On 22.11.2021 18:50:00, Aswath Govindraju wrote:

quoted

What about adding a devm_mux_control_get_optional(), which doesn't
return a -ENODEV but a NULL pointer if the device doesn't exist?

I tried adding it in the following manner,

+/**
+ * devm_mux_control_optional_get() - Optionally get the mux-control for a
+ *                                  device, with resource management.
+ * @dev: The device that needs a mux-control.
+ * @mux_name: The name identifying the mux-control.
+ *
+ * This differs from devm_mux_control_get in that if the mux does not
+ * exist, it is not considered an error and -ENODEV will not be
+ * returned. Instead the NULL is returned.
+ *
+ * Return: Pointer to the mux-control, or an ERR_PTR with a negative errno.
+ */
+struct mux_control *devm_mux_control_optional_get(struct device *dev,
+                                                 const char *mux_name)
+{
+       struct mux_control *mux_ctrl;
+
+       mux_ctrl = devm_mux_control_get(dev, mux_name);
+       if (PTR_ERR(mux_ctrl) == -ENOENT)
+                mux_ctrl = NULL;
+
+       return mux_ctrl;
+}
+EXPORT_SYMBOL_GPL(devm_mux_control_optional_get);
+

However the issue is that there is a print in mux_control_get()
 dev_err(dev, "%pOF: failed to get mux-control %s(%i)\n",

which is getting printed, whenever mux-controls property is not found.
Therefore, I was not sure about how to go about this issue and did not
implement it.

Ok, this would require more tweaking in the mux layer. Then leave it as
is.

regards,
Marc

-- 
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