cpufreq_64.c

linux 内核源代码

	.name		= "powermac",
	.owner		= THIS_MODULE,
	.flags		= CPUFREQ_CONST_LOOPS,
	.init		= g5_cpufreq_cpu_init,
	.verify		= g5_cpufreq_verify,
	.target		= g5_cpufreq_target,
	.get		= g5_cpufreq_get_speed,
	.attr 		= g5_cpu_freqs_attr,
};


#ifdef CONFIG_PMAC_SMU

static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
{
	struct device_node *cpunode;
	unsigned int psize, ssize;
	unsigned long max_freq;
	char *freq_method, *volt_method;
	const u32 *valp;
	u32 pvr_hi;
	int use_volts_vdnap = 0;
	int use_volts_smu = 0;
	int rc = -ENODEV;

	/* Check supported platforms */
	if (machine_is_compatible("PowerMac8,1") ||
	    machine_is_compatible("PowerMac8,2") ||
	    machine_is_compatible("PowerMac9,1"))
		use_volts_smu = 1;
	else if (machine_is_compatible("PowerMac11,2"))
		use_volts_vdnap = 1;
	else
		return -ENODEV;

	/* Get first CPU node */
	for (cpunode = NULL;
	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
		const u32 *reg = of_get_property(cpunode, "reg", NULL);
		if (reg == NULL || (*reg) != 0)
			continue;
		if (!strcmp(cpunode->type, "cpu"))
			break;
	}
	if (cpunode == NULL) {
		printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
		return -ENODEV;
	}

	/* Check 970FX for now */
	valp = of_get_property(cpunode, "cpu-version", NULL);
	if (!valp) {
		DBG("No cpu-version property !\n");
		goto bail_noprops;
	}
	pvr_hi = (*valp) >> 16;
	if (pvr_hi != 0x3c && pvr_hi != 0x44) {
		printk(KERN_ERR "cpufreq: Unsupported CPU version\n");
		goto bail_noprops;
	}

	/* Look for the powertune data in the device-tree */
	g5_pmode_data = of_get_property(cpunode, "power-mode-data",&psize);
	if (!g5_pmode_data) {
		DBG("No power-mode-data !\n");
		goto bail_noprops;
	}
	g5_pmode_max = psize / sizeof(u32) - 1;

	if (use_volts_smu) {
		const struct smu_sdbp_header *shdr;

		/* Look for the FVT table */
		shdr = smu_get_sdb_partition(SMU_SDB_FVT_ID, NULL);
		if (!shdr)
			goto bail_noprops;
		g5_fvt_table = (struct smu_sdbp_fvt *)&shdr[1];
		ssize = (shdr->len * sizeof(u32)) -
			sizeof(struct smu_sdbp_header);
		g5_fvt_count = ssize / sizeof(struct smu_sdbp_fvt);
		g5_fvt_cur = 0;

		/* Sanity checking */
		if (g5_fvt_count < 1 || g5_pmode_max < 1)
			goto bail_noprops;

		g5_switch_volt = g5_smu_switch_volt;
		volt_method = "SMU";
	} else if (use_volts_vdnap) {
		struct device_node *root;

		root = of_find_node_by_path("/");
		if (root == NULL) {
			printk(KERN_ERR "cpufreq: Can't find root of "
			       "device tree\n");
			goto bail_noprops;
		}
		pfunc_set_vdnap0 = pmf_find_function(root, "set-vdnap0");
		pfunc_vdnap0_complete =
			pmf_find_function(root, "slewing-done");
		if (pfunc_set_vdnap0 == NULL ||
		    pfunc_vdnap0_complete == NULL) {
			printk(KERN_ERR "cpufreq: Can't find required "
			       "platform function\n");
			goto bail_noprops;
		}

		g5_switch_volt = g5_vdnap_switch_volt;
		volt_method = "GPIO";
	} else {
		g5_switch_volt = g5_dummy_switch_volt;
		volt_method = "none";
	}

	/*
	 * From what I see, clock-frequency is always the maximal frequency.
	 * The current driver can not slew sysclk yet, so we really only deal
	 * with powertune steps for now. We also only implement full freq and
	 * half freq in this version. So far, I haven't yet seen a machine
	 * supporting anything else.
	 */
	valp = of_get_property(cpunode, "clock-frequency", NULL);
	if (!valp)
		return -ENODEV;
	max_freq = (*valp)/1000;
	g5_cpu_freqs[0].frequency = max_freq;
	g5_cpu_freqs[1].frequency = max_freq/2;

	/* Set callbacks */
	g5_switch_freq = g5_scom_switch_freq;
	g5_query_freq = g5_scom_query_freq;
	freq_method = "SCOM";

	/* Force apply current frequency to make sure everything is in
	 * sync (voltage is right for example). Firmware may leave us with
	 * a strange setting ...
	 */
	g5_switch_volt(CPUFREQ_HIGH);
	msleep(10);
	g5_pmode_cur = -1;
	g5_switch_freq(g5_query_freq());

	printk(KERN_INFO "Registering G5 CPU frequency driver\n");
	printk(KERN_INFO "Frequency method: %s, Voltage method: %s\n",
	       freq_method, volt_method);
	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
		g5_cpu_freqs[1].frequency/1000,
		g5_cpu_freqs[0].frequency/1000,
		g5_cpu_freqs[g5_pmode_cur].frequency/1000);

	rc = cpufreq_register_driver(&g5_cpufreq_driver);

	/* We keep the CPU node on hold... hopefully, Apple G5 don't have
	 * hotplug CPU with a dynamic device-tree ...
	 */
	return rc;

 bail_noprops:
	of_node_put(cpunode);

	return rc;
}

#endif /* CONFIG_PMAC_SMU */


static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
{
	struct device_node *cpuid = NULL, *hwclock = NULL, *cpunode = NULL;
	const u8 *eeprom = NULL;
	const u32 *valp;
	u64 max_freq, min_freq, ih, il;
	int has_volt = 1, rc = 0;

	DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
	    " RackMac3,1...\n");

	/* Get first CPU node */
	for (cpunode = NULL;
	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
		if (!strcmp(cpunode->type, "cpu"))
			break;
	}
	if (cpunode == NULL) {
		printk(KERN_ERR "cpufreq: Can't find any CPU node\n");
		return -ENODEV;
	}

	/* Lookup the cpuid eeprom node */
        cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
	if (cpuid != NULL)
		eeprom = of_get_property(cpuid, "cpuid", NULL);
	if (eeprom == NULL) {
		printk(KERN_ERR "cpufreq: Can't find cpuid EEPROM !\n");
		rc = -ENODEV;
		goto bail;
	}

	/* Lookup the i2c hwclock */
	for (hwclock = NULL;
	     (hwclock = of_find_node_by_name(hwclock, "i2c-hwclock")) != NULL;){
		const char *loc = of_get_property(hwclock,
				"hwctrl-location", NULL);
		if (loc == NULL)
			continue;
		if (strcmp(loc, "CPU CLOCK"))
			continue;
		if (!of_get_property(hwclock, "platform-get-frequency", NULL))
			continue;
		break;
	}
	if (hwclock == NULL) {
		printk(KERN_ERR "cpufreq: Can't find i2c clock chip !\n");
		rc = -ENODEV;
		goto bail;
	}

	DBG("cpufreq: i2c clock chip found: %s\n", hwclock->full_name);

	/* Now get all the platform functions */
	pfunc_cpu_getfreq =
		pmf_find_function(hwclock, "get-frequency");
	pfunc_cpu_setfreq_high =
		pmf_find_function(hwclock, "set-frequency-high");
	pfunc_cpu_setfreq_low =
		pmf_find_function(hwclock, "set-frequency-low");
	pfunc_slewing_done =
		pmf_find_function(hwclock, "slewing-done");
	pfunc_cpu0_volt_high =
		pmf_find_function(hwclock, "set-voltage-high-0");
	pfunc_cpu0_volt_low =
		pmf_find_function(hwclock, "set-voltage-low-0");
	pfunc_cpu1_volt_high =
		pmf_find_function(hwclock, "set-voltage-high-1");
	pfunc_cpu1_volt_low =
		pmf_find_function(hwclock, "set-voltage-low-1");

	/* Check we have minimum requirements */
	if (pfunc_cpu_getfreq == NULL || pfunc_cpu_setfreq_high == NULL ||
	    pfunc_cpu_setfreq_low == NULL || pfunc_slewing_done == NULL) {
		printk(KERN_ERR "cpufreq: Can't find platform functions !\n");
		rc = -ENODEV;
		goto bail;
	}

	/* Check that we have complete sets */
	if (pfunc_cpu0_volt_high == NULL || pfunc_cpu0_volt_low == NULL) {
		pmf_put_function(pfunc_cpu0_volt_high);
		pmf_put_function(pfunc_cpu0_volt_low);
		pfunc_cpu0_volt_high = pfunc_cpu0_volt_low = NULL;
		has_volt = 0;
	}
	if (!has_volt ||
	    pfunc_cpu1_volt_high == NULL || pfunc_cpu1_volt_low == NULL) {
		pmf_put_function(pfunc_cpu1_volt_high);
		pmf_put_function(pfunc_cpu1_volt_low);
		pfunc_cpu1_volt_high = pfunc_cpu1_volt_low = NULL;
	}

	/* Note: The device tree also contains a "platform-set-values"
	 * function for which I haven't quite figured out the usage. It
	 * might have to be called on init and/or wakeup, I'm not too sure
	 * but things seem to work fine without it so far ...
	 */

	/* Get max frequency from device-tree */
	valp = of_get_property(cpunode, "clock-frequency", NULL);
	if (!valp) {
		printk(KERN_ERR "cpufreq: Can't find CPU frequency !\n");
		rc = -ENODEV;
		goto bail;
	}

	max_freq = (*valp)/1000;

	/* Now calculate reduced frequency by using the cpuid input freq
	 * ratio. This requires 64 bits math unless we are willing to lose
	 * some precision
	 */
	ih = *((u32 *)(eeprom + 0x10));
	il = *((u32 *)(eeprom + 0x20));

	/* Check for machines with no useful settings */
	if (il == ih) {
		printk(KERN_WARNING "cpufreq: No low frequency mode available"
		       " on this model !\n");
		rc = -ENODEV;
		goto bail;
	}

	min_freq = 0;
	if (ih != 0 && il != 0)
		min_freq = (max_freq * il) / ih;

	/* Sanity check */
	if (min_freq >= max_freq || min_freq < 1000) {
		printk(KERN_ERR "cpufreq: Can't calculate low frequency !\n");
		rc = -ENXIO;
		goto bail;
	}
	g5_cpu_freqs[0].frequency = max_freq;
	g5_cpu_freqs[1].frequency = min_freq;

	/* Set callbacks */
	g5_switch_volt = g5_pfunc_switch_volt;
	g5_switch_freq = g5_pfunc_switch_freq;
	g5_query_freq = g5_pfunc_query_freq;

	/* Force apply current frequency to make sure everything is in
	 * sync (voltage is right for example). Firmware may leave us with
	 * a strange setting ...
	 */
	g5_switch_volt(CPUFREQ_HIGH);
	msleep(10);
	g5_pmode_cur = -1;
	g5_switch_freq(g5_query_freq());

	printk(KERN_INFO "Registering G5 CPU frequency driver\n");
	printk(KERN_INFO "Frequency method: i2c/pfunc, "
	       "Voltage method: %s\n", has_volt ? "i2c/pfunc" : "none");
	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Cur: %d MHz\n",
		g5_cpu_freqs[1].frequency/1000,
		g5_cpu_freqs[0].frequency/1000,
		g5_cpu_freqs[g5_pmode_cur].frequency/1000);

	rc = cpufreq_register_driver(&g5_cpufreq_driver);
 bail:
	if (rc != 0) {
		pmf_put_function(pfunc_cpu_getfreq);
		pmf_put_function(pfunc_cpu_setfreq_high);
		pmf_put_function(pfunc_cpu_setfreq_low);
		pmf_put_function(pfunc_slewing_done);
		pmf_put_function(pfunc_cpu0_volt_high);
		pmf_put_function(pfunc_cpu0_volt_low);
		pmf_put_function(pfunc_cpu1_volt_high);
		pmf_put_function(pfunc_cpu1_volt_low);
	}
	of_node_put(hwclock);
	of_node_put(cpuid);
	of_node_put(cpunode);

	return rc;
}

static int __init g5_cpufreq_init(void)
{
	struct device_node *cpus;
	int rc = 0;

	cpus = of_find_node_by_path("/cpus");
	if (cpus == NULL) {
		DBG("No /cpus node !\n");
		return -ENODEV;
	}

	if (machine_is_compatible("PowerMac7,2") ||
	    machine_is_compatible("PowerMac7,3") ||
	    machine_is_compatible("RackMac3,1"))
		rc = g5_pm72_cpufreq_init(cpus);
#ifdef CONFIG_PMAC_SMU
	else
		rc = g5_neo2_cpufreq_init(cpus);
#endif /* CONFIG_PMAC_SMU */

	of_node_put(cpus);
	return rc;
}

module_init(g5_cpufreq_init);


MODULE_LICENSE("GPL");