1 files changed, 648 insertions, 0 deletions

diff --git a/drivers/cpufreq/s3c24xx-cpufreq.c b/drivers/cpufreq/s3c24xx-cpufreq.c
new file mode 100644
index 000000000..7380c32b2
--- /dev/null
+++ b/drivers/cpufreq/s3c24xx-cpufreq.c
@@ -0,0 +1,648 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2006-2008 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX CPU Frequency scaling
+*/
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 <linux/soc/samsung/s3c-cpufreq-core.h>
+#include <linux/soc/samsung/s3c-pm.h>
+
+#include <asm/mach/arch.h>
+#include <asm/mach/map.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 = s3c24xx_read_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) {
+		pr_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) {
+			pr_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:
+	pr_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) {
+		index = cpufreq_frequency_table_target(policy, target_freq,
+						       relation);
+
+		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;
+
+		/* 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;
+		tmp_policy.freq_table = pll_reg;
+
+		/* cpufreq_frequency_table_target returns the index
+		 * of the table entry, not the value of
+		 * the table entry's index field. */
+
+		index = cpufreq_frequency_table_target(&tmp_policy, target_freq,
+						       relation);
+		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);
+}
+
+struct clk *s3c_cpufreq_clk_get(struct device *dev, const char *name)
+{
+	struct clk *clk;
+
+	clk = clk_get(dev, name);
+	if (IS_ERR(clk))
+		pr_err("failed to get clock '%s'\n", name);
+
+	return clk;
+}
+
+static int s3c_cpufreq_init(struct cpufreq_policy *policy)
+{
+	policy->clk = clk_arm;
+	policy->cpuinfo.transition_latency = cpu_cur.info->latency;
+	policy->freq_table = 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)) {
+		pr_err("%s: could not get clock(s)\n", __func__);
+		return -ENOENT;
+	}
+
+	pr_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 = s3c24xx_read_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) {
+		pr_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_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) {
+		pr_err("%s: failed to pass valid information\n", __func__);
+		return -EINVAL;
+	}
+
+	pr_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) {
+		pr_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)
+		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) {
+		pr_err("%s: get_iotiming undefined\n", __func__);
+		return -ENOENT;
+	}
+
+	pr_info("%s: working out IO settings\n", __func__);
+
+	ret = (cpu_cur.info->get_iotiming)(&cpu_cur, &s3c24xx_iotiming);
+	if (ret)
+		pr_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);
+
+	pr_info("%s: new locktime is 0x%08x\n", __func__, val);
+	s3c24xx_write_locktime(val);
+}
+
+static int s3c_cpufreq_build_freq(void)
+{
+	int size, ret;
+
+	kfree(ftab);
+
+	size = cpu_cur.info->calc_freqtable(&cpu_cur, NULL, 0);
+	size++;
+
+	ftab = kcalloc(size, sizeof(*ftab), GFP_KERNEL);
+	if (!ftab)
+		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) {
+				pr_err("%s: failed to get io timing\n",
+				       __func__);
+				goto out;
+			}
+		}
+
+		if (cpu_cur.board->need_io && !cpu_cur.info->set_iotiming) {
+			pr_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 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;
+
+		pr_info("%d PLL entries\n", plls_no);
+	} else
+		pr_err("no memory for PLL tables\n");
+
+	return vals ? 0 : -ENOMEM;
+}