/* * 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/clock.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->info->set_fvco)(cfg); } static inline void s3c_cpufreq_resume_clocks(void) { cpu_cur.info->resume_clocks(); } 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_notify_transition(policy, &freqs.freqs, CPUFREQ_PRECHANGE); /* 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_notify_transition(policy, &freqs.freqs, CPUFREQ_POSTCHANGE); 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; } static unsigned int s3c_cpufreq_get(unsigned int cpu) { return clk_get_rate(clk_arm) / 1000; } 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) { printk(KERN_INFO "%s: initialising policy %p\n", __func__, policy); if (policy->cpu != 0) return -EINVAL; policy->cur = s3c_cpufreq_get(0); policy->min = policy->cpuinfo.min_freq = 0; policy->max = policy->cpuinfo.max_freq = cpu_cur.info->max.fclk / 1000; policy->governor = CPUFREQ_DEFAULT_GOVERNOR; /* feed the latency information from the cpu driver */ policy->cpuinfo.transition_latency = cpu_cur.info->latency; if (ftab) cpufreq_frequency_table_cpuinfo(policy, ftab); return 0; } 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; } static int s3c_cpufreq_verify(struct cpufreq_policy *policy) { if (policy->cpu != 0) return -EINVAL; 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 = s3c_cpufreq_get(0) * 1000; 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 */ /* first, find out what speed we resumed at. */ s3c_cpufreq_resume_clocks(); /* 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, .verify = s3c_cpufreq_verify, .target = s3c_cpufreq_target, .get = s3c_cpufreq_get, .init = s3c_cpufreq_init, .suspend = s3c_cpufreq_suspend, .resume = s3c_cpufreq_resume, .name = "s3c24xx", }; int __init 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; } 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 = kmalloc(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 = kmalloc(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; }