hwmon: (f75375s) Catch some attempts to write to r/o registers
It makes no sense to attempt to manually configure the fan in auto mode,
or set the duty cycle directly in closed loop mode. The corresponding
registers are then read-only. If the user tries it nonetheless, error out
with EINVAL instead of silently doing nothing.
Signed-off-by: Nikolaus Schulz <mail@microschulz.de>
[guenter.roeck@ericsson.com: Minor formatting cleanup]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
index 9ab034a..6aa5a9f 100644
--- a/drivers/hwmon/f75375s.c
+++ b/drivers/hwmon/f75375s.c
@@ -279,6 +279,21 @@
}
}
+static bool auto_mode_enabled(u8 pwm_enable)
+{
+ switch (pwm_enable) {
+ case 0: /* Manual, duty mode (full speed) */
+ case 1: /* Manual, duty mode */
+ case 3: /* Manual, speed mode */
+ return false;
+ case 2: /* Auto, speed mode */
+ case 4: /* Auto, duty mode */
+ return true;
+ default:
+ BUG();
+ }
+}
+
static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -312,6 +327,11 @@
if (err < 0)
return err;
+ if (auto_mode_enabled(data->pwm_enable[nr]))
+ return -EINVAL;
+ if (data->kind == f75387 && duty_mode_enabled(data->pwm_enable[nr]))
+ return -EINVAL;
+
mutex_lock(&data->update_lock);
data->fan_target[nr] = rpm_to_reg(val);
f75375_write16(client, F75375_REG_FAN_EXP(nr), data->fan_target[nr]);
@@ -332,6 +352,10 @@
if (err < 0)
return err;
+ if (auto_mode_enabled(data->pwm_enable[nr]) ||
+ !duty_mode_enabled(data->pwm_enable[nr]))
+ return -EINVAL;
+
mutex_lock(&data->update_lock);
data->pwm[nr] = SENSORS_LIMIT(val, 0, 255);
f75375_write_pwm(client, nr);
@@ -793,6 +817,9 @@
set_pwm_enable_direct(client, 0, f75375s_pdata->pwm_enable[0]);
set_pwm_enable_direct(client, 1, f75375s_pdata->pwm_enable[1]);
for (nr = 0; nr < 2; nr++) {
+ if (auto_mode_enabled(f75375s_pdata->pwm_enable[nr]) ||
+ !duty_mode_enabled(f75375s_pdata->pwm_enable[nr]))
+ continue;
data->pwm[nr] = SENSORS_LIMIT(f75375s_pdata->pwm[nr], 0, 255);
f75375_write_pwm(client, nr);
}