/arch/ppc/platforms/pmac_cpufreq.c
https://bitbucket.org/evzijst/gittest · C · 571 lines · 346 code · 95 blank · 130 comment · 69 complexity · ce19c6396c13f1bc0de1688a84befb1a MD5 · raw file
- /*
- * arch/ppc/platforms/pmac_cpufreq.c
- *
- * Copyright (C) 2002 - 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>
- * Copyright (C) 2004 John Steele Scott <toojays@toojays.net>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
- #include <linux/config.h>
- #include <linux/module.h>
- #include <linux/types.h>
- #include <linux/errno.h>
- #include <linux/kernel.h>
- #include <linux/delay.h>
- #include <linux/sched.h>
- #include <linux/adb.h>
- #include <linux/pmu.h>
- #include <linux/slab.h>
- #include <linux/cpufreq.h>
- #include <linux/init.h>
- #include <linux/sysdev.h>
- #include <linux/i2c.h>
- #include <linux/hardirq.h>
- #include <asm/prom.h>
- #include <asm/machdep.h>
- #include <asm/irq.h>
- #include <asm/pmac_feature.h>
- #include <asm/mmu_context.h>
- #include <asm/sections.h>
- #include <asm/cputable.h>
- #include <asm/time.h>
- #include <asm/system.h>
- #include <asm/open_pic.h>
- /* WARNING !!! This will cause calibrate_delay() to be called,
- * but this is an __init function ! So you MUST go edit
- * init/main.c to make it non-init before enabling DEBUG_FREQ
- */
- #undef DEBUG_FREQ
- /*
- * There is a problem with the core cpufreq code on SMP kernels,
- * it won't recalculate the Bogomips properly
- */
- #ifdef CONFIG_SMP
- #warning "WARNING, CPUFREQ not recommended on SMP kernels"
- #endif
- extern void low_choose_7447a_dfs(int dfs);
- extern void low_choose_750fx_pll(int pll);
- extern void low_sleep_handler(void);
- /*
- * Currently, PowerMac cpufreq supports only high & low frequencies
- * that are set by the firmware
- */
- static unsigned int low_freq;
- static unsigned int hi_freq;
- static unsigned int cur_freq;
- /*
- * Different models uses different mecanisms to switch the frequency
- */
- static int (*set_speed_proc)(int low_speed);
- /*
- * Some definitions used by the various speedprocs
- */
- static u32 voltage_gpio;
- static u32 frequency_gpio;
- static u32 slew_done_gpio;
- #define PMAC_CPU_LOW_SPEED 1
- #define PMAC_CPU_HIGH_SPEED 0
- /* There are only two frequency states for each processor. Values
- * are in kHz for the time being.
- */
- #define CPUFREQ_HIGH PMAC_CPU_HIGH_SPEED
- #define CPUFREQ_LOW PMAC_CPU_LOW_SPEED
- static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
- {CPUFREQ_HIGH, 0},
- {CPUFREQ_LOW, 0},
- {0, CPUFREQ_TABLE_END},
- };
- static inline void wakeup_decrementer(void)
- {
- set_dec(tb_ticks_per_jiffy);
- /* No currently-supported powerbook has a 601,
- * so use get_tbl, not native
- */
- last_jiffy_stamp(0) = tb_last_stamp = get_tbl();
- }
- #ifdef DEBUG_FREQ
- static inline void debug_calc_bogomips(void)
- {
- /* This will cause a recalc of bogomips and display the
- * result. We backup/restore the value to avoid affecting the
- * core cpufreq framework's own calculation.
- */
- extern void calibrate_delay(void);
- unsigned long save_lpj = loops_per_jiffy;
- calibrate_delay();
- loops_per_jiffy = save_lpj;
- }
- #endif /* DEBUG_FREQ */
- /* Switch CPU speed under 750FX CPU control
- */
- static int __pmac cpu_750fx_cpu_speed(int low_speed)
- {
- #ifdef DEBUG_FREQ
- printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
- #endif
- #ifdef CONFIG_6xx
- low_choose_750fx_pll(low_speed);
- #endif
- #ifdef DEBUG_FREQ
- printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
- debug_calc_bogomips();
- #endif
- return 0;
- }
- /* Switch CPU speed using DFS */
- static int __pmac dfs_set_cpu_speed(int low_speed)
- {
- if (low_speed == 0) {
- /* ramping up, set voltage first */
- pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
- /* Make sure we sleep for at least 1ms */
- msleep(1);
- }
- /* set frequency */
- low_choose_7447a_dfs(low_speed);
- if (low_speed == 1) {
- /* ramping down, set voltage last */
- pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
- msleep(1);
- }
- return 0;
- }
- static unsigned int __pmac dfs_get_cpu_speed(unsigned int cpu)
- {
- if (mfspr(SPRN_HID1) & HID1_DFS)
- return low_freq;
- else
- return hi_freq;
- }
- /* Switch CPU speed using slewing GPIOs
- */
- static int __pmac gpios_set_cpu_speed(int low_speed)
- {
- int gpio;
- /* If ramping up, set voltage first */
- if (low_speed == 0) {
- pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x05);
- /* Delay is way too big but it's ok, we schedule */
- msleep(10);
- }
- /* Set frequency */
- pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
- low_speed ? 0x04 : 0x05);
- udelay(200);
- do {
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(1);
- gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
- } while((gpio & 0x02) == 0);
- /* If ramping down, set voltage last */
- if (low_speed == 1) {
- pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
- /* Delay is way too big but it's ok, we schedule */
- msleep(10);
- }
- #ifdef DEBUG_FREQ
- debug_calc_bogomips();
- #endif
- return 0;
- }
- /* Switch CPU speed under PMU control
- */
- static int __pmac pmu_set_cpu_speed(int low_speed)
- {
- struct adb_request req;
- unsigned long save_l2cr;
- unsigned long save_l3cr;
- preempt_disable();
- #ifdef DEBUG_FREQ
- printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
- #endif
- /* Disable all interrupt sources on openpic */
- openpic_set_priority(0xf);
- /* Make sure the decrementer won't interrupt us */
- asm volatile("mtdec %0" : : "r" (0x7fffffff));
- /* Make sure any pending DEC interrupt occuring while we did
- * the above didn't re-enable the DEC */
- mb();
- asm volatile("mtdec %0" : : "r" (0x7fffffff));
- /* We can now disable MSR_EE */
- local_irq_disable();
- /* Giveup the FPU & vec */
- enable_kernel_fp();
- #ifdef CONFIG_ALTIVEC
- if (cpu_has_feature(CPU_FTR_ALTIVEC))
- enable_kernel_altivec();
- #endif /* CONFIG_ALTIVEC */
- /* Save & disable L2 and L3 caches */
- save_l3cr = _get_L3CR(); /* (returns -1 if not available) */
- save_l2cr = _get_L2CR(); /* (returns -1 if not available) */
- /* Send the new speed command. My assumption is that this command
- * will cause PLL_CFG[0..3] to be changed next time CPU goes to sleep
- */
- pmu_request(&req, NULL, 6, PMU_CPU_SPEED, 'W', 'O', 'O', 'F', low_speed);
- while (!req.complete)
- pmu_poll();
- /* Prepare the northbridge for the speed transition */
- pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,1);
- /* Call low level code to backup CPU state and recover from
- * hardware reset
- */
- low_sleep_handler();
- /* Restore the northbridge */
- pmac_call_feature(PMAC_FTR_SLEEP_STATE,NULL,1,0);
- /* Restore L2 cache */
- if (save_l2cr != 0xffffffff && (save_l2cr & L2CR_L2E) != 0)
- _set_L2CR(save_l2cr);
- /* Restore L3 cache */
- if (save_l3cr != 0xffffffff && (save_l3cr & L3CR_L3E) != 0)
- _set_L3CR(save_l3cr);
- /* Restore userland MMU context */
- set_context(current->active_mm->context, current->active_mm->pgd);
- #ifdef DEBUG_FREQ
- printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
- #endif
- /* Restore low level PMU operations */
- pmu_unlock();
- /* Restore decrementer */
- wakeup_decrementer();
- /* Restore interrupts */
- openpic_set_priority(0);
- /* Let interrupts flow again ... */
- local_irq_enable();
- #ifdef DEBUG_FREQ
- debug_calc_bogomips();
- #endif
- preempt_enable();
- return 0;
- }
- static int __pmac do_set_cpu_speed(int speed_mode)
- {
- struct cpufreq_freqs freqs;
- freqs.old = cur_freq;
- freqs.new = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
- freqs.cpu = smp_processor_id();
- if (freqs.old == freqs.new)
- return 0;
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- set_speed_proc(speed_mode == PMAC_CPU_LOW_SPEED);
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
- cur_freq = (speed_mode == PMAC_CPU_HIGH_SPEED) ? hi_freq : low_freq;
- return 0;
- }
- static int __pmac pmac_cpufreq_verify(struct cpufreq_policy *policy)
- {
- return cpufreq_frequency_table_verify(policy, pmac_cpu_freqs);
- }
- static int __pmac pmac_cpufreq_target( struct cpufreq_policy *policy,
- unsigned int target_freq,
- unsigned int relation)
- {
- unsigned int newstate = 0;
- if (cpufreq_frequency_table_target(policy, pmac_cpu_freqs,
- target_freq, relation, &newstate))
- return -EINVAL;
- return do_set_cpu_speed(newstate);
- }
- unsigned int __pmac pmac_get_one_cpufreq(int i)
- {
- /* Supports only one CPU for now */
- return (i == 0) ? cur_freq : 0;
- }
- static int __pmac pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
- {
- if (policy->cpu != 0)
- return -ENODEV;
- policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
- policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
- policy->cur = cur_freq;
- return cpufreq_frequency_table_cpuinfo(policy, &pmac_cpu_freqs[0]);
- }
- static u32 __pmac read_gpio(struct device_node *np)
- {
- u32 *reg = (u32 *)get_property(np, "reg", NULL);
- if (reg == NULL)
- return 0;
- /* That works for all keylargos but shall be fixed properly
- * some day...
- */
- return 0x50 + (*reg);
- }
- static struct cpufreq_driver pmac_cpufreq_driver = {
- .verify = pmac_cpufreq_verify,
- .target = pmac_cpufreq_target,
- .init = pmac_cpufreq_cpu_init,
- .name = "powermac",
- .owner = THIS_MODULE,
- };
- static int __pmac 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");
- 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;
- u32 *freqs, *ratio;
- freqs = (u32 *)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 = (u32 *)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 = (u32 *)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 = (u32 *)get_property(cpunode, "max-clock-frequency", NULL);
- if (!value)
- return 1;
- hi_freq = (*value) / 1000;
- set_speed_proc = pmu_set_cpu_speed;
- return 0;
- }
- static int __pmac pmac_cpufreq_init_7447A(struct device_node *cpunode)
- {
- struct device_node *volt_gpio_np;
- u32 *reg;
- struct cpufreq_driver *driver = &pmac_cpufreq_driver;
- /* Look for voltage GPIO */
- volt_gpio_np = of_find_node_by_name(NULL, "cpu-vcore-select");
- reg = (u32 *)get_property(volt_gpio_np, "reg", NULL);
- voltage_gpio = *reg;
- if (!volt_gpio_np){
- 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 */
- driver->get = dfs_get_cpu_speed;
- cur_freq = driver->get(0);
- set_speed_proc = dfs_set_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;
- u32 *value;
- if (strstr(cmd_line, "nocpufreq"))
- return 0;
- /* Assume only one CPU */
- cpunode = find_type_devices("cpu");
- if (!cpunode)
- goto out;
- /* Get current cpu clock freq */
- value = (u32 *)get_property(cpunode, "clock-frequency", NULL);
- if (!value)
- goto out;
- cur_freq = (*value) / 1000;
- /* Check for 7447A based MacRISC3 */
- if (machine_is_compatible("MacRISC3") &&
- 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;
- }
- /* 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;
- }
- /* Else check for 750FX */
- else if (PVR_VER(mfspr(SPRN_PVR)) == 0x7000) {
- if (get_property(cpunode, "dynamic-power-step", NULL) == NULL)
- goto out;
- hi_freq = cur_freq;
- value = (u32 *)get_property(cpunode, "reduced-clock-frequency", NULL);
- if (!value)
- goto out;
- low_freq = (*value) / 1000;
- set_speed_proc = cpu_750fx_cpu_speed;
- }
- out:
- if (set_speed_proc == NULL)
- return -ENODEV;
- pmac_cpu_freqs[CPUFREQ_LOW].frequency = low_freq;
- pmac_cpu_freqs[CPUFREQ_HIGH].frequency = hi_freq;
- 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);