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linux/arch/sparc/kernel/us2e_cpufreq.c
Sam Ravnborg a88b5ba8bd sparc,sparc64: unify kernel/ 
o Move all files from sparc64/kernel/ to sparc/kernel
  - rename as appropriate
o Update sparc/Makefile to the changes
o Update sparc/kernel/Makefile to include the sparc64 files

NOTE: This commit changes link order on sparc64!

Link order had to change for either of sparc32 and sparc64.
And assuming sparc64 see more testing than sparc32 change link
order on sparc64 where issues will be caught faster.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04 09:17:21 -08:00

414 lines
9.6 KiB
C
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/* us2e_cpufreq.c: UltraSPARC-IIe cpu frequency support
*
* Copyright (C) 2003 David S. Miller (davem@redhat.com)
*
* Many thanks to Dominik Brodowski for fixing up the cpufreq
* infrastructure in order to make this driver easier to implement.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/cpufreq.h>
#include <linux/threads.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <asm/asi.h>
#include <asm/timer.h>
static struct cpufreq_driver *cpufreq_us2e_driver;
struct us2e_freq_percpu_info {
struct cpufreq_frequency_table table[6];
};
/* Indexed by cpu number. */
static struct us2e_freq_percpu_info *us2e_freq_table;
#define HBIRD_MEM_CNTL0_ADDR 0x1fe0000f010UL
#define HBIRD_ESTAR_MODE_ADDR 0x1fe0000f080UL
/* UltraSPARC-IIe has five dividers: 1, 2, 4, 6, and 8. These are controlled
* in the ESTAR mode control register.
*/
#define ESTAR_MODE_DIV_1 0x0000000000000000UL
#define ESTAR_MODE_DIV_2 0x0000000000000001UL
#define ESTAR_MODE_DIV_4 0x0000000000000003UL
#define ESTAR_MODE_DIV_6 0x0000000000000002UL
#define ESTAR_MODE_DIV_8 0x0000000000000004UL
#define ESTAR_MODE_DIV_MASK 0x0000000000000007UL
#define MCTRL0_SREFRESH_ENAB 0x0000000000010000UL
#define MCTRL0_REFR_COUNT_MASK 0x0000000000007f00UL
#define MCTRL0_REFR_COUNT_SHIFT 8
#define MCTRL0_REFR_INTERVAL 7800
#define MCTRL0_REFR_CLKS_P_CNT 64
static unsigned long read_hbreg(unsigned long addr)
{
unsigned long ret;
__asm__ __volatile__("ldxa [%1] %2, %0"
: "=&r" (ret)
: "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E));
return ret;
}
static void write_hbreg(unsigned long addr, unsigned long val)
{
__asm__ __volatile__("stxa %0, [%1] %2\n\t"
"membar #Sync"
: /* no outputs */
: "r" (val), "r" (addr), "i" (ASI_PHYS_BYPASS_EC_E)
: "memory");
if (addr == HBIRD_ESTAR_MODE_ADDR) {
/* Need to wait 16 clock cycles for the PLL to lock. */
udelay(1);
}
}
static void self_refresh_ctl(int enable)
{
unsigned long mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
if (enable)
mctrl |= MCTRL0_SREFRESH_ENAB;
else
mctrl &= ~MCTRL0_SREFRESH_ENAB;
write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
(void) read_hbreg(HBIRD_MEM_CNTL0_ADDR);
}
static void frob_mem_refresh(int cpu_slowing_down,
unsigned long clock_tick,
unsigned long old_divisor, unsigned long divisor)
{
unsigned long old_refr_count, refr_count, mctrl;
refr_count = (clock_tick * MCTRL0_REFR_INTERVAL);
refr_count /= (MCTRL0_REFR_CLKS_P_CNT * divisor * 1000000000UL);
mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
old_refr_count = (mctrl & MCTRL0_REFR_COUNT_MASK)
>> MCTRL0_REFR_COUNT_SHIFT;
mctrl &= ~MCTRL0_REFR_COUNT_MASK;
mctrl |= refr_count << MCTRL0_REFR_COUNT_SHIFT;
write_hbreg(HBIRD_MEM_CNTL0_ADDR, mctrl);
mctrl = read_hbreg(HBIRD_MEM_CNTL0_ADDR);
if (cpu_slowing_down && !(mctrl & MCTRL0_SREFRESH_ENAB)) {
unsigned long usecs;
/* We have to wait for both refresh counts (old
* and new) to go to zero.
*/
usecs = (MCTRL0_REFR_CLKS_P_CNT *
(refr_count + old_refr_count) *
1000000UL *
old_divisor) / clock_tick;
udelay(usecs + 1UL);
}
}
static void us2e_transition(unsigned long estar, unsigned long new_bits,
unsigned long clock_tick,
unsigned long old_divisor, unsigned long divisor)
{
unsigned long flags;
local_irq_save(flags);
estar &= ~ESTAR_MODE_DIV_MASK;
/* This is based upon the state transition diagram in the IIe manual. */
if (old_divisor == 2 && divisor == 1) {
self_refresh_ctl(0);
write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
frob_mem_refresh(0, clock_tick, old_divisor, divisor);
} else if (old_divisor == 1 && divisor == 2) {
frob_mem_refresh(1, clock_tick, old_divisor, divisor);
write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
self_refresh_ctl(1);
} else if (old_divisor == 1 && divisor > 2) {
us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
1, 2);
us2e_transition(estar, new_bits, clock_tick,
2, divisor);
} else if (old_divisor > 2 && divisor == 1) {
us2e_transition(estar, ESTAR_MODE_DIV_2, clock_tick,
old_divisor, 2);
us2e_transition(estar, new_bits, clock_tick,
2, divisor);
} else if (old_divisor < divisor) {
frob_mem_refresh(0, clock_tick, old_divisor, divisor);
write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
} else if (old_divisor > divisor) {
write_hbreg(HBIRD_ESTAR_MODE_ADDR, estar | new_bits);
frob_mem_refresh(1, clock_tick, old_divisor, divisor);
} else {
BUG();
}
local_irq_restore(flags);
}
static unsigned long index_to_estar_mode(unsigned int index)
{
switch (index) {
case 0:
return ESTAR_MODE_DIV_1;
case 1:
return ESTAR_MODE_DIV_2;
case 2:
return ESTAR_MODE_DIV_4;
case 3:
return ESTAR_MODE_DIV_6;
case 4:
return ESTAR_MODE_DIV_8;
default:
BUG();
};
}
static unsigned long index_to_divisor(unsigned int index)
{
switch (index) {
case 0:
return 1;
case 1:
return 2;
case 2:
return 4;
case 3:
return 6;
case 4:
return 8;
default:
BUG();
};
}
static unsigned long estar_to_divisor(unsigned long estar)
{
unsigned long ret;
switch (estar & ESTAR_MODE_DIV_MASK) {
case ESTAR_MODE_DIV_1:
ret = 1;
break;
case ESTAR_MODE_DIV_2:
ret = 2;
break;
case ESTAR_MODE_DIV_4:
ret = 4;
break;
case ESTAR_MODE_DIV_6:
ret = 6;
break;
case ESTAR_MODE_DIV_8:
ret = 8;
break;
default:
BUG();
};
return ret;
}
static unsigned int us2e_freq_get(unsigned int cpu)
{
cpumask_t cpus_allowed;
unsigned long clock_tick, estar;
if (!cpu_online(cpu))
return 0;
cpus_allowed = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(cpu));
clock_tick = sparc64_get_clock_tick(cpu) / 1000;
estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
set_cpus_allowed(current, cpus_allowed);
return clock_tick / estar_to_divisor(estar);
}
static void us2e_set_cpu_divider_index(unsigned int cpu, unsigned int index)
{
unsigned long new_bits, new_freq;
unsigned long clock_tick, divisor, old_divisor, estar;
cpumask_t cpus_allowed;
struct cpufreq_freqs freqs;
if (!cpu_online(cpu))
return;
cpus_allowed = current->cpus_allowed;
set_cpus_allowed(current, cpumask_of_cpu(cpu));
new_freq = clock_tick = sparc64_get_clock_tick(cpu) / 1000;
new_bits = index_to_estar_mode(index);
divisor = index_to_divisor(index);
new_freq /= divisor;
estar = read_hbreg(HBIRD_ESTAR_MODE_ADDR);
old_divisor = estar_to_divisor(estar);
freqs.old = clock_tick / old_divisor;
freqs.new = new_freq;
freqs.cpu = cpu;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
if (old_divisor != divisor)
us2e_transition(estar, new_bits, clock_tick * 1000,
old_divisor, divisor);
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
set_cpus_allowed(current, cpus_allowed);
}
static int us2e_freq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int new_index = 0;
if (cpufreq_frequency_table_target(policy,
&us2e_freq_table[policy->cpu].table[0],
target_freq, relation, &new_index))
return -EINVAL;
us2e_set_cpu_divider_index(policy->cpu, new_index);
return 0;
}
static int us2e_freq_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy,
&us2e_freq_table[policy->cpu].table[0]);
}
static int __init us2e_freq_cpu_init(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
unsigned long clock_tick = sparc64_get_clock_tick(cpu) / 1000;
struct cpufreq_frequency_table *table =
&us2e_freq_table[cpu].table[0];
table[0].index = 0;
table[0].frequency = clock_tick / 1;
table[1].index = 1;
table[1].frequency = clock_tick / 2;
table[2].index = 2;
table[2].frequency = clock_tick / 4;
table[2].index = 3;
table[2].frequency = clock_tick / 6;
table[2].index = 4;
table[2].frequency = clock_tick / 8;
table[2].index = 5;
table[3].frequency = CPUFREQ_TABLE_END;
policy->cpuinfo.transition_latency = 0;
policy->cur = clock_tick;
return cpufreq_frequency_table_cpuinfo(policy, table);
}
static int us2e_freq_cpu_exit(struct cpufreq_policy *policy)
{
if (cpufreq_us2e_driver)
us2e_set_cpu_divider_index(policy->cpu, 0);
return 0;
}
static int __init us2e_freq_init(void)
{
unsigned long manuf, impl, ver;
int ret;
if (tlb_type != spitfire)
return -ENODEV;
__asm__("rdpr %%ver, %0" : "=r" (ver));
manuf = ((ver >> 48) & 0xffff);
impl = ((ver >> 32) & 0xffff);
if (manuf == 0x17 && impl == 0x13) {
struct cpufreq_driver *driver;
ret = -ENOMEM;
driver = kzalloc(sizeof(struct cpufreq_driver), GFP_KERNEL);
if (!driver)
goto err_out;
us2e_freq_table = kzalloc(
(NR_CPUS * sizeof(struct us2e_freq_percpu_info)),
GFP_KERNEL);
if (!us2e_freq_table)
goto err_out;
driver->init = us2e_freq_cpu_init;
driver->verify = us2e_freq_verify;
driver->target = us2e_freq_target;
driver->get = us2e_freq_get;
driver->exit = us2e_freq_cpu_exit;
driver->owner = THIS_MODULE,
strcpy(driver->name, "UltraSPARC-IIe");
cpufreq_us2e_driver = driver;
ret = cpufreq_register_driver(driver);
if (ret)
goto err_out;
return 0;
err_out:
if (driver) {
kfree(driver);
cpufreq_us2e_driver = NULL;
}
kfree(us2e_freq_table);
us2e_freq_table = NULL;
return ret;
}
return -ENODEV;
}
static void __exit us2e_freq_exit(void)
{
if (cpufreq_us2e_driver) {
cpufreq_unregister_driver(cpufreq_us2e_driver);
kfree(cpufreq_us2e_driver);
cpufreq_us2e_driver = NULL;
kfree(us2e_freq_table);
us2e_freq_table = NULL;
}
}
MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
MODULE_DESCRIPTION("cpufreq driver for UltraSPARC-IIe");
MODULE_LICENSE("GPL");
module_init(us2e_freq_init);
module_exit(us2e_freq_exit);
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