+++ /dev/null
-/*
- * 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
-
-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,
- .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);
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