longhaul.c

来自「优龙2410linux2.6.8内核源代码」· C语言 代码 · 共 588 行 · 第 1/2 页

	dprintk (KERN_INFO PFX "MinMult=%d.%dx MaxMult=%d.%dx\n",
		 minmult/10, minmult%10, maxmult/10, maxmult%10);

	if (fsb == -1) {
		printk (KERN_INFO PFX "Invalid (reserved) FSB!\n");
		return -EINVAL;
	}

	highest_speed = calc_speed (maxmult, fsb);
	lowest_speed = calc_speed (minmult,fsb);
	dprintk (KERN_INFO PFX "FSB: %dMHz Lowestspeed=%dMHz Highestspeed=%dMHz\n",
		 fsb, lowest_speed/1000, highest_speed/1000);

	if (lowest_speed == highest_speed) {
		printk (KERN_INFO PFX "highestspeed == lowest, aborting.\n");
		return -EINVAL;
	}
	if (lowest_speed > highest_speed) {
		printk (KERN_INFO PFX "nonsense! lowest (%d > %d) !\n",
			lowest_speed, highest_speed);
		return -EINVAL;
	}

	longhaul_table = kmalloc((numscales + 1) * sizeof(struct cpufreq_frequency_table), GFP_KERNEL);
	if(!longhaul_table)
		return -ENOMEM;

	for (j=0; j < numscales; j++) {
		unsigned int ratio;
		ratio = clock_ratio[j];
		if (ratio == -1)
			continue;
		if (ratio > maxmult || ratio < minmult)
			continue;
		longhaul_table[k].frequency = calc_speed (ratio, fsb);
		longhaul_table[k].index	= j;
		k++;
	}

	longhaul_table[k].frequency = CPUFREQ_TABLE_END;
	if (!k) {
		kfree (longhaul_table);
		return -EINVAL;
	}

	return 0;
}


static void __init longhaul_setup_voltagescaling(void)
{
	union msr_longhaul longhaul;

	rdmsrl (MSR_VIA_LONGHAUL, longhaul.val);

	if (!(longhaul.bits.RevisionID & 1))
		return;

	minvid = longhaul.bits.MinimumVID;
	maxvid = longhaul.bits.MaximumVID;
	vrmrev = longhaul.bits.VRMRev;

	if (minvid == 0 || maxvid == 0) {
		printk (KERN_INFO PFX "Bogus values Min:%d.%03d Max:%d.%03d. "
					"Voltage scaling disabled.\n",
					minvid/1000, minvid%1000, maxvid/1000, maxvid%1000);
		return;
	}

	if (minvid == maxvid) {
		printk (KERN_INFO PFX "Claims to support voltage scaling but min & max are "
				"both %d.%03d. Voltage scaling disabled\n",
				maxvid/1000, maxvid%1000);
		return;
	}

	if (vrmrev==0) {
		dprintk (KERN_INFO PFX "VRM 8.5 : ");
		memcpy (voltage_table, vrm85scales, sizeof(voltage_table));
		numvscales = (voltage_table[maxvid]-voltage_table[minvid])/25;
	} else {
		dprintk (KERN_INFO PFX "Mobile VRM : ");
		memcpy (voltage_table, mobilevrmscales, sizeof(voltage_table));
		numvscales = (voltage_table[maxvid]-voltage_table[minvid])/5;
	}

	/* Current voltage isn't readable at first, so we need to
	   set it to a known value. The spec says to use maxvid */
	longhaul.bits.RevisionKey = longhaul.bits.RevisionID;	/* FIXME: This is bad. */
	longhaul.bits.EnableSoftVID = 1;
	longhaul.bits.SoftVID = maxvid;
	wrmsrl (MSR_VIA_LONGHAUL, longhaul.val);

	minvid = voltage_table[minvid];
	maxvid = voltage_table[maxvid];

	dprintk ("Min VID=%d.%03d Max VID=%d.%03d, %d possible voltage scales\n",
		maxvid/1000, maxvid%1000, minvid/1000, minvid%1000, numvscales);

	can_scale_voltage = 1;
}


static int longhaul_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, longhaul_table);
}


static int longhaul_target(struct cpufreq_policy *policy,
			    unsigned int target_freq,
			    unsigned int relation)
{
	unsigned int table_index = 0;
	unsigned int new_clock_ratio = 0;

	if (cpufreq_frequency_table_target(policy, longhaul_table, target_freq, relation, &table_index))
		return -EINVAL;

	new_clock_ratio = longhaul_table[table_index].index & 0xFF;

	longhaul_setstate(new_clock_ratio);

	return 0;
}

static unsigned int longhaul_get(unsigned int cpu)
{
	if (cpu)
		return 0;
	return (calc_speed (longhaul_get_cpu_mult(), fsb));
}

static int __init longhaul_cpu_init(struct cpufreq_policy *policy)
{
	struct cpuinfo_x86 *c = cpu_data;
	char *cpuname=NULL;
	int ret;

	switch (c->x86_model) {
	case 6:
		cpuname = "C3 'Samuel' [C5A]";
		longhaul_version=1;
		memcpy (clock_ratio, samuel1_clock_ratio, sizeof(samuel1_clock_ratio));
		memcpy (eblcr_table, samuel1_eblcr, sizeof(samuel1_eblcr));
		break;

	case 7:		/* C5B / C5C */
		longhaul_version=1;
		switch (c->x86_mask) {
		case 0:
			cpuname = "C3 'Samuel 2' [C5B]";
			/* Note, this is not a typo, early Samuel2's had Samuel1 ratios. */
			memcpy (clock_ratio, samuel1_clock_ratio, sizeof(samuel1_clock_ratio));
			memcpy (eblcr_table, samuel2_eblcr, sizeof(samuel2_eblcr));
			break;
		case 1 ... 15:
			if (c->x86_mask < 8)
				cpuname = "C3 'Samuel 2' [C5B]";
			else
				cpuname = "C3 'Ezra' [C5C]";
			memcpy (clock_ratio, ezra_clock_ratio, sizeof(ezra_clock_ratio));
			memcpy (eblcr_table, ezra_eblcr, sizeof(ezra_eblcr));
			break;
		}
		break;

	case 8:
		cpuname = "C3 'Ezra-T' [C5M]";
		longhaul_version=2;
		numscales=32;
		memcpy (clock_ratio, ezrat_clock_ratio, sizeof(ezrat_clock_ratio));
		memcpy (eblcr_table, ezrat_eblcr, sizeof(ezrat_eblcr));
		break;

	case 9:
		longhaul_version=3;
		numscales=32;
		switch (c->x86_mask) {
		case 0 ... 1:
			cpuname = "C3 'Nehemiah A' [C5N]";
			memcpy (clock_ratio, nehemiah_a_clock_ratio, sizeof(nehemiah_a_clock_ratio));
			memcpy (eblcr_table, nehemiah_a_eblcr, sizeof(nehemiah_a_eblcr));
			break;
		case 2 ... 4:
			cpuname = "C3 'Nehemiah B' [C5N]";
			memcpy (clock_ratio, nehemiah_b_clock_ratio, sizeof(nehemiah_b_clock_ratio));
			memcpy (eblcr_table, nehemiah_b_eblcr, sizeof(nehemiah_b_eblcr));
			break;
		case 5 ... 15:
			cpuname = "C3 'Nehemiah C' [C5N]";
			memcpy (clock_ratio, nehemiah_c_clock_ratio, sizeof(nehemiah_c_clock_ratio));
			memcpy (eblcr_table, nehemiah_c_eblcr, sizeof(nehemiah_c_eblcr));
			break;
		}
		break;

	default:
		cpuname = "Unknown";
		break;
	}

	printk (KERN_INFO PFX "VIA %s CPU detected. Longhaul v%d supported.\n",
					cpuname, longhaul_version);

	ret = longhaul_get_ranges();
	if (ret != 0)
		return ret;

	if ((longhaul_version==2) && (dont_scale_voltage==0))
		longhaul_setup_voltagescaling();

	policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	policy->cur = calc_speed (longhaul_get_cpu_mult(), fsb);

	ret = cpufreq_frequency_table_cpuinfo(policy, longhaul_table);
	if (ret)
		return ret;

	cpufreq_frequency_table_get_attr(longhaul_table, policy->cpu);

	return 0;
}

static int __devexit longhaul_cpu_exit(struct cpufreq_policy *policy)
{
	cpufreq_frequency_table_put_attr(policy->cpu);
	return 0;
}

static struct freq_attr* longhaul_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver longhaul_driver = {
	.verify	= longhaul_verify,
	.target	= longhaul_target,
	.get	= longhaul_get,
	.init	= longhaul_cpu_init,
	.exit	= __devexit_p(longhaul_cpu_exit),
	.name	= "longhaul",
	.owner	= THIS_MODULE,
	.attr	= longhaul_attr,
};

static int __init longhaul_init(void)
{
	struct cpuinfo_x86 *c = cpu_data;

	if (c->x86_vendor != X86_VENDOR_CENTAUR || c->x86 != 6)
		return -ENODEV;

	switch (c->x86_model) {
	case 6 ... 9:
		return cpufreq_register_driver(&longhaul_driver);
	default:
		printk (KERN_INFO PFX "Unknown VIA CPU. Contact [e-mail]\n");
	}

	return -ENODEV;
}

static void __exit longhaul_exit(void)
{
	int i=0;
	unsigned int new_clock_ratio;

	while (clock_ratio[i] != maxmult)
		i++;

	new_clock_ratio = longhaul_table[i].index & 0xFF;
	longhaul_setstate(new_clock_ratio);

	cpufreq_unregister_driver(&longhaul_driver);
	kfree(longhaul_table);
}

module_param (dont_scale_voltage, int, 0644);
MODULE_PARM_DESC(dont_scale_voltage, "Don't scale voltage of processor");

module_param (debug, int, 0644);
MODULE_PARM_DESC(debug, "Dump debugging information.");

MODULE_AUTHOR ("Dave Jones <[e-mail]>");
MODULE_DESCRIPTION ("Longhaul driver for VIA Cyrix processors.");
MODULE_LICENSE ("GPL");

module_init(longhaul_init);
module_exit(longhaul_exit);