On 1/25/25 23:42, Vincent Mailhol wrote:
On 23/01/2025 at 18:11, Ming Yu wrote:
This driver supports Hardware monitor functionality for NCT6694 MFD
device based on USB interface.
Signed-off-by: Ming Yu <a0282524688@xxxxxxxxx>
---
(...)
+static int nct6694_temp_write(struct device *dev, u32 attr, int channel,
+ long val)
+{
+ struct nct6694_hwmon_data *data = dev_get_drvdata(dev);
+ struct nct6694_cmd_header cmd_hd;
+ unsigned char temp_hyst;
+ signed char temp_max;
+ int ret;
+
+ guard(mutex)(&data->lock);
+
+ switch (attr) {
+ case hwmon_temp_enable:
+ if (val == 0)
+ data->hwmon_en.tin_en[channel / 8] &= ~BIT(channel % 8);
+ else if (val == 1)
+ data->hwmon_en.tin_en[channel / 8] |= BIT(channel % 8);
+ else
+ return -EINVAL;
+
+ cmd_hd = (struct nct6694_cmd_header) {
+ .mod = NCT6694_HWMON_MOD,
+ .cmd = NCT6694_HWMON_CONTROL,
+ .sel = NCT6694_HWMON_CONTROL_SEL,
+ .len = cpu_to_le16(sizeof(data->hwmon_en))
+ };
+
+ return nct6694_write_msg(data->nct6694, &cmd_hd,
+ &data->hwmon_en);
+ case hwmon_temp_max:
+ cmd_hd = (struct nct6694_cmd_header) {
+ .mod = NCT6694_HWMON_MOD,
+ .cmd = NCT6694_HWMON_ALARM,
+ .sel = NCT6694_HWMON_ALARM_SEL,
+ .len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+ };
+ ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+ &data->msg->hwmon_alarm);
+ if (ret)
+ return ret;
+
+ val = clamp_val(val, -127000, 127000);
+ data->msg->hwmon_alarm.tin_cfg[channel].hl = temp_to_reg(val);
+
+ return nct6694_write_msg(data->nct6694, &cmd_hd,
+ &data->msg->hwmon_alarm);
+ case hwmon_temp_max_hyst:
+ cmd_hd = (struct nct6694_cmd_header) {
+ .mod = NCT6694_HWMON_MOD,
+ .cmd = NCT6694_HWMON_ALARM,
+ .sel = NCT6694_HWMON_ALARM_SEL,
+ .len = cpu_to_le16(sizeof(data->msg->hwmon_alarm))
+ };
+ ret = nct6694_read_msg(data->nct6694, &cmd_hd,
+ &data->msg->hwmon_alarm);
+
+ val = clamp_val(val, -127000, 127000);
+ temp_max = data->msg->hwmon_alarm.tin_cfg[channel].hl;
+ temp_hyst = temp_max - temp_to_reg(val);
+ temp_hyst = clamp_val(temp_hyst, 0, 7);
temp_hyst is unsigned. It can not be smaller than zero. No need for
clamp(), using min here is sufficient.
Wrong conclusion. It needs to be declared as signed variable because
"temp_max - temp_to_reg(val)" could be negative.
Guenter
