linux/arch/cris/arch-v32/mach-a3/cpufreq.c
Jesper Nilsson 035e111f9a CRIS v32: Add new machine dependent files for Etrax-FS and Artpec-3.
The two chips are somewhat different, and needs different handling.
Adds handing of the dma, dram initialization, hardware settings, io,
memory arbiter and pinmux

Also moves the dma, dram initialization and io from CRIS v32 common files.
2008-02-08 11:06:23 +01:00

154 lines
3.5 KiB
C

#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(unsigned int state)
{
int i = 0;
struct cpufreq_freqs freqs;
reg_clkgen_rw_clk_ctrl clk_ctrl;
clk_ctrl = REG_RD(clkgen, regi_clkgen, rw_clk_ctrl);
#ifdef CONFIG_SMP
for_each_present_cpu(i)
#endif
{
freqs.old = cris_freq_get_cpu_frequency(i);
freqs.new = cris_freq_table[state].frequency;
freqs.cpu = i;
}
cpufreq_notify_transition(&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(&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(newstate);
return 0;
}
static int cris_freq_cpu_init(struct cpufreq_policy *policy)
{
int result;
/* cpuinfo and default policy values */
policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
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);