[PATCH hwmon-next v3 1/1] hwmon: (mlxreg-fan) Extend driver to support multiply cooling devices

[Vadim Pasternak <vadimp@xxxxxxxxxx>]

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@xxxxxxxxxx>
---
v2->v3:
 Comments pointed out by Guenter:
 - Drop label "devm_thermal_of_cooling_device_register_fail".
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 | 73 ++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 26 deletions(-)

diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c
index 1a146cc4b0fd..35228ed112d7 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");
@@ -541,11 +547,32 @@ 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;
+
+	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");
+			return PTR_ERR(pwm->cdev);
+		}
+
+		/* 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;
 }
@@ -584,16 +611,10 @@ 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