mirror of https://gitee.com/openkylin/linux.git
92 lines
2.3 KiB
C
92 lines
2.3 KiB
C
#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/cpufreq.h>
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#include <hwregs/reg_map.h>
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#include <arch/hwregs/reg_rdwr.h>
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#include <arch/hwregs/config_defs.h>
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#include <arch/hwregs/bif_core_defs.h>
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static int
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cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
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void *data);
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static struct notifier_block cris_sdram_freq_notifier_block = {
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.notifier_call = cris_sdram_freq_notifier
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};
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static struct cpufreq_frequency_table cris_freq_table[] = {
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{0x01, 6000},
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{0x02, 200000},
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{0, CPUFREQ_TABLE_END},
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};
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static unsigned int cris_freq_get_cpu_frequency(unsigned int cpu)
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{
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reg_config_rw_clk_ctrl clk_ctrl;
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clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl);
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return clk_ctrl.pll ? 200000 : 6000;
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}
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static int cris_freq_target(struct cpufreq_policy *policy, unsigned int state)
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{
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reg_config_rw_clk_ctrl clk_ctrl;
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clk_ctrl = REG_RD(config, regi_config, rw_clk_ctrl);
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local_irq_disable();
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/* Even though we may be SMP they will share the same clock
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* so all settings are made on CPU0. */
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if (cris_freq_table[state].frequency == 200000)
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clk_ctrl.pll = 1;
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else
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clk_ctrl.pll = 0;
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REG_WR(config, regi_config, rw_clk_ctrl, clk_ctrl);
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local_irq_enable();
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return 0;
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}
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static int cris_freq_cpu_init(struct cpufreq_policy *policy)
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{
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return cpufreq_generic_init(policy, cris_freq_table, 1000000);
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}
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static struct cpufreq_driver cris_freq_driver = {
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.get = cris_freq_get_cpu_frequency,
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = cris_freq_target,
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.init = cris_freq_cpu_init,
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.name = "cris_freq",
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.attr = cpufreq_generic_attr,
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};
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static int __init cris_freq_init(void)
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{
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int ret;
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ret = cpufreq_register_driver(&cris_freq_driver);
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cpufreq_register_notifier(&cris_sdram_freq_notifier_block,
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CPUFREQ_TRANSITION_NOTIFIER);
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return ret;
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}
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static int
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cris_sdram_freq_notifier(struct notifier_block *nb, unsigned long val,
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void *data)
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{
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int i;
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struct cpufreq_freqs *freqs = data;
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if (val == CPUFREQ_PRECHANGE) {
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reg_bif_core_rw_sdram_timing timing =
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REG_RD(bif_core, regi_bif_core, rw_sdram_timing);
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timing.cpd = (freqs->new == 200000 ? 0 : 1);
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if (freqs->new == 200000)
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for (i = 0; i < 50000; i++) ;
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REG_WR(bif_core, regi_bif_core, rw_sdram_timing, timing);
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}
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return 0;
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}
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module_init(cris_freq_init);
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