ARM: OMAP2+: hwmod: add support for link registration

Add support for direct IP block interconnect ("link") registration to
the hwmod code via a new function, omap_hwmod_register_links().  This
will replace direct registration of hwmods, and a subsequent patch
will remove omap_hwmod_register().

This change will allow a subsequent patch to remove the hwmod data
link arrays.  This will reduce the size of the hwmod static data and
also make it easier to generate the data files.  It will also make it
possible to share some of the struct omap_hwmod records across
multiple SoCs, since the link array pointers will be removed from the
struct omap_hwmod.

The downside is that boot time will increase.  Minimizing boot time
was the reason why the link arrays were originally introduced.
Removing them will require extra computation during boot to allocate
memory and associate IP blocks with their interconnects.  However,
since the current kernel development focus is on reducing the number
of lines in arch/arm/mach-omap2/, boot time impact is now seemingly
considered a lower priority.

This patch contains additional complexity to reduce the number of
memory allocations required for this change.  This reduces the boot
time impact: total hwmod link registration time was ~ 2655
microseconds with a simple allocation strategy, but is now ~ 549
microseconds[1] with the approach taken by this patch.

1. Measured on a BeagleBoard 35xx @ 500MHz MPU/333 MHz CORE, average
   of 7 samples.  Total uncertainty is +/- 61 microseconds.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>

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

@@ -219,6 +219,10 @@ struct omap_hwmod_addr_space {
 #define OCPIF_SWSUP_IDLE		(1 << 0)
 #define OCPIF_CAN_BURST			(1 << 1)
 
+/* omap_hwmod_ocp_if._int_flags possibilities */
+#define _OCPIF_INT_FLAGS_REGISTERED	(1 << 0)
+
+
 /**
  * struct omap_hwmod_ocp_if - OCP interface data
  * @master: struct omap_hwmod that initiates OCP transactions on this link
@@ -230,6 +234,7 @@ struct omap_hwmod_addr_space {
  * @width: OCP data width
  * @user: initiators using this interface (see OCP_USER_* macros above)
  * @flags: OCP interface flags (see OCPIF_* macros above)
+ * @_int_flags: internal flags (see _OCPIF_INT_FLAGS* macros above)
  *
  * It may also be useful to add a tag_cnt field for OCP2.x devices.
  *
@@ -248,6 +253,7 @@ struct omap_hwmod_ocp_if {
 	u8				width;
 	u8				user;
 	u8				flags;
+	u8				_int_flags;
 };
 
 
@@ -476,6 +482,16 @@ struct omap_hwmod_class {
 	int					(*reset)(struct omap_hwmod *oh);
 };
 
+/**
+ * struct omap_hwmod_link - internal structure linking hwmods with ocp_ifs
+ * @ocp_if: OCP interface structure record pointer
+ * @node: list_head pointing to next struct omap_hwmod_link in a list
+ */
+struct omap_hwmod_link {
+	struct omap_hwmod_ocp_if	*ocp_if;
+	struct list_head		node;
+};
+
 /**
  * struct omap_hwmod - integration data for OMAP hardware "modules" (IP blocks)
  * @name: name of the hwmod
@@ -494,6 +510,7 @@ struct omap_hwmod_class {
  * @_sysc_cache: internal-use hwmod flags
  * @_mpu_rt_va: cached register target start address (internal use)
  * @_mpu_port_index: cached MPU register target slave ID (internal use)
+ * @_mpu_port: cached MPU register target slave (internal use)
  * @opt_clks_cnt: number of @opt_clks
  * @master_cnt: number of @master entries
  * @slaves_cnt: number of @slave entries
@@ -512,6 +529,8 @@ struct omap_hwmod_class {
  *
  * Parameter names beginning with an underscore are managed internally by
  * the omap_hwmod code and should not be set during initialization.
+ *
+ * @masters and @slaves are now deprecated.
  */
 struct omap_hwmod {
 	const char			*name;
@@ -532,11 +551,14 @@ struct omap_hwmod {
 	struct clockdomain		*clkdm;
 	struct omap_hwmod_ocp_if	**masters; /* connect to *_IA */
 	struct omap_hwmod_ocp_if	**slaves;  /* connect to *_TA */
+	struct list_head		master_ports; /* connect to *_IA */
+	struct list_head		slave_ports; /* connect to *_TA */
 	void				*dev_attr;
 	u32				_sysc_cache;
 	void __iomem			*_mpu_rt_va;
 	spinlock_t			_lock;
 	struct list_head		node;
+	struct omap_hwmod_ocp_if	*_mpu_port;
 	u16				flags;
 	u8				_mpu_port_index;
 	u8				response_lat;
@@ -622,4 +644,6 @@ extern int omap2430_hwmod_init(void);
 extern int omap3xxx_hwmod_init(void);
 extern int omap44xx_hwmod_init(void);
 
+extern int __init omap_hwmod_register_links(struct omap_hwmod_ocp_if **ois);
+
 #endif