pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c

This change separates two aspects of struct pinctrl:

a) The data representation of the parsed mapping table, into:

   1) The top-level struct pinctrl object, a single entity returned
      by pinctrl_get().

   2) The parsed version of each mapping table entry, struct
      pinctrl_setting, of which there is one per mapping table entry.

b) The code that handles this; the code for (1) above is in core.c, and
   the code to parse/execute each entry in (2) above is in pinmux.c, while
   the iteration over multiple settings is lifted to core.c.

This will allow the following future changes:

1) pinctrl_get() API rework, so that struct pinctrl represents all states
   for the device, and the device can select between them without calling
   put()/get() again.

2) To support that, a struct pinctrl_state object will be inserted into
   the data model between the struct pinctrl and struct pinctrl_setting.

3) The mapping table will be extended to allow specification of pin config
   settings too. To support this, struct pinctrl_setting will be enhanced
   to store either mux settings or config settings, and functions will be
   added to pinconf.c to parse/execute pin configuration settings.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/core.h

@@ -49,22 +49,31 @@ struct pinctrl_dev {
  * struct pinctrl - per-device pin control state holder
  * @node: global list node
  * @dev: the device using this pin control handle
+ * @state: the state name passed to pinctrl_get()
  * @usecount: the number of active users of this pin controller setting, used
  *	to keep track of nested use cases
- * @pctldev: pin control device handling this pin control handle
- * @groups: the group selectors for the pinmux device and
- *	selector combination handling this pinmux, this is a list that
- *	will be traversed on all pinmux operations such as
- *	get/put/enable/disable
+ * @settings: a list of settings for this device/state
  */
 struct pinctrl {
 	struct list_head node;
 	struct device *dev;
+	const char *state;
 	unsigned usecount;
+	struct list_head settings;
+};
+
+/**
+ * struct pinctrl_setting - an individual mux setting
+ * @node: list node for struct pinctrl's @settings field
+ * @pctldev: pin control device handling to be programmed
+ * @group_selector: the group selector to program
+ * @func_selector: the function selector to program
+ */
+struct pinctrl_setting {
+	struct list_head node;
 	struct pinctrl_dev *pctldev;
-#ifdef CONFIG_PINMUX
-	struct list_head groups;
-#endif
+	unsigned group_selector;
+	unsigned func_selector;
 };
 
 /**