linux/drivers/cpufreq/cris-etraxfs-cpufreq.c
Viresh Kumar 7f4b04614a cpufreq: create another field .flags in cpufreq_frequency_table
Currently cpufreq frequency table has two fields: frequency and driver_data.
driver_data is only for drivers' internal use and cpufreq core shouldn't use
it at all. But with the introduction of BOOST frequencies, this assumption
was broken and we started using it as a flag instead.

There are two problems due to this:
- It is against the description of this field, as driver's data is used by
  the core now.
- if drivers fill it with -3 for any frequency, then those frequencies are
  never considered by cpufreq core as it is exactly same as value of
  CPUFREQ_BOOST_FREQ, i.e. ~2.

The best way to get this fixed is by creating another field flags which
will be used for such flags. This patch does that. Along with that various
drivers need modifications due to the change of struct cpufreq_frequency_table.

Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-07 14:43:50 +02:00

91 lines
2.3 KiB
C

#include <linux/init.h>
#include <linux/module.h>
#include <linux/cpufreq.h>
#include <hwregs/reg_map.h>
#include <arch/hwregs/reg_rdwr.h>
#include <arch/hwregs/config_defs.h>
#include <arch/hwregs/bif_core_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[] = {
{0, 0x01, 6000},
{0, 0x02, 200000},
{0, 0, CPUFREQ_TABLE_END},
};
static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
{
reg_config_rw_clk_ctrl clk_ctrl;
clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl);
return clk_ctrl.pll ? 200000 : 6000;
}
static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
{
reg_config_rw_clk_ctrl clk_ctrl;
clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl);
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(config, regi_config, rw_clk_ctrl, clk_ctrl);
local_irq_enable();
return 0;
}
static int cris_freq_cpu_init(struct cpufreq_policy *policy)
{
return cpufreq_generic_init(policy, cris_freq_table, 1000000);
}
static struct cpufreq_driver cris_freq_driver = {
.get = cris_freq_get_cpu_frequency,
.verify = cpufreq_generic_frequency_table_verify,
.target_index = cris_freq_target,
.init = cris_freq_cpu_init,
.name = "cris_freq",
.attr = cpufreq_generic_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_bif_core_rw_sdram_timing timing =
REG_RD(bif_core, regi_bif_core, rw_sdram_timing);
timing.cpd = (freqs->new == 200000 ? 0 : 1);
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);