[PATCH linux dev-5.10] hwmon: (max31790) add fanN_enable

[Joel Stanley]

On Fri, 9 Sept 2022 at 03:45, Justin Ledford <justinledford at google.com> wrote:
>
> The MAX31790 has a tach input enable bit in each fan's configuration
> register. This is only enabled by the driver if RPM mode is selected,
> but the driver doesn't provide a way to independently enable tachometer
> input regardless of the regulator mode.
>
> By adding the fanN_enable sysfs files, we can decouple the tach input
> from the regulator mode. Also update the documentation.
>
> Upstream (hwmon-next) commit: ca221abcb7ca95c9f36e3fb04ec19ab3fa865af0
> Signed-off-by: Justin Ledford <justinledford at google.com>

Hi Justin,

You generally need to be subscribed to the list to post. I have
manually moderated your mail through, but be sure to subscribe before
you next post. You can subscribe but set delivery to be false, if you
aren't interested in the mail. We do this to avoid spam.

Secondly, the v5.10 openbmc tree is completely unmaintined, and
therefore not accepting new changes. You should move your platforms to
v5.15 and submit your patches against that, which is actively
maintained by myself.

Cheers,

Joel

> ---
>  Documentation/hwmon/max31790.rst |  1 +
>  drivers/hwmon/max31790.c         | 38 ++++++++++++++++++++++++++------
>  2 files changed, 32 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
> index 7b097c3b9b90..33c5c7330efc 100644
> --- a/Documentation/hwmon/max31790.rst
> +++ b/Documentation/hwmon/max31790.rst
> @@ -38,6 +38,7 @@ Sysfs entries
>  fan[1-12]_input    RO  fan tachometer speed in RPM
>  fan[1-12]_fault    RO  fan experienced fault
>  fan[1-6]_target    RW  desired fan speed in RPM
> +fan[1-6]_enable    RW  enable or disable the tachometer input
>  pwm[1-6]_enable    RW  regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
>  pwm[1-6]           RW  read: current pwm duty cycle,
>                         write: target pwm duty cycle (0-255)
> diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
> index 7e9362f6dc29..20bf5ffadefe 100644
> --- a/drivers/hwmon/max31790.c
> +++ b/drivers/hwmon/max31790.c
> @@ -202,6 +202,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
>                 }
>                 mutex_unlock(&data->update_lock);
>                 return 0;
> +       case hwmon_fan_enable:
> +               *val = !!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN);
> +               return 0;
>         default:
>                 return -EOPNOTSUPP;
>         }
> @@ -214,7 +217,7 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
>         struct i2c_client *client = data->client;
>         int target_count;
>         int err = 0;
> -       u8 bits;
> +       u8 bits, fan_config;
>         int sr;
>
>         mutex_lock(&data->update_lock);
> @@ -243,6 +246,23 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
>                                         MAX31790_REG_TARGET_COUNT(channel),
>                                         data->target_count[channel]);
>                 break;
> +       case hwmon_fan_enable:
> +               fan_config = data->fan_config[channel];
> +               if (val == 0) {
> +                       fan_config &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
> +               } else if (val == 1) {
> +                       fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
> +               } else {
> +                       err = -EINVAL;
> +                       break;
> +               }
> +               if (fan_config != data->fan_config[channel]) {
> +                       err = i2c_smbus_write_byte_data(client, MAX31790_REG_FAN_CONFIG(channel),
> +                                                       fan_config);
> +                       if (!err)
> +                               data->fan_config[channel] = fan_config;
> +               }
> +               break;
>         default:
>                 err = -EOPNOTSUPP;
>                 break;
> @@ -270,6 +290,10 @@ static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
>                     !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
>                         return 0644;
>                 return 0;
> +       case hwmon_fan_enable:
> +               if (channel < NR_CHANNEL)
> +                       return 0644;
> +               return 0;
>         default:
>                 return 0;
>         }
> @@ -423,12 +447,12 @@ static umode_t max31790_is_visible(const void *data,
>
>  static const struct hwmon_channel_info *max31790_info[] = {
>         HWMON_CHANNEL_INFO(fan,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
> +                          HWMON_F_INPUT | HWMON_F_TARGET | HWMON_F_FAULT | HWMON_F_ENABLE,
>                            HWMON_F_INPUT | HWMON_F_FAULT,
>                            HWMON_F_INPUT | HWMON_F_FAULT,
>                            HWMON_F_INPUT | HWMON_F_FAULT,
> --
> 2.37.2.789.g6183377224-goog
>