* [PATCH hwmon 1/2] hwmon: (mlxreg-fan) Separate methods of fan setting coming from different subsystems
2025-01-13 8:48 [PATCH hwmon 0/2] hwmon: (mlxreg-fan): Add bugfix and introduce new feature Vadim Pasternak
@ 2025-01-13 8:48 ` Vadim Pasternak
2025-09-24 19:39 ` Guenter Roeck
2025-01-13 8:48 ` [PATCH hwmon 2/2] hwmon: (mlxreg-fan) Add support for new flavour of capability register Vadim Pasternak
1 sibling, 1 reply; 5+ messages in thread
From: Vadim Pasternak @ 2025-01-13 8:48 UTC (permalink / raw)
To: linux; +Cc: linux-hwmon, Vadim Pasternak
Distinct between fan speed setting request coming for hwmon and
thermal subsystems.
There are fields 'last_hwmon_state' and 'last_thermal_state' in the
structure 'mlxreg_fan_pwm', which respectively store the cooling state
set by the 'hwmon' and 'thermal' subsystem.
The purpose is to make arbitration of fan speed setting. For example, if
fan speed required to be not lower than some limit, such setting is to
be performed through 'hwmon' subsystem, thus 'thermal' subsystem will
not set fan below this limit.
Currently, the 'last_thermal_state' is also be updated by 'hwmon' causing
cooling state to never be set to a lower value.
Eliminate update of 'last_thermal_state', when request is coming from
'hwmon' subsystem.
Fixes: da74944d3a46 ("hwmon: (mlxreg-fan) Use pwm attribute for setting fan speed low limit")
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
---
drivers/hwmon/mlxreg-fan.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
index a5f89aab3fb4..f848232c2c00 100644
--- a/drivers/hwmon/mlxreg-fan.c
+++ b/drivers/hwmon/mlxreg-fan.c
@@ -113,8 +113,8 @@ struct mlxreg_fan {
int divider;
};
-static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
- unsigned long state);
+static int _mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state, bool thermal);
static int
mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
@@ -224,8 +224,9 @@ mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
* last thermal state.
*/
if (pwm->last_hwmon_state >= pwm->last_thermal_state)
- return mlxreg_fan_set_cur_state(pwm->cdev,
- pwm->last_hwmon_state);
+ return _mlxreg_fan_set_cur_state(pwm->cdev,
+ pwm->last_hwmon_state,
+ false);
return 0;
}
return regmap_write(fan->regmap, pwm->reg, val);
@@ -357,9 +358,8 @@ static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
return 0;
}
-static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
- unsigned long state)
-
+static int _mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state, bool thermal)
{
struct mlxreg_fan_pwm *pwm = cdev->devdata;
struct mlxreg_fan *fan = pwm->fan;
@@ -369,7 +369,8 @@ static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
return -EINVAL;
/* Save thermal state. */
- pwm->last_thermal_state = state;
+ if (thermal)
+ pwm->last_thermal_state = state;
state = max_t(unsigned long, state, pwm->last_hwmon_state);
err = regmap_write(fan->regmap, pwm->reg,
@@ -381,6 +382,13 @@ static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
return 0;
}
+static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state)
+
+{
+ return _mlxreg_fan_set_cur_state(cdev, state, true);
+}
+
static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
.get_max_state = mlxreg_fan_get_max_state,
.get_cur_state = mlxreg_fan_get_cur_state,
--
2.44.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH hwmon 2/2] hwmon: (mlxreg-fan) Add support for new flavour of capability register
2025-01-13 8:48 [PATCH hwmon 0/2] hwmon: (mlxreg-fan): Add bugfix and introduce new feature Vadim Pasternak
2025-01-13 8:48 ` [PATCH hwmon 1/2] hwmon: (mlxreg-fan) Separate methods of fan setting coming from different subsystems Vadim Pasternak
@ 2025-01-13 8:48 ` Vadim Pasternak
2025-09-24 19:39 ` Guenter Roeck
1 sibling, 1 reply; 5+ messages in thread
From: Vadim Pasternak @ 2025-01-13 8:48 UTC (permalink / raw)
To: linux; +Cc: linux-hwmon, Vadim Pasternak
FAN platform data is common across the various systems, while fan
driver should be able to apply only the fan instances relevant
to specific system.
For example, platform data might contain descriptions for fan1,
fan2, ..., fan{n}, while some systems equipped with all 'n' fans,
others with less.
Also, on some systems fan drawer can be equipped with several
tachometers and on others only with one.
For detection of the real number of equipped drawers and tachometers
special capability registers are used.
These registers used to indicate presence of drawers and tachometers
through the bitmap.
For some new big modular systems this register will provide presence
data by counter.
Use slot parameter to distinct whether capability register contains
bitmask or counter.
Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
---
drivers/hwmon/mlxreg-fan.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
index f848232c2c00..01faf1a8f55a 100644
--- a/drivers/hwmon/mlxreg-fan.c
+++ b/drivers/hwmon/mlxreg-fan.c
@@ -63,12 +63,14 @@ struct mlxreg_fan;
* @reg: register offset;
* @mask: fault mask;
* @prsnt: present register offset;
+ * @shift: tacho presence bit shift;
*/
struct mlxreg_fan_tacho {
bool connected;
u32 reg;
u32 mask;
u32 prsnt;
+ u32 shift;
};
/*
@@ -143,8 +145,10 @@ mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
/*
* Map channel to presence bit - drawer can be equipped with
* one or few FANs, while presence is indicated per drawer.
+ * Shift channel value if necessary to align with register value.
*/
- if (BIT(channel / fan->tachos_per_drwr) & regval) {
+ if (BIT(rol32(channel, tacho->shift) / fan->tachos_per_drwr) &
+ regval) {
/* FAN is not connected - return zero for FAN speed. */
*val = 0;
return 0;
@@ -408,7 +412,7 @@ static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
return err;
}
- return !!(regval & data->bit);
+ return data->slot ? (data->slot <= regval ? 1 : 0) : !!(regval & data->bit);
}
static int mlxreg_pwm_connect_verify(struct mlxreg_fan *fan,
@@ -545,7 +549,15 @@ static int mlxreg_fan_config(struct mlxreg_fan *fan,
return err;
}
- drwr_avail = hweight32(regval);
+ /*
+ * The number of drawers could be specified in registers by counters for newer
+ * systems, or by bitmasks for older systems. In case the data is provided by
+ * counter, it is indicated through 'version' field.
+ */
+ if (pdata->version)
+ drwr_avail = regval;
+ else
+ drwr_avail = hweight32(regval);
if (!tacho_avail || !drwr_avail || tacho_avail < drwr_avail) {
dev_err(fan->dev, "Configuration is invalid: drawers num %d tachos num %d\n",
drwr_avail, tacho_avail);
--
2.44.0
^ permalink raw reply related [flat|nested] 5+ messages in thread