[ARM] 3992/1: i.MX/MX1 CPU Frequency scaling support

Support to change MX1 CPU frequency at runtime.
Tested on PiKRON's PiMX1 board and seems to be fully
stable up to 200 MHz end even as low as 8 MHz.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 7 insertions, 3 deletions

diff --git a/include/asm-arm/arch-imx/imx-regs.h b/include/asm-arm/arch-imx/imx-regs.h
index a6912b3d8671..e56a4e247d62 100644
--- a/include/asm-arm/arch-imx/imx-regs.h
+++ b/include/asm-arm/arch-imx/imx-regs.h
@@ -41,7 +41,13 @@
 
 /* PLL registers */
 #define CSCR   __REG(IMX_PLL_BASE)        /* Clock Source Control Register */
-#define CSCR_SYSTEM_SEL (1<<16)
+#define CSCR_SPLL_RESTART       (1<<22)
+#define CSCR_MPLL_RESTART       (1<<21)
+#define CSCR_SYSTEM_SEL         (1<<16)
+#define CSCR_BCLK_DIV           (0xf<<10)
+#define CSCR_MPU_PRESC          (1<<15)
+#define CSCR_SPEN               (1<<1)
+#define CSCR_MPEN               (1<<0)
 
 #define MPCTL0 __REG(IMX_PLL_BASE + 0x4)  /* MCU PLL Control Register 0 */
 #define MPCTL1 __REG(IMX_PLL_BASE + 0x8)  /* MCU PLL and System Clock Register 1 */
@@ -49,8 +55,6 @@
 #define SPCTL1 __REG(IMX_PLL_BASE + 0x10) /* System PLL Control Register 1 */
 #define PCDR   __REG(IMX_PLL_BASE + 0x20) /* Peripheral Clock Divider Register */
 
-#define CSCR_MPLL_RESTART (1<<21)
-
 /*
  *  GPIO Module and I/O Multiplexer
  *  x = 0..3 for reg_A, reg_B, reg_C, reg_D