[PATCH v6 07/22] regulator: core: Remove regulator_list

From: Tomeu Vizoso
Date: Mon Sep 21 2015 - 10:10:23 EST

As we are already registering a device with regulator_class for each
regulator device, regulator_list is redundant and can be replaced with
calls to class_find_device() and class_for_each_device().

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
---

Changes in v6:
- Merge changes to the regulator subsystem's locking so no references
are leaked between commits.

Changes in v5:
- Use regulator_class' klist of devices instead of regulator_list to
store and lookup regulator devices.

drivers/regulator/core.c | 255 ++++++++++++++++++++++++++++++-----------------
1 file changed, 164 insertions(+), 91 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index e5dbbe2f5212..af045e5a83ef 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -51,7 +51,6 @@
pr_debug("%s: " fmt, rdev_get_name(rdev), ##__VA_ARGS__)

static DEFINE_MUTEX(regulator_list_mutex);
-static LIST_HEAD(regulator_list);
static LIST_HEAD(regulator_map_list);
static LIST_HEAD(regulator_ena_gpio_list);
static LIST_HEAD(regulator_supply_alias_list);
@@ -59,6 +58,8 @@ static bool has_full_constraints;

static struct dentry *debugfs_root;

+static struct class regulator_class;
+
/*
* struct regulator_map
*
@@ -1325,6 +1326,47 @@ static void regulator_supply_alias(struct device **dev, const char **supply)
}
}

+static int of_node_match(struct device *dev, const void *data)
+{
+ return dev->of_node == data;
+}
+
+static struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
+{
+ struct device *dev;
+
+ dev = class_find_device(&regulator_class, NULL, np, of_node_match);
+
+ return dev ? dev_to_rdev(dev) : NULL;
+}
+
+static int regulator_match(struct device *dev, const void *data)
+{
+ struct regulator_dev *r = dev_to_rdev(dev);
+
+ return strcmp(rdev_get_name(r), data) == 0;
+}
+
+static struct regulator_dev *regulator_lookup_by_name(const char *name)
+{
+ struct device *dev;
+
+ dev = class_find_device(&regulator_class, NULL, name, regulator_match);
+
+ return dev ? dev_to_rdev(dev) : NULL;
+}
+
+/**
+ * regulator_dev_lookup - lookup a regulator device.
+ * @dev: device for regulator "consumer".
+ * @supply: Supply name or regulator ID.
+ * @ret: 0 on success, -ENODEV if lookup fails permanently, -EPROBE_DEFER if
+ * lookup could succeed in the future.
+ *
+ * If successful, returns a struct regulator_dev that corresponds to the name
+ * @supply and with the embedded struct device refcount incremented by one,
+ * or NULL on failure. The refcount must be dropped by calling put_device().
+ */
static struct regulator_dev *regulator_dev_lookup(struct device *dev,
const char *supply,
int *ret)
@@ -1340,10 +1382,9 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
if (dev && dev->of_node) {
node = of_get_regulator(dev, supply);
if (node) {
- list_for_each_entry(r, &regulator_list, list)
- if (r->dev.parent &&
- node == r->dev.of_node)
- return r;
+ r = of_find_regulator_by_node(node);
+ if (r)
+ return r;
*ret = -EPROBE_DEFER;
return NULL;
} else {
@@ -1361,20 +1402,24 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
if (dev)
devname = dev_name(dev);

- list_for_each_entry(r, &regulator_list, list)
- if (strcmp(rdev_get_name(r), supply) == 0)
- return r;
+ r = regulator_lookup_by_name(supply);
+ if (r)
+ return r;

+ mutex_lock(&regulator_list_mutex);
list_for_each_entry(map, &regulator_map_list, list) {
/* If the mapping has a device set up it must match */
if (map->dev_name &&
(!devname || strcmp(map->dev_name, devname)))
continue;

- if (strcmp(map->supply, supply) == 0)
+ if (strcmp(map->supply, supply) == 0 &&
+ get_device(&map->regulator->dev)) {
+ mutex_unlock(&regulator_list_mutex);
return map->regulator;
+ }
}
-
+ mutex_unlock(&regulator_list_mutex);

return NULL;
}
@@ -1405,6 +1450,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)

if (have_full_constraints()) {
r = dummy_regulator_rdev;
+ get_device(&r->dev);
} else {
dev_err(dev, "Failed to resolve %s-supply for %s\n",
rdev->supply_name, rdev->desc->name);
@@ -1414,12 +1460,16 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)

/* Recursively resolve the supply of the supply */
ret = regulator_resolve_supply(r);
- if (ret < 0)
+ if (ret < 0) {
+ put_device(&r->dev);
return ret;
+ }

ret = set_supply(rdev, r);
- if (ret < 0)
+ if (ret < 0) {
+ put_device(&r->dev);
return ret;
+ }

/* Cascade always-on state to supply */
if (_regulator_is_enabled(rdev) && rdev->supply) {
@@ -1455,8 +1505,6 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
else
ret = -EPROBE_DEFER;

- mutex_lock(&regulator_list_mutex);
-
rdev = regulator_dev_lookup(dev, id, &ret);
if (rdev)
goto found;
@@ -1468,7 +1516,7 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
* succeed, so, quit with appropriate error value
*/
if (ret && ret != -ENODEV)
- goto out;
+ return regulator;

if (!devname)
devname = "deviceless";
@@ -1482,40 +1530,46 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
devname, id);

rdev = dummy_regulator_rdev;
+ get_device(&rdev->dev);
goto found;
/* Don't log an error when called from regulator_get_optional() */
} else if (!have_full_constraints() || exclusive) {
dev_warn(dev, "dummy supplies not allowed\n");
}

- mutex_unlock(&regulator_list_mutex);
return regulator;

found:
if (rdev->exclusive) {
regulator = ERR_PTR(-EPERM);
- goto out;
+ put_device(&rdev->dev);
+ return regulator;
}

if (exclusive && rdev->open_count) {
regulator = ERR_PTR(-EBUSY);
- goto out;
+ put_device(&rdev->dev);
+ return regulator;
}

ret = regulator_resolve_supply(rdev);
if (ret < 0) {
regulator = ERR_PTR(ret);
- goto out;
+ put_device(&rdev->dev);
+ return regulator;
}

- if (!try_module_get(rdev->owner))
- goto out;
+ if (!try_module_get(rdev->owner)) {
+ put_device(&rdev->dev);
+ return regulator;
+ }

regulator = create_regulator(rdev, dev, id);
if (regulator == NULL) {
regulator = ERR_PTR(-ENOMEM);
+ put_device(&rdev->dev);
module_put(rdev->owner);
- goto out;
+ return regulator;
}

rdev->open_count++;
@@ -1529,9 +1583,6 @@ found:
rdev->use_count = 0;
}

-out:
- mutex_unlock(&regulator_list_mutex);
-
return regulator;
}

@@ -1629,6 +1680,7 @@ static void _regulator_put(struct regulator *regulator)

rdev->open_count--;
rdev->exclusive = 0;
+ put_device(&rdev->dev);
mutex_unlock(&rdev->mutex);

kfree(regulator->supply_name);
@@ -3806,8 +3858,6 @@ regulator_register(const struct regulator_desc *regulator_desc,
}
}

- list_add(&rdev->list, &regulator_list);
-
rdev_init_debugfs(rdev);
out:
mutex_unlock(&regulator_list_mutex);
@@ -3861,6 +3911,19 @@ void regulator_unregister(struct regulator_dev *rdev)
}
EXPORT_SYMBOL_GPL(regulator_unregister);

+static int _regulator_suspend_prepare(struct device *dev, void *data)
+{
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ const suspend_state_t *state = data;
+ int ret;
+
+ mutex_lock(&rdev->mutex);
+ ret = suspend_prepare(rdev, *state);
+ mutex_unlock(&rdev->mutex);
+
+ return ret;
+}
+
/**
* regulator_suspend_prepare - prepare regulators for system wide suspend
* @state: system suspend state
@@ -3870,30 +3933,45 @@ EXPORT_SYMBOL_GPL(regulator_unregister);
*/
int regulator_suspend_prepare(suspend_state_t state)
{
- struct regulator_dev *rdev;
- int ret = 0;
-
/* ON is handled by regulator active state */
if (state == PM_SUSPEND_ON)
return -EINVAL;

- mutex_lock(&regulator_list_mutex);
- list_for_each_entry(rdev, &regulator_list, list) {
+ return class_for_each_device(&regulator_class, NULL, &state,
+ _regulator_suspend_prepare);
+}
+EXPORT_SYMBOL_GPL(regulator_suspend_prepare);

- mutex_lock(&rdev->mutex);
- ret = suspend_prepare(rdev, state);
- mutex_unlock(&rdev->mutex);
+static int _regulator_suspend_finish(struct device *dev, void *data)
+{
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ int ret;

- if (ret < 0) {
- rdev_err(rdev, "failed to prepare\n");
- goto out;
+ mutex_lock(&rdev->mutex);
+ if (rdev->use_count > 0 || rdev->constraints->always_on) {
+ if (!_regulator_is_enabled(rdev)) {
+ ret = _regulator_do_enable(rdev);
+ if (ret)
+ dev_err(dev,
+ "Failed to resume regulator %d\n",
+ ret);
}
+ } else {
+ if (!have_full_constraints())
+ goto unlock;
+ if (!_regulator_is_enabled(rdev))
+ goto unlock;
+
+ ret = _regulator_do_disable(rdev);
+ if (ret)
+ dev_err(dev, "Failed to suspend regulator %d\n", ret);
}
-out:
- mutex_unlock(&regulator_list_mutex);
- return ret;
+unlock:
+ mutex_unlock(&rdev->mutex);
+
+ /* Keep processing regulators in spite of any errors */
+ return 0;
}
-EXPORT_SYMBOL_GPL(regulator_suspend_prepare);

/**
* regulator_suspend_finish - resume regulators from system wide suspend
@@ -3903,33 +3981,8 @@ EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
*/
int regulator_suspend_finish(void)
{
- struct regulator_dev *rdev;
- int ret = 0, error;
-
- mutex_lock(&regulator_list_mutex);
- list_for_each_entry(rdev, &regulator_list, list) {
- mutex_lock(&rdev->mutex);
- if (rdev->use_count > 0 || rdev->constraints->always_on) {
- if (!_regulator_is_enabled(rdev)) {
- error = _regulator_do_enable(rdev);
- if (error)
- ret = error;
- }
- } else {
- if (!have_full_constraints())
- goto unlock;
- if (!_regulator_is_enabled(rdev))
- goto unlock;
-
- error = _regulator_do_disable(rdev);
- if (error)
- ret = error;
- }
-unlock:
- mutex_unlock(&rdev->mutex);
- }
- mutex_unlock(&regulator_list_mutex);
- return ret;
+ return class_for_each_device(&regulator_class, NULL, NULL,
+ _regulator_suspend_finish);
}
EXPORT_SYMBOL_GPL(regulator_suspend_finish);

@@ -4049,14 +4102,35 @@ static const struct file_operations supply_map_fops = {
};

#ifdef CONFIG_DEBUG_FS
+struct summary_data {
+ struct seq_file *s;
+ struct regulator_dev *parent;
+ int level;
+};
+
+static void regulator_summary_show_subtree(struct seq_file *s,
+ struct regulator_dev *rdev,
+ int level);
+
+static int regulator_summary_show_children(struct device *dev, void *data)
+{
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ struct summary_data *summary_data = data;
+
+ if (rdev->supply && rdev->supply->rdev == summary_data->parent)
+ regulator_summary_show_subtree(summary_data->s, rdev,
+ summary_data->level + 1);
+
+ return 0;
+}
+
static void regulator_summary_show_subtree(struct seq_file *s,
struct regulator_dev *rdev,
int level)
{
- struct list_head *list = s->private;
- struct regulator_dev *child;
struct regulation_constraints *c;
struct regulator *consumer;
+ struct summary_data summary_data;

if (!rdev)
return;
@@ -4106,33 +4180,32 @@ static void regulator_summary_show_subtree(struct seq_file *s,
seq_puts(s, "\n");
}

- list_for_each_entry(child, list, list) {
- /* handle only non-root regulators supplied by current rdev */
- if (!child->supply || child->supply->rdev != rdev)
- continue;
+ summary_data.s = s;
+ summary_data.level = level;
+ summary_data.parent = rdev;

- regulator_summary_show_subtree(s, child, level + 1);
- }
+ class_for_each_device(&regulator_class, NULL, &summary_data,
+ regulator_summary_show_children);
}

-static int regulator_summary_show(struct seq_file *s, void *data)
+static int regulator_summary_show_roots(struct device *dev, void *data)
{
- struct list_head *list = s->private;
- struct regulator_dev *rdev;
-
- seq_puts(s, " regulator use open bypass voltage current min max\n");
- seq_puts(s, "-------------------------------------------------------------------------------\n");
+ struct regulator_dev *rdev = dev_to_rdev(dev);
+ struct seq_file *s = data;

- mutex_lock(&regulator_list_mutex);
+ if (!rdev->supply)
+ regulator_summary_show_subtree(s, rdev, 0);

- list_for_each_entry(rdev, list, list) {
- if (rdev->supply)
- continue;
+ return 0;
+}

- regulator_summary_show_subtree(s, rdev, 0);
- }
+static int regulator_summary_show(struct seq_file *s, void *data)
+{
+ seq_puts(s, " regulator use open bypass voltage current min max\n");
+ seq_puts(s, "-------------------------------------------------------------------------------\n");

- mutex_unlock(&regulator_list_mutex);
+ class_for_each_device(&regulator_class, NULL, s,
+ regulator_summary_show_roots);

return 0;
}
@@ -4166,7 +4239,7 @@ static int __init regulator_init(void)
&supply_map_fops);

debugfs_create_file("regulator_summary", 0444, debugfs_root,
- &regulator_list, &regulator_summary_fops);
+ NULL, &regulator_summary_fops);

regulator_dummy_init();

--
2.4.3

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