmi_ddv_fan_read_channel(struct dell_wmi_ddv_data *data, u32 attr, int channel,
> + long *val)
> +{
> + struct fan_sensor_entry *entry;
> + int ret;
> +
> + ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_FAN_SENSOR_INFORMATION,
> + &data->fans, sizeof(*entry));
> + if (ret < 0)
> + return ret;
> +
> + if (channel >= data->fans.entries)
> + return -ENXIO;
> +
> + entry = (struct fan_sensor_entry *)data->fans.obj->package.elements[1].buffer.pointer;
> + switch (attr) {
> + case hwmon_fan_input:
> + *val = get_unaligned_le16(&entry[channel].rpm);
> +
> + return 0;
> + default:
> + break;
> + }
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static int dell_wmi_ddv_temp_read_channel(struct dell_wmi_ddv_data *data, u32 attr, int channel,
> + long *val)
> +{
> + struct thermal_sensor_entry *entry;
> + int ret;
> +
> + ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION,
> + &data->temps, sizeof(*entry));
> + if (ret < 0)
> + return ret;
> +
> + if (channel >= data->temps.entries)
> + return -ENXIO;
> +
> + entry = (struct thermal_sensor_entry *)data->temps.obj->package.elements[1].buffer.pointer;
> + switch (attr) {
> + case hwmon_temp_input:
> + *val = entry[channel].now * 1000;
> +
> + return 0;
> + case hwmon_temp_min:
> + *val = entry[channel].min * 1000;
> +
> + return 0;
> + case hwmon_temp_max:
> + *val = entry[channel].max * 1000;
> +
> + return 0;
> + default:
> + break;
> + }
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static int dell_wmi_ddv_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> + int channel, long *val)
> +{
> + struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
> + int ret;
> +
> + switch (type) {
> + case hwmon_fan:
> + mutex_lock(&data->fans.lock);
> + ret = dell_wmi_ddv_fan_read_channel(data, attr, channel, val);
> + mutex_unlock(&data->fans.lock);
> +
> + return ret;
> + case hwmon_temp:
> + mutex_lock(&data->temps.lock);
> + ret = dell_wmi_ddv_temp_read_channel(data, attr, channel, val);
> + mutex_unlock(&data->temps.lock);
> +
> + return ret;
> + default:
> + break;
> + }
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static int dell_wmi_ddv_fan_read_string(struct dell_wmi_ddv_data *data, int channel,
> + const char **str)
> +{
> + struct fan_sensor_entry *entry;
> + int ret;
> + u8 type;
> +
> + ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_FAN_SENSOR_INFORMATION,
> + &data->fans, sizeof(*entry));
> + if (ret < 0)
> + return ret;
> +
> + if (channel >= data->fans.entries)
> + return -ENXIO;
> +
> + entry = (struct fan_sensor_entry *)data->fans.obj->package.elements[1].buffer.pointer;
> + type = entry[channel].type;
> + switch (type) {
> + case 0x00 ... 0x07:
> + *str = fan_labels[type];
> +
> + break;
> + case 0x11 ... 0x14:
> + *str = fan_dock_labels[type - 0x11];
> +
> + break;
> + default:
> + *str = "Unknown Fan";
> +
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int dell_wmi_ddv_temp_read_string(struct dell_wmi_ddv_data *data, int channel,
> + const char **str)
> +{
> + struct thermal_sensor_entry *entry;
> + int ret;
> +
> + ret = dell_wmi_ddv_update_sensors(data->wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION,
> + &data->temps, sizeof(*entry));
> + if (ret < 0)
> + return ret;
> +
> + if (channel >= data->temps.entries)
> + return -ENXIO;
> +
> + entry = (struct thermal_sensor_entry *)data->temps.obj->package.elements[1].buffer.pointer;
> + switch (entry[channel].type) {
> + case 0x00:
> + *str = "CPU";
> +
> + break;
> + case 0x11:
> + *str = "Video";
> +
> + break;
> + case 0x22:
> + *str = "Memory"; /* sometimes called DIMM */
> +
> + break;
> + case 0x33:
> + *str = "Other";
> +
> + break;
> + case 0x44:
> + *str = "Ambient"; /* sometimes called SKIN */
> +
> + break;
> + case 0x52:
> + *str = "SODIMM";
> +
> + break;
> + case 0x55:
> + *str = "HDD";
> +
> + break;
> + case 0x62:
> + *str = "SODIMM 2";
> +
> + break;
> + case 0x73:
> + *str = "NB";
> +
> + break;
> + case 0x83:
> + *str = "Charger";
> +
> + break;
> + case 0xbb:
> + *str = "Memory 3";
> +
> + break;
> + default:
> + *str = "Unknown";
> +
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int dell_wmi_ddv_read_string(struct device *dev, enum hwmon_sensor_types type, u32 attr,
> + int channel, const char **str)
> +{
> + struct dell_wmi_ddv_data *data = dev_get_drvdata(dev);
> + int ret;
> +
> + switch (type) {
> + case hwmon_fan:
> + switch (attr) {
> + case hwmon_fan_label:
> + mutex_lock(&data->fans.lock);
> + ret = dell_wmi_ddv_fan_read_string(data, channel, str);
> + mutex_unlock(&data->fans.lock);
> +
> + return ret;
> + default:
> + break;
> + }
> + break;
> + case hwmon_temp:
> + switch (attr) {
> + case hwmon_temp_label:
> + mutex_lock(&data->temps.lock);
> + ret = dell_wmi_ddv_temp_read_string(data, channel, str);
> + mutex_unlock(&data->temps.lock);
> +
> + return ret;
> + default:
> + break;
> + }
> + break;
> + default:
> + break;
> + }
> +
> + return -EOPNOTSUPP;
> +}
> +
> +static const struct hwmon_ops dell_wmi_ddv_ops = {
> + .is_visible = dell_wmi_ddv_is_visible,
> + .read = dell_wmi_ddv_read,
> + .read_string = dell_wmi_ddv_read_string,
> +};
> +
> +static struct hwmon_channel_info *dell_wmi_ddv_channel_create(struct device *dev, u64 count,
> + enum hwmon_sensor_types type,
> + u32 config)
> +{
> + struct combined_channel_info *cinfo;
> + int i;
> +
> + cinfo = devm_kzalloc(dev, struct_size(cinfo, config, count + 1), GFP_KERNEL);
> + if (!cinfo)
> + return ERR_PTR(-ENOMEM);
> +
> + cinfo->info.type = type;
> + cinfo->info.config = cinfo->config;
> +
> + for (i = 0; i < count; i++)
> + cinfo->config[i] = config;
> +
> + return &cinfo->info;
> +}
> +
> +static void dell_wmi_ddv_hwmon_cache_destroy(void *data)
> +{
> + struct dell_wmi_ddv_sensors *sensors = data;
> +
> + mutex_destroy(&sensors->lock);
> + kfree(sensors->obj);
> +}
> +
> +static struct hwmon_channel_info *dell_wmi_ddv_channel_init(struct wmi_device *wdev,
> + enum dell_ddv_method method,
> + struct dell_wmi_ddv_sensors *sensors,
> + size_t entry_size,
> + enum hwmon_sensor_types type,
> + u32 config)
> +{
> + struct hwmon_channel_info *info;
> + int ret;
> +
> + ret = dell_wmi_ddv_update_sensors(wdev, method, sensors, entry_size);
> + if (ret < 0)
> + return ERR_PTR(ret);
> +
> + mutex_init(&sensors->lock);
> +
> + ret = devm_add_action_or_reset(&wdev->dev, dell_wmi_ddv_hwmon_cache_destroy, sensors);
> + if (ret < 0)
> + return ERR_PTR(ret);
> +
> + info = dell_wmi_ddv_channel_create(&wdev->dev, sensors->entries, type, config);
> + if (IS_ERR(info))
> + devm_release_action(&wdev->dev, dell_wmi_ddv_hwmon_cache_destroy, sensors);
> +
> + return info;
> +}
> +
> +static int dell_wmi_ddv_hwmon_add(struct dell_wmi_ddv_data *data)
> +{
> + struct wmi_device *wdev = data->wdev;
> + struct combined_chip_info *cinfo;
> + struct hwmon_channel_info *info;
> + struct device *hdev;
> + int index = 0;
> + int ret;
> +
> + if (!devres_open_group(&wdev->dev, dell_wmi_ddv_hwmon_add, GFP_KERNEL))
> + return -ENOMEM;
> +
> + cinfo = devm_kzalloc(&wdev->dev, struct_size(cinfo, info, 4), GFP_KERNEL);
> + if (!cinfo) {
> + ret = -ENOMEM;
> +
> + goto err_release;
> + }
> +
> + cinfo->chip.ops = &dell_wmi_ddv_ops;
> + cinfo->chip.info = cinfo->info;
> +
> + info = dell_wmi_ddv_channel_create(&wdev->dev, 1, hwmon_chip, HWMON_C_REGISTER_TZ);
> + if (IS_ERR(info)) {
> + ret = PTR_ERR(info);
> +
> + goto err_release;
> + }
> +
> + cinfo->info[index] = info;
> + index++;
> +
> + info = dell_wmi_ddv_channel_init(wdev, DELL_DDV_FAN_SENSOR_INFORMATION, &data->fans,
> + sizeof(struct fan_sensor_entry), hwmon_fan,
> + (HWMON_F_INPUT | HWMON_F_LABEL));
> + if (!IS_ERR(info)) {
> + cinfo->info[index] = info;
> + index++;
> + }
> +
> + info = dell_wmi_ddv_channel_init(wdev, DELL_DDV_THERMAL_SENSOR_INFORMATION, &data->temps,
> + sizeof(struct thermal_sensor_entry), hwmon_temp,
> + (HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
> + HWMON_T_LABEL));
> + if (!IS_ERR(info)) {
> + cinfo->info[index] = info;
> + index++;
> + }
> +
> + if (index < 2) {
> + ret = -ENODEV;
> +
> + goto err_release;
> + }
> +
> + hdev = devm_hwmon_device_register_with_info(&wdev->dev, "dell_ddv", data, &cinfo->chip,
> + NULL);
> + if (IS_ERR(hdev)) {
> + ret = PTR_ERR(hdev);
> +
> + goto err_release;
> + }
> +
> + devres_close_group(&wdev->dev, dell_wmi_ddv_hwmon_add);
> +
> + return 0;
> +
> +err_release:
> + devres_release_group(&wdev->dev, dell_wmi_ddv_hwmon_add);
> +
> + return ret;
> +}
> +
> static int dell_wmi_ddv_battery_index(struct acpi_device *acpi_dev, u32 *index)
> {
> const char *uid_str;
> @@ -370,7 +848,19 @@ static int dell_wmi_ddv_probe(struct wmi_device *wdev, const void *context)
>
> dell_wmi_ddv_debugfs_init(wdev);
>
> - return dell_wmi_ddv_battery_add(data);
> + if (IS_REACHABLE(CONFIG_ACPI_BATTERY)) {
> + ret = dell_wmi_ddv_battery_add(data);
> + if (ret < 0 && ret != -ENODEV)
> + dev_warn(&wdev->dev, "Unable to register ACPI battery hook: %d\n", ret);
> + }
> +
> + if (IS_REACHABLE(CONFIG_HWMON)) {
> + ret = dell_wmi_ddv_hwmon_add(data);
> + if (ret < 0 && ret != -ENODEV)
> + dev_warn(&wdev->dev, "Unable to register hwmon interface: %d\n", ret);
> + }
> +
> + return 0;
> }
>
> static const struct wmi_device_id dell_wmi_ddv_id_table[] = {
> --
> 2.30.2
>

Next message: Hans de Goede: "Re: [PATCH 2/2] platform/x86: dell-ddv: Prefer asynchronous probing"
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In reply to: Armin Wolf: "[PATCH 1/2] platform/x86: dell-ddv: Add hwmon support"
Next in thread: Guenter Roeck: "Re: [PATCH 1/2] platform/x86: dell-ddv: Add hwmon support"
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