lkml.org 
[lkml]   [2021]   [Jul]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH AUTOSEL 5.10 54/70] hwmon: (max31790) Report correct current pwm duty cycles
    Date
    From: Guenter Roeck <linux@roeck-us.net>

    [ Upstream commit 897f6339893b741a5d68ae8e2475df65946041c2 ]

    The MAX31790 has two sets of registers for pwm duty cycles, one to request
    a duty cycle and one to read the actual current duty cycle. Both do not
    have to be the same.

    When reporting the pwm duty cycle to the user, the actual pwm duty cycle
    from pwm duty cycle registers needs to be reported. When setting it, the
    pwm target duty cycle needs to be written. Since we don't know the actual
    pwm duty cycle after a target pwm duty cycle has been written, set the
    valid flag to false to indicate that actual pwm duty cycle should be read
    from the chip instead of using cached values.

    Cc: Jan Kundrát <jan.kundrat@cesnet.cz>
    Cc: Václav Kubernát <kubernat@cesnet.cz>
    Signed-off-by: Guenter Roeck <linux@roeck-us.net>
    Tested-by: Václav Kubernát <kubernat@ceesnet.cz>
    Reviewed-by: Jan Kundrát <jan.kundrat@cesnet.cz>
    Link: https://lore.kernel.org/r/20210526154022.3223012-3-linux@roeck-us.net
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    Documentation/hwmon/max31790.rst | 3 ++-
    drivers/hwmon/max31790.c | 6 +++---
    2 files changed, 5 insertions(+), 4 deletions(-)

    diff --git a/Documentation/hwmon/max31790.rst b/Documentation/hwmon/max31790.rst
    index f301385d8cef..54ff0f49e28f 100644
    --- a/Documentation/hwmon/max31790.rst
    +++ b/Documentation/hwmon/max31790.rst
    @@ -39,5 +39,6 @@ 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] RW fan target duty cycle (0-255)
    +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 86e6c71db685..8ad7a45bfe68 100644
    --- a/drivers/hwmon/max31790.c
    +++ b/drivers/hwmon/max31790.c
    @@ -104,7 +104,7 @@ static struct max31790_data *max31790_update_device(struct device *dev)
    data->tach[NR_CHANNEL + i] = rv;
    } else {
    rv = i2c_smbus_read_word_swapped(client,
    - MAX31790_REG_PWMOUT(i));
    + MAX31790_REG_PWM_DUTY_CYCLE(i));
    if (rv < 0)
    goto abort;
    data->pwm[i] = rv;
    @@ -299,10 +299,10 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
    err = -EINVAL;
    break;
    }
    - data->pwm[channel] = val << 8;
    + data->valid = false;
    err = i2c_smbus_write_word_swapped(client,
    MAX31790_REG_PWMOUT(channel),
    - data->pwm[channel]);
    + val << 8);
    break;
    case hwmon_pwm_enable:
    fan_config = data->fan_config[channel];
    --
    2.30.2
    \
     
     \ /
      Last update: 2021-07-05 01:40    [W:2.939 / U:0.028 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site