PRM/CM: Add new PRM/CM register bit manipulation functions

This patch implements an idea from Igor Stoppa <igor.stoppa@nokia.com>
from last year.  We use functions to modify PRM/CM register bits,
rather than open-coding those operations.

The patch provides functions that do read + AND + OR + write sequences
on CM and PRM registers: {cm,prm}_rmw_reg_bits(), and
{cm,prm}_rmw_mod_reg_bits().  Several convenience functions are then
implemented on top of those functions for setting and clearing bits:
{cm,prm}_{set,clear}_mod_reg_bits().

These functions don't provide any locking; it is expected that the caller
will handle this.

Thanks to Jouni Högander <jouni.hogander@nokia.com> for catching some
embarrassing errors in earlier versions of this code.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/cm.h

@@ -14,6 +14,8 @@
  * published by the Free Software Foundation.
  */
 
+#include <asm/io.h>
+
 #include "prcm-common.h"
 
 #ifndef __ASSEMBLER__
@@ -54,6 +56,20 @@ static u32 __attribute__((unused)) cm_read_reg(void __iomem *addr)
 {
 	return __raw_readl(addr);
 }
+
+/* Read-modify-write bits in a CM register */
+static u32 __attribute__((unused)) cm_rmw_reg_bits(u32 mask, u32 bits, void __iomem *va)
+{
+	u32 v;
+
+	v = cm_read_reg(va);
+	v &= ~mask;
+	v |= bits;
+	cm_write_reg(v, va);
+
+	return v;
+}
+
 #endif
 
 /*
@@ -83,7 +99,6 @@ static u32 __attribute__((unused)) cm_read_reg(void __iomem *addr)
 #define CM_CLKSEL2					0x0044
 #define CM_CLKSTCTRL					0x0048
 
-
 /* Architecture-specific registers */
 
 #define OMAP24XX_CM_FCLKEN2				0x0004
@@ -122,6 +137,23 @@ static u32 __attribute__((unused)) cm_read_mod_reg(s16 module, s16 idx)
 {
 	return cm_read_reg(OMAP_CM_REGADDR(module, idx));
 }
+
+/* Read-modify-write bits in a CM register (by domain) */
+static inline u32 __attribute__((unused)) cm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
+{
+	return cm_rmw_reg_bits(mask, bits, OMAP_CM_REGADDR(module, idx));
+}
+
+static inline u32 __attribute__((unused)) cm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
+{
+	return cm_rmw_mod_reg_bits(bits, bits, module, idx);
+}
+
+static inline u32 __attribute__((unused)) cm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
+{
+	return cm_rmw_mod_reg_bits(bits, 0x0, module, idx);
+}
+
 #endif
 
 /* CM register bits shared between 24XX and 3430 */

arch/arm/mach-omap2/prm.h

@@ -4,8 +4,8 @@
 /*
  * OMAP2/3 Power/Reset Management (PRM) register definitions
  *
- * Copyright (C) 2007 Texas Instruments, Inc.
- * Copyright (C) 2007 Nokia Corporation
+ * Copyright (C) 2007-2008 Texas Instruments, Inc.
+ * Copyright (C) 2007-2008 Nokia Corporation
  *
  * Written by Paul Walmsley
  *
@@ -14,6 +14,9 @@
  * published by the Free Software Foundation.
  */
 
+#include <asm/io.h>
+#include <asm/bitops.h>
+
 #include "prcm-common.h"
 
 #ifndef __ASSEMBLER__
@@ -61,7 +64,6 @@
 #define OMAP3430_PRM_IRQSTATUS_MPU	OMAP_PRM_REGADDR(OCP_MOD, 0x0018)
 #define OMAP3430_PRM_IRQENABLE_MPU	OMAP_PRM_REGADDR(OCP_MOD, 0x001c)
 
-
 #define OMAP3430_PRM_VC_SMPS_SA		OMAP_PRM_REGADDR(OMAP3430_GR_MOD, 0x0020)
 #define OMAP3430_PRM_VC_SMPS_VOL_RA	OMAP_PRM_REGADDR(OMAP3430_GR_MOD, 0x0024)
 #define OMAP3430_PRM_VC_SMPS_CMD_RA	OMAP_PRM_REGADDR(OMAP3430_GR_MOD, 0x0028)
@@ -113,6 +115,19 @@ static u32 __attribute__((unused)) prm_read_reg(void __iomem *addr)
 	return __raw_readl(addr);
 }
 
+/* Read-modify-write bits in a PRM register */
+static u32 __attribute__((unused)) prm_rmw_reg_bits(u32 mask, u32 bits, void __iomem *va)
+{
+	u32 v;
+
+	v = prm_read_reg(va);
+	v &= ~mask;
+	v |= bits;
+	prm_write_reg(v, va);
+
+	return v;
+}
+
 #endif
 
 /*
@@ -154,6 +169,22 @@ static u32 __attribute__((unused)) prm_read_reg(void __iomem *addr)
 #define OMAP3430_PRM_IRQSTATUS_IVA2			0x00f8
 #define OMAP3430_PRM_IRQENABLE_IVA2			0x00fc
 
+/* Read-modify-write bits in a PRM register (by domain) */
+static u32 __attribute__((unused)) prm_rmw_mod_reg_bits(u32 mask, u32 bits,
+							s16 module, s16 idx)
+{
+	return prm_rmw_reg_bits(mask, bits, OMAP_PRM_REGADDR(module, idx));
+}
+
+static u32 __attribute__((unused)) prm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
+{
+	return prm_rmw_mod_reg_bits(bits, bits, module, idx);
+}
+
+static u32 __attribute__((unused)) prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
+{
+	return prm_rmw_mod_reg_bits(bits, 0x0, module, idx);
+}
 
 /* Architecture-specific registers */