Messages in this thread | | | Date | Sun, 27 Mar 2022 16:18:28 +0200 | From | Michael Walle <> | Subject | Re: [PATCH v1 4/4] hwmon: add driver for the Microchip LAN966x SoC |
| |
Am 2022-03-27 03:34, schrieb Guenter Roeck:
>> + /* >> + * Data is given in pulses per second. According to the hwmon ABI we >> + * have to assume two pulses per revolution. > > The hwmon ABI doesn't make any such assumptions. It wants to see RPM, > that is all. Pulses per revolution is a fan property.
There is fanY_pulses according to Documentation/ABI/testing/sysfs-class-hwmon:
Should only be created if the chip has a register to configure the number of pulses. In the absence of such a register (and thus attribute) the value assumed by all devices is 2 pulses per fan revolution.
The hardware returns just the pulses per second. Doesn't that mean I have to divide that value by two?
>> + */ >> + *val = FIELD_GET(FAN_CNT_DATA, data) * 60 / 2;
.. otherwise this should then be *val = FIELD_GET(FAN_CNT_DATA, data) * 60;
>> + >> + return 0; >> +} >> + >> +static int lan966x_hwmon_read_pwm(struct device *dev, long *val) >> +{ >> + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); >> + unsigned int data; >> + int ret; >> + >> + ret = regmap_read(hwmon->regmap_fan, FAN_CFG, &data); >> + if (ret < 0) >> + return ret; >> + >> + *val = FIELD_GET(FAN_CFG_DUTY_CYCLE, data); >> + >> + return 0; >> +} >> + >> +static int lan966x_hwmon_read_pwm_freq(struct device *dev, long *val) >> +{ >> + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); >> + unsigned long rate = clk_get_rate(hwmon->clk); > > Is that a dynamic frequency ? If not, it would be better to read it > once > and store it in struct lan966x_hwmon.
yes it is configurable, actually. See lan966x_hwmon_write_pwm_freq().
-michael
| |