/*
* Copyright (C) 2002 - 2005 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.
*
* TODO: Need a big cleanup here. Basically, we need to have different
* cpufreq_driver structures for the different type of HW instead of the
* current mess. We also need to better deal with the detection of the
* type of machine.
*
*/
#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/cpufreq.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/hardirq.h>
#include <linux/of_device.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/mpic.h>
#include <asm/keylargo.h>
#include <asm/switch_to.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
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;
static unsigned int sleep_freq;
static unsigned long transition_latency;
/*
* Different models uses different mechanisms to switch the frequency
*/
static int (*set_speed_proc)(int low_speed);
static unsigned int (*get_speed_proc)(void);
/*
* Some definitions used by the various speedprocs
*/
static u32 voltage_gpio;
static u32 frequency_gpio;
static u32 slew_done_gpio;
static int no_schedule;
static int has_cpu_l2lve;
static int is_pmu_based;
/* There are only two frequency states for each processor. Values
* are in kHz for the time being.
*/
#define CPUFREQ_HIGH 0
#define CPUFREQ_LOW 1
static struct cpufreq_frequency_table pmac_cpu_freqs[] = {
{0, CPUFREQ_HIGH, 0},
{0, CPUFREQ_LOW, 0},
{0, 0, CPUFREQ_TABLE_END},
};
static inline void local_delay(unsigned long ms)
{
if (no_schedule)
mdelay(ms);
else
msleep(ms);
}
#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.
*/
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 cpu_750fx_cpu_speed(int low_speed)
{
u32 hid2;
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 */
local_delay(10);
/* tweak L2 for high voltage */
if (has_cpu_l2lve) {
hid2 = mfspr(SPRN_HID2);
hid2 &= ~0x2000;
mtspr(SPRN_HID2, hid2);
}
}
#ifdef CONFIG_6xx
low_choose_750fx_pll(low_speed);
#endif
if (low_speed == 1) {
/* tweak L2 for low voltage */
if (has_cpu_l2lve) {
hid2 = mfspr(SPRN_HID2);
hid2 |= 0x2000;
mtspr(SPRN_HID2, hid2);
}
/* ramping down, set voltage last */
pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
local_delay(10);
}
return 0;
}
static unsigned int cpu_750fx_get_cpu_speed(void)
{
if (mfspr(SPRN_HID1) & HID1_PS)
return low_freq;
else
return hi_freq;
}
/* Switch CPU speed using DFS */
static int 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 */
local_delay(1);
}
/* set frequency */
#ifdef CONFIG_6xx
low_choose_7447a_dfs(low_speed);
#endif
udelay(100);
if (low_speed == 1) {
/* ramping down, set voltage last */
pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, voltage_gpio, 0x04);
local_delay(1);
}
return 0;
}
static unsigned int dfs_get_cpu_speed(void)
{
if (mfspr(SPRN_HID1) & HID1_DFS)
return low_freq;
else
return hi_freq;
}
/* Switch CPU speed using slewing GPIOs
*/
static int gpios_set_cpu_speed(int low_speed)
{
int gpio, timeout = 0;
/* 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 */
local_delay(10);
}
/* Set frequency */
gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, frequency_gpio, 0);
if (low_speed == ((gpio & 0x01) == 0))
goto skip;
pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, frequency_gpio,
low_speed ? 0x04 : 0x05);
udelay(200);
do {
if (++timeout > 100)
break;
local_delay(1);
gpio = pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, slew_done_gpio, 0);
} while((gpio & 0x02) == 0);
skip:
/* 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 */
local_delay(10);
}
#ifdef DEBUG_FREQ
debug_calc_bogomips();
#endif
return 0;
}
/* Switch CPU speed under PMU control
*/
static int pmu_set_cpu_speed(int low_speed)
{
struct adb_request req;
unsigned long save_l2cr;
unsigned long save_l3cr;
unsigned int pic_prio;
unsigned long flags;
preempt_disable();
#ifdef DEBUG_FREQ
printk(KERN_DEBUG "HID1, before: %x\n", mfspr(SPRN_HID1));
#endif
pmu_suspend();
/* Disable all interrupt sources on openpic */
pic_prio = mpic_cpu_get_priority();
mpic_cpu_set_priority(0xf);
/* Make sure the decrementer won't interrupt us */
asm volatile("mtdec %0" : : "r" (0x7fffffff));
/* Make sure any pending DEC interrupt occurring 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_save(flags);
/* 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 */
switch_mmu_context(NULL, current->active_mm);
#ifdef DEBUG_FREQ
printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));
#endif
/* Restore low level PMU operations */
pmu_unlock();
/*
* Restore decrementer; we'll take a decrementer interrupt
* as soon as interrupts are re-enabled and the generic
* clockevents code will reprogram it with the right value.
*/
set_dec(1);
/* Restore interrupts */
mpic_cpu_set_priority(pic_prio);
/* Let interrupts flow again ... */
local_irq_restore(flags);
#ifdef DEBUG_FREQ
debug_calc_bogomips();
#endif
pmu_resume();
preempt_enable();
return 0;
}
static int do_set_cpu_speed(struct cpufreq_policy *policy, int speed_mode)
{
unsigned long l3cr;
static unsigned long prev_l3cr;
if (speed_mode == CPUFREQ_LOW &&
cpu_has_feature(CPU_FTR_L3CR)) {
l3cr = _get_L3CR();
if (l3cr & L3CR_L3E) {
prev_l3cr = l3cr;
_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);
}
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_target( struct cpufreq_policy *policy,
unsigned int index)
{
int rc;
rc = do_set_cpu_speed(policy, index);
ppc_proc_freq = cur_freq * 1000ul;
return rc;
}
static int pmac_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
return cpufreq_generic_init(policy, pmac_cpu_freqs, transition_latency);
}
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)
{
/* 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(policy, CPUFREQ_HIGH);
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(policy, sleep_freq == low_freq ?
CPUFREQ_LOW : CPUFREQ_HIGH);
ppc_proc_freq = cur_freq * 1000ul;
no_schedule = 0;
return 0;
}
static struct cpufreq_driver pmac_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.target_index = 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 = cpufreq_generic_attr,
.name = "powermac",
};
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;
/* Get first CPU node */
cpunode = of_cpu_device_node_get(0);
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;
transition_latency = CPUFREQ_ETERNAL;
/* Check for 7447A based MacRISC3 */
if (of_machine_is_compatible("MacRISC3") &&
of_get_property(cpunode, "dynamic-power-step", NULL) &&
PVR_VER(mfspr(SPRN_PVR)) == 0x8003) {
pmac_cpufreq_init_7447A(cpunode);
transition_latency = 8000000;
/* Check for other MacRISC3 machines */
} else if (of_machine_is_compatible("PowerBook3,4") ||
of_machine_is_compatible("PowerBook3,5") ||
of_machine_is_compatible("MacRISC3")) {
pmac_cpufreq_init_MacRISC3(cpunode);
/* Else check for iBook2 500/600 */
} else if (of_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 (of_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 (of_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);
