pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs

When dt_to_map_one_config() is called with a pinctrl_dev passed
in, it should only be using this if the node being looked up
is a hog. The code was always using the passed pinctrl_dev
without checking whether the dt node referred to it.

A pin controller can have pinctrl-n dependencies on other pin
controllers in these cases:

- the pin controller hardware is external, for example I2C, so
  needs other pin controller(s) to be setup to communicate with
  the hardware device.

- it is a child of a composite MFD so its of_node is shared with
  the parent MFD and other children of that MFD. Any part of that
  MFD could have dependencies on other pin controllers.

Because of this, dt_to_map_one_config() can't assume that if it
has a pinctrl_dev passed in then the node it looks up must be
a hog. It could be a reference to some other pin controller.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index 1ff6c35..b601039 100644 (file)
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -122,8 +122,10 @@ static int dt_to_map_one_config(struct pinctrl *p,
                        /* OK let's just assume this will appear later then */
                        return -EPROBE_DEFER;
                }
-               if (!pctldev)
-                       pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
+               /* If we're creating a hog we can use the passed pctldev */
+               if (pctldev && (np_pctldev == p->dev->of_node))
+                       break;
+               pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
                if (pctldev)
                        break;
                /* Do not defer probing of hogs (circular loop) */