From 331255d35d6f517020485aee38dbb8b8dfaa1642 Mon Sep 17 00:00:00 2001 From: Nikolaus Schulz Date: Tue, 28 Feb 2012 22:15:51 +0100 Subject: [PATCH 1/4] hwmon: (f75375s) Fix writes to the pwm* attribute for the F75387 For the F75387, the register holding the current PWM duty cycle value is r/o; changing it requires writing to the fan expect register instead. Signed-off-by: Nikolaus Schulz [guenter.roeck@ericsson.com: Simplified function parameters] Signed-off-by: Guenter Roeck --- drivers/hwmon/f75375s.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c index 6bab2001ef3b..61cc9c396a98 100644 --- a/drivers/hwmon/f75375s.c +++ b/drivers/hwmon/f75375s.c @@ -178,6 +178,16 @@ static inline void f75375_write16(struct i2c_client *client, u8 reg, i2c_smbus_write_byte_data(client, reg + 1, (value & 0xFF)); } +static void f75375_write_pwm(struct i2c_client *client, int nr) +{ + struct f75375_data *data = i2c_get_clientdata(client); + if (data->kind == f75387) + f75375_write16(client, F75375_REG_FAN_EXP(nr), data->pwm[nr]); + else + f75375_write8(client, F75375_REG_FAN_PWM_DUTY(nr), + data->pwm[nr]); +} + static struct f75375_data *f75375_update_device(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); @@ -309,7 +319,7 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, mutex_lock(&data->update_lock); data->pwm[nr] = SENSORS_LIMIT(val, 0, 255); - f75375_write8(client, F75375_REG_FAN_PWM_DUTY(nr), data->pwm[nr]); + f75375_write_pwm(client, nr); mutex_unlock(&data->update_lock); return count; } @@ -374,8 +384,7 @@ static int set_pwm_enable_direct(struct i2c_client *client, int nr, int val) f75375_write8(client, F75375_REG_FAN_TIMER, fanmode); data->pwm_enable[nr] = val; if (val == 0) - f75375_write8(client, F75375_REG_FAN_PWM_DUTY(nr), - data->pwm[nr]); + f75375_write_pwm(client, nr); return 0; } @@ -759,8 +768,7 @@ static void f75375_init(struct i2c_client *client, struct f75375_data *data, set_pwm_enable_direct(client, 1, f75375s_pdata->pwm_enable[1]); for (nr = 0; nr < 2; nr++) { data->pwm[nr] = SENSORS_LIMIT(f75375s_pdata->pwm[nr], 0, 255); - f75375_write8(client, F75375_REG_FAN_PWM_DUTY(nr), - data->pwm[nr]); + f75375_write_pwm(client, nr); } } From edeea102857e33b5e9b17a3a2640da390732a693 Mon Sep 17 00:00:00 2001 From: Nikolaus Schulz Date: Tue, 28 Feb 2012 22:15:52 +0100 Subject: [PATCH 2/4] hwmon: (f75375s) Make pwm*_mode writable for the F75387 Signed-off-by: Nikolaus Schulz Signed-off-by: Guenter Roeck --- drivers/hwmon/f75375s.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c index 61cc9c396a98..eb648d9c91d6 100644 --- a/drivers/hwmon/f75375s.c +++ b/drivers/hwmon/f75375s.c @@ -795,7 +795,7 @@ static int f75375_probe(struct i2c_client *client, if (err) goto exit_free; - if (data->kind == f75375) { + if (data->kind != f75373) { err = sysfs_chmod_file(&client->dev.kobj, &sensor_dev_attr_pwm1_mode.dev_attr.attr, S_IRUGO | S_IWUSR); From b17d6561acc16265b65b1e0d27b649829b61a7e3 Mon Sep 17 00:00:00 2001 From: Nikolaus Schulz Date: Tue, 28 Feb 2012 16:15:53 -0500 Subject: [PATCH 3/4] 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 Signed-off-by: Guenter Roeck --- drivers/hwmon/f75375s.c | 42 +++++++++++++++++++++++++++++++++-------- 1 file 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)))) From 15d1ad0cc9d2d3f549afddbcdbc9c3637f0d1331 Mon Sep 17 00:00:00 2001 From: Nikolaus Schulz Date: Tue, 28 Feb 2012 16:15:54 -0500 Subject: [PATCH 4/4] 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 [guenter.roeck@ericsson.com: Minor formatting cleanup] Signed-off-by: Guenter Roeck --- drivers/hwmon/f75375s.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/hwmon/f75375s.c b/drivers/hwmon/f75375s.c index 9ab034a1b4c1..6aa5a9fad879 100644 --- a/drivers/hwmon/f75375s.c +++ b/drivers/hwmon/f75375s.c @@ -279,6 +279,21 @@ static bool duty_mode_enabled(u8 pwm_enable) } } +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 @@ static ssize_t set_fan_target(struct device *dev, struct device_attribute *attr, 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 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr, 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 @@ static void f75375_init(struct i2c_client *client, struct f75375_data *data, 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); }