pinctrl: Add the concept of peripheral IDs

My original pinctrl patch operating using a peripheral ID enum. This was
shared between pinmux and clock and provides an easy way to specify a device
that needs to be controlled, even it is does not (yet) have a driver within
driver model.

Masahiro's new simple pinctrl gets around this by providing a
set_state_simple() pinctrl method. By passing a device to that call the
peripheral ID becomes unnecessary. If the driver needs it, it can calculate
it itself and use it internally.

However this does not solve the problem for peripheral clocks. The 'pure'
solution would be to pass a driver to the clock uclass also. But this
requires that all devices should have a driver, and a struct udevide. Also
a key optimisation of the clock uclass is allowing a peripheral clock to
be set even when there is no device for that clock.

There may be a better way to achive the same goal, but for now it seems
expedient to add in peripheral ID to the pinctrl uclass. Two methods are
added - one to get the peripheral ID and one to select it. The existing
set_state_simple() is effectively the union of these.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pinctrl/pinctrl-uclass.c b/drivers/pinctrl/pinctrl-uclass.c
index d96c201..58001ef 100644
--- a/drivers/pinctrl/pinctrl-uclass.c
+++ b/drivers/pinctrl/pinctrl-uclass.c
@@ -11,6 +11,7 @@
 #include <dm/device.h>
 #include <dm/lists.h>
 #include <dm/pinctrl.h>
+#include <dm/root.h>
 #include <dm/uclass.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -159,7 +160,8 @@
 
 static int pinconfig_post_bind(struct udevice *dev)
 {
-	return 0;
+	/* Scan the bus for devices */
+	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
 }
 #endif
 
@@ -205,6 +207,31 @@
 	return 0;
 }
 
+int pinctrl_request(struct udevice *dev, int func, int flags)
+{
+	struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+
+	if (!ops->request)
+		return -ENOSYS;
+
+	return ops->request(dev, func, flags);
+}
+
+int pinctrl_request_noflags(struct udevice *dev, int func)
+{
+	return pinctrl_request(dev, func, 0);
+}
+
+int pinctrl_get_periph_id(struct udevice *dev, struct udevice *periph)
+{
+	struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+
+	if (!ops->get_periph_id)
+		return -ENOSYS;
+
+	return ops->get_periph_id(dev, periph);
+}
+
 /**
  * pinconfig_post-bind() - post binding for PINCTRL uclass
  * Recursively bind child nodes as pinconfig devices in case of full pinctrl.
@@ -222,15 +249,10 @@
 	}
 
 	/*
-	 * If set_state callback is set, we assume this pinctrl driver is the
-	 * full implementation.  In this case, its child nodes should be bound
-	 * so that peripheral devices can easily search in parent devices
-	 * during later DT-parsing.
+	 * The pinctrl driver child nodes should be bound so that peripheral
+	 * devices can easily search in parent devices during later DT-parsing.
 	 */
-	if (ops->set_state)
-		return pinconfig_post_bind(dev);
-
-	return 0;
+	return pinconfig_post_bind(dev);
 }
 
 UCLASS_DRIVER(pinctrl) = {