of_regulator.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* OF helpers for regulator framework
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Rajendra Nayak <rnayak@ti.com>
*/
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include "internal.h"
static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
[PM_SUSPEND_STANDBY] = "regulator-state-standby",
[PM_SUSPEND_MEM] = "regulator-state-mem",
[PM_SUSPEND_MAX] = "regulator-state-disk",
};
static int of_get_regulation_constraints(struct device *dev,
struct device_node *np,
struct regulator_init_data **init_data,
const struct regulator_desc *desc)
{
struct regulation_constraints *constraints = &(*init_data)->constraints;
struct regulator_state *suspend_state;
struct device_node *suspend_np;
unsigned int mode;
int ret, i, len;
int n_phandles;
u32 pval;
n_phandles = of_count_phandle_with_args(np, "regulator-coupled-with",
NULL);
n_phandles = max(n_phandles, 0);
constraints->name = of_get_property(np, "regulator-name", NULL);
if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
constraints->min_uV = pval;
if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
constraints->max_uV = pval;
/* Voltage change possible? */
if (constraints->min_uV != constraints->max_uV)
constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
/* Do we have a voltage range, if so try to apply it? */
if (constraints->min_uV && constraints->max_uV)
constraints->apply_uV = true;
if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
constraints->uV_offset = pval;
if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
constraints->min_uA = pval;
if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
constraints->max_uA = pval;
if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
&pval))
constraints->ilim_uA = pval;
/* Current change possible? */
if (constraints->min_uA != constraints->max_uA)
constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
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. */
constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
if (of_property_read_bool(np, "regulator-allow-bypass"))
constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
if (of_property_read_bool(np, "regulator-allow-set-load"))
constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
if (!ret) {
if (pval)
constraints->ramp_delay = pval;
else
constraints->ramp_disable = true;
}
ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
if (!ret)
constraints->settling_time = pval;
ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
if (!ret)
constraints->settling_time_up = pval;
if (constraints->settling_time_up && constraints->settling_time) {
pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
np);
constraints->settling_time_up = 0;
}
ret = of_property_read_u32(np, "regulator-settling-time-down-us",
&pval);
if (!ret)
constraints->settling_time_down = pval;
if (constraints->settling_time_down && constraints->settling_time) {
pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
np);
constraints->settling_time_down = 0;
}
ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
if (!ret)
constraints->enable_time = pval;
constraints->soft_start = of_property_read_bool(np,
"regulator-soft-start");
ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
if (!ret) {
constraints->active_discharge =
(pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
REGULATOR_ACTIVE_DISCHARGE_DISABLE;
}
if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
if (desc && desc->of_map_mode) {
mode = desc->of_map_mode(pval);
if (mode == REGULATOR_MODE_INVALID)
pr_err("%pOFn: invalid mode %u\n", np, pval);
else
constraints->initial_mode = mode;
} else {
pr_warn("%pOFn: mapping for mode %d not defined\n",
np, pval);
}
}
len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
sizeof(u32));
if (len > 0) {
if (desc && desc->of_map_mode) {
for (i = 0; i < len; i++) {
ret = of_property_read_u32_index(np,
"regulator-allowed-modes", i, &pval);
if (ret) {
pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
np, i, ret);
break;
}
mode = desc->of_map_mode(pval);
if (mode == REGULATOR_MODE_INVALID)
pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
np, pval);
else
constraints->valid_modes_mask |= mode;
}
if (constraints->valid_modes_mask)
constraints->valid_ops_mask
|= REGULATOR_CHANGE_MODE;
} else {
pr_warn("%pOFn: mode mapping not defined\n", np);
}
}
if (!of_property_read_u32(np, "regulator-system-load", &pval))
constraints->system_load = pval;
if (n_phandles) {
constraints->max_spread = devm_kzalloc(dev,
sizeof(*constraints->max_spread) * n_phandles,
GFP_KERNEL);
if (!constraints->max_spread)
return -ENOMEM;
of_property_read_u32_array(np, "regulator-coupled-max-spread",
constraints->max_spread, n_phandles);
}
if (!of_property_read_u32(np, "regulator-max-step-microvolt",
&pval))
constraints->max_uV_step = pval;
constraints->over_current_protection = of_property_read_bool(np,
"regulator-over-current-protection");
for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
switch (i) {
case PM_SUSPEND_MEM:
suspend_state = &constraints->state_mem;
break;
case PM_SUSPEND_MAX:
suspend_state = &constraints->state_disk;
break;
case PM_SUSPEND_STANDBY:
suspend_state = &constraints->state_standby;
break;
case PM_SUSPEND_ON:
case PM_SUSPEND_TO_IDLE:
default:
continue;
}
suspend_np = of_get_child_by_name(np, regulator_states[i]);
if (!suspend_np || !suspend_state)
continue;
if (!of_property_read_u32(suspend_np, "regulator-mode",
&pval)) {
if (desc && desc->of_map_mode) {
mode = desc->of_map_mode(pval);
if (mode == REGULATOR_MODE_INVALID)
pr_err("%pOFn: invalid mode %u\n",
np, pval);
else
suspend_state->mode = mode;
} else {
pr_warn("%pOFn: mapping for mode %d not defined\n",
np, pval);
}
}
if (of_property_read_bool(suspend_np,
"regulator-on-in-suspend"))
suspend_state->enabled = ENABLE_IN_SUSPEND;
else if (of_property_read_bool(suspend_np,
"regulator-off-in-suspend"))
suspend_state->enabled = DISABLE_IN_SUSPEND;
if (!of_property_read_u32(suspend_np,
"regulator-suspend-min-microvolt", &pval))
suspend_state->min_uV = pval;
if (!of_property_read_u32(suspend_np,
"regulator-suspend-max-microvolt", &pval))
suspend_state->max_uV = pval;
if (!of_property_read_u32(suspend_np,
"regulator-suspend-microvolt", &pval))
suspend_state->uV = pval;
else /* otherwise use min_uV as default suspend voltage */
suspend_state->uV = suspend_state->min_uV;
if (of_property_read_bool(suspend_np,
"regulator-changeable-in-suspend"))
suspend_state->changeable = true;
if (i == PM_SUSPEND_MEM)
constraints->initial_state = PM_SUSPEND_MEM;
of_node_put(suspend_np);
suspend_state = NULL;
suspend_np = NULL;
}
return 0;
}
/**
* of_get_regulator_init_data - extract regulator_init_data structure info
* @dev: device requesting for regulator_init_data
* @node: regulator device node
* @desc: regulator description
*
* Populates regulator_init_data structure by extracting data from device
* tree node, returns a pointer to the populated structure or NULL if memory
* alloc fails.
*/
struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
struct device_node *node,
const struct regulator_desc *desc)
{
struct regulator_init_data *init_data;
if (!node)
return NULL;
init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
if (!init_data)
return NULL; /* Out of memory? */
if (of_get_regulation_constraints(dev, node, &init_data, desc))
return NULL;
return init_data;
}
EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
struct devm_of_regulator_matches {
struct of_regulator_match *matches;
unsigned int num_matches;
};
static void devm_of_regulator_put_matches(struct device *dev, void *res)
{
struct devm_of_regulator_matches *devm_matches = res;
int i;
for (i = 0; i < devm_matches->num_matches; i++)
of_node_put(devm_matches->matches[i].of_node);
}
/**
* of_regulator_match - extract multiple regulator init data from device tree.
* @dev: device requesting the data
* @node: parent device node of the regulators
* @matches: match table for the regulators
* @num_matches: number of entries in match table
*
* This function uses a match table specified by the regulator driver to
* parse regulator init data from the device tree. @node is expected to
* contain a set of child nodes, each providing the init data for one
* regulator. The data parsed from a child node will be matched to a regulator
* based on either the deprecated property regulator-compatible if present,
* or otherwise the child node's name. Note that the match table is modified
* in place and an additional of_node reference is taken for each matched
* regulator.
*
* Returns the number of matches found or a negative error code on failure.
*/
int of_regulator_match(struct device *dev, struct device_node *node,
struct of_regulator_match *matches,
unsigned int num_matches)
{
unsigned int count = 0;
unsigned int i;
const char *name;
struct device_node *child;
struct devm_of_regulator_matches *devm_matches;
if (!dev || !node)
return -EINVAL;
devm_matches = devres_alloc(devm_of_regulator_put_matches,
sizeof(struct devm_of_regulator_matches),
GFP_KERNEL);
if (!devm_matches)
return -ENOMEM;
devm_matches->matches = matches;
devm_matches->num_matches = num_matches;
devres_add(dev, devm_matches);
for (i = 0; i < num_matches; i++) {
struct of_regulator_match *match = &matches[i];
match->init_data = NULL;
match->of_node = NULL;
}
for_each_child_of_node(node, child) {
name = of_get_property(child,
"regulator-compatible", NULL);
if (!name)
name = child->name;
for (i = 0; i < num_matches; i++) {
struct of_regulator_match *match = &matches[i];
if (match->of_node)
continue;
if (strcmp(match->name, name))
continue;
match->init_data =
of_get_regulator_init_data(dev, child,
match->desc);
if (!match->init_data) {
dev_err(dev,
"failed to parse DT for regulator %pOFn\n",
child);
of_node_put(child);
return -EINVAL;
}
match->of_node = of_node_get(child);
count++;
break;
}
}
return count;
}
EXPORT_SYMBOL_GPL(of_regulator_match);
static struct
device_node *regulator_of_get_init_node(struct device *dev,
const struct regulator_desc *desc)
{
struct device_node *search, *child;
const char *name;
if (!dev->of_node || !desc->of_match)
return NULL;
if (desc->regulators_node) {
search = of_get_child_by_name(dev->of_node,
desc->regulators_node);
} else {
search = of_node_get(dev->of_node);
if (!strcmp(desc->of_match, search->name))
return search;
}
if (!search) {
dev_dbg(dev, "Failed to find regulator container node '%s'\n",
desc->regulators_node);
return NULL;
}
for_each_available_child_of_node(search, child) {
name = of_get_property(child, "regulator-compatible", NULL);
if (!name) {
if (!desc->of_match_full_name)
name = child->name;
else
name = child->full_name;
}
if (!strcmp(desc->of_match, name)) {
of_node_put(search);
return of_node_get(child);
}
}
of_node_put(search);
return NULL;
}
struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
const struct regulator_desc *desc,
struct regulator_config *config,
struct device_node **node)
{
struct device_node *child;
struct regulator_init_data *init_data = NULL;
child = regulator_of_get_init_node(dev, desc);
if (!child)
return NULL;
init_data = of_get_regulator_init_data(dev, child, desc);
if (!init_data) {
dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
goto error;
}
if (desc->of_parse_cb) {
int ret;
ret = desc->of_parse_cb(child, desc, config);
if (ret) {
if (ret == -EPROBE_DEFER) {
of_node_put(child);
return ERR_PTR(-EPROBE_DEFER);
}
dev_err(dev,
"driver callback failed to parse DT for regulator %pOFn\n",
child);
goto error;
}
}
*node = child;
return init_data;
error:
of_node_put(child);
return NULL;
}
struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
{
struct device *dev;
dev = class_find_device_by_of_node(®ulator_class, np);
return dev ? dev_to_rdev(dev) : NULL;
}
/*
* Returns number of regulators coupled with rdev.
*/
int of_get_n_coupled(struct regulator_dev *rdev)
{
struct device_node *node = rdev->dev.of_node;
int n_phandles;
n_phandles = of_count_phandle_with_args(node,
"regulator-coupled-with",
NULL);
return (n_phandles > 0) ? n_phandles : 0;
}
/* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
static bool of_coupling_find_node(struct device_node *src,
struct device_node *to_find,
int *index)
{
int n_phandles, i;
bool found = false;
n_phandles = of_count_phandle_with_args(src,
"regulator-coupled-with",
NULL);
for (i = 0; i < n_phandles; i++) {
struct device_node *tmp = of_parse_phandle(src,
"regulator-coupled-with", i);
if (!tmp)
break;
/* found */
if (tmp == to_find)
found = true;
of_node_put(tmp);
if (found) {
*index = i;
break;
}
}
return found;
}
/**
* of_check_coupling_data - Parse rdev's coupling properties and check data
* consistency
* @rdev: pointer to regulator_dev whose data is checked
*
* Function checks if all the following conditions are met:
* - rdev's max_spread is greater than 0
* - all coupled regulators have the same max_spread
* - all coupled regulators have the same number of regulator_dev phandles
* - all regulators are linked to each other
*
* Returns true if all conditions are met.
*/
bool of_check_coupling_data(struct regulator_dev *rdev)
{
struct device_node *node = rdev->dev.of_node;
int n_phandles = of_get_n_coupled(rdev);
struct device_node *c_node;
int index;
int i;
bool ret = true;
/* iterate over rdev's phandles */
for (i = 0; i < n_phandles; i++) {
int max_spread = rdev->constraints->max_spread[i];
int c_max_spread, c_n_phandles;
if (max_spread <= 0) {
dev_err(&rdev->dev, "max_spread value invalid\n");
return false;
}
c_node = of_parse_phandle(node,
"regulator-coupled-with", i);
if (!c_node)
ret = false;
c_n_phandles = of_count_phandle_with_args(c_node,
"regulator-coupled-with",
NULL);
if (c_n_phandles != n_phandles) {
dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
ret = false;
goto clean;
}
if (!of_coupling_find_node(c_node, node, &index)) {
dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
ret = false;
goto clean;
}
if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
index, &c_max_spread)) {
ret = false;
goto clean;
}
if (c_max_spread != max_spread) {
dev_err(&rdev->dev,
"coupled regulators max_spread mismatch\n");
ret = false;
goto clean;
}
clean:
of_node_put(c_node);
if (!ret)
break;
}
return ret;
}
/**
* of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
* @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
* "regulator-coupled-with" property
* @index: Index in phandles array
*
* Returns the regulator_dev pointer parsed from DTS. If it has not been yet
* registered, returns NULL
*/
struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
int index)
{
struct device_node *node = rdev->dev.of_node;
struct device_node *c_node;
struct regulator_dev *c_rdev;
c_node = of_parse_phandle(node, "regulator-coupled-with", index);
if (!c_node)
return NULL;
c_rdev = of_find_regulator_by_node(c_node);
of_node_put(c_node);
return c_rdev;
}