[PATCH v3 03/19] bootstd: Add a function to get bootstd only if available

[Simon Glass <sjg@chromium.org>]

Provide a function which is safe to call in the 'unbind' path, which
returns the bootstd priv data if available.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

(no changes since v1)

 boot/bootstd-uclass.c | 11 +++++++++++
 include/bootstd.h     | 17 +++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/boot/bootstd-uclass.c b/boot/bootstd-uclass.c
index 596d3e5e41d..b2f80808c85 100644
--- a/boot/bootstd-uclass.c
+++ b/boot/bootstd-uclass.c
@@ -140,6 +140,17 @@ const char *const *const bootstd_get_prefixes(struct udevice *dev)
 	return std->prefixes ? std->prefixes : default_prefixes;
 }
 
+struct bootstd_priv *bootstd_try_priv(void)
+{
+	struct udevice *dev;
+
+	dev = uclass_try_first_device(UCLASS_BOOTSTD);
+	if (!dev || !device_active(dev))
+		return NULL;
+
+	return dev_get_priv(dev);
+}
+
 int bootstd_get_priv(struct bootstd_priv **stdp)
 {
 	struct udevice *dev;
diff --git a/include/bootstd.h b/include/bootstd.h
index 4220ece785d..4535d91e2ad 100644
--- a/include/bootstd.h
+++ b/include/bootstd.h
@@ -89,6 +89,23 @@ const char *const *const bootstd_get_prefixes(struct udevice *dev);
  */
 int bootstd_get_priv(struct bootstd_priv **stdp);
 
+/**
+ * bootstd_try_priv() - Try to get the (single) state for the bootstd system
+ *
+ * The state holds a global list of all bootflows that have been found. This
+ * function returns the state if available, but takes care not to create the
+ * device (or uclass) if it doesn't exist.
+ *
+ * This function is safe to use in the 'unbind' path. It will always return NULL
+ * unless the bootstd device is probed and ready, e.g. bootstd_get_priv() has
+ * previously been called.
+ *
+ * TODO(sjg@chromium.org): Consider adding a bootstd pointer to global_data
+ *
+ * Return: pointer if the device exists, else NULL
+ */
+struct bootstd_priv *bootstd_try_priv(void);
+
 /**
  * bootstd_clear_glob() - Clear the global list of bootflows
  *
-- 
2.34.1