linux/drivers/cpufreq/blackfin-cpufreq.c

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/*
* Blackfin core clock scaling
*
* Copyright 2008-2011 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/cpufreq.h>
#include <linux/fs.h>
#include <linux/delay.h>
#include <asm/blackfin.h>
#include <asm/time.h>
#include <asm/dpmc.h>
/* this is the table of CCLK frequencies, in Hz */
/* .driver_data is the entry in the auxiliary dpm_state_table[] */
static struct cpufreq_frequency_table bfin_freq_table[] = {
{
.frequency = CPUFREQ_TABLE_END,
.driver_data = 0,
},
{
.frequency = CPUFREQ_TABLE_END,
.driver_data = 1,
},
{
.frequency = CPUFREQ_TABLE_END,
.driver_data = 2,
},
{
.frequency = CPUFREQ_TABLE_END,
.driver_data = 0,
},
};
static struct bfin_dpm_state {
unsigned int csel; /* system clock divider */
unsigned int tscale; /* change the divider on the core timer interrupt */
} dpm_state_table[3];
#if defined(CONFIG_CYCLES_CLOCKSOURCE)
/*
* normalized to maximum frequency offset for CYCLES,
* used in time-ts cycles clock source, but could be used
* somewhere also.
*/
unsigned long long __bfin_cycles_off;
unsigned int __bfin_cycles_mod;
#endif
/**************************************************************************/
static void __init bfin_init_tables(unsigned long cclk, unsigned long sclk)
{
unsigned long csel, min_cclk;
int index;
/* Anomaly 273 seems to still exist on non-BF54x w/dcache turned on */
#if ANOMALY_05000273 || ANOMALY_05000274 || \
(!(defined(CONFIG_BF54x) || defined(CONFIG_BF60x)) \
&& defined(CONFIG_BFIN_EXTMEM_DCACHEABLE))
min_cclk = sclk * 2;
#else
min_cclk = sclk;
#endif
#ifndef CONFIG_BF60x
csel = ((bfin_read_PLL_DIV() & CSEL) >> 4);
#else
csel = bfin_read32(CGU0_DIV) & 0x1F;
#endif
for (index = 0; (cclk >> index) >= min_cclk && csel <= 3 && index < 3; index++, csel++) {
bfin_freq_table[index].frequency = cclk >> index;
#ifndef CONFIG_BF60x
dpm_state_table[index].csel = csel << 4; /* Shift now into PLL_DIV bitpos */
#else
dpm_state_table[index].csel = csel;
#endif
dpm_state_table[index].tscale = (TIME_SCALE >> index) - 1;
pr_debug("cpufreq: freq:%d csel:0x%x tscale:%d\n",
bfin_freq_table[index].frequency,
dpm_state_table[index].csel,
dpm_state_table[index].tscale);
}
return;
}
static void bfin_adjust_core_timer(void *info)
{
unsigned int tscale;
unsigned int index = *(unsigned int *)info;
/* we have to adjust the core timer, because it is using cclk */
tscale = dpm_state_table[index].tscale;
bfin_write_TSCALE(tscale);
return;
}
static unsigned int bfin_getfreq_khz(unsigned int cpu)
{
/* Both CoreA/B have the same core clock */
return get_cclk() / 1000;
}
#ifdef CONFIG_BF60x
static int cpu_set_cclk(int cpu, unsigned long new)
{
struct clk *clk;
int ret;
clk = clk_get(NULL, "CCLK");
if (IS_ERR(clk))
return -ENODEV;
ret = clk_set_rate(clk, new);
clk_put(clk);
return ret;
}
#endif
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 16:15:48 +02:00
static int bfin_target(struct cpufreq_policy *policy, unsigned int index)
{
#ifndef CONFIG_BF60x
unsigned int plldiv;
#endif
static unsigned long lpj_ref;
static unsigned int lpj_ref_freq;
unsigned int old_freq, new_freq;
int ret = 0;
#if defined(CONFIG_CYCLES_CLOCKSOURCE)
cycles_t cycles;
#endif
old_freq = bfin_getfreq_khz(0);
new_freq = bfin_freq_table[index].frequency;
#ifndef CONFIG_BF60x
plldiv = (bfin_read_PLL_DIV() & SSEL) | dpm_state_table[index].csel;
bfin_write_PLL_DIV(plldiv);
#else
ret = cpu_set_cclk(policy->cpu, new_freq * 1000);
if (ret != 0) {
WARN_ONCE(ret, "cpufreq set freq failed %d\n", ret);
return ret;
}
#endif
on_each_cpu(bfin_adjust_core_timer, &index, 1);
#if defined(CONFIG_CYCLES_CLOCKSOURCE)
cycles = get_cycles();
SSYNC();
cycles += 10; /* ~10 cycles we lose after get_cycles() */
__bfin_cycles_off += (cycles << __bfin_cycles_mod) - (cycles << index);
__bfin_cycles_mod = index;
#endif
if (!lpj_ref_freq) {
lpj_ref = loops_per_jiffy;
lpj_ref_freq = old_freq;
}
if (new_freq != old_freq) {
loops_per_jiffy = cpufreq_scale(lpj_ref,
lpj_ref_freq, new_freq);
}
return ret;
}
static int __bfin_cpu_init(struct cpufreq_policy *policy)
{
unsigned long cclk, sclk;
cclk = get_cclk() / 1000;
sclk = get_sclk() / 1000;
if (policy->cpu == CPUFREQ_CPU)
bfin_init_tables(cclk, sclk);
policy->cpuinfo.transition_latency = 50000; /* 50us assumed */
return cpufreq_table_validate_and_show(policy, bfin_freq_table);
}
static struct cpufreq_driver bfin_driver = {
.verify = cpufreq_generic_frequency_table_verify,
cpufreq: Implement light weight ->target_index() routine Currently, the prototype of cpufreq_drivers target routines is: int target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); And most of the drivers call cpufreq_frequency_table_target() to get a valid index of their frequency table which is closest to the target_freq. And they don't use target_freq and relation after that. So, it makes sense to just do this work in cpufreq core before calling cpufreq_frequency_table_target() and simply pass index instead. But this can be done only with drivers which expose their frequency table with cpufreq core. For others we need to stick with the old prototype of target() until those drivers are converted to expose frequency tables. This patch implements the new light weight prototype for target_index() routine. It looks like this: int target_index(struct cpufreq_policy *policy, unsigned int index); CPUFreq core will call cpufreq_frequency_table_target() before calling this routine and pass index to it. Because CPUFreq core now requires to call routines present in freq_table.c CONFIG_CPU_FREQ_TABLE must be enabled all the time. This also marks target() interface as deprecated. So, that new drivers avoid using it. And Documentation is updated accordingly. It also converts existing .target() to newly defined light weight .target_index() routine for many driver. Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Russell King <linux@arm.linux.org.uk> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@rjwysocki.net>
2013-10-25 16:15:48 +02:00
.target_index = bfin_target,
.get = bfin_getfreq_khz,
.init = __bfin_cpu_init,
.name = "bfin cpufreq",
.attr = cpufreq_generic_attr,
};
static int __init bfin_cpu_init(void)
{
return cpufreq_register_driver(&bfin_driver);
}
static void __exit bfin_cpu_exit(void)
{
cpufreq_unregister_driver(&bfin_driver);
}
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("cpufreq driver for Blackfin");
MODULE_LICENSE("GPL");
module_init(bfin_cpu_init);
module_exit(bfin_cpu_exit);