Add capability to turn fan control off (set max speed)

Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/nct6775.c b/nct6775.c
index 51ce45387722d3aca08a47cfb720975961fe34cb..499706e1bd5c3f6805c58b949ef0becdcbbd91a1 100644 (file)
--- a/nct6775.c
+++ b/nct6775.c
@@ -207,6 +207,7 @@ static const u16 NCT6775_REG_FAN_START_OUTPUT[] = {
 static const u16 NCT6775_REG_FAN_STOP_TIME[] = {
        0x107, 0x207, 0x307, 0x807, 0x907 };
 static const u16 NCT6775_REG_PWM[] = { 0x109, 0x209, 0x309, 0x809, 0x909 };
+static const u16 NCT6775_REG_PWM_READ[] = { 0x01, 0x03, 0x11, 0x13, 0x15 };
 
 static const u16 NCT6775_REG_FAN_MAX_OUTPUT[] = { 0x10a, 0x20a, 0x30a };
 static const u16 NCT6775_REG_FAN_STEP_OUTPUT[] = { 0x10b, 0x20b, 0x30b };
@@ -667,7 +668,7 @@ static void nct6775_update_pwm(struct device *dev)
        struct nct6775_data *data = dev_get_drvdata(dev);
        struct nct6775_sio_data *sio_data = dev->platform_data;
        int i;
-       int pwmcfg, fanmodecfg, tol;
+       int pwmcfg, fanmodecfg, mode, tol;
 
        for (i = 0; i < data->pwm_num; i++) {
                if (!i) {
@@ -681,7 +682,12 @@ static void nct6775_update_pwm(struct device *dev)
 
                fanmodecfg = nct6775_read_value(data,
                                                  NCT6775_REG_FAN_MODE[i]);
-               data->pwm_enable[i] = ((fanmodecfg >> 4) & 7) + 1;
+               data->pwm[i] = nct6775_read_value(data, NCT6775_REG_PWM[i]);
+               mode = ((fanmodecfg >> 4) & 7);
+               if (data->pwm[i] == 255 && mode == 0)
+                       data->pwm_enable[i] = 0;
+               else
+                       data->pwm_enable[i] = mode + 1;
                data->tolerance[i][0] = fanmodecfg & 0x0f;
                if (sio_data->kind == nct6779) {
                        tol = nct6775_read_value(data,
@@ -691,7 +697,6 @@ static void nct6775_update_pwm(struct device *dev)
                data->tolerance[i][1] =
                        nct6775_read_value(data,
                                        NCT6775_REG_CRITICAL_TEMP_TOLERANCE[i]);
-               data->pwm[i] = nct6775_read_value(data, NCT6775_REG_PWM[i]);
        }
 }
 
@@ -1455,7 +1460,24 @@ static ssize_t show_##reg(struct device *dev, struct device_attribute *attr, \
 
 show_pwm_reg(pwm_mode)
 show_pwm_reg(pwm_enable)
-show_pwm_reg(pwm)
+
+static ssize_t show_pwm(struct device *dev, struct device_attribute *attr,
+                       char *buf)
+{
+       struct nct6775_data *data = nct6775_update_device(dev);
+       struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
+       int nr = sensor_attr->index;
+
+       /*
+        * For automatic fan control modes, show current pwm readings.
+        * Otherwise, show the configured value.
+        */
+       return sprintf(buf, "%d\n",
+                      data->pwm_mode[nr] > 1 ?
+                               data->pwm[nr] :
+                               nct6775_read_value(data,
+                                                  NCT6775_REG_PWM_READ[nr]));
+}
 
 static ssize_t
 store_pwm_mode(struct device *dev, struct device_attribute *attr,
@@ -1557,7 +1579,7 @@ store_pwm_enable(struct device *dev, struct device_attribute *attr,
        if (err < 0)
                return err;
 
-       if (!val || val > 5)
+       if (val > 5)
                return -EINVAL;
 
        /* SmartFan III mode is only supported on NCT6775F */
@@ -1572,6 +1594,14 @@ store_pwm_enable(struct device *dev, struct device_attribute *attr,
 
        mutex_lock(&data->update_lock);
        data->pwm_enable[nr] = val;
+       if (!val) {
+               /*
+                * turn off pwm control: select manual mode, set pwm to maximum
+                */
+               val = 1;
+               data->pwm[nr] = 255;
+               nct6775_write_value(data, NCT6775_REG_PWM[nr], 255);
+       }
        reg = nct6775_read_value(data, NCT6775_REG_FAN_MODE[nr]);
        reg &= 0x0f;
        reg |= (val - 1) << 4;