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From: "Václav Kubernát" <kubernat@cesnet.cz>
To: Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/5] hwmon: (max31790) Fix and split pwm*_enable
Date: Wed, 12 May 2021 03:32:36 +0200	[thread overview]
Message-ID: <CABKa3noSQVtAp3Ath9=PNh2cDLgq8n8w2gudwWJerD5YQx5WMA@mail.gmail.com> (raw)
In-Reply-To: <20210512013052.903297-2-kubernat@cesnet.cz>

Hello,

I have updated the code and got rid of the "fullspeed" mode as
requested. Let me know what you think.

Thanks
Václav

st 12. 5. 2021 v 3:31 odesílatel Václav Kubernát <kubernat@cesnet.cz> napsal:
>
> In the old code, pwm*_enable does two things. Firstly, it sets whether
> the chip should run in PWM or RPM mode. Secondly, it tells the chip
> whether it should monitor fan RPM. However, these two settings aren't
> tied together, so they shouldn't be set with a single value. In the new
> code, fan*_enable now controls fan RPM monitoring (pwm*_enable no longer
> controls that).
>
> According to the sysfs hwmon documentation, pwm*_enable has three
> possible values, 0 for "no control / full-speed", 1 for manual mode, and
> 2+ for automatic. The old code works fine for 1 and 2, but 0 only
> differs from 1 in that it just turns off fan speed monitoring. The chip
> actually does have a way to turn off fan controls (and only monitor),
> and what that does is that it sets PWM to 0% duty cycle. In the new
> code, 0 in pwm*_enable turns off the "control" feature of the chip.
>
> These two changes are closely connected together, mainly because the
> detection of the pwm*_enable value depended on whether fan speed
> monitoring is enabled (which is now controlled as written in the first
> paragraph).
>
> Signed-off-by: Václav Kubernát <kubernat@cesnet.cz>
> ---
>  Documentation/hwmon/max31790.rst | 10 ++--
>  drivers/hwmon/max31790.c         | 78 +++++++++++++++++++++-----------
>  2 files changed, 58 insertions(+), 30 deletions(-)
>
> diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
> index f301385d8cef..d2ac4e926905 100644
> --- a/Documentation/hwmon/max31790.rst
> +++ b/Documentation/hwmon/max31790.rst
> @@ -34,10 +34,14 @@ also be configured to serve as tachometer inputs.
>  Sysfs entries
>  -------------
>
> -================== === =======================================================
> +================== === =============================================================
> +fan[1-12]_enable   RW  enable fan speed monitoring
>  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
> -pwm[1-6]_enable    RW  regulator mode, 0=disabled, 1=manual mode, 2=rpm mode
> +pwm[1-6]_enable    RW  regulator mode, 0=no control, sets 0% PWM,
> +                                      1=manual (pwm) mode,
> +                                      2=rpm mode
> +                       setting rpm mode sets fan*_enable to 1
>  pwm[1-6]           RW  fan target duty cycle (0-255)
> -================== === =======================================================
> +================== === =============================================================
> diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
> index e3765ce4444a..5d4c551df010 100644
> --- a/drivers/hwmon/max31790.c
> +++ b/drivers/hwmon/max31790.c
> @@ -30,6 +30,7 @@
>  #define MAX31790_FAN_CFG_RPM_MODE      0x80
>  #define MAX31790_FAN_CFG_TACH_INPUT_EN 0x08
>  #define MAX31790_FAN_CFG_TACH_INPUT    0x01
> +#define MAX31790_FAN_CFG_CTRL_MON      0x10
>
>  /* Fan Dynamics register bits */
>  #define MAX31790_FAN_DYN_SR_SHIFT      5
> @@ -191,6 +192,9 @@ static int max31790_read_fan(struct device *dev, u32 attr, int channel,
>                 else
>                         *val = !!(fault & (1 << channel));
>                 return 0;
> +       case hwmon_fan_enable:
> +               *val = !!(data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN);
> +               return 0;
>         default:
>                 return -EOPNOTSUPP;
>         }
> @@ -233,6 +237,15 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
>                                      MAX31790_REG_TARGET_COUNT(channel),
>                                      target_count);
>                 break;
> +       case hwmon_fan_enable:
> +               if (val == 0)
> +                       data->fan_config[channel] &= ~MAX31790_FAN_CFG_TACH_INPUT_EN;
> +               else
> +                       data->fan_config[channel] |= MAX31790_FAN_CFG_TACH_INPUT_EN;
> +               err = regmap_write(regmap,
> +                                  MAX31790_REG_FAN_CONFIG(channel),
> +                                  data->fan_config[channel]);
> +               break;
>         default:
>                 err = -EOPNOTSUPP;
>                 break;
> @@ -260,6 +273,11 @@ 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 ||
> +                   (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
> +                       return 0644;
> +               return 0;
>         default:
>                 return 0;
>         }
> @@ -281,12 +299,12 @@ static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
>                 *val = read >> 8;
>                 return 0;
>         case hwmon_pwm_enable:
> -               if (data->fan_config[channel] & MAX31790_FAN_CFG_RPM_MODE)
> +               if (data->fan_config[channel] & MAX31790_FAN_CFG_CTRL_MON)
> +                       *val = 0;
> +               else if (data->fan_config[channel] & MAX31790_FAN_CFG_RPM_MODE)
>                         *val = 2;
> -               else if (data->fan_config[channel] & MAX31790_FAN_CFG_TACH_INPUT_EN)
> +               else
>                         *val = 1;
> -               else
> -                       *val = 0;
>                 return 0;
>         default:
>                 return -EOPNOTSUPP;
> @@ -298,35 +316,41 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
>  {
>         struct max31790_data *data = dev_get_drvdata(dev);
>         struct regmap *regmap = data->regmap;
> -       u8 fan_config;
> +       u8 fan_config = data->fan_config[channel];
>         int err = 0;
>
>         mutex_lock(&data->update_lock);
>
>         switch (attr) {
>         case hwmon_pwm_input:
> -               if (val < 0 || val > 255) {
> +               if (fan_config & MAX31790_FAN_CFG_CTRL_MON || val < 0 || val > 255) {
>                         err = -EINVAL;
>                         break;
>                 }
> +
>                 err = write_reg_word(regmap, MAX31790_REG_PWMOUT(channel), val << 8);
>                 break;
>         case hwmon_pwm_enable:
>                 fan_config = data->fan_config[channel];
> -               if (val == 0) {
> -                       fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
> -                                       MAX31790_FAN_CFG_RPM_MODE);
> -               } else if (val == 1) {
> -                       fan_config = (fan_config |
> -                                     MAX31790_FAN_CFG_TACH_INPUT_EN) &
> -                                    ~MAX31790_FAN_CFG_RPM_MODE;
> +               if (val == 0)
> +                       fan_config |= MAX31790_FAN_CFG_CTRL_MON;
> +               else if (val == 1) {
> +                       fan_config &= ~(MAX31790_FAN_CFG_RPM_MODE | MAX31790_FAN_CFG_CTRL_MON);
>                 } else if (val == 2) {
> -                       fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
> -                                     MAX31790_FAN_CFG_RPM_MODE;
> +                       fan_config &= ~(MAX31790_FAN_CFG_CTRL_MON);
> +                       fan_config |= MAX31790_FAN_CFG_RPM_MODE;
>                 } else {
>                         err = -EINVAL;
>                         break;
>                 }
> +
> +               /*
> +                * RPM mode implies enabled TACH input, so enable it in RPM
> +                * mode.
> +                */
> +               if (val == 2)
> +                       fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN;
> +
>                 data->fan_config[channel] = fan_config;
>                 err = regmap_write(regmap,
>                                    MAX31790_REG_FAN_CONFIG(channel),
> @@ -400,18 +424,18 @@ 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_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | HWMON_F_FAULT,
> -                          HWMON_F_INPUT | 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_TARGET | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT,
> +                          HWMON_F_ENABLE | HWMON_F_INPUT | HWMON_F_FAULT),
>         HWMON_CHANNEL_INFO(pwm,
>                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
>                            HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
> --
> 2.31.1
>

  reply	other threads:[~2021-05-12  1:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-12  1:30 [PATCH v5 1/5] hwmon: (max31790) Rework to use regmap Václav Kubernát
2021-05-12  1:30 ` [PATCH v5 2/5] hwmon: (max31790) Fix and split pwm*_enable Václav Kubernát
2021-05-12  1:32   ` Václav Kubernát [this message]
2021-05-18 14:59     ` Guenter Roeck
2021-05-19 23:11   ` Guenter Roeck
2021-05-12  1:30 ` [PATCH v5 3/5] hwmon: (max31790) Show 0 RPM/fault when input disabled Václav Kubernát
2021-05-12  1:30 ` [PATCH v5 4/5] hwmon: (max31790) Allow setting fan*_div Václav Kubernát
2021-05-12  1:30 ` [PATCH v5 5/5] hwmon: (max31790) Update documentation Václav Kubernát
2021-05-19 19:00 ` [PATCH v5 1/5] hwmon: (max31790) Rework to use regmap Guenter Roeck
2021-05-20  5:12 ` Guenter Roeck
2021-05-18 21:16 [PATCH v5 2/5] hwmon: (max31790) Fix and split pwm*_enable Guenter Roeck
2021-05-19  9:10 ` Jan Kundrát
2021-05-19 13:55   ` Guenter Roeck
2021-05-20 11:29     ` Jan Kundrát
2021-05-20 11:50       ` Guenter Roeck

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