kernel: pse-pd: Fix missing regulator backport

Fixes: 528c9259a70f Backport the PSE-PD...

When the original backport bring-in was done, the regulator power budget
portion was missed.  This results in kernel build errors when trying to
bring in PSE_CONTROLLER or PSE_REGULATOR configs.  Which are required to
bring in further PSE drivers.
Bring in the backport to fix that up.  Patch series naming is a bit wrong
here, but keeps patches together in ordering, whilst reducing files
touched in this commit.

Without this patch, when adding config of
CONFIG_PSE_CONTROLLER=y
CONFIG_PSE_REGULATOR=y
CONFIG_PSE_TPS23881=y
CONFIG_REGULATOR=y

The following errors occur:
drivers/net/pse-pd/pse_core.c:446:9:
  error: implicit declaration of function 'regulator_free_power_budget'

drivers/net/pse-pd/pse_core.c:559:16:
  error: implicit declaration of function 'regulator_request_power_budget'

Signed-off-by: Bevan Weiss <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/21996
Signed-off-by: Robert Marko <[email protected]>

target/linux/generic/backport-6.12/626-16b-v6.17-regulator-Add-support-for-power-budget.patch

@@ -0,0 +1,257 @@
+From 42d7c87b4e1251f36eceac987e74623e7cda8577 Mon Sep 17 00:00:00 2001
+From: Kory Maincent <[email protected]>
+Date: Wed, 15 Jan 2025 15:41:57 +0100
+Subject: [PATCH] regulator: Add support for power budget
+
+Introduce power budget management for the regulator device. Enable tracking
+of available power capacity by providing helpers to request and release
+power budget allocations.
+
+Signed-off-by: Kory Maincent <[email protected]>
+Link: https://patch.msgid.link/20250115-feature_regulator_pw_budget-v2-1-0a44b949e6bc@bootlin.com
+Signed-off-by: Mark Brown <[email protected]>
+Signed-off-by: Bevan Weiss <[email protected]>
+---
+ drivers/regulator/core.c           | 114 +++++++++++++++++++++++++++++
+ drivers/regulator/of_regulator.c   |   3 +
+ include/linux/regulator/consumer.h |  21 ++++++
+ include/linux/regulator/driver.h   |   2 +
+ include/linux/regulator/machine.h  |   2 +
+ 5 files changed, 142 insertions(+)
+
+--- a/drivers/regulator/core.c
++++ b/drivers/regulator/core.c
+@@ -916,6 +916,26 @@ static ssize_t bypass_show(struct device
+ }
+ static DEVICE_ATTR_RO(bypass);
+ 
++static ssize_t power_budget_milliwatt_show(struct device *dev,
++					   struct device_attribute *attr,
++					   char *buf)
++{
++	struct regulator_dev *rdev = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%d\n", rdev->constraints->pw_budget_mW);
++}
++static DEVICE_ATTR_RO(power_budget_milliwatt);
++
++static ssize_t power_requested_milliwatt_show(struct device *dev,
++					      struct device_attribute *attr,
++					      char *buf)
++{
++	struct regulator_dev *rdev = dev_get_drvdata(dev);
++
++	return sprintf(buf, "%d\n", rdev->pw_requested_mW);
++}
++static DEVICE_ATTR_RO(power_requested_milliwatt);
++
+ #define REGULATOR_ERROR_ATTR(name, bit)							\
+ 	static ssize_t name##_show(struct device *dev, struct device_attribute *attr,	\
+ 				   char *buf)						\
+@@ -1148,6 +1168,10 @@ static void print_constraints_debug(stru
+ 	if (constraints->valid_modes_mask & REGULATOR_MODE_STANDBY)
+ 		count += scnprintf(buf + count, len - count, "standby ");
+ 
++	if (constraints->pw_budget_mW)
++		count += scnprintf(buf + count, len - count, "%d mW budget",
++				   constraints->pw_budget_mW);
++
+ 	if (!count)
+ 		count = scnprintf(buf, len, "no parameters");
+ 	else
+@@ -1631,6 +1655,9 @@ static int set_machine_constraints(struc
+ 		rdev->last_off = ktime_get();
+ 	}
+ 
++	if (!rdev->constraints->pw_budget_mW)
++		rdev->constraints->pw_budget_mW = INT_MAX;
++
+ 	print_constraints(rdev);
+ 	return 0;
+ }
+@@ -4646,6 +4673,87 @@ int regulator_get_current_limit(struct r
+ EXPORT_SYMBOL_GPL(regulator_get_current_limit);
+ 
+ /**
++ * regulator_get_unclaimed_power_budget - get regulator unclaimed power budget
++ * @regulator: regulator source
++ *
++ * Return: Unclaimed power budget of the regulator in mW.
++ */
++int regulator_get_unclaimed_power_budget(struct regulator *regulator)
++{
++	return regulator->rdev->constraints->pw_budget_mW -
++	       regulator->rdev->pw_requested_mW;
++}
++EXPORT_SYMBOL_GPL(regulator_get_unclaimed_power_budget);
++
++/**
++ * regulator_request_power_budget - request power budget on a regulator
++ * @regulator: regulator source
++ * @pw_req: Power requested
++ *
++ * Return: 0 on success or a negative error number on failure.
++ */
++int regulator_request_power_budget(struct regulator *regulator,
++				   unsigned int pw_req)
++{
++	struct regulator_dev *rdev = regulator->rdev;
++	int ret = 0, pw_tot_req;
++
++	regulator_lock(rdev);
++	if (rdev->supply) {
++		ret = regulator_request_power_budget(rdev->supply, pw_req);
++		if (ret < 0)
++			goto out;
++	}
++
++	pw_tot_req = rdev->pw_requested_mW + pw_req;
++	if (pw_tot_req > rdev->constraints->pw_budget_mW) {
++		rdev_warn(rdev, "power requested %d mW out of budget %d mW",
++			  pw_req,
++			  rdev->constraints->pw_budget_mW - rdev->pw_requested_mW);
++		regulator_notifier_call_chain(rdev,
++					      REGULATOR_EVENT_OVER_CURRENT_WARN,
++					      NULL);
++		ret = -ERANGE;
++		goto out;
++	}
++
++	rdev->pw_requested_mW = pw_tot_req;
++out:
++	regulator_unlock(rdev);
++	return ret;
++}
++EXPORT_SYMBOL_GPL(regulator_request_power_budget);
++
++/**
++ * regulator_free_power_budget - free power budget on a regulator
++ * @regulator: regulator source
++ * @pw: Power to be released.
++ *
++ * Return: Power budget of the regulator in mW.
++ */
++void regulator_free_power_budget(struct regulator *regulator,
++				 unsigned int pw)
++{
++	struct regulator_dev *rdev = regulator->rdev;
++	int pw_tot_req;
++
++	regulator_lock(rdev);
++	if (rdev->supply)
++		regulator_free_power_budget(rdev->supply, pw);
++
++	pw_tot_req = rdev->pw_requested_mW - pw;
++	if (pw_tot_req >= 0)
++		rdev->pw_requested_mW = pw_tot_req;
++	else
++		rdev_warn(rdev,
++			  "too much power freed %d mW (already requested %d mW)",
++			  pw, rdev->pw_requested_mW);
++
++	regulator_unlock(rdev);
++}
++EXPORT_SYMBOL_GPL(regulator_free_power_budget);
++
++/**
+  * regulator_set_mode - set regulator operating mode
+  * @regulator: regulator source
+  * @mode: operating mode - one of the REGULATOR_MODE constants
+@@ -5283,6 +5391,8 @@ static struct attribute *regulator_dev_a
+ 	&dev_attr_suspend_standby_mode.attr,
+ 	&dev_attr_suspend_mem_mode.attr,
+ 	&dev_attr_suspend_disk_mode.attr,
++	&dev_attr_power_budget_milliwatt.attr,
++	&dev_attr_power_requested_milliwatt.attr,
+ 	NULL
+ };
+ 
+@@ -5364,6 +5474,10 @@ static umode_t regulator_attr_is_visible
+ 	    attr == &dev_attr_suspend_disk_mode.attr)
+ 		return ops->set_suspend_mode ? mode : 0;
+ 
++	if (attr == &dev_attr_power_budget_milliwatt.attr ||
++	    attr == &dev_attr_power_requested_milliwatt.attr)
++		return rdev->constraints->pw_budget_mW != INT_MAX ? mode : 0;
++
+ 	return mode;
+ }
+ 
+--- a/drivers/regulator/of_regulator.c
++++ b/drivers/regulator/of_regulator.c
+@@ -125,6 +125,9 @@ static int of_get_regulation_constraints
+ 	if (constraints->min_uA != constraints->max_uA)
+ 		constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
+ 
++	if (!of_property_read_u32(np, "regulator-power-budget-milliwatt", &pval))
++		constraints->pw_budget_mW = pval;
++
+ 	constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
+ 	constraints->always_on = of_property_read_bool(np, "regulator-always-on");
+ 	if (!constraints->always_on) /* status change should be possible. */
+--- a/include/linux/regulator/consumer.h
++++ b/include/linux/regulator/consumer.h
+@@ -235,6 +235,11 @@ int regulator_sync_voltage(struct regula
+ int regulator_set_current_limit(struct regulator *regulator,
+ 			       int min_uA, int max_uA);
+ int regulator_get_current_limit(struct regulator *regulator);
++int regulator_get_unclaimed_power_budget(struct regulator *regulator);
++int regulator_request_power_budget(struct regulator *regulator,
++				   unsigned int pw_req);
++void regulator_free_power_budget(struct regulator *regulator,
++				 unsigned int pw);
+ 
+ int regulator_set_mode(struct regulator *regulator, unsigned int mode);
+ unsigned int regulator_get_mode(struct regulator *regulator);
+@@ -534,6 +539,22 @@ static inline int regulator_get_current_
+ 	return 0;
+ }
+ 
++static inline int regulator_get_unclaimed_power_budget(struct regulator *regulator)
++{
++	return INT_MAX;
++}
++
++static inline int regulator_request_power_budget(struct regulator *regulator,
++						 unsigned int pw_req)
++{
++	return -EOPNOTSUPP;
++}
++
++static inline void regulator_free_power_budget(struct regulator *regulator,
++					       unsigned int pw)
++{
++}
++
+ static inline int regulator_set_mode(struct regulator *regulator,
+ 	unsigned int mode)
+ {
+--- a/include/linux/regulator/driver.h
++++ b/include/linux/regulator/driver.h
+@@ -649,6 +649,8 @@ struct regulator_dev {
+ 	int cached_err;
+ 	bool use_cached_err;
+ 	spinlock_t err_lock;
++
++	int pw_requested_mW;
+ };
+ 
+ /*
+--- a/include/linux/regulator/machine.h
++++ b/include/linux/regulator/machine.h
+@@ -113,6 +113,7 @@ struct notification_limit {
+  * @min_uA: Smallest current consumers may set.
+  * @max_uA: Largest current consumers may set.
+  * @ilim_uA: Maximum input current.
++ * @pw_budget_mW: Power budget for the regulator in mW.
+  * @system_load: Load that isn't captured by any consumer requests.
+  *
+  * @over_curr_limits:		Limits for acting on over current.
+@@ -185,6 +186,7 @@ struct regulation_constraints {
+ 	int max_uA;
+ 	int ilim_uA;
+ 
++	int pw_budget_mW;
+ 	int system_load;
+ 
+ 	/* used for coupled regulators */