|  | @@ -128,3 +128,170 @@ static inline u_int ns_to_cycles(u_int ns, u_int khz)
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				|  |  |  	return (ns * khz + 999999) / 1000000;
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				|  |  |  }
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				|  |  |  
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				|  |  | +/*
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				|  |  | + * Create the MDCAS register bit pattern.
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				|  |  | + */
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				|  |  | +static inline void set_mdcas(u_int *mdcas, int delayed, u_int rcd)
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				|  |  | +{
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				|  |  | +	u_int shift;
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				|  |  | +
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				|  |  | +	rcd = 2 * rcd - 1;
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				|  |  | +	shift = delayed + 1 + rcd;
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				|  |  | +
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				|  |  | +	mdcas[0]  = (1 << rcd) - 1;
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				|  |  | +	mdcas[0] |= 0x55555555 << shift;
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				|  |  | +	mdcas[1]  = mdcas[2] = 0x55555555 << (shift & 1);
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				|  |  | +}
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				|  |  | +
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				|  |  | +static void
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				|  |  | +sdram_calculate_timing(struct sdram_info *sd, u_int cpu_khz,
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				|  |  | +		       struct sdram_params *sdram)
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				|  |  | +{
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				|  |  | +	u_int mem_khz, sd_khz, trp, twr;
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				|  |  | +
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				|  |  | +	mem_khz = cpu_khz / 2;
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				|  |  | +	sd_khz = mem_khz;
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				|  |  | +
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				|  |  | +	/*
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				|  |  | +	 * If SDCLK would invalidate the SDRAM timings,
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				|  |  | +	 * run SDCLK at half speed.
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				|  |  | +	 *
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				|  |  | +	 * CPU steppings prior to B2 must either run the memory at
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				|  |  | +	 * half speed or use delayed read latching (errata 13).
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				|  |  | +	 */
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				|  |  | +	if ((ns_to_cycles(sdram->tck, sd_khz) > 1) ||
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				|  |  | +	    (CPU_REVISION < CPU_SA1110_B2 && sd_khz < 62000))
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				|  |  | +		sd_khz /= 2;
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				|  |  | +
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				|  |  | +	sd->mdcnfg = MDCNFG & 0x007f007f;
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				|  |  | +
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				|  |  | +	twr = ns_to_cycles(sdram->twr, mem_khz);
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				|  |  | +
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				|  |  | +	/* trp should always be >1 */
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				|  |  | +	trp = ns_to_cycles(sdram->trp, mem_khz) - 1;
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				|  |  | +	if (trp < 1)
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				|  |  | +		trp = 1;
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				|  |  | +
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				|  |  | +	sd->mdcnfg |= trp << 8;
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				|  |  | +	sd->mdcnfg |= trp << 24;
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				|  |  | +	sd->mdcnfg |= sdram->cas_latency << 12;
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				|  |  | +	sd->mdcnfg |= sdram->cas_latency << 28;
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				|  |  | +	sd->mdcnfg |= twr << 14;
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				|  |  | +	sd->mdcnfg |= twr << 30;
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				|  |  | +
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				|  |  | +	sd->mdrefr = MDREFR & 0xffbffff0;
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				|  |  | +	sd->mdrefr |= 7;
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				|  |  | +
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				|  |  | +	if (sd_khz != mem_khz)
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				|  |  | +		sd->mdrefr |= MDREFR_K1DB2;
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				|  |  | +
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				|  |  | +	/* initial number of '1's in MDCAS + 1 */
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				|  |  | +	set_mdcas(sd->mdcas, sd_khz >= 62000,
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				|  |  | +		ns_to_cycles(sdram->trcd, mem_khz));
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				|  |  | +
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				|  |  | +#ifdef DEBUG
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				|  |  | +	printk(KERN_DEBUG "MDCNFG: %08x MDREFR: %08x MDCAS0: %08x MDCAS1: %08x MDCAS2: %08x\n",
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				|  |  | +		sd->mdcnfg, sd->mdrefr, sd->mdcas[0], sd->mdcas[1],
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				|  |  | +		sd->mdcas[2]);
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				|  |  | +#endif
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				|  |  | +}
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				|  |  | +
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				|  |  | +/*
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				|  |  | + * Set the SDRAM refresh rate.
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				|  |  | + */
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				|  |  | +static inline void sdram_set_refresh(u_int dri)
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				|  |  | +{
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				|  |  | +	MDREFR = (MDREFR & 0xffff000f) | (dri << 4);
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				|  |  | +	(void) MDREFR;
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				|  |  | +}
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				|  |  | +
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				|  |  | +/*
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				|  |  | + * Update the refresh period.  We do this such that we always refresh
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				|  |  | + * the SDRAMs within their permissible period.  The refresh period is
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				|  |  | + * always a multiple of the memory clock (fixed at cpu_clock / 2).
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				|  |  | + *
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				|  |  | + * FIXME: we don't currently take account of burst accesses here,
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				|  |  | + * but neither do Intels DM nor Angel.
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				|  |  | + */
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				|  |  | +static void
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				|  |  | +sdram_update_refresh(u_int cpu_khz, struct sdram_params *sdram)
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				|  |  | +{
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				|  |  | +	u_int ns_row = (sdram->refresh * 1000) >> sdram->rows;
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				|  |  | +	u_int dri = ns_to_cycles(ns_row, cpu_khz / 2) / 32;
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				|  |  | +
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				|  |  | +#ifdef DEBUG
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				|  |  | +	mdelay(250);
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				|  |  | +	printk(KERN_DEBUG "new dri value = %d\n", dri);
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				|  |  | +#endif
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				|  |  | +
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				|  |  | +	sdram_set_refresh(dri);
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				|  |  | +}
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				|  |  | +
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				|  |  | +/*
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				|  |  | + * Ok, set the CPU frequency.
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				|  |  | + */
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				|  |  | +static int sa1110_target(struct cpufreq_policy *policy,
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				|  |  | +			 unsigned int target_freq,
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				|  |  | +			 unsigned int relation)
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				|  |  | +{
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				|  |  | +	struct sdram_params *sdram = &sdram_params;
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				|  |  | +	struct cpufreq_freqs freqs;
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				|  |  | +	struct sdram_info sd;
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				|  |  | +	unsigned long flags;
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				|  |  | +	unsigned int ppcr, unused;
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				|  |  | +
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				|  |  | +	switch (relation) {
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				|  |  | +	case CPUFREQ_RELATION_L:
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				|  |  | +		ppcr = sa11x0_freq_to_ppcr(target_freq);
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				|  |  | +		if (sa11x0_ppcr_to_freq(ppcr) > policy->max)
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				|  |  | +			ppcr--;
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				|  |  | +		break;
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				|  |  | +	case CPUFREQ_RELATION_H:
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				|  |  | +		ppcr = sa11x0_freq_to_ppcr(target_freq);
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				|  |  | +		if (ppcr && (sa11x0_ppcr_to_freq(ppcr) > target_freq) &&
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				|  |  | +		    (sa11x0_ppcr_to_freq(ppcr-1) >= policy->min))
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				|  |  | +			ppcr--;
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				|  |  | +		break;
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				|  |  | +	default:
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				|  |  | +		return -EINVAL;
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				|  |  | +	}
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				|  |  | +
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				|  |  | +	freqs.old = sa11x0_getspeed(0);
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				|  |  | +	freqs.new = sa11x0_ppcr_to_freq(ppcr);
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				|  |  | +	freqs.cpu = 0;
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				|  |  | +
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				|  |  | +	sdram_calculate_timing(&sd, freqs.new, sdram);
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				|  |  | +
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				|  |  | +#if 0
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				|  |  | +	/*
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				|  |  | +	 * These values are wrong according to the SA1110 documentation
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				|  |  | +	 * and errata, but they seem to work.  Need to get a storage
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				|  |  | +	 * scope on to the SDRAM signals to work out why.
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				|  |  | +	 */
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				|  |  | +	if (policy->max < 147500) {
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				|  |  | +		sd.mdrefr |= MDREFR_K1DB2;
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				|  |  | +		sd.mdcas[0] = 0xaaaaaa7f;
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				|  |  | +	} else {
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				|  |  | +		sd.mdrefr &= ~MDREFR_K1DB2;
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				|  |  | +		sd.mdcas[0] = 0xaaaaaa9f;
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				|  |  | +	}
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				|  |  | +	sd.mdcas[1] = 0xaaaaaaaa;
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				|  |  | +	sd.mdcas[2] = 0xaaaaaaaa;
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				|  |  | +#endif
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				|  |  | +
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				|  |  | +	cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
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				|  |  | +
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				|  |  | +	/*
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				|  |  | +	 * The clock could be going away for some time.  Set the SDRAMs
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				|  |  | +	 * to refresh rapidly (every 64 memory clock cycles).  To get
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				|  |  | +	 * through the whole array, we need to wait 262144 mclk cycles.
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				|  |  | +	 * We wait 20ms to be safe.
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				|  |  | +	 */
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				|  |  | +	sdram_set_refresh(2);
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				|  |  | +	if (!irqs_disabled())
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				|  |  | +		msleep(20);
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				|  |  | +	else
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				|  |  | +		mdelay(20);
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				|  |  | +
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				|  |  | +	/*
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				|  |  | +	 * Reprogram the DRAM timings with interrupts disabled, and
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