diff options
Diffstat (limited to 'arch/ppc/platforms/pmac_cpufreq.c')
| -rw-r--r-- | arch/ppc/platforms/pmac_cpufreq.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/arch/ppc/platforms/pmac_cpufreq.c b/arch/ppc/platforms/pmac_cpufreq.c new file mode 100644 index 00000000000..9c85f9ca1cf --- /dev/null +++ b/arch/ppc/platforms/pmac_cpufreq.c @@ -0,0 +1,571 @@ +/* + * 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); + |