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Diffstat (limited to 'drivers/pinctrl/core.c')
-rw-r--r--drivers/pinctrl/core.c118
1 files changed, 91 insertions, 27 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index 59f5a965bdc4..b0de6e7f1fdb 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -14,6 +14,7 @@
#define pr_fmt(fmt) "pinctrl core: " fmt
#include <linux/kernel.h>
+#include <linux/kref.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/device.h>
@@ -31,17 +32,6 @@
#include "pinmux.h"
#include "pinconf.h"
-/**
- * struct pinctrl_maps - a list item containing part of the mapping table
- * @node: mapping table list node
- * @maps: array of mapping table entries
- * @num_maps: the number of entries in @maps
- */
-struct pinctrl_maps {
- struct list_head node;
- struct pinctrl_map const *maps;
- unsigned num_maps;
-};
static bool pinctrl_dummy_state;
@@ -55,13 +45,8 @@ LIST_HEAD(pinctrldev_list);
static LIST_HEAD(pinctrl_list);
/* List of pinctrl maps (struct pinctrl_maps) */
-static LIST_HEAD(pinctrl_maps);
+LIST_HEAD(pinctrl_maps);
-#define for_each_maps(_maps_node_, _i_, _map_) \
- list_for_each_entry(_maps_node_, &pinctrl_maps, node) \
- for (_i_ = 0, _map_ = &_maps_node_->maps[_i_]; \
- _i_ < _maps_node_->num_maps; \
- _i_++, _map_ = &_maps_node_->maps[_i_])
/**
* pinctrl_provide_dummies() - indicate if pinctrl provides dummy state support
@@ -83,6 +68,12 @@ const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev)
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_name);
+const char *pinctrl_dev_get_devname(struct pinctrl_dev *pctldev)
+{
+ return dev_name(pctldev->dev);
+}
+EXPORT_SYMBOL_GPL(pinctrl_dev_get_devname);
+
void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev)
{
return pctldev->driver_data;
@@ -609,13 +600,16 @@ static int add_setting(struct pinctrl *p, struct pinctrl_map const *map)
setting->pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
if (setting->pctldev == NULL) {
- dev_info(p->dev, "unknown pinctrl device %s in map entry, deferring probe",
- map->ctrl_dev_name);
kfree(setting);
+ /* Do not defer probing of hogs (circular loop) */
+ if (!strcmp(map->ctrl_dev_name, map->dev_name))
+ return -ENODEV;
/*
* OK let us guess that the driver is not there yet, and
* let's defer obtaining this pinctrl handle to later...
*/
+ dev_info(p->dev, "unknown pinctrl device %s in map entry, deferring probe",
+ map->ctrl_dev_name);
return -EPROBE_DEFER;
}
@@ -694,11 +688,31 @@ static struct pinctrl *create_pinctrl(struct device *dev)
continue;
ret = add_setting(p, map);
- if (ret < 0) {
+ /*
+ * At this point the adding of a setting may:
+ *
+ * - Defer, if the pinctrl device is not yet available
+ * - Fail, if the pinctrl device is not yet available,
+ * AND the setting is a hog. We cannot defer that, since
+ * the hog will kick in immediately after the device
+ * is registered.
+ *
+ * If the error returned was not -EPROBE_DEFER then we
+ * accumulate the errors to see if we end up with
+ * an -EPROBE_DEFER later, as that is the worst case.
+ */
+ if (ret == -EPROBE_DEFER) {
pinctrl_put_locked(p, false);
return ERR_PTR(ret);
}
}
+ if (ret < 0) {
+ /* If some other error than deferral occured, return here */
+ pinctrl_put_locked(p, false);
+ return ERR_PTR(ret);
+ }
+
+ kref_init(&p->users);
/* Add the pinctrl handle to the global list */
list_add_tail(&p->node, &pinctrl_list);
@@ -713,9 +727,17 @@ static struct pinctrl *pinctrl_get_locked(struct device *dev)
if (WARN_ON(!dev))
return ERR_PTR(-EINVAL);
+ /*
+ * See if somebody else (such as the device core) has already
+ * obtained a handle to the pinctrl for this device. In that case,
+ * return another pointer to it.
+ */
p = find_pinctrl(dev);
- if (p != NULL)
- return ERR_PTR(-EBUSY);
+ if (p != NULL) {
+ dev_dbg(dev, "obtain a copy of previously claimed pinctrl\n");
+ kref_get(&p->users);
+ return p;
+ }
return create_pinctrl(dev);
}
@@ -771,13 +793,24 @@ static void pinctrl_put_locked(struct pinctrl *p, bool inlist)
}
/**
- * pinctrl_put() - release a previously claimed pinctrl handle
+ * pinctrl_release() - release the pinctrl handle
+ * @kref: the kref in the pinctrl being released
+ */
+static void pinctrl_release(struct kref *kref)
+{
+ struct pinctrl *p = container_of(kref, struct pinctrl, users);
+
+ pinctrl_put_locked(p, true);
+}
+
+/**
+ * pinctrl_put() - decrease use count on a previously claimed pinctrl handle
* @p: the pinctrl handle to release
*/
void pinctrl_put(struct pinctrl *p)
{
mutex_lock(&pinctrl_mutex);
- pinctrl_put_locked(p, true);
+ kref_put(&p->users, pinctrl_release);
mutex_unlock(&pinctrl_mutex);
}
EXPORT_SYMBOL_GPL(pinctrl_put);
@@ -1055,6 +1088,30 @@ void pinctrl_unregister_map(struct pinctrl_map const *map)
}
}
+/**
+ * pinctrl_force_sleep() - turn a given controller device into sleep state
+ * @pctldev: pin controller device
+ */
+int pinctrl_force_sleep(struct pinctrl_dev *pctldev)
+{
+ if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_sleep))
+ return pinctrl_select_state(pctldev->p, pctldev->hog_sleep);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pinctrl_force_sleep);
+
+/**
+ * pinctrl_force_default() - turn a given controller device into default state
+ * @pctldev: pin controller device
+ */
+int pinctrl_force_default(struct pinctrl_dev *pctldev)
+{
+ if (!IS_ERR(pctldev->p) && !IS_ERR(pctldev->hog_default))
+ return pinctrl_select_state(pctldev->p, pctldev->hog_default);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pinctrl_force_default);
+
#ifdef CONFIG_DEBUG_FS
static int pinctrl_pins_show(struct seq_file *s, void *what)
@@ -1500,16 +1557,23 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
pctldev->p = pinctrl_get_locked(pctldev->dev);
if (!IS_ERR(pctldev->p)) {
- struct pinctrl_state *s =
+ pctldev->hog_default =
pinctrl_lookup_state_locked(pctldev->p,
PINCTRL_STATE_DEFAULT);
- if (IS_ERR(s)) {
+ if (IS_ERR(pctldev->hog_default)) {
dev_dbg(dev, "failed to lookup the default state\n");
} else {
- if (pinctrl_select_state_locked(pctldev->p, s))
+ if (pinctrl_select_state_locked(pctldev->p,
+ pctldev->hog_default))
dev_err(dev,
"failed to select default state\n");
}
+
+ pctldev->hog_sleep =
+ pinctrl_lookup_state_locked(pctldev->p,
+ PINCTRL_STATE_SLEEP);
+ if (IS_ERR(pctldev->hog_sleep))
+ dev_dbg(dev, "failed to lookup the sleep state\n");
}
mutex_unlock(&pinctrl_mutex);