Introduce customized regulators coupling

PATCH In review Dmitry Osipenko 2 participants 8 messages Jun 23, 2019 – Jun 25, 2019

Subsystems (3)

Device tree bindings Tegra architecture support Voltage and current regulator framework

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Dmitry Osipenko

author

2019-06-23 21:08 UTC #0 lore raw

v3 cover Introduce customized regulators coupling

Hello,

This series introduces a way of specifying a customized regulators coupler which is necessary for cases like a non-trivial DVFS implementation. For now I'm primarily targeting the CPUFreq driver of NVIDIA Tegra20 and Tegra30 SoC's to get into a better shape, such that things like CPU voltage scaling could be supported. Both these SoC's have voltage-coupled regulators, one of the coupled regulators powers CPU and other(s) power SoC peripherals. CPU and each of the SoC's peripherals have it's own demand for a minimal voltage (which basically depends on the clock rate), hence regulators voltage shall not get lower than the minimum value required by one of peripherals (or CPU). Right now none of peripheral drivers support voltage scaling in the upstream kernel and voltages are statically specified in board device-trees via minimum voltage values of the regulators. In order to implement a full-featured DVFS, all drivers should gain support for voltage scaling and then there should be some solution for having disabled drivers and hardware that is left in enabled state by bootloader. That is not an easy problem to solve, so I'm trying to start easy by getting some basics to work at first.

NVIDIA Tegra20 SoC's have a quite straight-forward voltage coupling between 3 regulators and the customized coupler is needed to address the missing support of a full-featured system-wide DVFS, support for coupling of more than 2 regulators and support for a "min-spread" voltage. Probably it should be possible to switch to a generic coupler later on, but for now it will be much easier to start with a custom coupler that has all necessary features in a simplified form.

NVIDIA Tegra30 SoC's have a bit more complicated coupling rules due to variable dependency between the regulators (min-spread value depends on a voltage of one of the coupled regulators).

This series has been tested on multiple devices by different people without any known issues. CPUFreq voltage scaling works perfectly well with it and voltage of peripherals is maintained at a good level. In a result thermal sensors show that SoC package is a less warm by few degrees during of CPU idling.

Changelog:

v3: Addressed review comments that were made by Mark Brown to the v2 by

- Extending doc-comments of the new Regulator Coupler API with more details about what couplers are expected to do and what's the context of callbacks execution (locking, etc).

- The Coupler API is now factored out into a standalone header file and thus likely that further changes to the API won't touch other headers related to regulator's core, avoiding unnecessary re-compilations.

- All required resources are allocated dynamically now and static MAX_COUPLED constant is gone.

- The attach_regulator callback now supports the return code 1, which tells that customized coupler didn't fail, but doesn't want to handle the given regulator. This allows to have multiple couplers in a system.

- SPDX comment-style now matches to the rest of the header in the newly added source files of this series.

- Corrected spellings, added COMPILE_TEST for the Tegra-couplers.

- Coupler's initialization now doesn't fail if regulator can't change voltage, i.e. REGULATOR_CHANGE_VOLTAGE flag is unset. This allows coupled regulators to not fail theirs registration and thus may allow kernel to bootup properly if the voltage change isn't crucial for the booting process. This problem was spotted during of a more broad testing, in particular this caused TPS6586x driver to fail the probe because one of the coupled regulators had a fixed voltage defined in a device-tree. Now the driver is probing successfully and the regulator's voltage change is what is failing instead. This also allows customized couplers to support handling of a fixed regulators if required.

v2: The coupler's registration is now done in a more generic fashion and
allow multiple couplers to be registered in a system.

Added device-tree binding document for NVIDIA Tegra20/30 SoC's that describes hardware specifics of these SoC's in regards to regulators voltage coupling. In a result coupled regulators that are dedicated to SoC could be distinguished from each other, which in turns is also useful for the customized couplers implementation.

The customized couplers got some more polish and now have a bit more stricter checkings for coupling rules violation.

The initial v1 of this series could be found here:

	https://lore.kernel.org/lkml/[email protected]/

This series, along with CPUFreq and other "in-progress" patches, could be found here:

https://github.com/grate-driver/linux/commits/master

Dmitry Osipenko (5):
regulator: core: Introduce API for regulators coupling customization
regulator: core: Expose some of core functions needed by couplers
dt-bindings: regulator: Document regulators coupling of NVIDIA

    Tegra20/30 SoCs

soc/tegra: regulators: Add regulators coupler for Tegra20 soc/tegra: regulators: Add regulators coupler for Tegra30

 .../nvidia,tegra-regulators-coupling.txt      |  65 ++++
 drivers/regulator/core.c                      | 194 +++++++---
 drivers/regulator/of_regulator.c              |  63 +++-
 drivers/soc/tegra/Kconfig                     |  10 +
 drivers/soc/tegra/Makefile                    |   2 +
 drivers/soc/tegra/regulators-tegra20.c        | 350 ++++++++++++++++++
 drivers/soc/tegra/regulators-tegra30.c        | 302 +++++++++++++++
 include/linux/regulator/coupler.h             |  97 +++++
 include/linux/regulator/driver.h              |   6 +-
 include/linux/regulator/machine.h             |   2 +-
 10 files changed, 1016 insertions(+), 75 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt
 create mode 100644 drivers/soc/tegra/regulators-tegra20.c
 create mode 100644 drivers/soc/tegra/regulators-tegra30.c
 create mode 100644 include/linux/regulator/coupler.h

Signature · 1 line

2.22.0

Dmitry Osipenko

author

2019-06-23 21:08 UTC #1 lore raw

PATCH v3 1/5 regulator: core: Introduce API for regulators coupling customization

Right now regulator core supports only one type of regulators coupling, the "voltage max-spread" which keeps voltages of coupled regulators in a given range from each other. A more sophisticated coupling may be required in practice, one example is the NVIDIA Tegra SoCs which besides the max-spreading have other restrictions that must be adhered. Introduce API that allow platforms to provide their own customized coupling algorithms.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 drivers/regulator/core.c          | 136 +++++++++++++++++++++++++-----
 drivers/regulator/of_regulator.c  |  63 +++++++++-----
 include/linux/regulator/coupler.h |  62 ++++++++++++++
 include/linux/regulator/driver.h  |   6 +-
 include/linux/regulator/machine.h |   2 +-
 5 files changed, 225 insertions(+), 44 deletions(-)
 create mode 100644 include/linux/regulator/coupler.h

drivers/regulator/core.c +116 ~~-20~~

index eb5670d7dcbb..98912f1c808d 100644
@@ -22,6 +22,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/regulator/consumer.h>
+#include <linux/regulator/coupler.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/machine.h>
 #include <linux/module.h>

@@ -49,6 +50,7 @@ static DEFINE_MUTEX(regulator_list_mutex);
 static LIST_HEAD(regulator_map_list);
 static LIST_HEAD(regulator_ena_gpio_list);
 static LIST_HEAD(regulator_supply_alias_list);
+static LIST_HEAD(regulator_coupler_list);
 static bool has_full_constraints;
 
 static struct dentry *debugfs_root;

@@ -3433,11 +3435,10 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
 	struct coupling_desc *c_desc = &rdev->coupling_desc;
 	struct regulator_dev **c_rdevs = c_desc->coupled_rdevs;
 	struct regulation_constraints *constraints = rdev->constraints;
-	int max_spread = constraints->max_spread;
 	int desired_min_uV = 0, desired_max_uV = INT_MAX;
 	int max_current_uV = 0, min_current_uV = INT_MAX;
 	int highest_min_uV = 0, target_uV, possible_uV;
-	int i, ret;
+	int i, ret, max_spread;
 	bool done;
 
 	*current_uV = -1;

@@ -3491,6 +3492,8 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
 		}
 	}
 
+	max_spread = constraints->max_spread[0];
+
 	/*
 	 * Let target_uV be equal to the desired one if possible.
 	 * If not, set it to minimum voltage, allowed by other coupled

@@ -3572,9 +3575,11 @@ static int regulator_balance_voltage(struct regulator_dev *rdev,
 	struct regulator_dev **c_rdevs;
 	struct regulator_dev *best_rdev;
 	struct coupling_desc *c_desc = &rdev->coupling_desc;
+	struct regulator_coupler *coupler = c_desc->coupler;
 	int i, ret, n_coupled, best_min_uV, best_max_uV, best_c_rdev;
-	bool best_c_rdev_done, c_rdev_done[MAX_COUPLED];
 	unsigned int delta, best_delta;
+	unsigned long c_rdev_done = 0;
+	bool best_c_rdev_done;
 
 	c_rdevs = c_desc->coupled_rdevs;
 	n_coupled = c_desc->n_coupled;

@@ -3591,8 +3596,9 @@ static int regulator_balance_voltage(struct regulator_dev *rdev,
 		return -EPERM;
 	}
 
-	for (i = 0; i < n_coupled; i++)
-		c_rdev_done[i] = false;
+	/* Invoke custom balancer for customized couplers */
+	if (coupler && coupler->balance_voltage)
+		return coupler->balance_voltage(coupler, rdev, state);
 
 	/*
 	 * Find the best possible voltage change on each loop. Leave the loop

@@ -3619,7 +3625,7 @@ static int regulator_balance_voltage(struct regulator_dev *rdev,
 			 */
 			int optimal_uV = 0, optimal_max_uV = 0, current_uV = 0;
 
-			if (c_rdev_done[i])
+			if (test_bit(i, &c_rdev_done))
 				continue;
 
 			ret = regulator_get_optimal_voltage(c_rdevs[i],

@@ -3654,7 +3660,8 @@ static int regulator_balance_voltage(struct regulator_dev *rdev,
 		if (ret < 0)
 			goto out;
 
-		c_rdev_done[best_c_rdev] = best_c_rdev_done;
+		if (best_c_rdev_done)
+			set_bit(best_c_rdev, &c_rdev_done);
 
 	} while (n_coupled > 1);

@@ -4706,8 +4713,60 @@ static int regulator_register_resolve_supply(struct device *dev, void *data)
 	return 0;
 }
 
+int regulator_coupler_register(struct regulator_coupler *coupler)
+{
+	mutex_lock(&regulator_list_mutex);
+	list_add_tail(&coupler->list, &regulator_coupler_list);
+	mutex_unlock(&regulator_list_mutex);
+
+	return 0;
+}
+
+static struct regulator_coupler *
+regulator_find_coupler(struct regulator_dev *rdev)
+{
+	struct regulator_coupler *coupler;
+	int err;
+
+	/*
+	 * Note that regulators are appended to the list and the generic
+	 * coupler is registered first, hence it will be attached at last
+	 * if nobody cared.
+	 */
+	list_for_each_entry_reverse(coupler, &regulator_coupler_list, list) {
+		err = coupler->attach_regulator(coupler, rdev);
+		if (!err) {
+			if (!coupler->balance_voltage &&
+			    rdev->coupling_desc.n_coupled > 2)
+				goto err_unsupported;
+
+			return coupler;
+		}
+
+		if (err < 0)
+			return ERR_PTR(err);
+
+		if (err == 1)
+			continue;
+
+		break;
+	}
+
+	return ERR_PTR(-EINVAL);
+
+err_unsupported:
+	if (coupler->detach_regulator)
+		coupler->detach_regulator(coupler, rdev);
+
+	rdev_err(rdev,
+		"Voltage balancing for multiple regulator couples is unimplemented\n");
+
+	return ERR_PTR(-EPERM);
+}
+
 static void regulator_resolve_coupling(struct regulator_dev *rdev)
 {
+	struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
 	struct coupling_desc *c_desc = &rdev->coupling_desc;
 	int n_coupled = c_desc->n_coupled;
 	struct regulator_dev *c_rdev;

@@ -4723,6 +4782,12 @@ static void regulator_resolve_coupling(struct regulator_dev *rdev)
 		if (!c_rdev)
 			continue;
 
+		if (c_rdev->coupling_desc.coupler != coupler) {
+			rdev_err(rdev, "coupler mismatch with %s\n",
+				 rdev_get_name(c_rdev));
+			return;
+		}
+
 		regulator_lock(c_rdev);
 
 		c_desc->coupled_rdevs[i] = c_rdev;

@@ -4736,10 +4801,12 @@ static void regulator_resolve_coupling(struct regulator_dev *rdev)
 
 static void regulator_remove_coupling(struct regulator_dev *rdev)
 {
+	struct regulator_coupler *coupler = rdev->coupling_desc.coupler;
 	struct coupling_desc *__c_desc, *c_desc = &rdev->coupling_desc;
 	struct regulator_dev *__c_rdev, *c_rdev;
 	unsigned int __n_coupled, n_coupled;
 	int i, k;
+	int err;
 
 	n_coupled = c_desc->n_coupled;

@@ -4769,21 +4836,33 @@ static void regulator_remove_coupling(struct regulator_dev *rdev)
 		c_desc->coupled_rdevs[i] = NULL;
 		c_desc->n_resolved--;
 	}
+
+	if (coupler && coupler->detach_regulator) {
+		err = coupler->detach_regulator(coupler, rdev);
+		if (err)
+			rdev_err(rdev, "failed to detach from coupler: %d\n",
+				 err);
+	}
+
+	kfree(rdev->coupling_desc.coupled_rdevs);
+	rdev->coupling_desc.coupled_rdevs = NULL;
 }
 
 static int regulator_init_coupling(struct regulator_dev *rdev)
 {
-	int n_phandles;
+	int err, n_phandles;
+	size_t alloc_size;
 
 	if (!IS_ENABLED(CONFIG_OF))
 		n_phandles = 0;
 	else
 		n_phandles = of_get_n_coupled(rdev);
 
-	if (n_phandles + 1 > MAX_COUPLED) {
-		rdev_err(rdev, "too many regulators coupled\n");
-		return -EPERM;
-	}
+	alloc_size = sizeof(*rdev) * (n_phandles + 1);
+
+	rdev->coupling_desc.coupled_rdevs = kzalloc(alloc_size, GFP_KERNEL);
+	if (!rdev->coupling_desc.coupled_rdevs)
+		return -ENOMEM;
 
 	/*
 	 * Every regulator should always have coupling descriptor filled with

@@ -4797,23 +4876,35 @@ static int regulator_init_coupling(struct regulator_dev *rdev)
 	if (n_phandles == 0)
 		return 0;
 
-	/* regulator, which can't change its voltage, can't be coupled */
-	if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
-		rdev_err(rdev, "voltage operation not allowed\n");
+	if (!of_check_coupling_data(rdev))
 		return -EPERM;
-	}
 
-	if (rdev->constraints->max_spread <= 0) {
-		rdev_err(rdev, "wrong max_spread value\n");
-		return -EPERM;
+	rdev->coupling_desc.coupler = regulator_find_coupler(rdev);
+	if (IS_ERR(rdev->coupling_desc.coupler)) {
+		err = PTR_ERR(rdev->coupling_desc.coupler);
+		rdev_err(rdev, "failed to get coupler: %d\n", err);
+		return err;
 	}
 
-	if (!of_check_coupling_data(rdev))
+	return 0;
+}
+
+static int generic_coupler_attach(struct regulator_coupler *coupler,
+				  struct regulator_dev *rdev)
+{
+	if (rdev->coupling_desc.n_coupled > 2) {
+		rdev_err(rdev,
+			 "Voltage balancing for multiple regulator couples is unimplemented\n");
 		return -EPERM;
+	}
 
 	return 0;
 }
 
+static struct regulator_coupler generic_regulator_coupler = {
+	.attach_regulator = generic_coupler_attach,
+};
+
 /**
  * regulator_register - register regulator
  * @regulator_desc: regulator to register

@@ -4975,7 +5066,9 @@ regulator_register(const struct regulator_desc *regulator_desc,
 	if (ret < 0)
 		goto wash;
 
+	mutex_lock(&regulator_list_mutex);
 	ret = regulator_init_coupling(rdev);
+	mutex_unlock(&regulator_list_mutex);
 	if (ret < 0)
 		goto wash;

@@ -5024,6 +5117,7 @@ regulator_register(const struct regulator_desc *regulator_desc,
 unset_supplies:
 	mutex_lock(&regulator_list_mutex);
 	unset_regulator_supplies(rdev);
+	regulator_remove_coupling(rdev);
 	mutex_unlock(&regulator_list_mutex);
 wash:
 	kfree(rdev->constraints);

@@ -5479,6 +5573,8 @@ static int __init regulator_init(void)
 #endif
 	regulator_dummy_init();
 
+	regulator_coupler_register(&generic_regulator_coupler);
+
 	return ret;
 }

drivers/regulator/of_regulator.c +43 ~~-20~~

139 lines not on this page · raw message

include/linux/regulator/coupler.h new file +62 -0

62 lines not on this page · raw message

include/linux/regulator/driver.h +3 -3

index 377da2357118..31b38a2b6995 100644
@@ -15,8 +15,6 @@
 #ifndef __LINUX_REGULATOR_DRIVER_H_
 #define __LINUX_REGULATOR_DRIVER_H_
 
-#define MAX_COUPLED		2
-
 #include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/regulator/consumer.h>

@@ -426,7 +424,8 @@ struct regulator_config {
  * incremented.
  */
 struct coupling_desc {
-	struct regulator_dev *coupled_rdevs[MAX_COUPLED];
+	struct regulator_dev **coupled_rdevs;
+	struct regulator_coupler *coupler;
 	int n_resolved;
 	int n_coupled;
 };

@@ -552,4 +551,5 @@ void regulator_unlock(struct regulator_dev *rdev);
  */
 int regulator_desc_list_voltage_linear_range(const struct regulator_desc *desc,
 					     unsigned int selector);
+
 #endif

include/linux/regulator/machine.h +1 -1

index 1d34a70ffda2..21db06e5c1ed 100644
@@ -156,7 +156,7 @@ struct regulation_constraints {
 	int system_load;
 
 	/* used for coupled regulators */
-	int max_spread;
+	u32 *max_spread;
 
 	/* used for changing voltage in steps */
 	int max_uV_step;

Signature · 1 line

2.22.0

Dmitry Osipenko

author

2019-06-23 21:08 UTC #2 lore raw

PATCH v3 2/5 regulator: core: Expose some of core functions needed by couplers

In reply to Dmitry Osipenko

Expose some of internal functions that are required for implementation of customized regulator couplers.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 drivers/regulator/core.c          | 58 ++++++++++++++-----------------
 include/linux/regulator/coupler.h | 35 +++++++++++++++++++
 2 files changed, 62 insertions(+), 31 deletions(-)

drivers/regulator/core.c +27 ~~-31~~

index 98912f1c808d..41a062eb1470 100644
@@ -94,7 +94,6 @@ struct regulator_supply_alias {
 
 static int _regulator_is_enabled(struct regulator_dev *rdev);
 static int _regulator_disable(struct regulator *regulator);
-static int _regulator_get_voltage(struct regulator_dev *rdev);
 static int _regulator_get_current_limit(struct regulator_dev *rdev);
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
 static int _notifier_call_chain(struct regulator_dev *rdev,

@@ -103,15 +102,12 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				     int min_uV, int max_uV);
 static int regulator_balance_voltage(struct regulator_dev *rdev,
 				     suspend_state_t state);
-static int regulator_set_voltage_rdev(struct regulator_dev *rdev,
-				      int min_uV, int max_uV,
-				      suspend_state_t state);
 static struct regulator *create_regulator(struct regulator_dev *rdev,
 					  struct device *dev,
 					  const char *supply_name);
 static void _regulator_put(struct regulator *regulator);
 
-static const char *rdev_get_name(struct regulator_dev *rdev)
+const char *rdev_get_name(struct regulator_dev *rdev)
 {
 	if (rdev->constraints && rdev->constraints->name)
 		return rdev->constraints->name;

@@ -425,8 +421,8 @@ static struct device_node *of_get_regulator(struct device *dev, const char *supp
 }
 
 /* Platform voltage constraint check */
-static int regulator_check_voltage(struct regulator_dev *rdev,
-				   int *min_uV, int *max_uV)
+int regulator_check_voltage(struct regulator_dev *rdev,
+			    int *min_uV, int *max_uV)
 {
 	BUG_ON(*min_uV > *max_uV);

@@ -458,9 +454,9 @@ static int regulator_check_states(suspend_state_t state)
 /* Make sure we select a voltage that suits the needs of all
  * regulator consumers
  */
-static int regulator_check_consumers(struct regulator_dev *rdev,
-				     int *min_uV, int *max_uV,
-				     suspend_state_t state)
+int regulator_check_consumers(struct regulator_dev *rdev,
+			      int *min_uV, int *max_uV,
+			      suspend_state_t state)
 {
 	struct regulator *regulator;
 	struct regulator_voltage *voltage;

@@ -571,7 +567,7 @@ static ssize_t regulator_uV_show(struct device *dev,
 	ssize_t ret;
 
 	regulator_lock(rdev);
-	ret = sprintf(buf, "%d\n", _regulator_get_voltage(rdev));
+	ret = sprintf(buf, "%d\n", regulator_get_voltage_rdev(rdev));
 	regulator_unlock(rdev);
 
 	return ret;

@@ -942,7 +938,7 @@ static int drms_uA_update(struct regulator_dev *rdev)
 			rdev_err(rdev, "failed to set load %d\n", current_uA);
 	} else {
 		/* get output voltage */
-		output_uV = _regulator_get_voltage(rdev);
+		output_uV = regulator_get_voltage_rdev(rdev);
 		if (output_uV <= 0) {
 			rdev_err(rdev, "invalid output voltage found\n");
 			return -EINVAL;

@@ -1055,7 +1051,7 @@ static void print_constraints(struct regulator_dev *rdev)
 
 	if (!constraints->min_uV ||
 	    constraints->min_uV != constraints->max_uV) {
-		ret = _regulator_get_voltage(rdev);
+		ret = regulator_get_voltage_rdev(rdev);
 		if (ret > 0)
 			count += scnprintf(buf + count, len - count,
 					   "at %d mV ", ret / 1000);

@@ -1114,7 +1110,7 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 	if (rdev->constraints->apply_uV &&
 	    rdev->constraints->min_uV && rdev->constraints->max_uV) {
 		int target_min, target_max;
-		int current_uV = _regulator_get_voltage(rdev);
+		int current_uV = regulator_get_voltage_rdev(rdev);
 
 		if (current_uV == -ENOTRECOVERABLE) {
 			/* This regulator can't be read and must be initialized */

@@ -1124,7 +1120,7 @@ static int machine_constraints_voltage(struct regulator_dev *rdev,
 			_regulator_do_set_voltage(rdev,
 						  rdev->constraints->min_uV,
 						  rdev->constraints->max_uV);
-			current_uV = _regulator_get_voltage(rdev);
+			current_uV = regulator_get_voltage_rdev(rdev);
 		}
 
 		if (current_uV < 0) {

@@ -3066,7 +3062,7 @@ static int _regulator_call_set_voltage(struct regulator_dev *rdev,
 	struct pre_voltage_change_data data;
 	int ret;
 
-	data.old_uV = _regulator_get_voltage(rdev);
+	data.old_uV = regulator_get_voltage_rdev(rdev);
 	data.min_uV = min_uV;
 	data.max_uV = max_uV;
 	ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,

@@ -3090,7 +3086,7 @@ static int _regulator_call_set_voltage_sel(struct regulator_dev *rdev,
 	struct pre_voltage_change_data data;
 	int ret;
 
-	data.old_uV = _regulator_get_voltage(rdev);
+	data.old_uV = regulator_get_voltage_rdev(rdev);
 	data.min_uV = uV;
 	data.max_uV = uV;
 	ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,

@@ -3143,7 +3139,7 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 	unsigned int selector;
 	int old_selector = -1;
 	const struct regulator_ops *ops = rdev->desc->ops;
-	int old_uV = _regulator_get_voltage(rdev);
+	int old_uV = regulator_get_voltage_rdev(rdev);
 
 	trace_regulator_set_voltage(rdev_get_name(rdev), min_uV, max_uV);

@@ -3170,7 +3166,7 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				best_val = ops->list_voltage(rdev,
 							     selector);
 			else
-				best_val = _regulator_get_voltage(rdev);
+				best_val = regulator_get_voltage_rdev(rdev);
 		}
 
 	} else if (ops->set_voltage_sel) {

@@ -3289,7 +3285,7 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
 	 * changing the voltage.
 	 */
 	if (!regulator_ops_is_valid(rdev, REGULATOR_CHANGE_VOLTAGE)) {
-		current_uV = _regulator_get_voltage(rdev);
+		current_uV = regulator_get_voltage_rdev(rdev);
 		if (min_uV <= current_uV && current_uV <= max_uV) {
 			voltage->min_uV = min_uV;
 			voltage->max_uV = max_uV;

@@ -3326,8 +3322,8 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,
 	return ret;
 }
 
-static int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,
-				      int max_uV, suspend_state_t state)
+int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,
+			       int max_uV, suspend_state_t state)
 {
 	int best_supply_uV = 0;
 	int supply_change_uV = 0;

@@ -3355,7 +3351,7 @@ static int regulator_set_voltage_rdev(struct regulator_dev *rdev, int min_uV,
 
 		best_supply_uV += rdev->desc->min_dropout_uV;
 
-		current_supply_uV = _regulator_get_voltage(rdev->supply->rdev);
+		current_supply_uV = regulator_get_voltage_rdev(rdev->supply->rdev);
 		if (current_supply_uV < 0) {
 			ret = current_supply_uV;
 			goto out;

@@ -3406,7 +3402,7 @@ static int regulator_limit_voltage_step(struct regulator_dev *rdev,
 		return 1;
 
 	if (*current_uV < 0) {
-		*current_uV = _regulator_get_voltage(rdev);
+		*current_uV = regulator_get_voltage_rdev(rdev);
 
 		if (*current_uV < 0)
 			return *current_uV;

@@ -3511,7 +3507,7 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
 		if (!_regulator_is_enabled(c_rdevs[i]))
 			continue;
 
-		tmp_act = _regulator_get_voltage(c_rdevs[i]);
+		tmp_act = regulator_get_voltage_rdev(c_rdevs[i]);
 		if (tmp_act < 0)
 			return tmp_act;

@@ -3553,7 +3549,7 @@ static int regulator_get_optimal_voltage(struct regulator_dev *rdev,
 	if (n_coupled > 1 && *current_uV == -1) {
 
 		if (_regulator_is_enabled(rdev)) {
-			ret = _regulator_get_voltage(rdev);
+			ret = regulator_get_voltage_rdev(rdev);
 			if (ret < 0)
 				return ret;

@@ -3917,7 +3913,7 @@ int regulator_sync_voltage(struct regulator *regulator)
 }
 EXPORT_SYMBOL_GPL(regulator_sync_voltage);
 
-static int _regulator_get_voltage(struct regulator_dev *rdev)
+int regulator_get_voltage_rdev(struct regulator_dev *rdev)
 {
 	int sel, ret;
 	bool bypassed;

@@ -3934,7 +3930,7 @@ static int _regulator_get_voltage(struct regulator_dev *rdev)
 				return -EPROBE_DEFER;
 			}
 
-			return _regulator_get_voltage(rdev->supply->rdev);
+			return regulator_get_voltage_rdev(rdev->supply->rdev);
 		}
 	}

@@ -3950,7 +3946,7 @@ static int _regulator_get_voltage(struct regulator_dev *rdev)
 	} else if (rdev->desc->fixed_uV && (rdev->desc->n_voltages == 1)) {
 		ret = rdev->desc->fixed_uV;
 	} else if (rdev->supply) {
-		ret = _regulator_get_voltage(rdev->supply->rdev);
+		ret = regulator_get_voltage_rdev(rdev->supply->rdev);
 	} else {
 		return -EINVAL;
 	}

@@ -3975,7 +3971,7 @@ int regulator_get_voltage(struct regulator *regulator)
 	int ret;
 
 	regulator_lock_dependent(regulator->rdev, &ww_ctx);
-	ret = _regulator_get_voltage(regulator->rdev);
+	ret = regulator_get_voltage_rdev(regulator->rdev);
 	regulator_unlock_dependent(regulator->rdev, &ww_ctx);
 
 	return ret;

@@ -5371,7 +5367,7 @@ static void regulator_summary_show_subtree(struct seq_file *s,
 		   rdev->use_count, rdev->open_count, rdev->bypass_count,
 		   regulator_opmode_to_str(opmode));
 
-	seq_printf(s, "%5dmV ", _regulator_get_voltage(rdev) / 1000);
+	seq_printf(s, "%5dmV ", regulator_get_voltage_rdev(rdev) / 1000);
 	seq_printf(s, "%5dmA ",
 		   _regulator_get_current_limit_unlocked(rdev) / 1000);

include/linux/regulator/coupler.h +35 -0

index 98dd1f74d605..0212d6255e4e 100644
@@ -52,11 +52,46 @@ struct regulator_coupler {
 
 #ifdef CONFIG_REGULATOR
 int regulator_coupler_register(struct regulator_coupler *coupler);
+const char *rdev_get_name(struct regulator_dev *rdev);
+int regulator_check_consumers(struct regulator_dev *rdev,
+			      int *min_uV, int *max_uV,
+			      suspend_state_t state);
+int regulator_check_voltage(struct regulator_dev *rdev,
+			    int *min_uV, int *max_uV);
+int regulator_get_voltage_rdev(struct regulator_dev *rdev);
+int regulator_set_voltage_rdev(struct regulator_dev *rdev,
+			       int min_uV, int max_uV,
+			       suspend_state_t state);
 #else
 static inline int regulator_coupler_register(struct regulator_coupler *coupler)
 {
 	return 0;
 }
+static inline const char *rdev_get_name(struct regulator_dev *rdev)
+{
+	return NULL;
+}
+static inline int regulator_check_consumers(struct regulator_dev *rdev,
+					    int *min_uV, int *max_uV,
+					    suspend_state_t state)
+{
+	return -EINVAL;
+}
+static inline int regulator_check_voltage(struct regulator_dev *rdev,
+					  int *min_uV, int *max_uV)
+{
+	return -EINVAL;
+}
+static inline int regulator_get_voltage_rdev(struct regulator_dev *rdev)
+{
+	return -EINVAL;
+}
+static inline int regulator_set_voltage_rdev(struct regulator_dev *rdev,
+					     int min_uV, int max_uV,
+					     suspend_state_t state)
+{
+	return -EINVAL;
+}
 #endif
 
 #endif

Signature · 1 line

2.22.0

Mark Brown

maintainer

2019-06-25 11:19 UTC #3 lore raw

Re: [PATCH v3 2/5] regulator: core: Expose some of core functions needed by couplers

Quoted 2 lines · Dmitry Osipenko

Expose some of internal functions that are required for implementation of customized regulator couplers.

The following changes since commit a188339ca5a396acc588e5851ed7e19f66b0ebd9:

Linux 5.2-rc1 (2019-05-19 15:47:09 -0700)

are available in the Git repository at:

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git tags/regulator-couple-api

for you to fetch changes up to d22b85a1b97d12a4940ef9d778f6122546736f78:

regulator: core: Expose some of core functions needed by couplers (2019-06-25 12:15:35 +0100)

----------------------------------------------------------------
regulator: Coupling API

This series introduces a way of specifying a customized regulators coupler which is necessary for cases like a non-trivial DVFS implementation.

----------------------------------------------------------------
Dmitry Osipenko (2):
regulator: core: Introduce API for regulators coupling customization
regulator: core: Expose some of core functions needed by couplers

 drivers/regulator/core.c          | 194 ++++++++++++++++++++++++++++----------
 drivers/regulator/of_regulator.c  |  63 +++++++++----
 include/linux/regulator/coupler.h |  97 +++++++++++++++++++
 include/linux/regulator/driver.h  |   6 +-
 include/linux/regulator/machine.h |   2 +-
 5 files changed, 287 insertions(+), 75 deletions(-)
 create mode 100644 include/linux/regulator/coupler.h

Dmitry Osipenko

author

2019-06-25 14:40 UTC #4 lore raw

Re: [PATCH v3 2/5] regulator: core: Expose some of core functions needed by couplers

25.06.2019 14:19, Mark Brown пишет:

Quoted 27 lines · Dmitry Osipenko

Quoted 2 lines
Expose some of internal functions that are required for implementation of customized regulator couplers.
The following changes since commit a188339ca5a396acc588e5851ed7e19f66b0ebd9:
Linux 5.2-rc1 (2019-05-19 15:47:09 -0700)
are available in the Git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git tags/regulator-couple-api
for you to fetch changes up to d22b85a1b97d12a4940ef9d778f6122546736f78:
regulator: core: Expose some of core functions needed by couplers (2019-06-25 12:15:35 +0100)
----------------------------------------------------------------
regulator: Coupling API
This series introduces a way of specifying a customized regulators coupler which is necessary for cases like a non-trivial DVFS implementation.
----------------------------------------------------------------
Dmitry Osipenko (2):
regulator: core: Introduce API for regulators coupling customization
regulator: core: Expose some of core functions needed by couplers

Quoted 8 lines

 drivers/regulator/core.c          | 194 ++++++++++++++++++++++++++++----------
 drivers/regulator/of_regulator.c  |  63 +++++++++----
 include/linux/regulator/coupler.h |  97 +++++++++++++++++++
 include/linux/regulator/driver.h  |   6 +-
 include/linux/regulator/machine.h |   2 +-
 5 files changed, 287 insertions(+), 75 deletions(-)
 create mode 100644 include/linux/regulator/coupler.h

Thank you very much! Very nice to see some more progress!

Dmitry Osipenko

author

2019-06-23 21:08 UTC #5 lore raw

PATCH v3 3/5 dt-bindings: regulator: Document regulators coupling of NVIDIA Tegra20/30 SoCs

In reply to Dmitry Osipenko

There is voltage coupling between three regulators on Tegra20 boards and between two on Tegra30. The voltage coupling is a SoC-level feature and thus it is mandatory and common for all of the Tegra boards.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 .../nvidia,tegra-regulators-coupling.txt      | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt

Documentation/devicetree/bindings/regulator/nvidia,tegra-regulators-coupling.txt new file +65 -0

new file mode 100644
index 000000000000..4bf2dbf7c6cc
@@ -0,0 +1,65 @@
+NVIDIA Tegra Regulators Coupling
+================================
+
+NVIDIA Tegra SoC's have a mandatory voltage-coupling between regulators.
+Thus on Tegra20 there are 3 coupled regulators and on NVIDIA Tegra30
+there are 2.
+
+Tegra20 voltage coupling
+------------------------
+
+On Tegra20 SoC's there are 3 coupled regulators: CORE, RTC and CPU.
+The CORE and RTC voltages shall be in a range of 170mV from each other
+and they both shall be higher than the CPU voltage by at least 120mV.
+
+Tegra30 voltage coupling
+------------------------
+
+On Tegra30 SoC's there are 2 coupled regulators: CORE and CPU. The CORE
+and CPU voltages shall be in a range of 300mV from each other and CORE
+voltage shall be higher than the CPU by N mV, where N depends on the CPU
+voltage.
+
+Required properties:
+- nvidia,tegra-core-regulator: Boolean property that designates regulator
+  as the "Core domain" voltage regulator.
+- nvidia,tegra-rtc-regulator: Boolean property that designates regulator
+  as the "RTC domain" voltage regulator.
+- nvidia,tegra-cpu-regulator: Boolean property that designates regulator
+  as the "CPU domain" voltage regulator.
+
+Example:
+
+	pmic {
+		regulators {
+			core_vdd_reg: core {
+				regulator-name = "vdd_core";
+				regulator-min-microvolt = <950000>;
+				regulator-max-microvolt = <1300000>;
+				regulator-coupled-with = <&rtc_vdd_reg &cpu_vdd_reg>;
+				regulator-coupled-max-spread = <170000 550000>;
+
+				nvidia,tegra-core-regulator;
+			};
+
+			rtc_vdd_reg: rtc {
+				regulator-name = "vdd_rtc";
+				regulator-min-microvolt = <950000>;
+				regulator-max-microvolt = <1300000>;
+				regulator-coupled-with = <&core_vdd_reg &cpu_vdd_reg>;
+				regulator-coupled-max-spread = <170000 550000>;
+
+				nvidia,tegra-rtc-regulator;
+			};
+
+			cpu_vdd_reg: cpu {
+				regulator-name = "vdd_cpu";
+				regulator-min-microvolt = <750000>;
+				regulator-max-microvolt = <1125000>;
+				regulator-coupled-with = <&core_vdd_reg &rtc_vdd_reg>;
+				regulator-coupled-max-spread = <550000 550000>;
+
+				nvidia,tegra-cpu-regulator;
+			};
+		};
+	};

Signature · 1 line

2.22.0

Dmitry Osipenko

author

2019-06-23 21:08 UTC #6 lore raw

PATCH v3 4/5 soc/tegra: regulators: Add regulators coupler for Tegra20

In reply to Dmitry Osipenko

Add regulators coupler for Tegra20 SoCs that performs voltage balancing of a coupled regulators and thus provides voltage scaling functionality.

There are 3 coupled regulators on all Tegra20 SoCs: CORE, RTC and CPU. The CORE and RTC voltages shall be in range of 170mV from each other and they both shall be higher than the CPU voltage by at least 120mV. This sounds like it could be handle by a generic voltage balancer, but the CORE voltage scaling isn't implemented in any of the upstream drivers yet. It will take quite some time and effort to hook up voltage scaling for all of the drivers, hence we will use a custom coupler that will manage the CPU voltage scaling for the starter.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 drivers/soc/tegra/Kconfig              |   6 +
 drivers/soc/tegra/Makefile             |   1 +
 drivers/soc/tegra/regulators-tegra20.c | 350 +++++++++++++++++++++++++
 3 files changed, 357 insertions(+)
 create mode 100644 drivers/soc/tegra/regulators-tegra20.c

drivers/soc/tegra/Kconfig +6 -0

index c8ef05d6b8c7..539c01012b00 100644
@@ -15,6 +15,7 @@ config ARCH_TEGRA_2x_SOC
 	select PL310_ERRATA_769419 if CACHE_L2X0
 	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
+	select SOC_TEGRA20_VOLTAGE_COUPLER
 	select TEGRA_TIMER
 	help
 	  Support for NVIDIA Tegra AP20 and T20 processors, based on the

@@ -135,3 +136,8 @@ config SOC_TEGRA_POWERGATE_BPMP
 	def_bool y
 	depends on PM_GENERIC_DOMAINS
 	depends on TEGRA_BPMP
+
+config SOC_TEGRA20_VOLTAGE_COUPLER
+	bool "Voltage scaling support for Tegra20 SoCs"
+	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
+

drivers/soc/tegra/Makefile +1 -0

index 902759fe5f4d..9f0bdd53bef8 100644
@@ -5,3 +5,4 @@ obj-y += common.o
 obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o
 obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA_POWERGATE_BPMP) += powergate-bpmp.o
+obj-$(CONFIG_SOC_TEGRA20_VOLTAGE_COUPLER) += regulators-tegra20.o

drivers/soc/tegra/regulators-tegra20.c new file +350 -0

350 lines not on this page · raw message

Signature · 1 line

2.22.0

Dmitry Osipenko

author

2019-06-23 21:08 UTC #7 lore raw

PATCH v3 5/5 soc/tegra: regulators: Add regulators coupler for Tegra30

In reply to Dmitry Osipenko

Add regulators coupler for Tegra30 SoCs that performs voltage balancing of a coupled regulators and thus provides voltage scaling functionality.

There are 2 coupled regulators on all Tegra30 SoCs: CORE and CPU. The coupled regulator voltages shall be in a range of 300mV from each other and CORE voltage shall be higher than the CPU by N mV, where N depends on the CPU voltage.

Signed-off-by Dmitry Osipenko <[email protected]>

---
 drivers/soc/tegra/Kconfig              |   4 +
 drivers/soc/tegra/Makefile             |   1 +
 drivers/soc/tegra/regulators-tegra30.c | 302 +++++++++++++++++++++++++
 3 files changed, 307 insertions(+)
 create mode 100644 drivers/soc/tegra/regulators-tegra30.c

drivers/soc/tegra/Kconfig +4 -0

index 539c01012b00..84bd615c4a92 100644
@@ -29,6 +29,7 @@ config ARCH_TEGRA_3x_SOC
 	select PL310_ERRATA_769419 if CACHE_L2X0
 	select SOC_TEGRA_FLOWCTRL
 	select SOC_TEGRA_PMC
+	select SOC_TEGRA30_VOLTAGE_COUPLER
 	select TEGRA_TIMER
 	help
 	  Support for NVIDIA Tegra T30 processor family, based on the

@@ -141,3 +142,6 @@ config SOC_TEGRA20_VOLTAGE_COUPLER
 	bool "Voltage scaling support for Tegra20 SoCs"
 	depends on ARCH_TEGRA_2x_SOC || COMPILE_TEST
 
+config SOC_TEGRA30_VOLTAGE_COUPLER
+	bool "Voltage scaling support for Tegra30 SoCs"
+	depends on ARCH_TEGRA_3x_SOC || COMPILE_TEST

drivers/soc/tegra/Makefile +1 -0

index 9f0bdd53bef8..9c809c1814bd 100644
@@ -6,3 +6,4 @@ obj-$(CONFIG_SOC_TEGRA_FLOWCTRL) += flowctrl.o
 obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA_POWERGATE_BPMP) += powergate-bpmp.o
 obj-$(CONFIG_SOC_TEGRA20_VOLTAGE_COUPLER) += regulators-tegra20.o
+obj-$(CONFIG_SOC_TEGRA30_VOLTAGE_COUPLER) += regulators-tegra30.o

drivers/soc/tegra/regulators-tegra30.c new file +302 -0

302 lines not on this page · raw message

Signature · 1 line

2.22.0