[PATCH hwmon-next v2 3/3] hwmon: (mlxreg-fan) Extend driver to support multiply cooling devices

Vadim Pasternak
2021-09-16T19:47:49Z

Add support for additional cooling devices in order to support the
systems, which can be equipped with up-to four PWM controllers.

Signed-off-by: Vadim Pasternak <vadimp@nvidia.com>
---
v0->v2:
Comments pointed out by Guenter:
- Drop call to thermal_cooling_device_unregister() in error flow,
devices registered by devm_thermal_of_cooling_device_register()
should be cleaned automatically.
---
drivers/hwmon/mlxreg-fan.c | 76 +++++++++++++++++++++++++-------------
1 file changed, 50 insertions(+), 26 deletions(-)

diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
index 1a146cc4b0fd..566bee333c3c 100644
--- a/drivers/hwmon/mlxreg-fan.c
+++ b/drivers/hwmon/mlxreg-fan.c
@@ -63,6 +63,8 @@
MLXREG_FAN_MAX_DUTY, \
MLXREG_FAN_MAX_STATE))

+struct mlxreg_fan;
+
/*
* struct mlxreg_fan_tacho - tachometer data (internal use):
*
@@ -81,12 +83,18 @@ struct mlxreg_fan_tacho {
/*
* struct mlxreg_fan_pwm - PWM data (internal use):
*
+ * @fan: private data;
* @connected: indicates if PWM is connected;
* @reg: register offset;
+ * @cooling: cooling device levels;
+ * @cdev: cooling device;
*/
struct mlxreg_fan_pwm {
+ struct mlxreg_fan *fan;
bool connected;
u32 reg;
+ u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
+ struct thermal_cooling_device *cdev;
};

/*
@@ -99,8 +107,6 @@ struct mlxreg_fan_pwm {
* @tachos_per_drwr - number of tachometers per drawer;
* @samples: minimum allowed samples per pulse;
* @divider: divider value for tachometer RPM calculation;
- * @cooling: cooling device levels;
- * @cdev: cooling device;
*/
struct mlxreg_fan {
struct device *dev;
@@ -111,8 +117,6 @@ struct mlxreg_fan {
int tachos_per_drwr;
int samples;
int divider;
- u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
- struct thermal_cooling_device *cdev;
};

static int
@@ -305,11 +309,12 @@ static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)

{
- struct mlxreg_fan *fan = cdev->devdata;
+ struct mlxreg_fan_pwm *pwm = cdev->devdata;
+ struct mlxreg_fan *fan = pwm->fan;
u32 regval;
int err;

- err = regmap_read(fan->regmap, fan->pwm[0].reg, &regval);
+ err = regmap_read(fan->regmap, pwm->reg, &regval);
if (err) {
dev_err(fan->dev, "Failed to query PWM duty\n");
return err;
@@ -324,7 +329,8 @@ static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)

{
- struct mlxreg_fan *fan = cdev->devdata;
+ struct mlxreg_fan_pwm *pwm = cdev->devdata;
+ struct mlxreg_fan *fan = pwm->fan;
unsigned long cur_state;
int i, config = 0;
u32 regval;
@@ -348,11 +354,11 @@ static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
config = 1;
state -= MLXREG_FAN_MAX_STATE;
for (i = 0; i < state; i++)
- fan->cooling_levels[i] = state;
+ pwm->cooling_levels[i] = state;
for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
- fan->cooling_levels[i] = i;
+ pwm->cooling_levels[i] = i;

- err = regmap_read(fan->regmap, fan->pwm[0].reg, &regval);
+ err = regmap_read(fan->regmap, pwm->reg, &regval);
if (err) {
dev_err(fan->dev, "Failed to query PWM duty\n");
return err;
@@ -369,8 +375,8 @@ static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
return -EINVAL;

/* Normalize the state to the valid speed range. */
- state = fan->cooling_levels[state];
- err = regmap_write(fan->regmap, fan->pwm[0].reg,
+ state = pwm->cooling_levels[state];
+ err = regmap_write(fan->regmap, pwm->reg,
MLXREG_FAN_PWM_STATE2DUTY(state));
if (err) {
dev_err(fan->dev, "Failed to write PWM duty\n");
@@ -541,13 +547,37 @@ static int mlxreg_fan_config(struct mlxreg_fan *fan,
fan->tachos_per_drwr = tacho_avail / drwr_avail;
}

- /* Init cooling levels per PWM state. */
- for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
- fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
- for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
- fan->cooling_levels[i] = i;
+ return 0;
+}
+
+static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
+{
+ int i, j, err;
+
+ for (i = 0; i <= MLXREG_FAN_MAX_PWM; i++) {
+ struct mlxreg_fan_pwm *pwm = &fan->pwm[i];
+
+ if (!pwm->connected)
+ continue;
+ pwm->fan = fan;
+ pwm->cdev = devm_thermal_of_cooling_device_register(dev, NULL, "mlxreg_fan", pwm,
+ &mlxreg_fan_cooling_ops);
+ if (IS_ERR(pwm->cdev)) {
+ dev_err(dev, "Failed to register cooling device\n");
+ err = PTR_ERR(pwm->cdev);
+ goto devm_thermal_of_cooling_device_register_fail;
+ }
+
+ /* Init cooling levels per PWM state. */
+ for (j = 0; j < MLXREG_FAN_SPEED_MIN_LEVEL; j++)
+ pwm->cooling_levels[j] = MLXREG_FAN_SPEED_MIN_LEVEL;
+ for (j = MLXREG_FAN_SPEED_MIN_LEVEL; j <= MLXREG_FAN_MAX_STATE; j++)
+ pwm->cooling_levels[j] = j;
+ }

return 0;
+devm_thermal_of_cooling_device_register_fail:
+ return err;
}

static int mlxreg_fan_probe(struct platform_device *pdev)
@@ -584,16 +614,10 @@ static int mlxreg_fan_probe(struct platform_device *pdev)
return PTR_ERR(hwm);
}

- if (IS_REACHABLE(CONFIG_THERMAL)) {
- fan->cdev = devm_thermal_of_cooling_device_register(dev,
- NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
- if (IS_ERR(fan->cdev)) {
- dev_err(dev, "Failed to register cooling device\n");
- return PTR_ERR(fan->cdev);
- }
- }
+ if (IS_REACHABLE(CONFIG_THERMAL))
+ err = mlxreg_fan_cooling_config(dev, fan);

- return 0;
+ return err;
}

static struct platform_driver mlxreg_fan_driver = {
--
2.20.1