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regulator: core: Parse coupled regulators properties

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On Odroid XU3/4 and other Exynos5422 based boards there is a case, that
different devices on the board are supplied by different regulators
with non-fixed voltages. If one of these devices temporarily requires
higher voltage, there might occur a situation that the spread between
devices' voltages is so high, that there is a risk of changing
'high' and 'low' states on the interconnection between devices powered
by those regulators.

Add new structure "coupling_desc" to regulator_dev, which contains
pointers to all coupled regulators including the owner of the structure,
number of coupled regulators and counter of currently resolved
regulators.

Add of_functions to parse all data needed in regulator coupling.
Provide method to check DTS data consistency. Check if each coupled
regulator's max_spread is equal and if their lists of regulators match.

Signed-off-by: Maciej Purski <m.purski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Maciej Purski 2018-04-23 16:33:39 +02:00 committed by Mark Brown
parent f98618b345
commit a085a31af5
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
4 changed files with 199 additions and 2 deletions
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28
drivers/regulator/internal.h
View file

@ -62,6 +62,14 @@ 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 regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
int index);
int of_get_n_coupled(struct regulator_dev *rdev);
bool of_check_coupling_data(struct regulator_dev *rdev);
#else
static inline struct regulator_dev *
of_find_regulator_by_node(struct device_node *np)
@ -77,8 +85,25 @@ regulator_of_get_init_data(struct device *dev,
{
return NULL;
}
#endif
static inline struct regulator_dev *
of_parse_coupled_regulator(struct regulator_dev *rdev,
int index)
{
return NULL;
}
static inline int of_get_n_coupled(struct regulator_dev *rdev)
{
return 0;
}
static inline bool of_check_coupling_data(struct regulator_dev *rdev)
{
return false;
}
#endif
enum regulator_get_type {
NORMAL_GET,
EXCLUSIVE_GET,
@ -88,5 +113,4 @@ enum regulator_get_type {
struct regulator *_regulator_get(struct device *dev, const char *id,
enum regulator_get_type get_type);
#endif

151
drivers/regulator/of_regulator.c
View file

@ -166,6 +166,10 @@ static void of_get_regulation_constraints(struct device_node *np,
if (!of_property_read_u32(np, "regulator-system-load", &pval))
constraints->system_load = pval;
if (!of_property_read_u32(np, "regulator-coupled-max-spread",
&pval))
constraints->max_spread = pval;
constraints->over_current_protection = of_property_read_bool(np,
"regulator-over-current-protection");
@ -435,3 +439,150 @@ struct regulator_dev *of_find_regulator_by_node(struct device_node *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 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)
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)
{
int max_spread = rdev->constraints->max_spread;
struct device_node *node = rdev->dev.of_node;
int n_phandles = of_get_n_coupled(rdev);
struct device_node *c_node;
int i;
bool ret = true;
if (max_spread <= 0) {
dev_err(&rdev->dev, "max_spread value invalid\n");
return false;
}
/* iterate over rdev's phandles */
for (i = 0; i < n_phandles; i++) {
int c_max_spread, c_n_phandles;
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 couped reg phandles mismatch\n");
ret = false;
goto clean;
}
if (of_property_read_u32(c_node, "regulator-coupled-max-spread",
&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;
}
if (!of_coupling_find_node(c_node, node)) {
dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
ret = false;
}
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;
}

18
include/linux/regulator/driver.h
View file

@ -15,6 +15,8 @@
#ifndef __LINUX_REGULATOR_DRIVER_H_
#define __LINUX_REGULATOR_DRIVER_H_
#define MAX_COUPLED 4
#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/regulator/consumer.h>
@ -409,6 +411,20 @@ struct regulator_config {
unsigned int ena_gpio_flags;
};
/*
* struct coupling_desc
*
* Describes coupling of regulators. Each regulator should have
* at least a pointer to itself in coupled_rdevs array.
* When a new coupled regulator is resolved, n_resolved is
* incremented.
*/
struct coupling_desc {
struct regulator_dev *coupled_rdevs[MAX_COUPLED];
int n_resolved;
int n_coupled;
};
/*
* struct regulator_dev
*
@ -432,6 +448,8 @@ struct regulator_dev {
/* lists we own */
struct list_head consumer_list; /* consumers we supply */
struct coupling_desc coupling_desc;
struct blocking_notifier_head notifier;
struct mutex mutex; /* consumer lock */
struct task_struct *mutex_owner;

4
include/linux/regulator/machine.h
View file

@ -103,6 +103,7 @@ struct regulator_state {
* @ilim_uA: Maximum input current.
* @system_load: Load that isn't captured by any consumer requests.
*
* @max_spread: Max possible spread between coupled regulators
* @valid_modes_mask: Mask of modes which may be configured by consumers.
* @valid_ops_mask: Operations which may be performed by consumers.
*
@ -154,6 +155,9 @@ struct regulation_constraints {
int system_load;
/* used for coupled regulators */
int max_spread;
/* valid regulator operating modes for this machine */
unsigned int valid_modes_mask;