m68k: move coldfire platform code

Move the m68k ColdFire platform support code directory to be with the
existing m68k platforms. Although the ColdFire is not a platform as such,
we have always kept all its support together. No reason to change that
as this time.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

1 files changed, 588 insertions, 0 deletions

diff --git a/arch/m68k/coldfire/m53xx.c b/arch/m68k/coldfire/m53xx.c
new file mode 100644
index 000000000000..80879a7fe3d5
--- /dev/null
+++ b/arch/m68k/coldfire/m53xx.c
@@ -0,0 +1,588 @@
+/***************************************************************************/
+
+/*
+ *	m53xx.c -- platform support for ColdFire 53xx based boards
+ *
+ *	Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
+ *	Copyright (C) 2000, Lineo (www.lineo.com)
+ *	Yaroslav Vinogradov yaroslav.vinogradov@freescale.com
+ *	Copyright Freescale Semiconductor, Inc 2006
+ *	Copyright (c) 2006, emlix, Sebastian Hess <shess@hessware.de>
+ *
+ * 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.
+ */
+
+/***************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <asm/machdep.h>
+#include <asm/coldfire.h>
+#include <asm/mcfsim.h>
+#include <asm/mcfuart.h>
+#include <asm/mcfdma.h>
+#include <asm/mcfwdebug.h>
+#include <asm/mcfclk.h>
+
+/***************************************************************************/
+
+DEFINE_CLK(0, "flexbus", 2, MCF_CLK);
+DEFINE_CLK(0, "mcfcan.0", 8, MCF_CLK);
+DEFINE_CLK(0, "fec.0", 12, MCF_CLK);
+DEFINE_CLK(0, "edma", 17, MCF_CLK);
+DEFINE_CLK(0, "intc.0", 18, MCF_CLK);
+DEFINE_CLK(0, "intc.1", 19, MCF_CLK);
+DEFINE_CLK(0, "iack.0", 21, MCF_CLK);
+DEFINE_CLK(0, "mcfi2c.0", 22, MCF_CLK);
+DEFINE_CLK(0, "mcfqspi.0", 23, MCF_CLK);
+DEFINE_CLK(0, "mcfuart.0", 24, MCF_BUSCLK);
+DEFINE_CLK(0, "mcfuart.1", 25, MCF_BUSCLK);
+DEFINE_CLK(0, "mcfuart.2", 26, MCF_BUSCLK);
+DEFINE_CLK(0, "mcftmr.0", 28, MCF_CLK);
+DEFINE_CLK(0, "mcftmr.1", 29, MCF_CLK);
+DEFINE_CLK(0, "mcftmr.2", 30, MCF_CLK);
+DEFINE_CLK(0, "mcftmr.3", 31, MCF_CLK);
+
+DEFINE_CLK(0, "mcfpit.0", 32, MCF_CLK);
+DEFINE_CLK(0, "mcfpit.1", 33, MCF_CLK);
+DEFINE_CLK(0, "mcfpit.2", 34, MCF_CLK);
+DEFINE_CLK(0, "mcfpit.3", 35, MCF_CLK);
+DEFINE_CLK(0, "mcfpwm.0", 36, MCF_CLK);
+DEFINE_CLK(0, "mcfeport.0", 37, MCF_CLK);
+DEFINE_CLK(0, "mcfwdt.0", 38, MCF_CLK);
+DEFINE_CLK(0, "sys.0", 40, MCF_BUSCLK);
+DEFINE_CLK(0, "gpio.0", 41, MCF_BUSCLK);
+DEFINE_CLK(0, "mcfrtc.0", 42, MCF_CLK);
+DEFINE_CLK(0, "mcflcd.0", 43, MCF_CLK);
+DEFINE_CLK(0, "mcfusb-otg.0", 44, MCF_CLK);
+DEFINE_CLK(0, "mcfusb-host.0", 45, MCF_CLK);
+DEFINE_CLK(0, "sdram.0", 46, MCF_CLK);
+DEFINE_CLK(0, "ssi.0", 47, MCF_CLK);
+DEFINE_CLK(0, "pll.0", 48, MCF_CLK);
+
+DEFINE_CLK(1, "mdha.0", 32, MCF_CLK);
+DEFINE_CLK(1, "skha.0", 33, MCF_CLK);
+DEFINE_CLK(1, "rng.0", 34, MCF_CLK);
+
+struct clk *mcf_clks[] = {
+	&__clk_0_2,	/* flexbus */
+	&__clk_0_8,	/* mcfcan.0 */
+	&__clk_0_12,	/* fec.0 */
+	&__clk_0_17,	/* edma */
+	&__clk_0_18,	/* intc.0 */
+	&__clk_0_19,	/* intc.1 */
+	&__clk_0_21,	/* iack.0 */
+	&__clk_0_22,	/* mcfi2c.0 */
+	&__clk_0_23,	/* mcfqspi.0 */
+	&__clk_0_24,	/* mcfuart.0 */
+	&__clk_0_25,	/* mcfuart.1 */
+	&__clk_0_26,	/* mcfuart.2 */
+	&__clk_0_28,	/* mcftmr.0 */
+	&__clk_0_29,	/* mcftmr.1 */
+	&__clk_0_30,	/* mcftmr.2 */
+	&__clk_0_31,	/* mcftmr.3 */
+
+	&__clk_0_32,	/* mcfpit.0 */
+	&__clk_0_33,	/* mcfpit.1 */
+	&__clk_0_34,	/* mcfpit.2 */
+	&__clk_0_35,	/* mcfpit.3 */
+	&__clk_0_36,	/* mcfpwm.0 */
+	&__clk_0_37,	/* mcfeport.0 */
+	&__clk_0_38,	/* mcfwdt.0 */
+	&__clk_0_40,	/* sys.0 */
+	&__clk_0_41,	/* gpio.0 */
+	&__clk_0_42,	/* mcfrtc.0 */
+	&__clk_0_43,	/* mcflcd.0 */
+	&__clk_0_44,	/* mcfusb-otg.0 */
+	&__clk_0_45,	/* mcfusb-host.0 */
+	&__clk_0_46,	/* sdram.0 */
+	&__clk_0_47,	/* ssi.0 */
+	&__clk_0_48,	/* pll.0 */
+
+	&__clk_1_32,	/* mdha.0 */
+	&__clk_1_33,	/* skha.0 */
+	&__clk_1_34,	/* rng.0 */
+	NULL,
+};
+
+static struct clk * const enable_clks[] __initconst = {
+	&__clk_0_2,	/* flexbus */
+	&__clk_0_18,	/* intc.0 */
+	&__clk_0_19,	/* intc.1 */
+	&__clk_0_21,	/* iack.0 */
+	&__clk_0_24,	/* mcfuart.0 */
+	&__clk_0_25,	/* mcfuart.1 */
+	&__clk_0_26,	/* mcfuart.2 */
+	&__clk_0_28,	/* mcftmr.0 */
+	&__clk_0_29,	/* mcftmr.1 */
+	&__clk_0_32,	/* mcfpit.0 */
+	&__clk_0_33,	/* mcfpit.1 */
+	&__clk_0_37,	/* mcfeport.0 */
+	&__clk_0_40,	/* sys.0 */
+	&__clk_0_41,	/* gpio.0 */
+	&__clk_0_46,	/* sdram.0 */
+	&__clk_0_48,	/* pll.0 */
+};
+
+static struct clk * const disable_clks[] __initconst = {
+	&__clk_0_8,	/* mcfcan.0 */
+	&__clk_0_12,	/* fec.0 */
+	&__clk_0_17,	/* edma */
+	&__clk_0_22,	/* mcfi2c.0 */
+	&__clk_0_23,	/* mcfqspi.0 */
+	&__clk_0_30,	/* mcftmr.2 */
+	&__clk_0_31,	/* mcftmr.3 */
+	&__clk_0_34,	/* mcfpit.2 */
+	&__clk_0_35,	/* mcfpit.3 */
+	&__clk_0_36,	/* mcfpwm.0 */
+	&__clk_0_38,	/* mcfwdt.0 */
+	&__clk_0_42,	/* mcfrtc.0 */
+	&__clk_0_43,	/* mcflcd.0 */
+	&__clk_0_44,	/* mcfusb-otg.0 */
+	&__clk_0_45,	/* mcfusb-host.0 */
+	&__clk_0_47,	/* ssi.0 */
+	&__clk_1_32,	/* mdha.0 */
+	&__clk_1_33,	/* skha.0 */
+	&__clk_1_34,	/* rng.0 */
+};
+
+
+static void __init m53xx_clk_init(void)
+{
+	unsigned i;
+
+	/* make sure these clocks are enabled */
+	for (i = 0; i < ARRAY_SIZE(enable_clks); ++i)
+		__clk_init_enabled(enable_clks[i]);
+	/* make sure these clocks are disabled */
+	for (i = 0; i < ARRAY_SIZE(disable_clks); ++i)
+		__clk_init_disabled(disable_clks[i]);
+}
+
+/***************************************************************************/
+
+static void __init m53xx_qspi_init(void)
+{
+#if IS_ENABLED(CONFIG_SPI_COLDFIRE_QSPI)
+	/* setup QSPS pins for QSPI with gpio CS control */
+	writew(0x01f0, MCFGPIO_PAR_QSPI);
+#endif /* IS_ENABLED(CONFIG_SPI_COLDFIRE_QSPI) */
+}
+
+/***************************************************************************/
+
+static void __init m53xx_uarts_init(void)
+{
+	/* UART GPIO initialization */
+	writew(readw(MCFGPIO_PAR_UART) | 0x0FFF, MCFGPIO_PAR_UART);
+}
+
+/***************************************************************************/
+
+static void __init m53xx_fec_init(void)
+{
+	u8 v;
+
+	/* Set multi-function pins to ethernet mode for fec0 */
+	v = readb(MCFGPIO_PAR_FECI2C);
+	v |= MCF_GPIO_PAR_FECI2C_PAR_MDC_EMDC |
+		MCF_GPIO_PAR_FECI2C_PAR_MDIO_EMDIO;
+	writeb(v, MCFGPIO_PAR_FECI2C);
+
+	v = readb(MCFGPIO_PAR_FEC);
+	v = MCF_GPIO_PAR_FEC_PAR_FEC_7W_FEC | MCF_GPIO_PAR_FEC_PAR_FEC_MII_FEC;
+	writeb(v, MCFGPIO_PAR_FEC);
+}
+
+/***************************************************************************/
+
+void __init config_BSP(char *commandp, int size)
+{
+#if !defined(CONFIG_BOOTPARAM)
+	/* Copy command line from FLASH to local buffer... */
+	memcpy(commandp, (char *) 0x4000, 4);
+	if(strncmp(commandp, "kcl ", 4) == 0){
+		memcpy(commandp, (char *) 0x4004, size);
+		commandp[size-1] = 0;
+	} else {
+		memset(commandp, 0, size);
+	}
+#endif
+	mach_sched_init = hw_timer_init;
+	m53xx_clk_init();
+	m53xx_uarts_init();
+	m53xx_fec_init();
+	m53xx_qspi_init();
+
+#ifdef CONFIG_BDM_DISABLE
+	/*
+	 * Disable the BDM clocking.  This also turns off most of the rest of
+	 * the BDM device.  This is good for EMC reasons. This option is not
+	 * incompatible with the memory protection option.
+	 */
+	wdebug(MCFDEBUG_CSR, MCFDEBUG_CSR_PSTCLK);
+#endif
+}
+
+/***************************************************************************/
+/* Board initialization */
+/***************************************************************************/
+/* 
+ * PLL min/max specifications
+ */
+#define MAX_FVCO	500000	/* KHz */
+#define MAX_FSYS	80000 	/* KHz */
+#define MIN_FSYS	58333 	/* KHz */
+#define FREF		16000   /* KHz */
+
+
+#define MAX_MFD		135     /* Multiplier */
+#define MIN_MFD		88      /* Multiplier */
+#define BUSDIV		6       /* Divider */
+
+/*
+ * Low Power Divider specifications
+ */
+#define MIN_LPD		(1 << 0)    /* Divider (not encoded) */
+#define MAX_LPD		(1 << 15)   /* Divider (not encoded) */
+#define DEFAULT_LPD	(1 << 1)	/* Divider (not encoded) */
+
+#define SYS_CLK_KHZ	80000
+#define SYSTEM_PERIOD	12.5
+/*
+ *  SDRAM Timing Parameters
+ */  
+#define SDRAM_BL	8	/* # of beats in a burst */
+#define SDRAM_TWR	2	/* in clocks */
+#define SDRAM_CASL	2.5	/* CASL in clocks */
+#define SDRAM_TRCD	2	/* in clocks */
+#define SDRAM_TRP	2	/* in clocks */
+#define SDRAM_TRFC	7	/* in clocks */
+#define SDRAM_TREFI	7800	/* in ns */
+
+#define EXT_SRAM_ADDRESS	(0xC0000000)
+#define FLASH_ADDRESS		(0x00000000)
+#define SDRAM_ADDRESS		(0x40000000)
+
+#define NAND_FLASH_ADDRESS	(0xD0000000)
+
+int sys_clk_khz = 0;
+int sys_clk_mhz = 0;
+
+void wtm_init(void);
+void scm_init(void);
+void gpio_init(void);
+void fbcs_init(void);
+void sdramc_init(void);
+int  clock_pll (int fsys, int flags);
+int  clock_limp (int);
+int  clock_exit_limp (void);
+int  get_sys_clock (void);
+
+asmlinkage void __init sysinit(void)
+{
+	sys_clk_khz = clock_pll(0, 0);
+	sys_clk_mhz = sys_clk_khz/1000;
+	
+	wtm_init();
+	scm_init();
+	gpio_init();
+	fbcs_init();
+	sdramc_init();
+}
+
+void wtm_init(void)
+{
+	/* Disable watchdog timer */
+	writew(0, MCF_WTM_WCR);
+}
+
+#define MCF_SCM_BCR_GBW		(0x00000100)
+#define MCF_SCM_BCR_GBR		(0x00000200)
+
+void scm_init(void)
+{
+	/* All masters are trusted */
+	writel(0x77777777, MCF_SCM_MPR);
+    
+	/* Allow supervisor/user, read/write, and trusted/untrusted
+	   access to all slaves */
+	writel(0, MCF_SCM_PACRA);
+	writel(0, MCF_SCM_PACRB);
+	writel(0, MCF_SCM_PACRC);
+	writel(0, MCF_SCM_PACRD);
+	writel(0, MCF_SCM_PACRE);
+	writel(0, MCF_SCM_PACRF);
+
+	/* Enable bursts */
+	writel(MCF_SCM_BCR_GBR | MCF_SCM_BCR_GBW, MCF_SCM_BCR);
+}
+
+
+void fbcs_init(void)
+{
+	writeb(0x3E, MCFGPIO_PAR_CS);
+
+	/* Latch chip select */
+	writel(0x10080000, MCF_FBCS1_CSAR);
+
+	writel(0x002A3780, MCF_FBCS1_CSCR);
+	writel(MCF_FBCS_CSMR_BAM_2M | MCF_FBCS_CSMR_V, MCF_FBCS1_CSMR);
+
+	/* Initialize latch to drive signals to inactive states */
+	writew(0xffff, 0x10080000);
+
+	/* External SRAM */
+	writel(EXT_SRAM_ADDRESS, MCF_FBCS1_CSAR);
+	writel(MCF_FBCS_CSCR_PS_16 |
+		MCF_FBCS_CSCR_AA |
+		MCF_FBCS_CSCR_SBM |
+		MCF_FBCS_CSCR_WS(1),
+		MCF_FBCS1_CSCR);
+	writel(MCF_FBCS_CSMR_BAM_512K | MCF_FBCS_CSMR_V, MCF_FBCS1_CSMR);
+
+	/* Boot Flash connected to FBCS0 */
+	writel(FLASH_ADDRESS, MCF_FBCS0_CSAR);
+	writel(MCF_FBCS_CSCR_PS_16 |
+		MCF_FBCS_CSCR_BEM |
+		MCF_FBCS_CSCR_AA |
+		MCF_FBCS_CSCR_SBM |
+		MCF_FBCS_CSCR_WS(7),
+		MCF_FBCS0_CSCR);
+	writel(MCF_FBCS_CSMR_BAM_32M | MCF_FBCS_CSMR_V, MCF_FBCS0_CSMR);
+}
+
+void sdramc_init(void)
+{
+	/*
+	 * Check to see if the SDRAM has already been initialized
+	 * by a run control tool
+	 */
+	if (!(readl(MCF_SDRAMC_SDCR) & MCF_SDRAMC_SDCR_REF)) {
+		/* SDRAM chip select initialization */
+		
+		/* Initialize SDRAM chip select */
+		writel(MCF_SDRAMC_SDCS_BA(SDRAM_ADDRESS) |
+			MCF_SDRAMC_SDCS_CSSZ(MCF_SDRAMC_SDCS_CSSZ_32MBYTE),
+			MCF_SDRAMC_SDCS0);
+
+	/*
+	 * Basic configuration and initialization
+	 */
+	writel(MCF_SDRAMC_SDCFG1_SRD2RW((int)((SDRAM_CASL + 2) + 0.5)) |
+		MCF_SDRAMC_SDCFG1_SWT2RD(SDRAM_TWR + 1) |
+		MCF_SDRAMC_SDCFG1_RDLAT((int)((SDRAM_CASL * 2) + 2)) |
+		MCF_SDRAMC_SDCFG1_ACT2RW((int)(SDRAM_TRCD + 0.5)) |
+		MCF_SDRAMC_SDCFG1_PRE2ACT((int)(SDRAM_TRP + 0.5)) |
+		MCF_SDRAMC_SDCFG1_REF2ACT((int)(SDRAM_TRFC + 0.5)) |
+		MCF_SDRAMC_SDCFG1_WTLAT(3),
+		MCF_SDRAMC_SDCFG1);
+	writel(MCF_SDRAMC_SDCFG2_BRD2PRE(SDRAM_BL / 2 + 1) |
+		MCF_SDRAMC_SDCFG2_BWT2RW(SDRAM_BL / 2 + SDRAM_TWR) |
+		MCF_SDRAMC_SDCFG2_BRD2WT((int)((SDRAM_CASL + SDRAM_BL / 2 - 1.0) + 0.5)) |
+		MCF_SDRAMC_SDCFG2_BL(SDRAM_BL - 1),
+		MCF_SDRAMC_SDCFG2);
+
+            
+	/*
+	 * Precharge and enable write to SDMR
+	 */
+	writel(MCF_SDRAMC_SDCR_MODE_EN |
+		MCF_SDRAMC_SDCR_CKE |
+		MCF_SDRAMC_SDCR_DDR |
+		MCF_SDRAMC_SDCR_MUX(1) |
+		MCF_SDRAMC_SDCR_RCNT((int)(((SDRAM_TREFI / (SYSTEM_PERIOD * 64)) - 1) + 0.5)) |
+		MCF_SDRAMC_SDCR_PS_16 |
+		MCF_SDRAMC_SDCR_IPALL,
+		MCF_SDRAMC_SDCR);
+
+	/*
+	 * Write extended mode register
+	 */
+	writel(MCF_SDRAMC_SDMR_BNKAD_LEMR |
+		MCF_SDRAMC_SDMR_AD(0x0) |
+		MCF_SDRAMC_SDMR_CMD,
+		MCF_SDRAMC_SDMR);
+
+	/*
+	 * Write mode register and reset DLL
+	 */
+	writel(MCF_SDRAMC_SDMR_BNKAD_LMR |
+		MCF_SDRAMC_SDMR_AD(0x163) |
+		MCF_SDRAMC_SDMR_CMD,
+		MCF_SDRAMC_SDMR);
+
+	/*
+	 * Execute a PALL command
+	 */
+	writel(readl(MCF_SDRAMC_SDCR) | MCF_SDRAMC_SDCR_IPALL, MCF_SDRAMC_SDCR);
+
+	/*
+	 * Perform two REF cycles
+	 */
+	writel(readl(MCF_SDRAMC_SDCR) | MCF_SDRAMC_SDCR_IREF, MCF_SDRAMC_SDCR);
+	writel(readl(MCF_SDRAMC_SDCR) | MCF_SDRAMC_SDCR_IREF, MCF_SDRAMC_SDCR);
+
+	/*
+	 * Write mode register and clear reset DLL
+	 */
+	writel(MCF_SDRAMC_SDMR_BNKAD_LMR |
+		MCF_SDRAMC_SDMR_AD(0x063) |
+		MCF_SDRAMC_SDMR_CMD,
+		MCF_SDRAMC_SDMR);
+				
+	/*
+	 * Enable auto refresh and lock SDMR
+	 */
+	writel(readl(MCF_SDRAMC_SDCR) & ~MCF_SDRAMC_SDCR_MODE_EN,
+		MCF_SDRAMC_SDCR);
+	writel(MCF_SDRAMC_SDCR_REF | MCF_SDRAMC_SDCR_DQS_OE(0xC),
+		MCF_SDRAMC_SDCR);
+	}
+}
+
+void gpio_init(void)
+{
+	/* Enable UART0 pins */
+	writew(MCF_GPIO_PAR_UART_PAR_URXD0 | MCF_GPIO_PAR_UART_PAR_UTXD0,
+		MCFGPIO_PAR_UART);
+
+	/*
+	 * Initialize TIN3 as a GPIO output to enable the write
+	 * half of the latch.
+	 */
+	writeb(0x00, MCFGPIO_PAR_TIMER);
+	writeb(0x08, MCFGPIO_PDDR_TIMER);
+	writeb(0x00, MCFGPIO_PCLRR_TIMER);
+}
+
+int clock_pll(int fsys, int flags)
+{
+	int fref, temp, fout, mfd;
+	u32 i;
+
+	fref = FREF;
+        
+	if (fsys == 0) {
+		/* Return current PLL output */
+		mfd = readb(MCF_PLL_PFDR);
+
+		return (fref * mfd / (BUSDIV * 4));
+	}
+
+	/* Check bounds of requested system clock */
+	if (fsys > MAX_FSYS)
+		fsys = MAX_FSYS;
+	if (fsys < MIN_FSYS)
+		fsys = MIN_FSYS;
+
+	/* Multiplying by 100 when calculating the temp value,
+	   and then dividing by 100 to calculate the mfd allows
+	   for exact values without needing to include floating
+	   point libraries. */
+	temp = 100 * fsys / fref;
+	mfd = 4 * BUSDIV * temp / 100;
+    	    	    	
+	/* Determine the output frequency for selected values */
+	fout = (fref * mfd / (BUSDIV * 4));
+
+	/*
+	 * Check to see if the SDRAM has already been initialized.
+	 * If it has then the SDRAM needs to be put into self refresh
+	 * mode before reprogramming the PLL.
+	 */
+	if (readl(MCF_SDRAMC_SDCR) & MCF_SDRAMC_SDCR_REF)
+		/* Put SDRAM into self refresh mode */
+		writel(readl(MCF_SDRAMC_SDCR) & ~MCF_SDRAMC_SDCR_CKE,
+			MCF_SDRAMC_SDCR);
+
+	/*
+	 * Initialize the PLL to generate the new system clock frequency.
+	 * The device must be put into LIMP mode to reprogram the PLL.
+	 */
+
+	/* Enter LIMP mode */
+	clock_limp(DEFAULT_LPD);
+     					
+	/* Reprogram PLL for desired fsys */
+	writeb(MCF_PLL_PODR_CPUDIV(BUSDIV/3) | MCF_PLL_PODR_BUSDIV(BUSDIV),
+		MCF_PLL_PODR);
+						
+	writeb(mfd, MCF_PLL_PFDR);
+		
+	/* Exit LIMP mode */
+	clock_exit_limp();
+	
+	/*
+	 * Return the SDRAM to normal operation if it is in use.
+	 */
+	if (readl(MCF_SDRAMC_SDCR) & MCF_SDRAMC_SDCR_REF)
+		/* Exit self refresh mode */
+		writel(readl(MCF_SDRAMC_SDCR) | MCF_SDRAMC_SDCR_CKE,
+			MCF_SDRAMC_SDCR);
+
+	/* Errata - workaround for SDRAM opeartion after exiting LIMP mode */
+	writel(MCF_SDRAMC_REFRESH, MCF_SDRAMC_LIMP_FIX);
+
+	/* wait for DQS logic to relock */
+	for (i = 0; i < 0x200; i++)
+		;
+
+	return fout;
+}
+
+int clock_limp(int div)
+{
+	u32 temp;
+
+	/* Check bounds of divider */
+	if (div < MIN_LPD)
+		div = MIN_LPD;
+	if (div > MAX_LPD)
+		div = MAX_LPD;
+    
+	/* Save of the current value of the SSIDIV so we don't
+	   overwrite the value*/
+	temp = readw(MCF_CCM_CDR) & MCF_CCM_CDR_SSIDIV(0xF);
+      
+	/* Apply the divider to the system clock */
+	writew(MCF_CCM_CDR_LPDIV(div) | MCF_CCM_CDR_SSIDIV(temp), MCF_CCM_CDR);
+    
+	writew(readw(MCF_CCM_MISCCR) | MCF_CCM_MISCCR_LIMP, MCF_CCM_MISCCR);
+    
+	return (FREF/(3*(1 << div)));
+}
+
+int clock_exit_limp(void)
+{
+	int fout;
+	
+	/* Exit LIMP mode */
+	writew(readw(MCF_CCM_MISCCR) & ~MCF_CCM_MISCCR_LIMP, MCF_CCM_MISCCR);
+
+	/* Wait for PLL to lock */
+	while (!(readw(MCF_CCM_MISCCR) & MCF_CCM_MISCCR_PLL_LOCK))
+		;
+	
+	fout = get_sys_clock();
+
+	return fout;
+}
+
+int get_sys_clock(void)
+{
+	int divider;
+	
+	/* Test to see if device is in LIMP mode */
+	if (readw(MCF_CCM_MISCCR) & MCF_CCM_MISCCR_LIMP) {
+		divider = readw(MCF_CCM_CDR) & MCF_CCM_CDR_LPDIV(0xF);
+		return (FREF/(2 << divider));
+	}
+	else
+		return (FREF * readb(MCF_PLL_PFDR)) / (BUSDIV * 4);
+}