reset: modify the way reset lookup works for board files

Commit 7af1bb19f1d7 ("reset: add support for non-DT systems")
introduced reset control lookup mechanism for boards that still use
board files.

The routine used to register lookup entries takes the corresponding
reset_controlled_dev structure as argument.

It's been determined however that for the first user of this new
interface - davinci psc driver - it will be easier to register the
lookup entries using the reset controller device name.

This patch changes the way lookup entries are added.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
[p.zabel@pengutronix.de: added missing ERR_PTR]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 31 insertions, 7 deletions

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 06fa4907afc4..6488292e129c 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -153,12 +153,10 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
 
 /**
  * reset_controller_add_lookup - register a set of lookup entries
- * @rcdev: initialized reset controller device owning the reset line
  * @lookup: array of reset lookup entries
  * @num_entries: number of entries in the lookup array
  */
-void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
-                                 struct reset_control_lookup *lookup,
+void reset_controller_add_lookup(struct reset_control_lookup *lookup,
                                  unsigned int num_entries)
 {
         struct reset_control_lookup *entry;
@@ -168,13 +166,12 @@ void reset_controller_add_lookup(struct reset_controller_dev *rcdev,
         for (i = 0; i < num_entries; i++) {
                 entry = &lookup[i];
 
-                if (!entry->dev_id) {
-                        pr_warn("%s(): reset lookup entry has no dev_id, skipping\n",
+                if (!entry->dev_id || !entry->provider) {
+                        pr_warn("%s(): reset lookup entry badly specified, skipping\n",
                                 __func__);
                         continue;
                 }
 
-                entry->rcdev = rcdev;
                 list_add_tail(&entry->list, &reset_lookup_list);
         }
         mutex_unlock(&reset_lookup_mutex);
@@ -526,11 +523,30 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
+static struct reset_controller_dev *
+__reset_controller_by_name(const char *name)
+{
+        struct reset_controller_dev *rcdev;
+
+        lockdep_assert_held(&reset_list_mutex);
+
+        list_for_each_entry(rcdev, &reset_controller_list, list) {
+                if (!rcdev->dev)
+                        continue;
+
+                if (!strcmp(name, dev_name(rcdev->dev)))
+                        return rcdev;
+        }
+
+        return NULL;
+}
+
 static struct reset_control *
 __reset_control_get_from_lookup(struct device *dev, const char *con_id,
                                 bool shared, bool optional)
 {
         const struct reset_control_lookup *lookup;
+        struct reset_controller_dev *rcdev;
         const char *dev_id = dev_name(dev);
         struct reset_control *rstc = NULL;
 
@@ -547,7 +563,15 @@ __reset_control_get_from_lookup(struct device *dev, const char *con_id,
                     ((con_id && lookup->con_id) &&
                      !strcmp(con_id, lookup->con_id))) {
                         mutex_lock(&reset_list_mutex);
-                        rstc = __reset_control_get_internal(lookup->rcdev,
+                        rcdev = __reset_controller_by_name(lookup->provider);
+                        if (!rcdev) {
+                                mutex_unlock(&reset_list_mutex);
+                                mutex_unlock(&reset_lookup_mutex);
+                                /* Reset provider may not be ready yet. */
+                                return ERR_PTR(-EPROBE_DEFER);
+                        }
+
+                        rstc = __reset_control_get_internal(rcdev,
                                                             lookup->index,
                                                             shared);
                         mutex_unlock(&reset_list_mutex);