Re: [PATCH v3 4/4] hwmon: (adt7475) add high frequency support

From: Chris Packham
Date: Thu May 11 2017 - 17:32:25 EST


On 11/05/17 15:45, Chris Packham wrote:
> Systems using 4-wire fans usually require high frequency (22.5kHz)
> output on the pwm. Add 22500 as a valid option in the pwmfreq_table. In
> high frequency mode the low-order bit are ignored so they can safely be
> set to 0.
>
> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes in v3:
> - New
>
> drivers/hwmon/adt7475.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
> index f7322330789c..f5a65d1166cd 100644
> --- a/drivers/hwmon/adt7475.c
> +++ b/drivers/hwmon/adt7475.c
> @@ -936,7 +936,7 @@ static ssize_t set_pwmctrl(struct device *dev, struct device_attribute *attr,
>
> /* List of frequencies for the PWM */
> static const int pwmfreq_table[] = {
> - 11, 14, 22, 29, 35, 44, 58, 88
> + 11, 14, 22, 29, 35, 44, 58, 88, 22500
> };
>
> static ssize_t show_pwmfreq(struct device *dev, struct device_attribute *attr,
> @@ -944,9 +944,10 @@ static ssize_t show_pwmfreq(struct device *dev, struct device_attribute *attr,
> {
> struct adt7475_data *data = adt7475_update_device(dev);
> struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> + int i = clamp_val(data->range[sattr->index] & 0xf, 0,
> + sizeof(pwmfreq_table));

Oops that should probably be

+ ARRAY_SIZE(pwmfreq_table) - 1);

Guenter, do you want me to send a v4 or can you fix it up at your end?

>
> - return sprintf(buf, "%d\n",
> - pwmfreq_table[data->range[sattr->index] & 7]);
> + return sprintf(buf, "%d\n", pwmfreq_table[i]);
> }
>
> static ssize_t set_pwmfreq(struct device *dev, struct device_attribute *attr,
> @@ -967,7 +968,7 @@ static ssize_t set_pwmfreq(struct device *dev, struct device_attribute *attr,
>
> data->range[sattr->index] =
> adt7475_read(TEMP_TRANGE_REG(sattr->index));
> - data->range[sattr->index] &= ~7;
> + data->range[sattr->index] &= ~0xf;
> data->range[sattr->index] |= out;
>
> i2c_smbus_write_byte_data(client, TEMP_TRANGE_REG(sattr->index),
>