hwmon: (w83795) Unconditionally support manual fan speed control

Manual fan speed control uses a standard interface and has received
sufficient testing and review by now, it can be enabled
unconditionally. This includes attributes pwm[1-8], pwm[1-8]_enable,
pwm[1-8]_mode and pwm[1-8]_freq.

We only let the user switch from automatic mode to manual mode, but
not the other way around, as automatic control settings may not have
been set properly by the BIOS.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>

2 files changed, 29 insertions, 18 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 811e6c47e7e..783a3144ffd 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1229,18 +1229,19 @@ config SENSORS_W83795
         depends on I2C && EXPERIMENTAL
         help
           If you say yes here you get support for the Winbond W83795G and
-          W83795ADG hardware monitoring chip.
+          W83795ADG hardware monitoring chip, including manual fan speed
+          control.
 
           This driver can also be built as a module.  If so, the module
           will be called w83795.
 
 config SENSORS_W83795_FANCTRL
-        boolean "Include fan control support (DANGEROUS)"
+        boolean "Include automatic fan control support (DANGEROUS)"
         depends on SENSORS_W83795 && EXPERIMENTAL
         default n
         help
-          If you say yes here, support for the both manual and automatic
-          fan control features will be included in the driver.
+          If you say yes here, support for automatic fan speed control
+          will be included in the driver.
 
           This part of the code wasn't carefully reviewed and tested yet,
           so enabling this option is strongly discouraged on production
diff --git a/drivers/hwmon/w83795.c b/drivers/hwmon/w83795.c
index deb12c98280..5478dd13623 100644
--- a/drivers/hwmon/w83795.c
+++ b/drivers/hwmon/w83795.c
@@ -929,6 +929,14 @@ store_pwm_enable(struct device *dev, struct device_attribute *attr,
         if (val < 1 || val > 2)
                 return -EINVAL;
 
+#ifndef CONFIG_SENSORS_W83795_FANCTRL
+        if (val > 1) {
+                dev_warn(dev, "Automatic fan speed control support disabled\n");
+                dev_warn(dev, "Build with CONFIG_SENSORS_W83795_FANCTRL=y if you want it\n");
+                return -EOPNOTSUPP;
+        }
+#endif
+
         mutex_lock(&data->update_lock);
         switch (val) {
         case 1:
@@ -1625,18 +1633,18 @@ store_sf_setup(struct device *dev, struct device_attribute *attr,
 #define SENSOR_ATTR_PWM(index) {                                        \
         SENSOR_ATTR_2(pwm##index, S_IWUSR | S_IRUGO, show_pwm,          \
                 store_pwm, PWM_OUTPUT, index - 1),                      \
+        SENSOR_ATTR_2(pwm##index##_enable, S_IWUSR | S_IRUGO,           \
+                show_pwm_enable, store_pwm_enable, NOT_USED, index - 1), \
+        SENSOR_ATTR_2(pwm##index##_mode, S_IRUGO,                       \
+                show_pwm_mode, NULL, NOT_USED, index - 1),              \
+        SENSOR_ATTR_2(pwm##index##_freq, S_IWUSR | S_IRUGO,             \
+                show_pwm, store_pwm, PWM_FREQ, index - 1),              \
         SENSOR_ATTR_2(pwm##index##_nonstop, S_IWUSR | S_IRUGO,          \
                 show_pwm, store_pwm, PWM_NONSTOP, index - 1),           \
         SENSOR_ATTR_2(pwm##index##_start, S_IWUSR | S_IRUGO,            \
                 show_pwm, store_pwm, PWM_START, index - 1),             \
         SENSOR_ATTR_2(pwm##index##_stop_time, S_IWUSR | S_IRUGO,        \
                 show_pwm, store_pwm, PWM_STOP_TIME, index - 1),  \
-        SENSOR_ATTR_2(pwm##index##_freq, S_IWUSR | S_IRUGO,     \
-                show_pwm, store_pwm, PWM_FREQ, index - 1),       \
-        SENSOR_ATTR_2(pwm##index##_enable, S_IWUSR | S_IRUGO,           \
-                show_pwm_enable, store_pwm_enable, NOT_USED, index - 1), \
-        SENSOR_ATTR_2(pwm##index##_mode, S_IRUGO,                       \
-                show_pwm_mode, NULL, NOT_USED, index - 1),              \
         SENSOR_ATTR_2(fan##index##_target, S_IWUSR | S_IRUGO, \
                 show_fanin, store_fanin, FANIN_TARGET, index - 1) }
 
@@ -1953,6 +1961,14 @@ static int w83795_detect(struct i2c_client *client,
         return 0;
 }
 
+#ifdef CONFIG_SENSORS_W83795_FANCTRL
+#define NUM_PWM_ATTRIBUTES      ARRAY_SIZE(w83795_pwm[0])
+#define NUM_TEMP_ATTRIBUTES     ARRAY_SIZE(w83795_temp[0])
+#else
+#define NUM_PWM_ATTRIBUTES      4
+#define NUM_TEMP_ATTRIBUTES     8
+#endif
+
 static int w83795_handle_files(struct device *dev, int (*fn)(struct device *,
                                const struct device_attribute *))
 {
@@ -2006,24 +2022,18 @@ static int w83795_handle_files(struct device *dev, int (*fn)(struct device *,
                 }
         }
 
-#ifdef CONFIG_SENSORS_W83795_FANCTRL
         for (i = 0; i < data->has_pwm; i++) {
-                for (j = 0; j < ARRAY_SIZE(w83795_pwm[0]); j++) {
+                for (j = 0; j < NUM_PWM_ATTRIBUTES; j++) {
                         err = fn(dev, &w83795_pwm[i][j].dev_attr);
                         if (err)
                                 return err;
                 }
         }
-#endif
 
         for (i = 0; i < ARRAY_SIZE(w83795_temp); i++) {
                 if (!(data->has_temp & (1 << i)))
                         continue;
-#ifdef CONFIG_SENSORS_W83795_FANCTRL
-                for (j = 0; j < ARRAY_SIZE(w83795_temp[0]); j++) {
-#else
-                for (j = 0; j < 8; j++) {
-#endif
+                for (j = 0; j < NUM_TEMP_ATTRIBUTES; j++) {
                         if (j == 7 && !data->enable_beep)
                                 continue;
                         err = fn(dev, &w83795_temp[i][j].dev_attr);