Re: [PATCH v1 2/5] platform/x86: ayaneo-ec: Add hwmon support

[Armin Wolf <W_Armin@gmx.de>]

Am 22.08.25 um 22:56 schrieb Antheas Kapenekakis:

> On Fri, 22 Aug 2025 at 14:35, Armin Wolf <W_Armin@gmx.de> wrote:
>> Am 20.08.25 um 18:06 schrieb Antheas Kapenekakis:
>>
>>> Add hwmon single fan sensor reads and control for Ayaneo devices.
>>> The register and method of access is the same for all devices.
>>>
>>> Signed-off-by: Antheas Kapenekakis <lkml@antheas.dev>
>>> ---
>>>    drivers/platform/x86/Kconfig     |   2 +
>>>    drivers/platform/x86/ayaneo-ec.c | 132 +++++++++++++++++++++++++++++++
>>>    2 files changed, 134 insertions(+)
>>>
>>> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
>>> index 6d4a33791cc1..0a7ca2c78456 100644
>>> --- a/drivers/platform/x86/Kconfig
>>> +++ b/drivers/platform/x86/Kconfig
>>> @@ -307,6 +307,8 @@ config ASUS_TF103C_DOCK
>>>    config AYANEO_EC
>>>        tristate "Ayaneo EC platform control"
>>>        depends on X86
>>> +     depends on ACPI_EC
>>> +     depends on HWMON
>>>        help
>>>          Enables support for the platform EC of Ayaneo devices. This
>>>          includes fan control, fan speed, charge limit, magic
>>> diff --git a/drivers/platform/x86/ayaneo-ec.c b/drivers/platform/x86/ayaneo-ec.c
>>> index 90b86527ab0d..8b1902706b81 100644
>>> --- a/drivers/platform/x86/ayaneo-ec.c
>>> +++ b/drivers/platform/x86/ayaneo-ec.c
>>> @@ -7,13 +7,23 @@
>>>     * Copyright (C) 2025 Antheas Kapenekakis <lkml@antheas.dev>
>>>     */
>>>
>>> +#include <linux/acpi.h>
>>>    #include <linux/dmi.h>
>>> +#include <linux/hwmon.h>
>>>    #include <linux/init.h>
>>>    #include <linux/kernel.h>
>>>    #include <linux/module.h>
>>>    #include <linux/platform_device.h>
>>>
>>> +#define AYANEO_PWM_ENABLE_REG         0x4A
>>> +#define AYANEO_PWM_REG                0x4B
>>> +#define AYANEO_PWM_MODE_AUTO  0x00
>>> +#define AYANEO_PWM_MODE_MANUAL        0x01
>>> +
>>> +#define AYANEO_FAN_REG                0x76
>>> +
>>>    struct ayaneo_ec_quirk {
>>> +     bool has_fan_control;
>>>    };
>>>
>>>    struct ayaneo_ec_platform_data {
>>> @@ -22,6 +32,7 @@ struct ayaneo_ec_platform_data {
>>>    };
>>>
>>>    static const struct ayaneo_ec_quirk ayaneo3 = {
>>> +     .has_fan_control = true,
>>>    };
>>>
>>>    static const struct dmi_system_id dmi_table[] = {
>>> @@ -35,10 +46,124 @@ static const struct dmi_system_id dmi_table[] = {
>>>        {},
>>>    };
>>>
>>> +/* Callbacks for hwmon interface */
>>> +static umode_t ayaneo_ec_hwmon_is_visible(const void *drvdata,
>>> +                                    enum hwmon_sensor_types type, u32 attr,
>>> +                                    int channel)
>>> +{
>>> +     switch (type) {
>>> +     case hwmon_fan:
>>> +             return 0444;
>>> +     case hwmon_pwm:
>>> +             return 0644;
>>> +     default:
>>> +             return 0;
>>> +     }
>>> +}
>>> +
>>> +static int ayaneo_ec_read(struct device *dev, enum hwmon_sensor_types type,
>>> +                          u32 attr, int channel, long *val)
>>> +{
>>> +     u8 tmp;
>>> +     int ret;
>>> +
>>> +     switch (type) {
>>> +     case hwmon_fan:
>>> +             switch (attr) {
>>> +             case hwmon_fan_input:
>>> +                     ret = ec_read(AYANEO_FAN_REG, &tmp);
>>> +                     if (ret)
>>> +                             return ret;
>>> +                     *val = tmp << 8;
>>> +                     ret = ec_read(AYANEO_FAN_REG + 1, &tmp);
>>> +                     if (ret)
>>> +                             return ret;
>>> +                     *val += tmp;
>>> +                     return 0;
>>> +             default:
>>> +                     break;
>>> +             }
>>> +             break;
>>> +     case hwmon_pwm:
>>> +             switch (attr) {
>>> +             case hwmon_pwm_input:
>>> +                     ret = ec_read(AYANEO_PWM_REG, &tmp);
>>> +                     if (ret)
>>> +                             return ret;
>>> +                     *val = (255 * tmp) / 100;
>>> +                     if (*val < 0 || *val > 255)
>>> +                             return -EINVAL;
>>> +                     return 0;
>>> +             case hwmon_pwm_enable:
>>> +                     ret = ec_read(AYANEO_PWM_ENABLE_REG, &tmp);
>>> +                     if (ret)
>>> +                             return ret;
>>> +                     if (tmp == AYANEO_PWM_MODE_MANUAL)
>>> +                             *val = 1;
>>> +                     else
>>> +                             *val = 2;
>>> +                     return 0;
>>> +             default:
>>> +                     break;
>>> +             }
>>> +             break;
>>> +     default:
>>> +             break;
>>> +     }
>>> +     return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static int ayaneo_ec_write(struct device *dev, enum hwmon_sensor_types type,
>>> +                           u32 attr, int channel, long val)
>>> +{
>>> +     switch (type) {
>>> +     case hwmon_pwm:
>>> +             switch (attr) {
>>> +             case hwmon_pwm_enable:
>>> +                     if (val == 1)
>>> +                             return ec_write(AYANEO_PWM_ENABLE_REG,
>>> +                                             AYANEO_PWM_MODE_MANUAL);
>>> +                     else if (val == 2)
>>> +                             return ec_write(AYANEO_PWM_ENABLE_REG,
>>> +                                             AYANEO_PWM_MODE_AUTO);
>>> +                     else
>>> +                             return -EINVAL;
>> Consider using a switch statement here.
>>
>>> +             case hwmon_pwm_input:
>>> +                     if (val < 0 || val > 255)
>>> +                             return -EINVAL;
>>> +                     return ec_write(AYANEO_PWM_REG, (val * 100) / 255);
>> Better use fixp_linear_interpolate() for that. Also you need to restore those registers
>> after suspend. I suggest that you use regmap for that.
> The registers appear to maintain their state after sleep. If I get a
> report that some devices do not, I will amend the driver with a
> suspend hook.

Even during hibernation?

Thanks,
Armin Wolf

>
> ack on the interpolate.
>
> Antheas
>
>> Thanks,
>> Armin Wolf
>>
>>> +             default:
>>> +                     break;
>>> +             }
>>> +             break;
>>> +     default:
>>> +             break;
>>> +     }
>>> +     return -EOPNOTSUPP;
>>> +}
>>> +
>>> +static const struct hwmon_ops ayaneo_ec_hwmon_ops = {
>>> +     .is_visible = ayaneo_ec_hwmon_is_visible,
>>> +     .read = ayaneo_ec_read,
>>> +     .write = ayaneo_ec_write,
>>> +};
>>> +
>>> +static const struct hwmon_channel_info *const ayaneo_ec_sensors[] = {
>>> +     HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
>>> +     HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
>>> +     NULL,
>>> +};
>>> +
>>> +static const struct hwmon_chip_info ayaneo_ec_chip_info = {
>>> +     .ops = &ayaneo_ec_hwmon_ops,
>>> +     .info = ayaneo_ec_sensors,
>>> +};
>>> +
>>>    static int ayaneo_ec_probe(struct platform_device *pdev)
>>>    {
>>>        const struct dmi_system_id *dmi_entry;
>>>        struct ayaneo_ec_platform_data *data;
>>> +     struct device *hwdev;
>>>
>>>        dmi_entry = dmi_first_match(dmi_table);
>>>        if (!dmi_entry)
>>> @@ -52,6 +177,13 @@ static int ayaneo_ec_probe(struct platform_device *pdev)
>>>        data->quirks = dmi_entry->driver_data;
>>>        platform_set_drvdata(pdev, data);
>>>
>>> +     if (data->quirks->has_fan_control) {
>>> +             hwdev = devm_hwmon_device_register_with_info(
>>> +                     &pdev->dev, "ayaneo_ec", NULL, &ayaneo_ec_chip_info, NULL);
>>> +             if (IS_ERR(hwdev))
>>> +                     return PTR_ERR(hwdev);
>>> +     }
>>> +
>>>        return 0;
>>>    }
>>>