cpufreq_32.c

linux内核源码

			_set_L3CR(0);
		}
	}
	set_speed_proc(speed_mode == CPUFREQ_LOW);
	if (speed_mode == CPUFREQ_HIGH &&
	    cpu_has_feature(CPU_FTR_L3CR)) {
		l3cr = _get_L3CR();
		if ((prev_l3cr & L3CR_L3E) && l3cr != prev_l3cr)
			_set_L3CR(prev_l3cr);
	}
	if (notify)
		cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
	cur_freq = (speed_mode == CPUFREQ_HIGH) ? hi_freq : low_freq;

	return 0;
}

static unsigned int pmac_cpufreq_get_speed(unsigned int cpu)
{
	return cur_freq;
}

static int pmac_cpufreq_verify(struct cpufreq_policy *policy)
{
	return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
}

static int pmac_cpufreq_target(	struct cpufreq_policy *policy,
					unsigned int target_freq,
					unsigned int relation)
{
	unsigned int    newstate = 0;
	int		rc;

	if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
			target_freq, relation, &newstate))
		return -EINVAL;

	rc = do_set_cpu_speed(newstate, 1);

	ppc_proc_freq = cur_freq * 1000ul;
	return rc;
}

static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
	if (policy->cpu != 0)
		return -ENODEV;

	policy->cpuinfo.transition_latency	= CPUFREQ_ETERNAL;
	policy->cur = cur_freq;

	cpufreq_frequency_table_get_attr(pmac_cpu_freqs, policy->cpu);
	return cpufreq_frequency_table_cpuinfo(policy, pmac_cpu_freqs);
}

static u32 read_gpio(struct device_node *np)
{
	const u32 *reg = of_get_property(np, "reg", NULL);
	u32 offset;

	if (reg == NULL)
		return 0;
	/* That works for all keylargos but shall be fixed properly
	 * some day... The problem is that it seems we can't rely
	 * on the "reg" property of the GPIO nodes, they are either
	 * relative to the base of KeyLargo or to the base of the
	 * GPIO space, and the device-tree doesn't help.
	 */
	offset = *reg;
	if (offset < KEYLARGO_GPIO_LEVELS0)
		offset += KEYLARGO_GPIO_LEVELS0;
	return offset;
}

static int pmac_cpufreq_suspend(struct cpufreq_policy *policy, pm_message_t pmsg)
{
	/* Ok, this could be made a bit smarter, but let's be robust for now. We
	 * always force a speed change to high speed before sleep, to make sure
	 * we have appropriate voltage and/or bus speed for the wakeup process,
	 * and to make sure our loops_per_jiffies are "good enough", that is will
	 * not cause too short delays if we sleep in low speed and wake in high
	 * speed..
	 */
	no_schedule = 1;
	sleep_freq = cur_freq;
	if (cur_freq == low_freq && !is_pmu_based)
		do_set_cpu_speed(CPUFREQ_HIGH, 0);
	return 0;
}

static int pmac_cpufreq_resume(struct cpufreq_policy *policy)
{
	/* If we resume, first check if we have a get() function */
	if (get_speed_proc)
		cur_freq = get_speed_proc();
	else
		cur_freq = 0;

	/* We don't, hrm... we don't really know our speed here, best
	 * is that we force a switch to whatever it was, which is
	 * probably high speed due to our suspend() routine
	 */
	do_set_cpu_speed(sleep_freq == low_freq ?
			 CPUFREQ_LOW : CPUFREQ_HIGH, 0);

	ppc_proc_freq = cur_freq * 1000ul;

	no_schedule = 0;
	return 0;
}

static struct cpufreq_driver pmac_cpufreq_driver = {
	.verify 	= pmac_cpufreq_verify,
	.target 	= pmac_cpufreq_target,
	.get		= pmac_cpufreq_get_speed,
	.init		= pmac_cpufreq_cpu_init,
	.suspend	= pmac_cpufreq_suspend,
	.resume		= pmac_cpufreq_resume,
	.flags		= CPUFREQ_PM_NO_WARN,
	.attr		= pmac_cpu_freqs_attr,
	.name		= "powermac",
	.owner		= THIS_MODULE,
};


static int pmac_cpufreq_init_MacRISC3(struct device_node *cpunode)
{
	struct device_node *volt_gpio_np = of_find_node_by_name(NULL,
								"voltage-gpio");
	struct device_node *freq_gpio_np = of_find_node_by_name(NULL,
								"frequency-gpio");
	struct device_node *slew_done_gpio_np = of_find_node_by_name(NULL,
								     "slewing-done");
	const u32 *value;

	/*
	 * Check to see if it's GPIO driven or PMU only
	 *
	 * The way we extract the GPIO address is slightly hackish, but it
	 * works well enough for now. We need to abstract the whole GPIO
	 * stuff sooner or later anyway
	 */

	if (volt_gpio_np)
		voltage_gpio = read_gpio(volt_gpio_np);
	if (freq_gpio_np)
		frequency_gpio = read_gpio(freq_gpio_np);
	if (slew_done_gpio_np)
		slew_done_gpio = read_gpio(slew_done_gpio_np);

	/* If we use the frequency GPIOs, calculate the min/max speeds based
	 * on the bus frequencies
	 */
	if (frequency_gpio && slew_done_gpio) {
		int lenp, rc;
		const u32 *freqs, *ratio;

		freqs = of_get_property(cpunode, "bus-frequencies", &lenp);
		lenp /= sizeof(u32);
		if (freqs == NULL || lenp != 2) {
			printk(KERN_ERR "cpufreq: bus-frequencies incorrect or missing\n");
			return 1;
		}
		ratio = of_get_property(cpunode, "processor-to-bus-ratio*2",
						NULL);
		if (ratio == NULL) {
			printk(KERN_ERR "cpufreq: processor-to-bus-ratio*2 missing\n");
			return 1;
		}

		/* Get the min/max bus frequencies */
		low_freq = min(freqs[0], freqs[1]);
		hi_freq = max(freqs[0], freqs[1]);

		/* Grrrr.. It _seems_ that the device-tree is lying on the low bus
		 * frequency, it claims it to be around 84Mhz on some models while
		 * it appears to be approx. 101Mhz on all. Let's hack around here...
		 * fortunately, we don't need to be too precise
		 */
		if (low_freq < 98000000)
			low_freq = 101000000;

		/* Convert those to CPU core clocks */
		low_freq = (low_freq * (*ratio)) / 2000;
		hi_freq = (hi_freq * (*ratio)) / 2000;

		/* Now we get the frequencies, we read the GPIO to see what is out current
		 * speed
		 */
		rc = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
		cur_freq = (rc & 0x01) ? hi_freq : low_freq;

		set_speed_proc = gpios_set_cpu_speed;
		return 1;
	}

	/* If we use the PMU, look for the min & max frequencies in the
	 * device-tree
	 */
	value = of_get_property(cpunode, "min-clock-frequency", NULL);
	if (!value)
		return 1;
	low_freq = (*value) / 1000;
	/* The PowerBook G4 12" (PowerBook6,1) has an error in the device-tree
	 * here */
	if (low_freq < 100000)
		low_freq *= 10;

	value = of_get_property(cpunode, "max-clock-frequency", NULL);
	if (!value)
		return 1;
	hi_freq = (*value) / 1000;
	set_speed_proc = pmu_set_cpu_speed;
	is_pmu_based = 1;

	return 0;
}

static int pmac_cpufreq_init_7447A(struct device_node *cpunode)
{
	struct device_node *volt_gpio_np;

	if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
		return 1;

	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
	if (volt_gpio_np)
		voltage_gpio = read_gpio(volt_gpio_np);
	if (!voltage_gpio){
		printk(KERN_ERR "cpufreq: missing cpu-vcore-select gpio\n");
		return 1;
	}

	/* OF only reports the high frequency */
	hi_freq = cur_freq;
	low_freq = cur_freq/2;

	/* Read actual frequency from CPU */
	cur_freq = dfs_get_cpu_speed();
	set_speed_proc = dfs_set_cpu_speed;
	get_speed_proc = dfs_get_cpu_speed;

	return 0;
}

static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
{
	struct device_node *volt_gpio_np;
	u32 pvr;
	const u32 *value;

	if (of_get_property(cpunode, "dynamic-power-step", NULL) == NULL)
		return 1;

	hi_freq = cur_freq;
	value = of_get_property(cpunode, "reduced-clock-frequency", NULL);
	if (!value)
		return 1;
	low_freq = (*value) / 1000;

	volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
	if (volt_gpio_np)
		voltage_gpio = read_gpio(volt_gpio_np);

	pvr = mfspr(SPRN_PVR);
	has_cpu_l2lve = !((pvr & 0xf00) == 0x100);

	set_speed_proc = cpu_750fx_cpu_speed;
	get_speed_proc = cpu_750fx_get_cpu_speed;
	cur_freq = cpu_750fx_get_cpu_speed();

	return 0;
}

/* Currently, we support the following machines:
 *
 *  - Titanium PowerBook 1Ghz (PMU based, 667Mhz & 1Ghz)
 *  - Titanium PowerBook 800 (PMU based, 667Mhz & 800Mhz)
 *  - Titanium PowerBook 400 (PMU based, 300Mhz & 400Mhz)
 *  - Titanium PowerBook 500 (PMU based, 300Mhz & 500Mhz)
 *  - iBook2 500/600 (PMU based, 400Mhz & 500/600Mhz)
 *  - iBook2 700 (CPU based, 400Mhz & 700Mhz, support low voltage)
 *  - Recent MacRISC3 laptops
 *  - All new machines with 7447A CPUs
 */
static int __init pmac_cpufreq_setup(void)
{
	struct device_node	*cpunode;
	const u32		*value;

	if (strstr(cmd_line, "nocpufreq"))
		return 0;

	/* Assume only one CPU */
	cpunode = of_find_node_by_type(NULL, "cpu");
	if (!cpunode)
		goto out;

	/* Get current cpu clock freq */
	value = of_get_property(cpunode, "clock-frequency", NULL);
	if (!value)
		goto out;
	cur_freq = (*value) / 1000;

	/*  Check for 7447A based MacRISC3 */
	if (machine_is_compatible("MacRISC3") &&
	    of_get_property(cpunode, "dynamic-power-step", NULL) &&
	    PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
		pmac_cpufreq_init_7447A(cpunode);
	/* Check for other MacRISC3 machines */
	} else if (machine_is_compatible("PowerBook3,4") ||
		   machine_is_compatible("PowerBook3,5") ||
		   machine_is_compatible("MacRISC3")) {
		pmac_cpufreq_init_MacRISC3(cpunode);
	/* Else check for iBook2 500/600 */
	} else if (machine_is_compatible("PowerBook4,1")) {
		hi_freq = cur_freq;
		low_freq = 400000;
		set_speed_proc = pmu_set_cpu_speed;
		is_pmu_based = 1;
	}
	/* Else check for TiPb 550 */
	else if (machine_is_compatible("PowerBook3,3") && cur_freq == 550000) {
		hi_freq = cur_freq;
		low_freq = 500000;
		set_speed_proc = pmu_set_cpu_speed;
		is_pmu_based = 1;
	}
	/* Else check for TiPb 400 & 500 */
	else if (machine_is_compatible("PowerBook3,2")) {
		/* We only know about the 400 MHz and the 500Mhz model
		 * they both have 300 MHz as low frequency
		 */
		if (cur_freq < 350000 || cur_freq > 550000)
			goto out;
		hi_freq = cur_freq;
		low_freq = 300000;
		set_speed_proc = pmu_set_cpu_speed;
		is_pmu_based = 1;
	}
	/* Else check for 750FX */
	else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000)
		pmac_cpufreq_init_750FX(cpunode);
out:
	of_node_put(cpunode);
	if (set_speed_proc == NULL)
		return -ENODEV;

	pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
	pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
	ppc_proc_freq = cur_freq * 1000ul;

	printk(KERN_INFO "Registering PowerMac CPU frequency driver\n");
	printk(KERN_INFO "Low: %d Mhz, High: %d Mhz, Boot: %d Mhz\n",
	       low_freq/1000, hi_freq/1000, cur_freq/1000);

	return cpufreq_register_driver(&pmac_cpufreq_driver);
}

module_init(pmac_cpufreq_setup);