OMAP2+: hwmod: add ability to setup individual hwmods

Add omap_hwmod_setup_one(), which is intended for use early in boot to
selectively setup the hwmods needed for system clocksources and
clockevents, and any other hwmod that is needed in early boot.
omap_hwmod_setup_all() can then be called later in the boot process.
The point is to minimize the amount of code that needs to be run
early.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap_hwmod.c

@@ -901,7 +901,7 @@ static struct omap_hwmod *_lookup(const char *name)
  * @oh: struct omap_hwmod *
  * @data: not used; pass NULL
  *
- * Called by omap_hwmod_setup_all() (after omap2_clk_init()).
+ * Called by omap_hwmod_setup_*() (after omap2_clk_init()).
  * Resolves all clock names embedded in the hwmod.  Returns 0 on
  * success, or a negative error code on failure.
  */
@@ -1616,7 +1616,7 @@ int __init omap_hwmod_register(struct omap_hwmod **ohs)
 /*
  * _populate_mpu_rt_base - populate the virtual address for a hwmod
  *
- * Must be called only from omap_hwmod_setup_all() so ioremap works properly.
+ * Must be called only from omap_hwmod_setup_*() so ioremap works properly.
  * Assumes the caller takes care of locking if needed.
  */
 static int __init _populate_mpu_rt_base(struct omap_hwmod *oh, void *data)
@@ -1635,12 +1635,60 @@ static int __init _populate_mpu_rt_base(struct omap_hwmod *oh, void *data)
 	return 0;
 }
 
+/**
+ * omap_hwmod_setup_one - set up a single hwmod
+ * @oh_name: const char * name of the already-registered hwmod to set up
+ *
+ * Must be called after omap2_clk_init().  Resolves the struct clk
+ * names to struct clk pointers for each registered omap_hwmod.  Also
+ * calls _setup() on each hwmod.  Returns -EINVAL upon error or 0 upon
+ * success.
+ */
+int __init omap_hwmod_setup_one(const char *oh_name)
+{
+	struct omap_hwmod *oh;
+	int r;
+
+	pr_debug("omap_hwmod: %s: %s\n", oh_name, __func__);
+
+	if (!mpu_oh) {
+		pr_err("omap_hwmod: %s: cannot setup_one: MPU initiator hwmod %s not yet registered\n",
+		       oh_name, MPU_INITIATOR_NAME);
+		return -EINVAL;
+	}
+
+	oh = _lookup(oh_name);
+	if (!oh) {
+		WARN(1, "omap_hwmod: %s: hwmod not yet registered\n", oh_name);
+		return -EINVAL;
+	}
+
+	if (mpu_oh->_state == _HWMOD_STATE_REGISTERED && oh != mpu_oh)
+		omap_hwmod_setup_one(MPU_INITIATOR_NAME);
+
+	r = _populate_mpu_rt_base(oh, NULL);
+	if (IS_ERR_VALUE(r)) {
+		WARN(1, "omap_hwmod: %s: couldn't set mpu_rt_base\n", oh_name);
+		return -EINVAL;
+	}
+
+	r = _init_clocks(oh, NULL);
+	if (IS_ERR_VALUE(r)) {
+		WARN(1, "omap_hwmod: %s: couldn't init clocks\n", oh_name);
+		return -EINVAL;
+	}
+
+	_setup(oh, NULL);
+
+	return 0;
+}
+
 /**
  * omap_hwmod_setup - do some post-clock framework initialization
  *
  * Must be called after omap2_clk_init().  Resolves the struct clk names
  * to struct clk pointers for each registered omap_hwmod.  Also calls
- * _setup() on each hwmod.  Returns 0 upon success or -EINVAL upon error.
+ * _setup() on each hwmod.  Returns 0 upon success.
  */
 static int __init omap_hwmod_setup_all(void)
 {
@@ -1654,9 +1702,9 @@ static int __init omap_hwmod_setup_all(void)
 
 	r = omap_hwmod_for_each(_populate_mpu_rt_base, NULL);
 
-	/* XXX check return value */
 	r = omap_hwmod_for_each(_init_clocks, NULL);
-	WARN(r, "omap_hwmod: %s: _init_clocks failed\n", __func__);
+	WARN(IS_ERR_VALUE(r),
+	     "omap_hwmod: %s: _init_clocks failed\n", __func__);
 
 	omap_hwmod_for_each(_setup, NULL);
 
@@ -2182,8 +2230,8 @@ int omap_hwmod_for_each_by_class(const char *classname,
  * @state: state that _setup() should leave the hwmod in
  *
  * Sets the hwmod state that @oh will enter at the end of _setup()
- * (called by omap_hwmod_setup_all()).  Only valid to call between
- * calling omap_hwmod_register() and omap_hwmod_setup_all().  Returns
+ * (called by omap_hwmod_setup_*()).  Only valid to call between
+ * calling omap_hwmod_register() and omap_hwmod_setup_*().  Returns
  * 0 upon success or -EINVAL if there is a problem with the arguments
  * or if the hwmod is in the wrong state.
  */

arch/arm/plat-omap/include/plat/omap_hwmod.h

@@ -30,6 +30,7 @@
 #define __ARCH_ARM_PLAT_OMAP_INCLUDE_MACH_OMAP_HWMOD_H
 
 #include <linux/kernel.h>
+#include <linux/init.h>
 #include <linux/list.h>
 #include <linux/ioport.h>
 #include <linux/spinlock.h>
@@ -542,6 +543,8 @@ struct omap_hwmod *omap_hwmod_lookup(const char *name);
 int omap_hwmod_for_each(int (*fn)(struct omap_hwmod *oh, void *data),
 			void *data);
 
+int __init omap_hwmod_setup_one(const char *name);
+
 int omap_hwmod_enable(struct omap_hwmod *oh);
 int _omap_hwmod_enable(struct omap_hwmod *oh);
 int omap_hwmod_idle(struct omap_hwmod *oh);