Remove atomic register bit manipulation functions from i.MX and s3c target code and introduce generic functions for ARM (bitmod32, bitset32, and bitclr32). Multiprocessor support is possible but just not implemented at the moment, only interrupt lockout.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27188 a1c6a512-1295-4272-9138-f99709370657

28 files changed, 271 insertions, 190 deletions

diff --git a/firmware/SOURCES b/firmware/SOURCES
index 53c38e0ee9..ea309a12f4 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -893,6 +893,7 @@ target/arm/usb-fw-pp502x.c
 
 #ifdef GIGABEAT_F
 #ifndef SIMULATOR
+target/arm/bits-armv4.S
 target/arm/lcd-as-memframe.S
 target/arm/mmu-arm.S
 target/arm/s3c2440/adc-s3c2440.c
@@ -918,6 +919,7 @@ target/arm/s3c2440/gigabeat-fx/wmcodec-meg-fx.c
 
 #ifdef GIGABEAT_S
 #ifndef SIMULATOR
+target/arm/bits-armv6.S
 target/arm/lcd-as-memframe.S
 target/arm/mmu-armv6.S
 target/arm/imx31/ata-imx31.c
@@ -1553,6 +1555,7 @@ target/arm/at91sam/lyre_proto1/timer-lyre_proto1.c
 
 #if defined(MINI2440)
 #ifndef SIMULATOR
+target/arm/bits-armv4.S
 target/arm/lcd-as-memframe.S
 target/arm/mmu-arm.S
 target/arm/s3c2440/debug-s3c2440.c
diff --git a/firmware/export/system.h b/firmware/export/system.h
index fe8121ce20..ee668c87e4 100644
--- a/firmware/export/system.h
+++ b/firmware/export/system.h
@@ -214,6 +214,11 @@ static inline __attribute__((always_inline))
 uint32_t isolate_first_bit(uint32_t val)
     { return val & -val; }
 
+/* Functions to set and clear register or variable bits atomically */
+void bitmod32(volatile uint32_t *addr, uint32_t bits, uint32_t mask);
+void bitset32(volatile uint32_t *addr, uint32_t mask);
+void bitclr32(volatile uint32_t *addr, uint32_t mask);
+
 /* gcc 3.4 changed the format of the constraints */
 #if (__GNUC__ >= 3) && (__GNUC_MINOR__ > 3) || (__GNUC__ >= 4)
 #define I_CONSTRAINT "I08"
diff --git a/firmware/target/arm/bits-armv4.S b/firmware/target/arm/bits-armv4.S
new file mode 100644
index 0000000000..05d61b8b7e
--- /dev/null
+++ b/firmware/target/arm/bits-armv4.S
@@ -0,0 +1,77 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2010 by Michael Sevakis
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+/***************************************************************************
+ * void bitmod32(volatile uint32_t *addr, uint32_t bits, uint32_t mask)
+ */
+    .section    .text, "ax", %progbits
+    .align      2
+    .global     bitmod32
+    .type       bitmod32, %function
+bitmod32:
+    mrs    r12, cpsr
+    orr    r3, r12, #0xc0
+    msr    cpsr_c, r3
+    ldr    r3, [r0]
+    and    r1, r1, r2               @ Only allow mod of bits in 'mask'
+    bic    r3, r3, r2               @ Clear mask bits
+    orr    r3, r3, r1               @ Set according to 'bits'
+    str    r3, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitmod32, .-bitmod32
+
+/***************************************************************************
+ * void bitset32(volatile uint32_t *addr, uint32_t mask)
+ */
+    .section    .text, "ax", %progbits
+    .align      2
+    .global     bitset32
+    .type       bitset32, %function
+bitset32:
+    mrs    r12, cpsr
+    orr    r2, r12, #0xc0
+    msr    cpsr_c, r2
+    ldr    r2, [r0]
+    orr    r2, r2, r1
+    str    r2, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitset32, .-bitset32
+
+
+/***************************************************************************
+ * void bitclr32(volatile uint32_t *addr, uint32_t mask)
+ */
+     .section    .text, "ax", %progbits
+     .align      2
+     .global     bitclr32
+     .type       bitclr32, %function
+bitclr32:
+    mrs    r12, cpsr
+    orr    r2, r12, #0xc0
+    msr    cpsr_c, r2
+    ldr    r2, [r0]
+    bic    r2, r2, r1
+    str    r2, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitclr32, .-bitclr32
diff --git a/firmware/target/arm/bits-armv6.S b/firmware/target/arm/bits-armv6.S
new file mode 100644
index 0000000000..0a15805f87
--- /dev/null
+++ b/firmware/target/arm/bits-armv6.S
@@ -0,0 +1,74 @@
+/***************************************************************************
+*             __________               __   ___.
+*   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+*   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+*   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+*   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+*                     \/            \/     \/    \/            \/
+* $Id$
+*
+* Copyright (C) 2010 by Michael Sevakis
+*
+* This program is free software; you can redistribute it and/or
+* modify it under the terms of the GNU General Public License
+* as published by the Free Software Foundation; either version 2
+* of the License, or (at your option) any later version.
+*
+* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+* KIND, either express or implied.
+*
+****************************************************************************/
+
+/***************************************************************************
+ * void bitmod32(volatile uint32_t *addr, uint32_t bits, uint32_t mask)
+ */
+    .section    .text, "ax", %progbits
+    .align      2
+    .global     bitmod32
+    .type       bitmod32, %function
+bitmod32:
+    mrs    r12, cpsr
+    cpsid  if
+    ldr    r3, [r0]
+    and    r1, r1, r2               @ Only allow mod of bits in 'mask'
+    bic    r3, r3, r2               @ Clear mask bits
+    orr    r3, r3, r1               @ Set according to 'bits'
+    str    r3, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitmod32, .-bitmod32
+
+/***************************************************************************
+ * void bitset32(volatile uint32_t *addr, uint32_t mask)
+ */
+    .section    .text, "ax", %progbits
+    .align      2
+    .global     bitset32
+    .type       bitset32, %function
+bitset32:
+    mrs    r12, cpsr
+    cpsid  if
+    ldr    r2, [r0]
+    orr    r2, r2, r1
+    str    r2, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitset32, .-bitset32
+
+
+/***************************************************************************
+ * void bitclr32(volatile uint32_t *addr, uint32_t mask)
+ */
+     .section    .text, "ax", %progbits
+     .align      2
+     .global     bitclr32
+     .type       bitclr32, %function
+bitclr32:
+    mrs    r12, cpsr
+    cpsid  if
+    ldr    r2, [r0]
+    bic    r2, r2, r1
+    str    r2, [r0]
+    msr    cpsr_c, r12
+    bx     lr
+    .size  bitclr32, .-bitclr32
diff --git a/firmware/target/arm/imx31/ccm-imx31.c b/firmware/target/arm/imx31/ccm-imx31.c
index 2cf2080cf1..00a7d859b1 100644
--- a/firmware/target/arm/imx31/ccm-imx31.c
+++ b/firmware/target/arm/imx31/ccm-imx31.c
@@ -43,7 +43,7 @@ void ccm_module_clock_gating(enum IMX31_CG_LIST cg, enum IMX31_CG_MODES mode)
     shift = 2*(cg % 16);        /* Get field shift */
     mask = CG_MASK << shift;    /* Select field */
 
-    imx31_regmod32(reg, mode << shift, mask);
+    bitmod32(reg, mode << shift, mask);
 }
 
 /* Decode PLL output frequency from register value */
diff --git a/firmware/target/arm/imx31/dvfs_dptc-imx31.c b/firmware/target/arm/imx31/dvfs_dptc-imx31.c
index 6bacc20c10..aa8d0f52fb 100644
--- a/firmware/target/arm/imx31/dvfs_dptc-imx31.c
+++ b/firmware/target/arm/imx31/dvfs_dptc-imx31.c
@@ -275,7 +275,7 @@ static void INIT_ATTR dvfs_init(void)
 
 #ifndef DVFS_NO_PWRRDY
     /* Configure PWRRDY signal pin. */
-    imx31_regclr32(&GPIO1_GDIR, (1 << 5));
+    bitclr32(&GPIO1_GDIR, (1 << 5));
     iomuxc_set_pin_mux(IOMUXC_GPIO1_5,
                        IOMUXC_MUX_OUT_FUNCTIONAL | IOMUXC_MUX_IN_FUNCTIONAL);
 #endif
@@ -289,27 +289,26 @@ static void INIT_ATTR dvfs_init(void)
     }
 
     /* Set up LTR0. */
-    imx31_regmod32(&CCM_LTR0,
-                   DVFS_UPTHR << CCM_LTR0_UPTHR_POS |
-                   DVFS_DNTHR << CCM_LTR0_DNTHR_POS |
-                   DVFS_DIV3CK << CCM_LTR0_DIV3CK_POS,
-                   CCM_LTR0_UPTHR | CCM_LTR0_DNTHR | CCM_LTR0_DIV3CK);
+    bitmod32(&CCM_LTR0,
+             DVFS_UPTHR << CCM_LTR0_UPTHR_POS |
+             DVFS_DNTHR << CCM_LTR0_DNTHR_POS |
+             DVFS_DIV3CK << CCM_LTR0_DIV3CK_POS,
+             CCM_LTR0_UPTHR | CCM_LTR0_DNTHR | CCM_LTR0_DIV3CK);
 
     /* Set up LTR1. */
-    imx31_regmod32(&CCM_LTR1,
-                   DVFS_DNCNT << CCM_LTR1_DNCNT_POS |
-                   DVFS_UPCNT << CCM_LTR1_UPCNT_POS |
-                   DVFS_PNCTHR << CCM_LTR1_PNCTHR_POS |
-                   CCM_LTR1_LTBRSR,
-                   CCM_LTR1_DNCNT | CCM_LTR1_UPCNT |
-                   CCM_LTR1_PNCTHR | CCM_LTR1_LTBRSR);
+    bitmod32(&CCM_LTR1,
+             DVFS_DNCNT << CCM_LTR1_DNCNT_POS |
+             DVFS_UPCNT << CCM_LTR1_UPCNT_POS |
+             DVFS_PNCTHR << CCM_LTR1_PNCTHR_POS |
+             CCM_LTR1_LTBRSR,
+             CCM_LTR1_DNCNT | CCM_LTR1_UPCNT |
+             CCM_LTR1_PNCTHR | CCM_LTR1_LTBRSR);
 
     /* Set up LTR2-- EMA configuration. */
-    imx31_regmod32(&CCM_LTR2, DVFS_EMAC << CCM_LTR2_EMAC_POS,
-                   CCM_LTR2_EMAC);
+    bitmod32(&CCM_LTR2, DVFS_EMAC << CCM_LTR2_EMAC_POS, CCM_LTR2_EMAC);
 
     /* DVFS interrupt goes to MCU. Mask load buffer full interrupt. */
-    imx31_regset32(&CCM_PMCR0, CCM_PMCR0_DVFIS | CCM_PMCR0_LBMI);
+    bitset32(&CCM_PMCR0, CCM_PMCR0_DVFIS | CCM_PMCR0_LBMI);
 
     /* Initialize current core PLL and dividers for default level. Assumes
      * clocking scheme has been set up appropriately in other init code. */
@@ -517,8 +516,8 @@ static __attribute__((interrupt("IRQ"))) void CCM_CLK_HANDLER(void)
 static void INIT_ATTR dptc_init(void)
 {
     /* Force DPTC off if running for some reason. */
-    imx31_regmod32(&CCM_PMCR0, CCM_PMCR0_PTVAIM,
-                   CCM_PMCR0_PTVAIM | CCM_PMCR0_DPTEN);
+    bitmod32(&CCM_PMCR0, CCM_PMCR0_PTVAIM,
+             CCM_PMCR0_PTVAIM | CCM_PMCR0_DPTEN);
 
      /* Shadow the regulator registers */
     mc13783_read_regs(dptc_pmic_regs, dptc_reg_shadows, 2);
@@ -528,14 +527,14 @@ static void INIT_ATTR dptc_init(void)
 
     /* Interrupt goes to MCU, specified reference circuits enabled when
      * DPTC is active. */
-    imx31_regset32(&CCM_PMCR0, CCM_PMCR0_PTVIS);
+    bitset32(&CCM_PMCR0, CCM_PMCR0_PTVIS);
 
-    imx31_regmod32(&CCM_PMCR0, DPTC_DRCE_MASK,
-                   CCM_PMCR0_DRCE0 | CCM_PMCR0_DRCE1 |
-                   CCM_PMCR0_DRCE2 | CCM_PMCR0_DRCE3);
+    bitmod32(&CCM_PMCR0, DPTC_DRCE_MASK,
+             CCM_PMCR0_DRCE0 | CCM_PMCR0_DRCE1 |
+             CCM_PMCR0_DRCE2 | CCM_PMCR0_DRCE3);
 
     /* DPTC counting range = 256 system clocks */
-    imx31_regclr32(&CCM_PMCR0, CCM_PMCR0_DCR);
+    bitclr32(&CCM_PMCR0, CCM_PMCR0_DCR);
 
     logf("DPTC: Initialized");
 }
@@ -629,7 +628,7 @@ void dvfs_set_lt_weight(enum DVFS_LT_SIGS index, unsigned long value)
         shift -= 16; /* Bits 13:11, 16:14 ... 31:29 */
     }
 
-    imx31_regmod32(reg_p, value << shift, 0x7 << shift);
+    bitmod32(reg_p, value << shift, 0x7 << shift);
 }
 
 
@@ -643,7 +642,7 @@ void dvfs_set_lt_detect(enum DVFS_LT_SIGS index, bool edge)
     else if ((unsigned)index < 16)
         bit = 1ul << (index + 29);
 
-    imx31_regmod32(&CCM_LTR0, edge ? bit : 0, bit);
+    bitmod32(&CCM_LTR0, edge ? bit : 0, bit);
 }
 
 
@@ -652,7 +651,7 @@ void dvfs_set_gp_bit(enum DVFS_DVGPS dvgp, bool assert)
     if ((unsigned)dvgp <= 3)
     {
         unsigned long bit = 1ul << dvgp;
-        imx31_regmod32(&CCM_PMCR1, assert ? bit : 0, bit);
+        bitmod32(&CCM_PMCR1, assert ? bit : 0, bit);
     }
 }
 
@@ -660,8 +659,7 @@ void dvfs_set_gp_bit(enum DVFS_DVGPS dvgp, bool assert)
 /* Turn the wait-for-interrupt monitoring on or off */
 void dvfs_wfi_monitor(bool on)
 {
-    imx31_regmod32(&CCM_PMCR0, on ? 0 : CCM_PMCR0_WFIM,
-                   CCM_PMCR0_WFIM);
+    bitmod32(&CCM_PMCR0, on ? 0 : CCM_PMCR0_WFIM, CCM_PMCR0_WFIM);
 }
 
 
diff --git a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
index f720921fad..39a2cdab04 100644
--- a/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/fmradio-i2c-gigabeat-s.c
@@ -38,14 +38,14 @@ static struct i2c_node si4700_i2c_node =
 void fmradio_i2c_init(void)
 {
     /* RST: LOW */
-    imx31_regclr32(&GPIO1_DR, (1 << 26));
+    bitclr32(&GPIO1_DR, (1 << 26));
     /* RST: OUT */
-    imx31_regset32(&GPIO1_GDIR, (1 << 26));
+    bitset32(&GPIO1_GDIR, (1 << 26));
 
     /* I2C2 SCL: IN, I2C2: SDA IN */
-    imx31_regclr32(&GPIO2_GDIR, (3 << 14));
+    bitclr32(&GPIO2_GDIR, (3 << 14));
     /* I2C2 SCL LO, I2C2 SDA LO */
-    imx31_regclr32(&GPIO2_DR, (3 << 14));
+    bitclr32(&GPIO2_DR, (3 << 14));
 
     /* open-drain pins - external pullups on PCB. Pullup default but
      * disabled */
@@ -73,17 +73,17 @@ void fmradio_i2c_enable(bool enable)
     {
         /* place in GPIO mode to hold SDIO low during RESET release,
          * SEN1 should be high already (pullup) and GPIO3 left alone */
-        imx31_regset32(&GPIO2_GDIR, (1 << 15)); /* SDIO OUT */
+        bitset32(&GPIO2_GDIR, (1 << 15)); /* SDIO OUT */
         /* I2C2_SDA => MCU2_15 */ 
         iomuxc_set_pin_mux(IOMUXC_DCD_DTE1,
                            IOMUXC_MUX_OUT_GPIO | IOMUXC_MUX_IN_GPIO);
         /* enable CLK32KMCU clock */
         mc13783_set(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
         /* enable the fm chip (release RESET) */
-        imx31_regset32(&GPIO1_DR, (1 << 26));
+        bitset32(&GPIO1_DR, (1 << 26));
         sleep(HZ/100);
         /* busmode should be selected - OK to release SDIO */
-        imx31_regclr32(&GPIO2_GDIR, (1 << 15)); /* SDIO IN */
+        bitclr32(&GPIO2_GDIR, (1 << 15)); /* SDIO IN */
         /* restore pin mux (MCU2_15 => I2C2_SDA) */
         iomuxc_set_pin_mux(IOMUXC_DCD_DTE1,
                            IOMUXC_MUX_OUT_ALT2 | IOMUXC_MUX_IN_ALT2);
@@ -97,7 +97,7 @@ void fmradio_i2c_enable(bool enable)
            we can diable the i2c module when not in use */
         i2c_enable_node(&si4700_i2c_node, false);
         /* disable the fm chip */
-        imx31_regclr32(&GPIO1_DR, (1 << 26));
+        bitclr32(&GPIO1_DR, (1 << 26));
         /* disable CLK32KMCU clock */
         mc13783_clear(MC13783_POWER_CONTROL0, MC13783_CLK32KMCUEN);
     }
diff --git a/firmware/target/arm/imx31/gigabeat-s/i2s-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/i2s-gigabeat-s.c
index c2ec0d6cab..6291a9cf18 100644
--- a/firmware/target/arm/imx31/gigabeat-s/i2s-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/i2s-gigabeat-s.c
@@ -35,11 +35,11 @@ void i2s_reset(void)
      * WM Codec post divider (MCLKDIV=1.5):
      * INT_BIT_CLK (MCLK) / 1.5 = 11289600Hz = 256*fs = SYSCLK
      */
-    imx31_regmod32(&CCM_PDR1,
-                   ((1-1) << CCM_PDR1_SSI1_PRE_PODF_POS) |
-                   ((5-1) << CCM_PDR1_SSI1_PODF_POS) |
-                   ((8-1) << CCM_PDR1_SSI2_PRE_PODF_POS) |
-                   ((64-1) << CCM_PDR1_SSI2_PODF_POS),
-                   CCM_PDR1_SSI1_PODF | CCM_PDR1_SSI2_PODF |
-                   CCM_PDR1_SSI1_PRE_PODF | CCM_PDR1_SSI2_PRE_PODF);
+    bitmod32(&CCM_PDR1,
+             ((1-1) << CCM_PDR1_SSI1_PRE_PODF_POS) |
+             ((5-1) << CCM_PDR1_SSI1_PODF_POS) |
+             ((8-1) << CCM_PDR1_SSI2_PRE_PODF_POS) |
+             ((64-1) << CCM_PDR1_SSI2_PODF_POS),
+             CCM_PDR1_SSI1_PODF | CCM_PDR1_SSI2_PODF |
+             CCM_PDR1_SSI1_PRE_PODF | CCM_PDR1_SSI2_PRE_PODF);
 }
diff --git a/firmware/target/arm/imx31/gigabeat-s/lcd-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/lcd-gigabeat-s.c
index cadd0e7ae8..cd583ecd6b 100644
--- a/firmware/target/arm/imx31/gigabeat-s/lcd-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/lcd-gigabeat-s.c
@@ -133,13 +133,13 @@ static void lcd_set_power(bool powered)
         lcd_powered = false;
         lcd_write_reg(0x04, 0x00);
         lcd_enable_interface(false);
-        imx31_regclr32(&GPIO3_DR, (1 << 12));
+        bitclr32(&GPIO3_DR, (1 << 12));
         mc13783_clear(MC13783_REGULATOR_MODE1, MC13783_VCAMEN);
     }
     else
     {
         mc13783_set(MC13783_REGULATOR_MODE1, MC13783_VCAMEN);
-        imx31_regset32(&GPIO3_DR, (1 << 12));
+        bitset32(&GPIO3_DR, (1 << 12));
         lcd_enable_interface(true);
         lcd_write_reg(0x04, 0x01);
         lcd_powered = true;
diff --git a/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
index cfd83f0794..15f9d0bd1c 100644
--- a/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/pcm-gigabeat-s.c
@@ -458,7 +458,7 @@ void pcm_rec_dma_stop(void)
     /* Stop receiving data */
     sdma_channel_stop(DMA_REC_CH_NUM);
 
-    imx31_regclr32(&SSI_SIER1, SSI_SIER_RDMAE);
+    bitclr32(&SSI_SIER1, SSI_SIER_RDMAE);
 
     SSI_SCR1 &= ~SSI_SCR_RE;      /* Disable RX */
     SSI_SRCR1 &= ~SSI_SRCR_RFEN0; /* Disable RX FIFO */
diff --git a/firmware/target/arm/imx31/gigabeat-s/power-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/power-gigabeat-s.c
index 4540be671a..9d7d30547b 100644
--- a/firmware/target/arm/imx31/gigabeat-s/power-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/power-gigabeat-s.c
@@ -85,17 +85,17 @@ void ide_power_enable(bool on)
     if (!on)
     {
         /* Bus must be isolated before power off */
-        imx31_regset32(&GPIO2_DR, (1 << 16));
+        bitset32(&GPIO2_DR, (1 << 16));
     }
 
     /* HD power switch */
-    imx31_regmod32(&GPIO3_DR, on ? (1 << 5) : 0, (1 << 5));
+    bitmod32(&GPIO3_DR, on ? (1 << 5) : 0, (1 << 5));
 
     if (on)
     {
         /* Bus switch may be turned on after powerup */
         sleep(HZ/10);
-        imx31_regclr32(&GPIO2_DR, (1 << 16));
+        bitclr32(&GPIO2_DR, (1 << 16));
     }
 }
 
diff --git a/firmware/target/arm/imx31/gigabeat-s/system-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/system-gigabeat-s.c
index 80b6f22397..f458561731 100644
--- a/firmware/target/arm/imx31/gigabeat-s/system-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/system-gigabeat-s.c
@@ -186,18 +186,18 @@ void INIT_ATTR system_init(void)
     cpu_frequency = ccm_get_mcu_clk();
 
     /* MCR WFI enables wait mode (CCM_CCMR_LPM_WAIT_MODE = 0) */
-    imx31_regclr32(&CCM_CCMR, CCM_CCMR_LPM);
+    bitclr32(&CCM_CCMR, CCM_CCMR_LPM);
 
     iim_init();
 
-    imx31_regset32(&SDHC1_CLOCK_CONTROL, STOP_CLK);
-    imx31_regset32(&SDHC2_CLOCK_CONTROL, STOP_CLK);
-    imx31_regset32(&RNGA_CONTROL, RNGA_CONTROL_SLEEP);
-    imx31_regclr32(&UCR1_1, EUARTUCR1_UARTEN);
-    imx31_regclr32(&UCR1_2, EUARTUCR1_UARTEN);
-    imx31_regclr32(&UCR1_3, EUARTUCR1_UARTEN);
-    imx31_regclr32(&UCR1_4, EUARTUCR1_UARTEN);
-    imx31_regclr32(&UCR1_5, EUARTUCR1_UARTEN);
+    bitset32(&SDHC1_CLOCK_CONTROL, STOP_CLK);
+    bitset32(&SDHC2_CLOCK_CONTROL, STOP_CLK);
+    bitset32(&RNGA_CONTROL, RNGA_CONTROL_SLEEP);
+    bitclr32(&UCR1_1, EUARTUCR1_UARTEN);
+    bitclr32(&UCR1_2, EUARTUCR1_UARTEN);
+    bitclr32(&UCR1_3, EUARTUCR1_UARTEN);
+    bitclr32(&UCR1_4, EUARTUCR1_UARTEN);
+    bitclr32(&UCR1_5, EUARTUCR1_UARTEN);
 
     for (i = 0; i < ARRAYLEN(disable_clocks); i++)
         ccm_module_clock_gating(disable_clocks[i], CGM_OFF);
@@ -207,49 +207,6 @@ void INIT_ATTR system_init(void)
     gpio_init();
 }
 
-void  __attribute__((naked)) imx31_regmod32(volatile uint32_t *reg_p,
-                                            uint32_t value,
-                                            uint32_t mask)
-{
-    asm volatile("and    r1, r1, r2 \n"
-                 "mrs    ip, cpsr   \n"
-                 "cpsid  if         \n"
-                 "ldr    r3, [r0]   \n"
-                 "bic    r3, r3, r2 \n" 
-                 "orr    r3, r3, r1 \n"
-                 "str    r3, [r0]   \n"
-                 "msr    cpsr_c, ip \n"
-                 "bx     lr         \n");
-    (void)reg_p; (void)value; (void)mask;
-}
-
-void __attribute__((naked)) imx31_regset32(volatile uint32_t *reg_p,
-                                           uint32_t mask)
-{
-    asm volatile("mrs    r3, cpsr   \n"
-                 "cpsid  if         \n"
-                 "ldr    r2, [r0]   \n"
-                 "orr    r2, r2, r1 \n"
-                 "str    r2, [r0]   \n"
-                 "msr    cpsr_c, r3 \n"
-                 "bx     lr         \n");
-    (void)reg_p; (void)mask;
-}
-
-void __attribute__((naked)) imx31_regclr32(volatile uint32_t *reg_p,
-                                           uint32_t mask)
-{
-    asm volatile("mrs    r3, cpsr   \n"
-                 "cpsid  if         \n"
-                 "ldr    r2, [r0]   \n"
-                 "bic    r2, r2, r1 \n"
-                 "str    r2, [r0]   \n"
-                 "msr    cpsr_c, r3 \n"
-                 "bx     lr         \n");
-    (void)reg_p; (void)mask;
-}
-
-
 void system_prepare_fw_start(void)
 {
     dvfs_dptc_stop();
diff --git a/firmware/target/arm/imx31/gigabeat-s/system-target.h b/firmware/target/arm/imx31/gigabeat-s/system-target.h
index af95471db6..a13f87a4cd 100644
--- a/firmware/target/arm/imx31/gigabeat-s/system-target.h
+++ b/firmware/target/arm/imx31/gigabeat-s/system-target.h
@@ -51,11 +51,6 @@ void tick_stop(void);
 void kernel_device_init(void);
 void system_halt(void);
 
-void imx31_regmod32(volatile uint32_t *reg_p, uint32_t value,
-                    uint32_t mask);
-void imx31_regset32(volatile uint32_t *reg_p, uint32_t mask);
-void imx31_regclr32(volatile uint32_t *reg_p, uint32_t mask);
-
 #define KDEV_INIT
 
 struct ARM_REGS {
diff --git a/firmware/target/arm/imx31/gigabeat-s/usb-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/usb-gigabeat-s.c
index d873c19ed3..016f24fc48 100644
--- a/firmware/target/arm/imx31/gigabeat-s/usb-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/usb-gigabeat-s.c
@@ -40,16 +40,16 @@ static void enable_transceiver(bool enable)
     {
         if (GPIO1_DR & (1 << 30))
         {
-            imx31_regclr32(&GPIO3_DR, (1 << 16)); /* Reset ISP1504 */
+            bitclr32(&GPIO3_DR, (1 << 16)); /* Reset ISP1504 */
             sleep(HZ/100);
-            imx31_regset32(&GPIO3_DR, (1 << 16));
+            bitset32(&GPIO3_DR, (1 << 16));
             sleep(HZ/10);
-            imx31_regclr32(&GPIO1_DR, (1 << 30)); /* Select ISP1504 */
+            bitclr32(&GPIO1_DR, (1 << 30)); /* Select ISP1504 */
         }
     }
     else
     {
-        imx31_regset32(&GPIO1_DR, (1 << 30)); /* Deselect ISP1504 */
+        bitset32(&GPIO1_DR, (1 << 30)); /* Deselect ISP1504 */
     }
 }
 
diff --git a/firmware/target/arm/imx31/gigabeat-s/wmcodec-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/wmcodec-gigabeat-s.c
index 96324cc162..36ab33a5dc 100644
--- a/firmware/target/arm/imx31/gigabeat-s/wmcodec-gigabeat-s.c
+++ b/firmware/target/arm/imx31/gigabeat-s/wmcodec-gigabeat-s.c
@@ -48,13 +48,13 @@ void audiohw_init(void)
 
     audiohw_preinit();
 
-    imx31_regset32(&GPIO3_DR, (1 << 21)); /* Turn on analogue LDO */
+    bitset32(&GPIO3_DR, (1 << 21)); /* Turn on analogue LDO */
 }
 
 void audiohw_enable_headphone_jack(bool enable)
 {
     /* Turn headphone jack output on or off. */
-    imx31_regmod32(&GPIO3_DR, enable ? (1 << 22) : 0, (1 << 22));
+    bitmod32(&GPIO3_DR, enable ? (1 << 22) : 0, (1 << 22));
 }
 
 void wmcodec_write(int reg, int data)
diff --git a/firmware/target/arm/imx31/iomuxc-imx31.c b/firmware/target/arm/imx31/iomuxc-imx31.c
index 876b8b2a9c..412693e221 100644
--- a/firmware/target/arm/imx31/iomuxc-imx31.c
+++ b/firmware/target/arm/imx31/iomuxc-imx31.c
@@ -32,8 +32,8 @@ void iomuxc_set_pin_mux(enum IMX31_IOMUXC_PINS pin,
     unsigned long index = pin / 4;
     unsigned int shift = 8*(pin % 4);
 
-    imx31_regmod32((unsigned long *)(IOMUXC_BASE_ADDR + 0xc) + index,
-                   mux << shift, IOMUXC_MUX_MASK << shift);
+    bitmod32((unsigned long *)(IOMUXC_BASE_ADDR + 0xc) + index,
+              mux << shift, IOMUXC_MUX_MASK << shift);
 }
 
 
@@ -45,6 +45,6 @@ void iomuxc_set_pad_config(enum IMX31_IOMUXC_PINS pin,
     unsigned long index = padoffs / 3;
     unsigned int shift = 10*(padoffs % 3);
 
-    imx31_regmod32((unsigned long *)(IOMUXC_BASE_ADDR + 0x154) + index,
-                   config << shift, IOMUXC_PAD_MASK << shift);
+    bitmod32((unsigned long *)(IOMUXC_BASE_ADDR + 0x154) + index,
+             config << shift, IOMUXC_PAD_MASK << shift);
 }
diff --git a/firmware/target/arm/imx31/mc13783-imx31.c b/firmware/target/arm/imx31/mc13783-imx31.c
index 6e982af3d3..b236dcd2ab 100644
--- a/firmware/target/arm/imx31/mc13783-imx31.c
+++ b/firmware/target/arm/imx31/mc13783-imx31.c
@@ -106,7 +106,7 @@ static void mc13783_interrupt_thread(void)
          * acknowledged. Reenable interrupt and if anything was still
          * pending or became pending again, another signal will be
          * generated. */
-        imx31_regset32(&MC13783_GPIO_IMR, 1ul << MC13783_GPIO_LINE);
+        bitset32(&MC13783_GPIO_IMR, 1ul << MC13783_GPIO_LINE);
 
         event = mc13783_events;
         event_last = event + MC13783_NUM_EVENTS;
@@ -138,7 +138,7 @@ static void mc13783_interrupt_thread(void)
 void mc13783_event(void)
 {
     /* Mask the interrupt (unmasked when PMIC thread services it). */
-    imx31_regclr32(&MC13783_GPIO_IMR, 1ul << MC13783_GPIO_LINE);
+    bitclr32(&MC13783_GPIO_IMR, 1ul << MC13783_GPIO_LINE);
     MC13783_GPIO_ISR = (1ul << MC13783_GPIO_LINE);
     wakeup_signal(&mc13783_svc_wake);
 }
diff --git a/firmware/target/arm/imx31/sdma-imx31.c b/firmware/target/arm/imx31/sdma-imx31.c
index 4928108f67..381e589c08 100644
--- a/firmware/target/arm/imx31/sdma-imx31.c
+++ b/firmware/target/arm/imx31/sdma-imx31.c
@@ -414,12 +414,12 @@ static void set_channel_ownership(unsigned int channel, unsigned int config)
 
     /* DSP side */
 #if 0 /* Not using this */
-    imx31_regmod32(&SDMA_DSPOVR, (config & CH_OWNSHP_DSP) ? 0 : bit, bit);
+    bitmod32(&SDMA_DSPOVR, (config & CH_OWNSHP_DSP) ? 0 : bit, bit);
 #endif
     /* Event */
-    imx31_regmod32(&SDMA_EVTOVR, (config & CH_OWNSHP_EVT) ? 0 : bit, bit);
+    bitmod32(&SDMA_EVTOVR, (config & CH_OWNSHP_EVT) ? 0 : bit, bit);
     /* MCU side */
-    imx31_regmod32(&SDMA_HOSTOVR, (config & CH_OWNSHP_MCU) ? 0 : bit, bit);
+    bitmod32(&SDMA_HOSTOVR, (config & CH_OWNSHP_MCU) ? 0 : bit, bit);
 }
 
 static bool setup_channel(struct channel_control_block *ccb_p)
@@ -485,12 +485,12 @@ static bool setup_channel(struct channel_control_block *ccb_p)
     if (channel_cfg & CH_OWNSHP_EVT)
     {
         /* Set event ID to channel activation bitmapping */
-        imx31_regset32(&SDMA_CHNENBL(cd_p->event_id1), 1ul << channel);
+        bitset32(&SDMA_CHNENBL(cd_p->event_id1), 1ul << channel);
 
         if (cd_p->per_type == SDMA_PER_ATA)
         {
             /* ATA has two */
-            imx31_regset32(&SDMA_CHNENBL(cd_p->event_id2), 1ul << channel);
+            bitset32(&SDMA_CHNENBL(cd_p->event_id2), 1ul << channel);
         }
     }
 
@@ -676,7 +676,7 @@ void sdma_channel_stop(unsigned int channel)
 
     /* Unlock callback if it was set */
     if (intmsk & chmsk)
-        imx31_regset32(&sdma_enabled_ints, chmsk);
+        bitset32(&sdma_enabled_ints, chmsk);
 
     logf("SDMA ch closed: %d", channel);
 }
@@ -721,7 +721,7 @@ bool sdma_channel_init(unsigned int channel,
 
     /* Enable interrupt if a callback is specified. */
     if (cd_p->callback != NULL)
-        imx31_regset32(&sdma_enabled_ints, 1ul << channel);
+        bitset32(&sdma_enabled_ints, 1ul << channel);
 
     /* Minimum schedulable = 1 */
     sdma_channel_set_priority(channel, 1);
@@ -741,7 +741,7 @@ void sdma_channel_close(unsigned int channel)
     ccb_p = &ccb_array[channel];
 
     /* Block callbacks (if not initialized, it won't be set). */
-    imx31_regclr32(&sdma_enabled_ints, 1ul << channel);
+    bitclr32(&sdma_enabled_ints, 1ul << channel);
 
     if (ccb_p->status.opened_init == 0)
         return;
diff --git a/firmware/target/arm/s3c2440/adc-s3c2440.c b/firmware/target/arm/s3c2440/adc-s3c2440.c
index f42a3d2b6a..2e0cf8a512 100644
--- a/firmware/target/arm/s3c2440/adc-s3c2440.c
+++ b/firmware/target/arm/s3c2440/adc-s3c2440.c
@@ -39,7 +39,7 @@ void adc_init(void)
     int i;
 
     /* Turn on the ADC PCLK */
-    s3c_regset32(&CLKCON, 1<<15);
+    bitset32(&CLKCON, 1<<15);
 
     /* Set channel 0, normal mode, disable "start by read" */
     ADCCON &= ~(0x3F);
diff --git a/firmware/target/arm/s3c2440/dma-s3c2440.c b/firmware/target/arm/s3c2440/dma-s3c2440.c
index b83897cb22..c8df4fcc75 100644
--- a/firmware/target/arm/s3c2440/dma-s3c2440.c
+++ b/firmware/target/arm/s3c2440/dma-s3c2440.c
@@ -76,8 +76,8 @@ void dma_init(void)
     INTPND = DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK;
     
     /* Enable interrupt in controller */
-    s3c_regclr32(&INTMOD, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
-    s3c_regclr32(&INTMSK, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
+    bitclr32(&INTMOD, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
+    bitclr32(&INTMSK, DMA0_MASK | DMA1_MASK | DMA2_MASK | DMA3_MASK);
 }
 
 void dma_retain(void)
diff --git a/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c b/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
index e9f55479c7..c1c9017fbb 100644
--- a/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
+++ b/firmware/target/arm/s3c2440/gigabeat-fx/pcm-meg-fx.c
@@ -50,14 +50,14 @@ void fiq_handler(void) __attribute__((interrupt ("FIQ")));
 void pcm_play_lock(void)
 {
     if (++dma_play_lock.locked == 1)
-        s3c_regset32(&INTMSK, DMA2_MASK);
+        bitset32(&INTMSK, DMA2_MASK);
 }
 
 /* Unmask the DMA interrupt if enabled */
 void pcm_play_unlock(void)
 {
     if (--dma_play_lock.locked == 0)
-        s3c_regclr32(&INTMSK, dma_play_lock.state);
+        bitclr32(&INTMSK, dma_play_lock.state);
 }
 
 void pcm_play_dma_init(void)
@@ -65,7 +65,7 @@ void pcm_play_dma_init(void)
     /* There seem to be problems when changing the IIS interface configuration
      * when a clock is not present.
      */
-    s3c_regset32(&CLKCON, 1<<17);
+    bitset32(&CLKCON, 1<<17);
     /* slave, transmit mode, 16 bit samples - MCLK 384fs - use 16.9344Mhz -
        BCLK 32fs */
     IISMOD = (1<<9) | (1<<8) | (2<<6) | (1<<3) | (1<<2) | (1<<0);
@@ -73,7 +73,7 @@ void pcm_play_dma_init(void)
     /* RX,TX off,on */
     IISCON |= (1<<3) | (1<<2);
 
-    s3c_regclr32(&CLKCON, 1<<17);
+    bitclr32(&CLKCON, 1<<17);
 
     audiohw_init();
 
@@ -86,11 +86,11 @@ void pcm_play_dma_init(void)
     /* Do not service DMA requests, yet */
 
     /* clear any pending int and mask it */
-    s3c_regset32(&INTMSK, DMA2_MASK);
+    bitset32(&INTMSK, DMA2_MASK);
     SRCPND = DMA2_MASK;
 
     /* connect to FIQ */
-    s3c_regset32(&INTMOD, DMA2_MASK);
+    bitset32(&INTMOD, DMA2_MASK);
 }
 
 void pcm_postinit(void)
@@ -132,7 +132,7 @@ static void play_start_pcm(void)
 static void play_stop_pcm(void)
 {
     /* Mask DMA interrupt */
-    s3c_regset32(&INTMSK, DMA2_MASK);
+    bitset32(&INTMSK, DMA2_MASK);
 
     /* De-Activate the DMA channel */
     DMASKTRIG2 = 0x4;
@@ -160,7 +160,7 @@ static void play_stop_pcm(void)
 void pcm_play_dma_start(const void *addr, size_t size)
 {
     /* Enable the IIS clock */
-    s3c_regset32(&CLKCON, 1<<17);
+    bitset32(&CLKCON, 1<<17);
 
     /* stop any DMA in progress - idle IIS */
     play_stop_pcm();
@@ -191,7 +191,7 @@ void pcm_play_dma_stop(void)
     play_stop_pcm();
 
     /* Disconnect the IIS clock */
-    s3c_regclr32(&CLKCON, 1<<17);
+    bitclr32(&CLKCON, 1<<17);
 }
 
 void pcm_play_dma_pause(bool pause)
diff --git a/firmware/target/arm/s3c2440/i2c-s3c2440.c b/firmware/target/arm/s3c2440/i2c-s3c2440.c
index 4669186a4c..155eb2f956 100644
--- a/firmware/target/arm/s3c2440/i2c-s3c2440.c
+++ b/firmware/target/arm/s3c2440/i2c-s3c2440.c
@@ -43,7 +43,7 @@ void i2c_write(int addr, const unsigned char *buf, int count)
     mutex_lock(&i2c_mtx);
 
     /* Turn on I2C clock */
-    s3c_regset32(&CLKCON, 1 << 16);
+    bitset32(&CLKCON, 1 << 16);
 
     /* Set mode to master transmitter and enable lines */
     IICSTAT = I2C_MODE_MASTER | I2C_MODE_TX | I2C_RXTX_ENB;
@@ -76,7 +76,7 @@ void i2c_write(int addr, const unsigned char *buf, int count)
     IICSTAT = 0;
 
     /* Turn off I2C clock */
-    s3c_regclr32(&CLKCON, 1 << 16);
+    bitclr32(&CLKCON, 1 << 16);
 
     mutex_unlock(&i2c_mtx);
 }
@@ -92,11 +92,11 @@ void i2c_init(void)
     INTPND = IIC_MASK;
 
     /* Enable i2c interrupt in controller */
-    s3c_regclr32(&INTMOD, IIC_MASK);
-    s3c_regclr32(&INTMSK, IIC_MASK);
+    bitclr32(&INTMOD, IIC_MASK);
+    bitclr32(&INTMSK, IIC_MASK);
 
     /* Turn on I2C clock */
-    s3c_regset32(&CLKCON, 1 << 16);
+    bitset32(&CLKCON, 1 << 16);
 
     /* Set GPE15 (IICSDA) and GPE14 (IICSCL) to IIC */
     GPECON = (GPECON & ~((3 << 30) | (3 << 28))) |
@@ -110,7 +110,7 @@ void i2c_init(void)
     IICLC = (0 << 0);
 
     /* Turn off I2C clock */
-    s3c_regclr32(&CLKCON, 1 << 16);
+    bitclr32(&CLKCON, 1 << 16);
 }
 
 void IIC(void)
diff --git a/firmware/target/arm/s3c2440/kernel-s3c2440.c b/firmware/target/arm/s3c2440/kernel-s3c2440.c
index 6cabc8dc81..892758e147 100644
--- a/firmware/target/arm/s3c2440/kernel-s3c2440.c
+++ b/firmware/target/arm/s3c2440/kernel-s3c2440.c
@@ -62,7 +62,7 @@ void tick_start(unsigned int interval_in_ms)
 #ifdef BOOTLOADER
 void tick_stop(void)
 {
-    s3c_regset32(&INTMSK, TIMER4_MASK);
+    bitset32(&INTMSK, TIMER4_MASK);
     TCON &= ~(1 << 20);
     SRCPND = TIMER4_MASK;
     INTPND = TIMER4_MASK;
diff --git a/firmware/target/arm/s3c2440/lcd-s3c2440.c b/firmware/target/arm/s3c2440/lcd-s3c2440.c
index b9f7d3ef3d..77be29f556 100644
--- a/firmware/target/arm/s3c2440/lcd-s3c2440.c
+++ b/firmware/target/arm/s3c2440/lcd-s3c2440.c
@@ -101,7 +101,7 @@ static void LCD_CTRL_clock(bool onoff)
         GPDCON  |= 0xAAA0AAA0;
         GPDUP   |= 0xFCFC;
 
-        s3c_regset32(&CLKCON, 0x20);  /* enable LCD clock */
+        bitset32(&CLKCON, 0x20);  /* enable LCD clock */
         LCDCON1 |= LCD_ENVID;
     }
     else
@@ -113,7 +113,7 @@ static void LCD_CTRL_clock(bool onoff)
         GPDUP   &= ~0xFCFC;
 
         LCDCON1 &= ~LCD_ENVID;        /* Must disable first or bus may freeze */
-        s3c_regclr32(&CLKCON, 0x20);  /* disable LCD clock */
+        bitclr32(&CLKCON, 0x20);  /* disable LCD clock */
     }
 }
 
@@ -165,7 +165,7 @@ static void LCD_SPI_SS(bool select)
 
 static void LCD_SPI_start(void)
 {
-    s3c_regset32(&CLKCON, 0x40000);   /* enable SPI clock */
+    bitset32(&CLKCON, 0x40000);   /* enable SPI clock */
     LCD_SPI_SS(false);
     SPCON0=0x3E;
     SPPRE0=24;
@@ -179,7 +179,7 @@ static void LCD_SPI_stop(void)
     LCD_SPI_SS(false);
 
     SPCON0 &= ~0x10;
-    s3c_regclr32(&CLKCON, 0x40000);    /* disable SPI clock */
+    bitclr32(&CLKCON, 0x40000);    /* disable SPI clock */
 }
 
 static void LCD_SPI_init(void)
@@ -253,7 +253,7 @@ void lcd_init_device(void)
     GPBUP   |= 0x181;
 #endif
 
-    s3c_regset32(&CLKCON, 0x20);  /* enable LCD clock */
+    bitset32(&CLKCON, 0x20);  /* enable LCD clock */
 
     LCD_CTRL_setup();
 #ifdef GIGABEAT_F
diff --git a/firmware/target/arm/s3c2440/mini2440/pcm-mini2440.c b/firmware/target/arm/s3c2440/mini2440/pcm-mini2440.c
index 30db29c42c..8a6b62f31f 100644
--- a/firmware/target/arm/s3c2440/mini2440/pcm-mini2440.c
+++ b/firmware/target/arm/s3c2440/mini2440/pcm-mini2440.c
@@ -62,14 +62,14 @@ void fiq_handler(void) __attribute__((interrupt ("FIQ")));
 void pcm_play_lock(void)
 {
     if (++dma_play_lock.locked == 1)
-        s3c_regset32(&INTMSK, DMA2_MASK);
+        bitset32(&INTMSK, DMA2_MASK);
 }
 
 /* Unmask the DMA interrupt if enabled */
 void pcm_play_unlock(void)
 {
     if (--dma_play_lock.locked == 0)
-        s3c_regclr32(&INTMSK, dma_play_lock.state);
+        bitclr32(&INTMSK, dma_play_lock.state);
 }
 
 void pcm_play_dma_init(void)
@@ -77,7 +77,7 @@ void pcm_play_dma_init(void)
     /* There seem to be problems when changing the IIS interface configuration
      * when a clock is not present.
      */
-    s3c_regset32(&CLKCON, 1<<17);
+    bitset32(&CLKCON, 1<<17);
     
 #ifdef HAVE_UDA1341
     /* master, transmit mode, 16 bit samples, BCLK 32fs, PCLK */
@@ -95,7 +95,7 @@ void pcm_play_dma_init(void)
     IISCON |= (1<<3) | (1<<2);
 #endif
 
-    s3c_regclr32(&CLKCON, 1<<17);
+    bitclr32(&CLKCON, 1<<17);
 
     audiohw_init();
 
@@ -112,11 +112,11 @@ void pcm_play_dma_init(void)
     /* Do not service DMA requests, yet */
 
     /* clear any pending int and mask it */
-    s3c_regset32(&INTMSK, DMA2_MASK);
+    bitset32(&INTMSK, DMA2_MASK);
     SRCPND = DMA2_MASK;
 
     /* connect to FIQ */
-    s3c_regset32(&INTMOD, DMA2_MASK);
+    bitset32(&INTMOD, DMA2_MASK);
 }
 
 void pcm_postinit(void)
@@ -172,7 +172,7 @@ static void play_start_pcm(void)
 static void play_stop_pcm(void)
 {
     /* Mask DMA interrupt */
-    s3c_regset32(&INTMSK, DMA2_MASK);
+    bitset32(&INTMSK, DMA2_MASK);
 
     /* De-Activate the DMA channel */
     DMASKTRIG2 = 0x4;
@@ -200,7 +200,7 @@ static void play_stop_pcm(void)
 void pcm_play_dma_start(const void *addr, size_t size)
 {
     /* Enable the IIS clock */
-    s3c_regset32(&CLKCON, 1<<17);
+    bitset32(&CLKCON, 1<<17);
 
     /* stop any DMA in progress - idle IIS */
     play_stop_pcm();
@@ -231,7 +231,7 @@ void pcm_play_dma_stop(void)
     play_stop_pcm();
 
     /* Disconnect the IIS clock */
-    s3c_regclr32(&CLKCON, 1<<17);
+    bitclr32(&CLKCON, 1<<17);
 }
 
 void pcm_play_dma_pause(bool pause)
diff --git a/firmware/target/arm/s3c2440/sd-s3c2440.c b/firmware/target/arm/s3c2440/sd-s3c2440.c
index f4c8a4f599..d42405db65 100644
--- a/firmware/target/arm/s3c2440/sd-s3c2440.c
+++ b/firmware/target/arm/s3c2440/sd-s3c2440.c
@@ -299,8 +299,8 @@ static void init_sdi_controller(const int card_no)
 
 #if 1
     /* Enable interrupt in controller */
-    s3c_regclr32(&INTMOD, SDI_MASK);
-    s3c_regclr32(&INTMSK, SDI_MASK);
+    bitclr32(&INTMOD, SDI_MASK);
+    bitclr32(&INTMSK, SDI_MASK);
     
     SDIIMSK |= S3C2410_SDIIMSK_DATAFINISH 
                | S3C2410_SDIIMSK_DATATIMEOUT
diff --git a/firmware/target/arm/s3c2440/system-s3c2440.c b/firmware/target/arm/s3c2440/system-s3c2440.c
index cb273ad4df..577b46966c 100644
--- a/firmware/target/arm/s3c2440/system-s3c2440.c
+++ b/firmware/target/arm/s3c2440/system-s3c2440.c
@@ -136,24 +136,6 @@ void memory_init(void)
     enable_mmu();
 }
 
-void s3c_regmod32(volatile unsigned long *reg, unsigned long bits,
-                  unsigned long mask)
-{
-    int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS);
-    *reg = (*reg & ~mask) | (bits & mask);
-    restore_interrupt(oldstatus);
-}
-
-void s3c_regset32(volatile unsigned long *reg, unsigned long bits)
-{
-    s3c_regmod32(reg, bits, bits);
-}
-
-void s3c_regclr32(volatile unsigned long *reg, unsigned long bits)
-{
-    s3c_regmod32(reg, 0, bits);
-}
-
 #ifdef BOOTLOADER
 void system_prepare_fw_start(void)
 {
diff --git a/firmware/target/arm/s3c2440/system-target.h b/firmware/target/arm/s3c2440/system-target.h
index ad32f89552..c48a62cf47 100644
--- a/firmware/target/arm/s3c2440/system-target.h
+++ b/firmware/target/arm/s3c2440/system-target.h
@@ -69,14 +69,4 @@
 void system_prepare_fw_start(void);
 void tick_stop(void);
 
-/* Functions to set and clear register bits atomically */
-
-/* Set and clear register bits */
-void s3c_regmod32(volatile unsigned long *reg, unsigned long bits,
-                  unsigned long mask);
-/* Set register bits */
-void s3c_regset32(volatile unsigned long *reg, unsigned long bits);
-/* Clear register bits */
-void s3c_regclr32(volatile unsigned long *reg, unsigned long bits);
-
 #endif /* SYSTEM_TARGET_H */