OMAP4: PRCM: add OMAP4-specific accessor/mutator functions

In some ways, the OMAP4 PRCM register layout is quite different than
the OMAP2/3 PRCM register layout.  For example, on OMAP2/3, from a
register layout point of view, all CM instances were located in the CM
subsystem, and all PRM instances were located in the PRM subsystem.
OMAP4 changes this.  Now, for example, some CM instances, such as
WKUP_CM and EMU_CM, are located in the system PRM subsystem.  And a
"local PRCM" exists for the MPU - this PRCM combines registers that
would normally appear in both CM and PRM instances, but uses its own
register layout which matches neither the OMAP2/3 PRCM layout nor the
OMAP4 PRCM layout.

To try to deal with this, introduce some new functions, omap4_cminst*
and omap4_prminst*.  The former is to be used when writing to a CM
instance register (no matter what subsystem or hardware module it
exists in), and the latter, similarly, with PRM instance registers.
To determine which "PRCM partition" to write to, the functions take a
PRCM instance ID argument.  Subsequent patches add these partition IDs
to the OMAP4 powerdomain and clockdomain definitions.

As far as I can see, there's really no good way to handle these types
of register access inconsistencies.  This patch seemed like the least
bad approach.

Moving forward, the long-term goal is to remove all direct PRCM
register access from the PM code.  PRCM register access should go
through layers such as the powerdomain and clockdomain code that can
hide the details of how to interact with the specific hardware
variant.

While here, rename cm4xxx.c to cm44xx.c to match the naming convention
of the other OMAP4 PRCM files.

Thanks to Santosh Shilimkar <santosh.shilimkar@ti.com>, Rajendra Nayak
<rnayak@ti.com>, and Benoît Cousson <b-cousson@ti.com> for some comments.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>

1 files changed, 4 insertions, 3 deletions

diff --git a/arch/arm/plat-omap/include/plat/prcm.h b/arch/arm/plat-omap/include/plat/prcm.h
index d059a05bc45..078906d86b6 100644
--- a/arch/arm/plat-omap/include/plat/prcm.h
+++ b/arch/arm/plat-omap/include/plat/prcm.h
@@ -18,6 +18,10 @@
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * XXX This file is deprecated.  The PRCM is an OMAP2+-only subsystem,
+ * so this file doesn't belong in plat-omap/include/plat.  Please
+ * do not add anything new to this file.
  */
 
 #ifndef __ASM_ARM_ARCH_OMAP_PRCM_H
@@ -31,9 +35,6 @@ int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, u8 idlest,
 #define START_PADCONF_SAVE 0x2
 #define PADCONF_SAVE_DONE  0x1
 
-u32 omap4_prm_read_bits_shift(void __iomem *reg, u32 mask);
-u32 omap4_prm_rmw_reg_bits(u32 mask, u32 bits, void __iomem *reg);
-
 #endif