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path: root/drivers/cpufreq/s3c24xx-cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/s3c24xx-cpufreq.c')
-rw-r--r--drivers/cpufreq/s3c24xx-cpufreq.c674
1 files changed, 674 insertions, 0 deletions
diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
new file mode 100644
index 000000000..733aa5153
--- /dev/null
+++ b/drivers/cpufreq/s3c24xx-cpufreq.c
@@ -0,0 +1,674 @@
+/*
+ * Copyright (c) 2006-2008 Simtec Electronics
+ * http://armlinux.simtec.co.uk/
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX CPU Frequency scaling
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/cpu.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/device.h>
+#include <linux/sysfs.h>
+#include <linux/slab.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.h>
+
+#include <plat/cpu.h>
+#include <plat/cpu-freq-core.h>
+
+#include <mach/regs-clock.h>
+
+/* note, cpufreq support deals in kHz, no Hz */
+
+static struct cpufreq_driver s3c24xx_driver;
+static struct s3c_cpufreq_config cpu_cur;
+static struct s3c_iotimings s3c24xx_iotiming;
+static struct cpufreq_frequency_table *pll_reg;
+static unsigned int last_target = ~0;
+static unsigned int ftab_size;
+static struct cpufreq_frequency_table *ftab;
+
+static struct clk *_clk_mpll;
+static struct clk *_clk_xtal;
+static struct clk *clk_fclk;
+static struct clk *clk_hclk;
+static struct clk *clk_pclk;
+static struct clk *clk_arm;
+
+#ifdef CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS
+struct s3c_cpufreq_config *s3c_cpufreq_getconfig(void)
+{
+ return &cpu_cur;
+}
+
+struct s3c_iotimings *s3c_cpufreq_getiotimings(void)
+{
+ return &s3c24xx_iotiming;
+}
+#endif /* CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS */
+
+static void s3c_cpufreq_getcur(struct s3c_cpufreq_config *cfg)
+{
+ unsigned long fclk, pclk, hclk, armclk;
+
+ cfg->freq.fclk = fclk = clk_get_rate(clk_fclk);
+ cfg->freq.hclk = hclk = clk_get_rate(clk_hclk);
+ cfg->freq.pclk = pclk = clk_get_rate(clk_pclk);
+ cfg->freq.armclk = armclk = clk_get_rate(clk_arm);
+
+ cfg->pll.driver_data = __raw_readl(S3C2410_MPLLCON);
+ cfg->pll.frequency = fclk;
+
+ cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
+
+ cfg->divs.h_divisor = fclk / hclk;
+ cfg->divs.p_divisor = fclk / pclk;
+}
+
+static inline void s3c_cpufreq_calc(struct s3c_cpufreq_config *cfg)
+{
+ unsigned long pll = cfg->pll.frequency;
+
+ cfg->freq.fclk = pll;
+ cfg->freq.hclk = pll / cfg->divs.h_divisor;
+ cfg->freq.pclk = pll / cfg->divs.p_divisor;
+
+ /* convert hclk into 10ths of nanoseconds for io calcs */
+ cfg->freq.hclk_tns = 1000000000 / (cfg->freq.hclk / 10);
+}
+
+static inline int closer(unsigned int target, unsigned int n, unsigned int c)
+{
+ int diff_cur = abs(target - c);
+ int diff_new = abs(target - n);
+
+ return (diff_new < diff_cur);
+}
+
+static void s3c_cpufreq_show(const char *pfx,
+ struct s3c_cpufreq_config *cfg)
+{
+ s3c_freq_dbg("%s: Fvco=%u, F=%lu, A=%lu, H=%lu (%u), P=%lu (%u)\n",
+ pfx, cfg->pll.frequency, cfg->freq.fclk, cfg->freq.armclk,
+ cfg->freq.hclk, cfg->divs.h_divisor,
+ cfg->freq.pclk, cfg->divs.p_divisor);
+}
+
+/* functions to wrapper the driver info calls to do the cpu specific work */
+
+static void s3c_cpufreq_setio(struct s3c_cpufreq_config *cfg)
+{
+ if (cfg->info->set_iotiming)
+ (cfg->info->set_iotiming)(cfg, &s3c24xx_iotiming);
+}
+
+static int s3c_cpufreq_calcio(struct s3c_cpufreq_config *cfg)
+{
+ if (cfg->info->calc_iotiming)
+ return (cfg->info->calc_iotiming)(cfg, &s3c24xx_iotiming);
+
+ return 0;
+}
+
+static void s3c_cpufreq_setrefresh(struct s3c_cpufreq_config *cfg)
+{
+ (cfg->info->set_refresh)(cfg);
+}
+
+static void s3c_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
+{
+ (cfg->info->set_divs)(cfg);
+}
+
+static int s3c_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
+{
+ return (cfg->info->calc_divs)(cfg);
+}
+
+static void s3c_cpufreq_setfvco(struct s3c_cpufreq_config *cfg)
+{
+ cfg->mpll = _clk_mpll;
+ (cfg->info->set_fvco)(cfg);
+}
+
+static inline void s3c_cpufreq_updateclk(struct clk *clk,
+ unsigned int freq)
+{
+ clk_set_rate(clk, freq);
+}
+
+static int s3c_cpufreq_settarget(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ struct cpufreq_frequency_table *pll)
+{
+ struct s3c_cpufreq_freqs freqs;
+ struct s3c_cpufreq_config cpu_new;
+ unsigned long flags;
+
+ cpu_new = cpu_cur; /* copy new from current */
+
+ s3c_cpufreq_show("cur", &cpu_cur);
+
+ /* TODO - check for DMA currently outstanding */
+
+ cpu_new.pll = pll ? *pll : cpu_cur.pll;
+
+ if (pll)
+ freqs.pll_changing = 1;
+
+ /* update our frequencies */
+
+ cpu_new.freq.armclk = target_freq;
+ cpu_new.freq.fclk = cpu_new.pll.frequency;
+
+ if (s3c_cpufreq_calcdivs(&cpu_new) < 0) {
+ printk(KERN_ERR "no divisors for %d\n", target_freq);
+ goto err_notpossible;
+ }
+
+ s3c_freq_dbg("%s: got divs\n", __func__);
+
+ s3c_cpufreq_calc(&cpu_new);
+
+ s3c_freq_dbg("%s: calculated frequencies for new\n", __func__);
+
+ if (cpu_new.freq.hclk != cpu_cur.freq.hclk) {
+ if (s3c_cpufreq_calcio(&cpu_new) < 0) {
+ printk(KERN_ERR "%s: no IO timings\n", __func__);
+ goto err_notpossible;
+ }
+ }
+
+ s3c_cpufreq_show("new", &cpu_new);
+
+ /* setup our cpufreq parameters */
+
+ freqs.old = cpu_cur.freq;
+ freqs.new = cpu_new.freq;
+
+ freqs.freqs.old = cpu_cur.freq.armclk / 1000;
+ freqs.freqs.new = cpu_new.freq.armclk / 1000;
+
+ /* update f/h/p clock settings before we issue the change
+ * notification, so that drivers do not need to do anything
+ * special if they want to recalculate on CPUFREQ_PRECHANGE. */
+
+ s3c_cpufreq_updateclk(_clk_mpll, cpu_new.pll.frequency);
+ s3c_cpufreq_updateclk(clk_fclk, cpu_new.freq.fclk);
+ s3c_cpufreq_updateclk(clk_hclk, cpu_new.freq.hclk);
+ s3c_cpufreq_updateclk(clk_pclk, cpu_new.freq.pclk);
+
+ /* start the frequency change */
+ cpufreq_freq_transition_begin(policy, &freqs.freqs);
+
+ /* If hclk is staying the same, then we do not need to
+ * re-write the IO or the refresh timings whilst we are changing
+ * speed. */
+
+ local_irq_save(flags);
+
+ /* is our memory clock slowing down? */
+ if (cpu_new.freq.hclk < cpu_cur.freq.hclk) {
+ s3c_cpufreq_setrefresh(&cpu_new);
+ s3c_cpufreq_setio(&cpu_new);
+ }
+
+ if (cpu_new.freq.fclk == cpu_cur.freq.fclk) {
+ /* not changing PLL, just set the divisors */
+
+ s3c_cpufreq_setdivs(&cpu_new);
+ } else {
+ if (cpu_new.freq.fclk < cpu_cur.freq.fclk) {
+ /* slow the cpu down, then set divisors */
+
+ s3c_cpufreq_setfvco(&cpu_new);
+ s3c_cpufreq_setdivs(&cpu_new);
+ } else {
+ /* set the divisors, then speed up */
+
+ s3c_cpufreq_setdivs(&cpu_new);
+ s3c_cpufreq_setfvco(&cpu_new);
+ }
+ }
+
+ /* did our memory clock speed up */
+ if (cpu_new.freq.hclk > cpu_cur.freq.hclk) {
+ s3c_cpufreq_setrefresh(&cpu_new);
+ s3c_cpufreq_setio(&cpu_new);
+ }
+
+ /* update our current settings */
+ cpu_cur = cpu_new;
+
+ local_irq_restore(flags);
+
+ /* notify everyone we've done this */
+ cpufreq_freq_transition_end(policy, &freqs.freqs, 0);
+
+ s3c_freq_dbg("%s: finished\n", __func__);
+ return 0;
+
+ err_notpossible:
+ printk(KERN_ERR "no compatible settings for %d\n", target_freq);
+ return -EINVAL;
+}
+
+/* s3c_cpufreq_target
+ *
+ * called by the cpufreq core to adjust the frequency that the CPU
+ * is currently running at.
+ */
+
+static int s3c_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cpufreq_frequency_table *pll;
+ unsigned int index;
+
+ /* avoid repeated calls which cause a needless amout of duplicated
+ * logging output (and CPU time as the calculation process is
+ * done) */
+ if (target_freq == last_target)
+ return 0;
+
+ last_target = target_freq;
+
+ s3c_freq_dbg("%s: policy %p, target %u, relation %u\n",
+ __func__, policy, target_freq, relation);
+
+ if (ftab) {
+ if (cpufreq_frequency_table_target(policy, ftab,
+ target_freq, relation,
+ &index)) {
+ s3c_freq_dbg("%s: table failed\n", __func__);
+ return -EINVAL;
+ }
+
+ s3c_freq_dbg("%s: adjust %d to entry %d (%u)\n", __func__,
+ target_freq, index, ftab[index].frequency);
+ target_freq = ftab[index].frequency;
+ }
+
+ target_freq *= 1000; /* convert target to Hz */
+
+ /* find the settings for our new frequency */
+
+ if (!pll_reg || cpu_cur.lock_pll) {
+ /* either we've not got any PLL values, or we've locked
+ * to the current one. */
+ pll = NULL;
+ } else {
+ struct cpufreq_policy tmp_policy;
+ int ret;
+
+ /* we keep the cpu pll table in Hz, to ensure we get an
+ * accurate value for the PLL output. */
+
+ tmp_policy.min = policy->min * 1000;
+ tmp_policy.max = policy->max * 1000;
+ tmp_policy.cpu = policy->cpu;
+
+ /* cpufreq_frequency_table_target uses a pointer to 'index'
+ * which is the number of the table entry, not the value of
+ * the table entry's index field. */
+
+ ret = cpufreq_frequency_table_target(&tmp_policy, pll_reg,
+ target_freq, relation,
+ &index);
+
+ if (ret < 0) {
+ printk(KERN_ERR "%s: no PLL available\n", __func__);
+ goto err_notpossible;
+ }
+
+ pll = pll_reg + index;
+
+ s3c_freq_dbg("%s: target %u => %u\n",
+ __func__, target_freq, pll->frequency);
+
+ target_freq = pll->frequency;
+ }
+
+ return s3c_cpufreq_settarget(policy, target_freq, pll);
+
+ err_notpossible:
+ printk(KERN_ERR "no compatible settings for %d\n", target_freq);
+ return -EINVAL;
+}
+
+struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
+{
+ struct clk *clk;
+
+ clk = clk_get(dev, name);
+ if (IS_ERR(clk))
+ printk(KERN_ERR "cpufreq: failed to get clock '%s'\n", name);
+
+ return clk;
+}
+
+static int s3c_cpufreq_init(struct cpufreq_policy *policy)
+{
+ policy->clk = clk_arm;
+ return cpufreq_generic_init(policy, ftab, cpu_cur.info->latency);
+}
+
+static int __init s3c_cpufreq_initclks(void)
+{
+ _clk_mpll = s3c_cpufreq_clk_get(NULL, "mpll");
+ _clk_xtal = s3c_cpufreq_clk_get(NULL, "xtal");
+ clk_fclk = s3c_cpufreq_clk_get(NULL, "fclk");
+ clk_hclk = s3c_cpufreq_clk_get(NULL, "hclk");
+ clk_pclk = s3c_cpufreq_clk_get(NULL, "pclk");
+ clk_arm = s3c_cpufreq_clk_get(NULL, "armclk");
+
+ if (IS_ERR(clk_fclk) || IS_ERR(clk_hclk) || IS_ERR(clk_pclk) ||
+ IS_ERR(_clk_mpll) || IS_ERR(clk_arm) || IS_ERR(_clk_xtal)) {
+ printk(KERN_ERR "%s: could not get clock(s)\n", __func__);
+ return -ENOENT;
+ }
+
+ printk(KERN_INFO "%s: clocks f=%lu,h=%lu,p=%lu,a=%lu\n", __func__,
+ clk_get_rate(clk_fclk) / 1000,
+ clk_get_rate(clk_hclk) / 1000,
+ clk_get_rate(clk_pclk) / 1000,
+ clk_get_rate(clk_arm) / 1000);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static struct cpufreq_frequency_table suspend_pll;
+static unsigned int suspend_freq;
+
+static int s3c_cpufreq_suspend(struct cpufreq_policy *policy)
+{
+ suspend_pll.frequency = clk_get_rate(_clk_mpll);
+ suspend_pll.driver_data = __raw_readl(S3C2410_MPLLCON);
+ suspend_freq = clk_get_rate(clk_arm);
+
+ return 0;
+}
+
+static int s3c_cpufreq_resume(struct cpufreq_policy *policy)
+{
+ int ret;
+
+ s3c_freq_dbg("%s: resuming with policy %p\n", __func__, policy);
+
+ last_target = ~0; /* invalidate last_target setting */
+
+ /* whilst we will be called later on, we try and re-set the
+ * cpu frequencies as soon as possible so that we do not end
+ * up resuming devices and then immediately having to re-set
+ * a number of settings once these devices have restarted.
+ *
+ * as a note, it is expected devices are not used until they
+ * have been un-suspended and at that time they should have
+ * used the updated clock settings.
+ */
+
+ ret = s3c_cpufreq_settarget(NULL, suspend_freq, &suspend_pll);
+ if (ret) {
+ printk(KERN_ERR "%s: failed to reset pll/freq\n", __func__);
+ return ret;
+ }
+
+ return 0;
+}
+#else
+#define s3c_cpufreq_resume NULL
+#define s3c_cpufreq_suspend NULL
+#endif
+
+static struct cpufreq_driver s3c24xx_driver = {
+ .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .target = s3c_cpufreq_target,
+ .get = cpufreq_generic_get,
+ .init = s3c_cpufreq_init,
+ .suspend = s3c_cpufreq_suspend,
+ .resume = s3c_cpufreq_resume,
+ .name = "s3c24xx",
+};
+
+
+int s3c_cpufreq_register(struct s3c_cpufreq_info *info)
+{
+ if (!info || !info->name) {
+ printk(KERN_ERR "%s: failed to pass valid information\n",
+ __func__);
+ return -EINVAL;
+ }
+
+ printk(KERN_INFO "S3C24XX CPU Frequency driver, %s cpu support\n",
+ info->name);
+
+ /* check our driver info has valid data */
+
+ BUG_ON(info->set_refresh == NULL);
+ BUG_ON(info->set_divs == NULL);
+ BUG_ON(info->calc_divs == NULL);
+
+ /* info->set_fvco is optional, depending on whether there
+ * is a need to set the clock code. */
+
+ cpu_cur.info = info;
+
+ /* Note, driver registering should probably update locktime */
+
+ return 0;
+}
+
+int __init s3c_cpufreq_setboard(struct s3c_cpufreq_board *board)
+{
+ struct s3c_cpufreq_board *ours;
+
+ if (!board) {
+ printk(KERN_INFO "%s: no board data\n", __func__);
+ return -EINVAL;
+ }
+
+ /* Copy the board information so that each board can make this
+ * initdata. */
+
+ ours = kzalloc(sizeof(*ours), GFP_KERNEL);
+ if (ours == NULL) {
+ printk(KERN_ERR "%s: no memory\n", __func__);
+ return -ENOMEM;
+ }
+
+ *ours = *board;
+ cpu_cur.board = ours;
+
+ return 0;
+}
+
+static int __init s3c_cpufreq_auto_io(void)
+{
+ int ret;
+
+ if (!cpu_cur.info->get_iotiming) {
+ printk(KERN_ERR "%s: get_iotiming undefined\n", __func__);
+ return -ENOENT;
+ }
+
+ printk(KERN_INFO "%s: working out IO settings\n", __func__);
+
+ ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
+ if (ret)
+ printk(KERN_ERR "%s: failed to get timings\n", __func__);
+
+ return ret;
+}
+
+/* if one or is zero, then return the other, otherwise return the min */
+#define do_min(_a, _b) ((_a) == 0 ? (_b) : (_b) == 0 ? (_a) : min(_a, _b))
+
+/**
+ * s3c_cpufreq_freq_min - find the minimum settings for the given freq.
+ * @dst: The destination structure
+ * @a: One argument.
+ * @b: The other argument.
+ *
+ * Create a minimum of each frequency entry in the 'struct s3c_freq',
+ * unless the entry is zero when it is ignored and the non-zero argument
+ * used.
+ */
+static void s3c_cpufreq_freq_min(struct s3c_freq *dst,
+ struct s3c_freq *a, struct s3c_freq *b)
+{
+ dst->fclk = do_min(a->fclk, b->fclk);
+ dst->hclk = do_min(a->hclk, b->hclk);
+ dst->pclk = do_min(a->pclk, b->pclk);
+ dst->armclk = do_min(a->armclk, b->armclk);
+}
+
+static inline u32 calc_locktime(u32 freq, u32 time_us)
+{
+ u32 result;
+
+ result = freq * time_us;
+ result = DIV_ROUND_UP(result, 1000 * 1000);
+
+ return result;
+}
+
+static void s3c_cpufreq_update_loctkime(void)
+{
+ unsigned int bits = cpu_cur.info->locktime_bits;
+ u32 rate = (u32)clk_get_rate(_clk_xtal);
+ u32 val;
+
+ if (bits == 0) {
+ WARN_ON(1);
+ return;
+ }
+
+ val = calc_locktime(rate, cpu_cur.info->locktime_u) << bits;
+ val |= calc_locktime(rate, cpu_cur.info->locktime_m);
+
+ printk(KERN_INFO "%s: new locktime is 0x%08x\n", __func__, val);
+ __raw_writel(val, S3C2410_LOCKTIME);
+}
+
+static int s3c_cpufreq_build_freq(void)
+{
+ int size, ret;
+
+ if (!cpu_cur.info->calc_freqtable)
+ return -EINVAL;
+
+ kfree(ftab);
+ ftab = NULL;
+
+ size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
+ size++;
+
+ ftab = kzalloc(sizeof(*ftab) * size, GFP_KERNEL);
+ if (!ftab) {
+ printk(KERN_ERR "%s: no memory for tables\n", __func__);
+ return -ENOMEM;
+ }
+
+ ftab_size = size;
+
+ ret = cpu_cur.info->calc_freqtable(&cpu_cur, ftab, size);
+ s3c_cpufreq_addfreq(ftab, ret, size, CPUFREQ_TABLE_END);
+
+ return 0;
+}
+
+static int __init s3c_cpufreq_initcall(void)
+{
+ int ret = 0;
+
+ if (cpu_cur.info && cpu_cur.board) {
+ ret = s3c_cpufreq_initclks();
+ if (ret)
+ goto out;
+
+ /* get current settings */
+ s3c_cpufreq_getcur(&cpu_cur);
+ s3c_cpufreq_show("cur", &cpu_cur);
+
+ if (cpu_cur.board->auto_io) {
+ ret = s3c_cpufreq_auto_io();
+ if (ret) {
+ printk(KERN_ERR "%s: failed to get io timing\n",
+ __func__);
+ goto out;
+ }
+ }
+
+ if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
+ printk(KERN_ERR "%s: no IO support registered\n",
+ __func__);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!cpu_cur.info->need_pll)
+ cpu_cur.lock_pll = 1;
+
+ s3c_cpufreq_update_loctkime();
+
+ s3c_cpufreq_freq_min(&cpu_cur.max, &cpu_cur.board->max,
+ &cpu_cur.info->max);
+
+ if (cpu_cur.info->calc_freqtable)
+ s3c_cpufreq_build_freq();
+
+ ret = cpufreq_register_driver(&s3c24xx_driver);
+ }
+
+ out:
+ return ret;
+}
+
+late_initcall(s3c_cpufreq_initcall);
+
+/**
+ * s3c_plltab_register - register CPU PLL table.
+ * @plls: The list of PLL entries.
+ * @plls_no: The size of the PLL entries @plls.
+ *
+ * Register the given set of PLLs with the system.
+ */
+int __init s3c_plltab_register(struct cpufreq_frequency_table *plls,
+ unsigned int plls_no)
+{
+ struct cpufreq_frequency_table *vals;
+ unsigned int size;
+
+ size = sizeof(*vals) * (plls_no + 1);
+
+ vals = kzalloc(size, GFP_KERNEL);
+ if (vals) {
+ memcpy(vals, plls, size);
+ pll_reg = vals;
+
+ /* write a terminating entry, we don't store it in the
+ * table that is stored in the kernel */
+ vals += plls_no;
+ vals->frequency = CPUFREQ_TABLE_END;
+
+ printk(KERN_INFO "cpufreq: %d PLL entries\n", plls_no);
+ } else
+ printk(KERN_ERR "cpufreq: no memory for PLL tables\n");
+
+ return vals ? 0 : -ENOMEM;
+}