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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/m68k/coldfire/m53xx.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/m68k/coldfire/m53xx.c')
-rw-r--r-- | arch/m68k/coldfire/m53xx.c | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/arch/m68k/coldfire/m53xx.c b/arch/m68k/coldfire/m53xx.c new file mode 100644 index 0000000000..17af5f6737 --- /dev/null +++ b/arch/m68k/coldfire/m53xx.c @@ -0,0 +1,594 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/***************************************************************************/ + +/* + * 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> + */ + +/***************************************************************************/ + +#include <linux/clkdev.h> +#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, "imx1-i2c.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); + +static struct clk_lookup m53xx_clk_lookup[] = { + CLKDEV_INIT("flexbus", NULL, &__clk_0_2), + CLKDEV_INIT("mcfcan.0", NULL, &__clk_0_8), + CLKDEV_INIT("fec.0", NULL, &__clk_0_12), + CLKDEV_INIT("edma", NULL, &__clk_0_17), + CLKDEV_INIT("intc.0", NULL, &__clk_0_18), + CLKDEV_INIT("intc.1", NULL, &__clk_0_19), + CLKDEV_INIT("iack.0", NULL, &__clk_0_21), + CLKDEV_INIT("imx1-i2c.0", NULL, &__clk_0_22), + CLKDEV_INIT("mcfqspi.0", NULL, &__clk_0_23), + CLKDEV_INIT("mcfuart.0", NULL, &__clk_0_24), + CLKDEV_INIT("mcfuart.1", NULL, &__clk_0_25), + CLKDEV_INIT("mcfuart.2", NULL, &__clk_0_26), + CLKDEV_INIT("mcftmr.0", NULL, &__clk_0_28), + CLKDEV_INIT("mcftmr.1", NULL, &__clk_0_29), + CLKDEV_INIT("mcftmr.2", NULL, &__clk_0_30), + CLKDEV_INIT("mcftmr.3", NULL, &__clk_0_31), + CLKDEV_INIT("mcfpit.0", NULL, &__clk_0_32), + CLKDEV_INIT("mcfpit.1", NULL, &__clk_0_33), + CLKDEV_INIT("mcfpit.2", NULL, &__clk_0_34), + CLKDEV_INIT("mcfpit.3", NULL, &__clk_0_35), + CLKDEV_INIT("mcfpwm.0", NULL, &__clk_0_36), + CLKDEV_INIT("mcfeport.0", NULL, &__clk_0_37), + CLKDEV_INIT("mcfwdt.0", NULL, &__clk_0_38), + CLKDEV_INIT(NULL, "sys.0", &__clk_0_40), + CLKDEV_INIT("gpio.0", NULL, &__clk_0_41), + CLKDEV_INIT("mcfrtc.0", NULL, &__clk_0_42), + CLKDEV_INIT("mcflcd.0", NULL, &__clk_0_43), + CLKDEV_INIT("mcfusb-otg.0", NULL, &__clk_0_44), + CLKDEV_INIT("mcfusb-host.0", NULL, &__clk_0_45), + CLKDEV_INIT("sdram.0", NULL, &__clk_0_46), + CLKDEV_INIT("ssi.0", NULL, &__clk_0_47), + CLKDEV_INIT(NULL, "pll.0", &__clk_0_48), + CLKDEV_INIT("mdha.0", NULL, &__clk_1_32), + CLKDEV_INIT("skha.0", NULL, &__clk_1_33), + CLKDEV_INIT("rng.0", NULL, &__clk_1_34), +}; + +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, /* imx1-i2c.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]); + + clkdev_add_table(m53xx_clk_lookup, ARRAY_SIZE(m53xx_clk_lookup)); +} + +/***************************************************************************/ + +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_i2c_init(void) +{ +#if IS_ENABLED(CONFIG_I2C_IMX) + /* setup Port AS Pin Assignment Register for I2C */ + /* set PASPA0 to SCL and PASPA1 to SDA */ + u8 r = readb(MCFGPIO_PAR_FECI2C); + r |= 0x0f; + writeb(r, MCFGPIO_PAR_FECI2C); +#endif /* IS_ENABLED(CONFIG_I2C_IMX) */ +} + +/***************************************************************************/ + +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(); + m53xx_i2c_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) + +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) +{ + clock_pll(0, 0); + + 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 operation 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); +} |