#include <linux/init.h>
#include <linux/module.h>
#include <linux/cpufreq.h>
#include <hwregs/reg_map.h>
#include <hwregs/reg_rdwr.h>
#include <hwregs/clkgen_defs.h>
#include <hwregs/ddr2_defs.h>
static int
cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
void *data);
static struct notifier_block cris_sdram_freq_notifier_block = {
.notifier_call = cris_sdram_freq_notifier
};
static struct cpufreq_frequency_table cris_freq_table[] = {
{0x01, 6000},
{0x02, 200000},
{0, CPUFREQ_TABLE_END},
};
static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
{
reg_clkgen_rw_clk_ctrl clk_ctrl;
clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
return clk_ctrl.pll ? 200000 : 6000;
}
static void cris_freq_set_cpu_state(struct cpufreq_policy *policy,
unsigned int state)
{
struct cpufreq_freqs freqs;
reg_clkgen_rw_clk_ctrl clk_ctrl;
clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
freqs.old = cris_freq_get_cpu_frequency(policy->cpu);
freqs.new = cris_freq_table[state].frequency;
cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
local_irq_disable();
/* Even though we may be SMP they will share the same clock
* so all settings are made on CPU0. */
if (cris_freq_table[state].frequency == 200000)
clk_ctrl.pll = 1;
else
clk_ctrl.pll = 0;
REG_WR(clkgen, regi_clkgen, rw_clk_ctrl, clk_ctrl);
local_irq_enable();
cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
};
static int cris_freq_verify(struct cpufreq_policy *policy)
{
return cpufreq_frequency_table_verify(policy, &cris_freq_table[0]);
}
static int cris_freq_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
unsigned int newstate = 0;
if (cpufreq_frequency_table_target(policy, cris_freq_table,
target_freq, relation, &newstate))
return -EINVAL;
cris_freq_set_cpu_state(policy, newstate);
return 0;
}
static int cris_freq_cpu_init(struct cpufreq_policy *policy)
{
int result;
/* cpuinfo and default policy values */
policy->cpuinfo.transition_latency = 1000000; /* 1ms */
policy->cur = cris_freq_get_cpu_frequency(0);
result = cpufreq_frequency_table_cpuinfo(policy, cris_freq_table);
if (result)
return (result);
cpufreq_frequency_table_get_attr(cris_freq_table, policy->cpu);
return 0;
}
static int cris_freq_cpu_exit(struct cpufreq_policy *policy)
{
cpufreq_frequency_table_put_attr(policy->cpu);
return 0;
}
static struct freq_attr *cris_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
};
static struct cpufreq_driver cris_freq_driver = {
.get = cris_freq_get_cpu_frequency,
.verify = cris_freq_verify,
.target = cris_freq_target,
.init = cris_freq_cpu_init,
.exit = cris_freq_cpu_exit,
.name = "cris_freq",
.owner = THIS_MODULE,
.attr = cris_freq_attr,
};
static int __init cris_freq_init(void)
{
int ret;
ret = cpufreq_register_driver(&cris_freq_driver);
cpufreq_register_notifier(&cris_sdram_freq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
return ret;
}
static int
cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
void *data)
{
int i;
struct cpufreq_freqs *freqs = data;
if (val == CPUFREQ_PRECHANGE) {
reg_ddr2_rw_cfg cfg =
REG_RD(ddr2, regi_ddr2_ctrl, rw_cfg);
cfg.ref_interval = (freqs->new == 200000 ? 1560 : 46);
if (freqs->new == 200000)
for (i = 0; i < 50000; i++);
REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing);
}
return 0;
}
module_init(cris_freq_init);
