mvebu: puzzle: fix fan thermal cooling driver

Several fixes for the Puzzle WT61P803 hwmon driver were needed to make
it behave well as thermal cooling device:
 - wire-up cooling device with OF node in device tree
 - properly parse cooling-levels (u32 with range check vs. u8)
 - actually use cooling-levels
 - keep current state and only write to uC if state has changed
   (avoids flooding the uC with commands which will result in uC crashing)

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

2 files changed, 110 insertions, 46 deletions

diff --git a/target/linux/mvebu/patches-5.10/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch b/target/linux/mvebu/patches-5.10/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
index 684f09c800..d31709fd85 100644
--- a/target/linux/mvebu/patches-5.10/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
+++ b/target/linux/mvebu/patches-5.10/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
@@ -53,7 +53,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
  obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 --- /dev/null
 +++ b/drivers/hwmon/iei-wt61p803-puzzle-hwmon.c
-@@ -0,0 +1,413 @@
+@@ -0,0 +1,445 @@
 +// SPDX-License-Identifier: GPL-2.0-only
 +/* IEI WT61P803 PUZZLE MCU HWMON Driver
 + *
@@ -84,13 +84,17 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 + * @name:		Thermal cooling device name
 + * @pwm_channel:	Controlled PWM channel (0 or 1)
 + * @cooling_levels:	Thermal cooling device cooling levels (DT)
++ * @cur_level:		Current cooling level
++ * @num_levels:	Number of cooling levels
 + */
 +struct iei_wt61p803_puzzle_thermal_cooling_device {
 +	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon;
 +	struct thermal_cooling_device *tcdev;
 +	char name[THERMAL_NAME_LENGTH];
 +	int pwm_channel;
-+	u8 *cooling_levels;
++	u32 *cooling_levels;
++	int cur_level;
++	u8 num_levels;
 +};
 +
 +/**
@@ -326,8 +330,12 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +static int iei_wt61p803_puzzle_get_max_state(struct thermal_cooling_device *tcdev,
 +					     unsigned long *state)
 +{
-+	*state = IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL;
++	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
++
++	if (!cdev)
++		return -EINVAL;
 +
++	*state = cdev->num_levels - 1;
 +	return 0;
 +}
 +
@@ -335,14 +343,14 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +					     unsigned long *state)
 +{
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
-+	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
-+	long value;
-+	int ret;
 +
-+	ret = iei_wt61p803_puzzle_read_pwm_channel(mcu_hwmon, cdev->pwm_channel, &value);
-+	if (ret)
-+		return ret;
-+	*state = value;
++	if (!cdev)
++		return -EINVAL;
++
++	if (cdev->cur_level < 0)
++		return -EAGAIN;
++
++	*state = cdev->cur_level;
 +	return 0;
 +}
 +
@@ -350,9 +358,21 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +					     unsigned long state)
 +{
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
-+	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
++	u8 pwm_level;
++
++	if (!cdev)
++		return -EINVAL;
 +
-+	return iei_wt61p803_puzzle_write_pwm_channel(mcu_hwmon, cdev->pwm_channel, state);
++	if (state >= cdev->num_levels)
++		return -EINVAL;
++
++	if (state == cdev->cur_level)
++		return 0;
++
++	cdev->cur_level = state;
++	pwm_level = cdev->cooling_levels[state];
++
++	return iei_wt61p803_puzzle_write_pwm_channel(cdev->mcu_hwmon, cdev->pwm_channel, pwm_level);
 +}
 +
 +static const struct thermal_cooling_device_ops iei_wt61p803_puzzle_cooling_ops = {
@@ -369,7 +389,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev;
 +	u32 pwm_channel;
 +	u8 num_levels;
-+	int ret;
++	int i, ret;
 +
 +	ret = fwnode_property_read_u32(child, "reg", &pwm_channel);
 +	if (ret)
@@ -377,7 +397,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +
 +	mcu_hwmon->thermal_cooling_dev_present[pwm_channel] = true;
 +
-+	num_levels = fwnode_property_count_u8(child, "cooling-levels");
++	num_levels = fwnode_property_count_u32(child, "cooling-levels");
 +	if (!num_levels)
 +		return -EINVAL;
 +
@@ -385,28 +405,40 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +	if (!cdev)
 +		return -ENOMEM;
 +
-+	cdev->cooling_levels = devm_kmalloc_array(dev, num_levels, sizeof(u8), GFP_KERNEL);
++	cdev->cooling_levels = devm_kmalloc_array(dev, num_levels, sizeof(u32), GFP_KERNEL);
 +	if (!cdev->cooling_levels)
 +		return -ENOMEM;
 +
-+	ret = fwnode_property_read_u8_array(child, "cooling-levels",
-+					    cdev->cooling_levels,
-+					    num_levels);
++	ret = fwnode_property_read_u32_array(child, "cooling-levels",
++					     cdev->cooling_levels,
++					     num_levels);
 +	if (ret) {
 +		dev_err(dev, "Couldn't read property 'cooling-levels'\n");
 +		return ret;
 +	}
 +
-+	snprintf(cdev->name, THERMAL_NAME_LENGTH, "wt61p803_puzzle_%d", pwm_channel);
-+	cdev->tcdev = devm_thermal_of_cooling_device_register(dev, NULL, cdev->name, cdev,
-+							      &iei_wt61p803_puzzle_cooling_ops);
-+	if (IS_ERR(cdev->tcdev))
-+		return PTR_ERR(cdev->tcdev);
++	for (i = 0; i < num_levels; i++) {
++		if (cdev->cooling_levels[i] >
++		    IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL) {
++			dev_err(dev, "iei_wt61p803_fan state[%d]:%d > %d\n", i,
++				cdev->cooling_levels[i],
++				IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL);
++			return -EINVAL;
++		}
++	}
 +
 +	cdev->mcu_hwmon = mcu_hwmon;
 +	cdev->pwm_channel = pwm_channel;
++	cdev->num_levels = num_levels;
++	cdev->cur_level = -1;
 +	mcu_hwmon->cdev[pwm_channel] = cdev;
 +
++	snprintf(cdev->name, THERMAL_NAME_LENGTH, "wt61p803_puzzle_%d", pwm_channel);
++	cdev->tcdev = devm_thermal_of_cooling_device_register(dev, to_of_node(child), cdev->name,
++							      cdev, &iei_wt61p803_puzzle_cooling_ops);
++	if (IS_ERR(cdev->tcdev))
++		return PTR_ERR(cdev->tcdev);
++
 +	return 0;
 +}
 +
diff --git a/target/linux/mvebu/patches-5.15/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch b/target/linux/mvebu/patches-5.15/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
index c22314e41c..023495373b 100644
--- a/target/linux/mvebu/patches-5.15/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
+++ b/target/linux/mvebu/patches-5.15/903-drivers-hwmon-Add-the-IEI-WT61P803-PUZZLE-HWMON-driv.patch
@@ -53,7 +53,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
  obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 --- /dev/null
 +++ b/drivers/hwmon/iei-wt61p803-puzzle-hwmon.c
-@@ -0,0 +1,413 @@
+@@ -0,0 +1,445 @@
 +// SPDX-License-Identifier: GPL-2.0-only
 +/* IEI WT61P803 PUZZLE MCU HWMON Driver
 + *
@@ -84,13 +84,17 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 + * @name:		Thermal cooling device name
 + * @pwm_channel:	Controlled PWM channel (0 or 1)
 + * @cooling_levels:	Thermal cooling device cooling levels (DT)
++ * @cur_level:		Current cooling level
++ * @num_levels:	Number of cooling levels
 + */
 +struct iei_wt61p803_puzzle_thermal_cooling_device {
 +	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon;
 +	struct thermal_cooling_device *tcdev;
 +	char name[THERMAL_NAME_LENGTH];
 +	int pwm_channel;
-+	u8 *cooling_levels;
++	u32 *cooling_levels;
++	int cur_level;
++	u8 num_levels;
 +};
 +
 +/**
@@ -326,8 +330,12 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +static int iei_wt61p803_puzzle_get_max_state(struct thermal_cooling_device *tcdev,
 +					     unsigned long *state)
 +{
-+	*state = IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL;
++	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
++
++	if (!cdev)
++		return -EINVAL;
 +
++	*state = cdev->num_levels - 1;
 +	return 0;
 +}
 +
@@ -335,14 +343,14 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +					     unsigned long *state)
 +{
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
-+	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
-+	long value;
-+	int ret;
 +
-+	ret = iei_wt61p803_puzzle_read_pwm_channel(mcu_hwmon, cdev->pwm_channel, &value);
-+	if (ret)
-+		return ret;
-+	*state = value;
++	if (!cdev)
++		return -EINVAL;
++
++	if (cdev->cur_level < 0)
++		return -EAGAIN;
++
++	*state = cdev->cur_level;
 +	return 0;
 +}
 +
@@ -350,9 +358,21 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +					     unsigned long state)
 +{
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev = tcdev->devdata;
-+	struct iei_wt61p803_puzzle_hwmon *mcu_hwmon = cdev->mcu_hwmon;
++	u8 pwm_level;
++
++	if (!cdev)
++		return -EINVAL;
 +
-+	return iei_wt61p803_puzzle_write_pwm_channel(mcu_hwmon, cdev->pwm_channel, state);
++	if (state >= cdev->num_levels)
++		return -EINVAL;
++
++	if (state == cdev->cur_level)
++		return 0;
++
++	cdev->cur_level = state;
++	pwm_level = cdev->cooling_levels[state];
++
++	return iei_wt61p803_puzzle_write_pwm_channel(cdev->mcu_hwmon, cdev->pwm_channel, pwm_level);
 +}
 +
 +static const struct thermal_cooling_device_ops iei_wt61p803_puzzle_cooling_ops = {
@@ -369,7 +389,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +	struct iei_wt61p803_puzzle_thermal_cooling_device *cdev;
 +	u32 pwm_channel;
 +	u8 num_levels;
-+	int ret;
++	int i, ret;
 +
 +	ret = fwnode_property_read_u32(child, "reg", &pwm_channel);
 +	if (ret)
@@ -377,7 +397,7 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +
 +	mcu_hwmon->thermal_cooling_dev_present[pwm_channel] = true;
 +
-+	num_levels = fwnode_property_count_u8(child, "cooling-levels");
++	num_levels = fwnode_property_count_u32(child, "cooling-levels");
 +	if (!num_levels)
 +		return -EINVAL;
 +
@@ -385,28 +405,40 @@ Cc: Robert Marko <robert.marko@sartura.hr>
 +	if (!cdev)
 +		return -ENOMEM;
 +
-+	cdev->cooling_levels = devm_kmalloc_array(dev, num_levels, sizeof(u8), GFP_KERNEL);
++	cdev->cooling_levels = devm_kmalloc_array(dev, num_levels, sizeof(u32), GFP_KERNEL);
 +	if (!cdev->cooling_levels)
 +		return -ENOMEM;
 +
-+	ret = fwnode_property_read_u8_array(child, "cooling-levels",
-+					    cdev->cooling_levels,
-+					    num_levels);
++	ret = fwnode_property_read_u32_array(child, "cooling-levels",
++					     cdev->cooling_levels,
++					     num_levels);
 +	if (ret) {
 +		dev_err(dev, "Couldn't read property 'cooling-levels'\n");
 +		return ret;
 +	}
 +
-+	snprintf(cdev->name, THERMAL_NAME_LENGTH, "wt61p803_puzzle_%d", pwm_channel);
-+	cdev->tcdev = devm_thermal_of_cooling_device_register(dev, NULL, cdev->name, cdev,
-+							      &iei_wt61p803_puzzle_cooling_ops);
-+	if (IS_ERR(cdev->tcdev))
-+		return PTR_ERR(cdev->tcdev);
++	for (i = 0; i < num_levels; i++) {
++		if (cdev->cooling_levels[i] >
++		    IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL) {
++			dev_err(dev, "iei_wt61p803_fan state[%d]:%d > %d\n", i,
++				cdev->cooling_levels[i],
++				IEI_WT61P803_PUZZLE_HWMON_MAX_PWM_VAL);
++			return -EINVAL;
++		}
++	}
 +
 +	cdev->mcu_hwmon = mcu_hwmon;
 +	cdev->pwm_channel = pwm_channel;
++	cdev->num_levels = num_levels;
++	cdev->cur_level = -1;
 +	mcu_hwmon->cdev[pwm_channel] = cdev;
 +
++	snprintf(cdev->name, THERMAL_NAME_LENGTH, "wt61p803_puzzle_%d", pwm_channel);
++	cdev->tcdev = devm_thermal_of_cooling_device_register(dev, to_of_node(child), cdev->name,
++							      cdev, &iei_wt61p803_puzzle_cooling_ops);
++	if (IS_ERR(cdev->tcdev))
++		return PTR_ERR(cdev->tcdev);
++
 +	return 0;
 +}
 +