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authorNikolaus Schulz <schulz@macnetix.de>2012-02-28 16:15:53 -0500
committerGuenter Roeck <guenter.roeck@ericsson.com>2012-03-02 11:56:43 -0800
commitb17d6561acc16265b65b1e0d27b649829b61a7e3 (patch)
tree0bcfd3e723d7af6787f5c9a01d825a1cc665bab1
parentedeea102857e33b5e9b17a3a2640da390732a693 (diff)
downloadlinux-stericsson-b17d6561acc16265b65b1e0d27b649829b61a7e3.tar.gz
hwmon: (f75375s) Properly map the F75387 automatic modes to pwm_enable
The F75387 supports automatic fan control using either PWM duty cycle or RPM speed values. Make the driver detect the latter mode, and expose the different modes in sysfs as per pwm_enable, so that the user can switch between them. The interpretation of the pwm_enable attribute for the F75387 is adjusted to be a superset of those values used for similar Fintek chips which do not support automatic duty mode, with 2 mapping to automatic speed mode, and moving automatic duty mode to the new value 4. Toggling the duty mode via pwm_enable is currently denied for the F75387, as the chip then simply reinterprets the fan configuration register values according to the new mode, switching between RPM and PWM units, which makes this a dangerous operation. This patch introduces a new pwm mode into the driver. This is necessary because the new mode (automatic pwm mode, 4) may already be enabled by the BIOS, and the driver should not break existing functionality. This was seen on at least one board. Signed-off-by: Nikolaus Schulz <mail@microschulz.de> Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
-rw-r--r--drivers/hwmon/f75375s.c42
1 files changed, 34 insertions, 8 deletions
diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c
index eb648d9c91d6..9ab034a1b4c1 100644
--- a/drivers/hwmon/f75375s.c
+++ b/drivers/hwmon/f75375s.c
@@ -264,6 +264,21 @@ static inline u16 rpm_to_reg(int rpm)
return 1500000 / rpm;
}
+static bool duty_mode_enabled(u8 pwm_enable)
+{
+ switch (pwm_enable) {
+ case 0: /* Manual, duty mode (full speed) */
+ case 1: /* Manual, duty mode */
+ case 4: /* Auto, duty mode */
+ return true;
+ case 2: /* Auto, speed mode */
+ case 3: /* Manual, speed mode */
+ return false;
+ default:
+ BUG();
+ }
+}
+
static ssize_t set_fan_min(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
@@ -337,11 +352,15 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
struct f75375_data *data = i2c_get_clientdata(client);
u8 fanmode;
- if (val < 0 || val > 3)
+ if (val < 0 || val > 4)
return -EINVAL;
fanmode = f75375_read8(client, F75375_REG_FAN_TIMER);
if (data->kind == f75387) {
+ /* For now, deny dangerous toggling of duty mode */
+ if (duty_mode_enabled(data->pwm_enable[nr]) !=
+ duty_mode_enabled(val))
+ return -EOPNOTSUPP;
/* clear each fanX_mode bit before setting them properly */
fanmode &= ~(1 << F75387_FAN_DUTY_MODE(nr));
fanmode &= ~(1 << F75387_FAN_MANU_MODE(nr));
@@ -355,12 +374,14 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
fanmode |= (1 << F75387_FAN_MANU_MODE(nr));
fanmode |= (1 << F75387_FAN_DUTY_MODE(nr));
break;
- case 2: /* AUTOMATIC*/
- fanmode |= (1 << F75387_FAN_DUTY_MODE(nr));
+ case 2: /* Automatic, speed mode */
break;
case 3: /* fan speed */
fanmode |= (1 << F75387_FAN_MANU_MODE(nr));
break;
+ case 4: /* Automatic, pwm */
+ fanmode |= (1 << F75387_FAN_DUTY_MODE(nr));
+ break;
}
} else {
/* clear each fanX_mode bit before setting them properly */
@@ -378,6 +399,8 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val)
break;
case 3: /* fan speed */
break;
+ case 4: /* Automatic pwm */
+ return -EINVAL;
}
}
@@ -735,14 +758,17 @@ static void f75375_init(struct i2c_client *client, struct f75375_data *data,
manu = ((mode >> F75387_FAN_MANU_MODE(nr)) & 1);
duty = ((mode >> F75387_FAN_DUTY_MODE(nr)) & 1);
- if (manu && duty)
- /* speed */
+ if (!manu && duty)
+ /* auto, pwm */
+ data->pwm_enable[nr] = 4;
+ else if (manu && !duty)
+ /* manual, speed */
data->pwm_enable[nr] = 3;
- else if (!manu && duty)
- /* automatic */
+ else if (!manu && !duty)
+ /* automatic, speed */
data->pwm_enable[nr] = 2;
else
- /* manual */
+ /* manual, pwm */
data->pwm_enable[nr] = 1;
} else {
if (!(conf & (1 << F75375_FAN_CTRL_LINEAR(nr))))