pinctrl: core: Use delayed work for hogs

Having the pin control framework call pin controller functions
before it's probe has finished is not nice as the pin controller
device driver does not yet have struct pinctrl_dev handle.

Let's fix this issue by adding deferred work for late init. This is
needed to be able to add pinctrl generic helper functions that expect
to know struct pinctrl_dev handle. Note that we now need to call
create_pinctrl() directly as we don't want to add the pin controller
to the list of controllers until the hogs are claimed. We also need
to pass the pinctrl_dev to the device tree parser functions as they
otherwise won't find the right controller at this point.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 58 insertions, 32 deletions

diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index fb38e208f32d..d02e8def9506 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -720,7 +720,8 @@ static struct pinctrl_state *create_state(struct pinctrl *p,
 	return state;
 }
 
-static int add_setting(struct pinctrl *p, struct pinctrl_map const *map)
+static int add_setting(struct pinctrl *p, struct pinctrl_dev *pctldev,
+		       struct pinctrl_map const *map)
 {
 	struct pinctrl_state *state;
 	struct pinctrl_setting *setting;
@@ -744,7 +745,11 @@ static int add_setting(struct pinctrl *p, struct pinctrl_map const *map)
 
 	setting->type = map->type;
 
-	setting->pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
+	if (pctldev)
+		setting->pctldev = pctldev;
+	else
+		setting->pctldev =
+			get_pinctrl_dev_from_devname(map->ctrl_dev_name);
 	if (setting->pctldev == NULL) {
 		kfree(setting);
 		/* Do not defer probing of hogs (circular loop) */
@@ -800,7 +805,8 @@ static struct pinctrl *find_pinctrl(struct device *dev)
 
 static void pinctrl_free(struct pinctrl *p, bool inlist);
 
-static struct pinctrl *create_pinctrl(struct device *dev)
+static struct pinctrl *create_pinctrl(struct device *dev,
+				      struct pinctrl_dev *pctldev)
 {
 	struct pinctrl *p;
 	const char *devname;
@@ -823,7 +829,7 @@ static struct pinctrl *create_pinctrl(struct device *dev)
 	INIT_LIST_HEAD(&p->states);
 	INIT_LIST_HEAD(&p->dt_maps);
 
-	ret = pinctrl_dt_to_map(p);
+	ret = pinctrl_dt_to_map(p, pctldev);
 	if (ret < 0) {
 		kfree(p);
 		return ERR_PTR(ret);
@@ -838,7 +844,7 @@ static struct pinctrl *create_pinctrl(struct device *dev)
 		if (strcmp(map->dev_name, devname))
 			continue;
 
-		ret = add_setting(p, map);
+		ret = add_setting(p, pctldev, map);
 		/*
 		 * At this point the adding of a setting may:
 		 *
@@ -899,7 +905,7 @@ struct pinctrl *pinctrl_get(struct device *dev)
 		return p;
 	}
 
-	return create_pinctrl(dev);
+	return create_pinctrl(dev, NULL);
 }
 EXPORT_SYMBOL_GPL(pinctrl_get);
 
@@ -1738,6 +1744,46 @@ static int pinctrl_check_ops(struct pinctrl_dev *pctldev)
 }
 
 /**
+ * pinctrl_late_init() - finish pin controller device registration
+ * @work: work struct
+ */
+static void pinctrl_late_init(struct work_struct *work)
+{
+	struct pinctrl_dev *pctldev;
+
+	pctldev = container_of(work, struct pinctrl_dev, late_init.work);
+
+	pctldev->p = create_pinctrl(pctldev->dev, pctldev);
+	if (!IS_ERR(pctldev->p)) {
+		kref_get(&pctldev->p->users);
+		pctldev->hog_default =
+			pinctrl_lookup_state(pctldev->p, PINCTRL_STATE_DEFAULT);
+		if (IS_ERR(pctldev->hog_default)) {
+			dev_dbg(pctldev->dev,
+				"failed to lookup the default state\n");
+		} else {
+			if (pinctrl_select_state(pctldev->p,
+						 pctldev->hog_default))
+				dev_err(pctldev->dev,
+					"failed to select default state\n");
+		}
+
+		pctldev->hog_sleep =
+			pinctrl_lookup_state(pctldev->p,
+					     PINCTRL_STATE_SLEEP);
+		if (IS_ERR(pctldev->hog_sleep))
+			dev_dbg(pctldev->dev,
+				"failed to lookup the sleep state\n");
+	}
+
+	mutex_lock(&pinctrldev_list_mutex);
+	list_add_tail(&pctldev->node, &pinctrldev_list);
+	mutex_unlock(&pinctrldev_list_mutex);
+
+	pinctrl_init_device_debugfs(pctldev);
+}
+
+/**
  * pinctrl_register() - register a pin controller device
  * @pctldesc: descriptor for this pin controller
  * @dev: parent device for this pin controller
@@ -1766,6 +1812,7 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
 	pctldev->driver_data = driver_data;
 	INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
 	INIT_LIST_HEAD(&pctldev->gpio_ranges);
+	INIT_DELAYED_WORK(&pctldev->late_init, pinctrl_late_init);
 	pctldev->dev = dev;
 	mutex_init(&pctldev->mutex);
 
@@ -1800,32 +1847,10 @@ struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
 		goto out_err;
 	}
 
-	mutex_lock(&pinctrldev_list_mutex);
-	list_add_tail(&pctldev->node, &pinctrldev_list);
-	mutex_unlock(&pinctrldev_list_mutex);
-
-	pctldev->p = pinctrl_get(pctldev->dev);
-
-	if (!IS_ERR(pctldev->p)) {
-		pctldev->hog_default =
-			pinctrl_lookup_state(pctldev->p, PINCTRL_STATE_DEFAULT);
-		if (IS_ERR(pctldev->hog_default)) {
-			dev_dbg(dev, "failed to lookup the default state\n");
-		} else {
-			if (pinctrl_select_state(pctldev->p,
-						pctldev->hog_default))
-				dev_err(dev,
-					"failed to select default state\n");
-		}
-
-		pctldev->hog_sleep =
-			pinctrl_lookup_state(pctldev->p,
-						    PINCTRL_STATE_SLEEP);
-		if (IS_ERR(pctldev->hog_sleep))
-			dev_dbg(dev, "failed to lookup the sleep state\n");
-	}
-
-	pinctrl_init_device_debugfs(pctldev);
+	if (pinctrl_dt_has_hogs(pctldev))
+		schedule_delayed_work(&pctldev->late_init, 0);
+	else
+		pinctrl_late_init(&pctldev->late_init.work);
 
 	return pctldev;
 
@@ -1848,6 +1873,7 @@ void pinctrl_unregister(struct pinctrl_dev *pctldev)
 	if (pctldev == NULL)
 		return;
 
+	cancel_delayed_work_sync(&pctldev->late_init);
 	mutex_lock(&pctldev->mutex);
 	pinctrl_remove_device_debugfs(pctldev);
 	mutex_unlock(&pctldev->mutex);