1 files changed, 670 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
new file mode 100644
index 00000000..008772e3
--- /dev/null
+++ b/arch/arm/mach-davinci/clock.c
@@ -0,0 +1,670 @@
+/*
+ * Clock and PLL control for DaVinci devices
+ *
+ * Copyright (C) 2006-2007 Texas Instruments.
+ * Copyright (C) 2008-2009 Deep Root Systems, LLC
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+
+#include <mach/hardware.h>
+
+#include <mach/clock.h>
+#include <mach/psc.h>
+#include <mach/cputype.h>
+#include "clock.h"
+
+static LIST_HEAD(clocks);
+static DEFINE_MUTEX(clocks_mutex);
+static DEFINE_SPINLOCK(clockfw_lock);
+
+static void __clk_enable(struct clk *clk)
+{
+	if (clk->parent)
+		__clk_enable(clk->parent);
+	if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
+		davinci_psc_config(clk->domain, clk->gpsc, clk->lpsc,
+				true, clk->flags);
+}
+
+static void __clk_disable(struct clk *clk)
+{
+	if (WARN_ON(clk->usecount == 0))
+		return;
+	if (--clk->usecount == 0 && !(clk->flags & CLK_PLL) &&
+	    (clk->flags & CLK_PSC))
+		davinci_psc_config(clk->domain, clk->gpsc, clk->lpsc,
+				false, clk->flags);
+	if (clk->parent)
+		__clk_disable(clk->parent);
+}
+
+int clk_enable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	__clk_enable(clk);
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+	unsigned long flags;
+
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	__clk_disable(clk);
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+}
+EXPORT_SYMBOL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	return clk->rate;
+}
+EXPORT_SYMBOL(clk_get_rate);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	if (clk->round_rate)
+		return clk->round_rate(clk, rate);
+
+	return clk->rate;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+/* Propagate rate to children */
+static void propagate_rate(struct clk *root)
+{
+	struct clk *clk;
+
+	list_for_each_entry(clk, &root->children, childnode) {
+		if (clk->recalc)
+			clk->rate = clk->recalc(clk);
+		propagate_rate(clk);
+	}
+}
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long flags;
+	int ret = -EINVAL;
+
+	if (clk == NULL || IS_ERR(clk))
+		return ret;
+
+	if (clk->set_rate)
+		ret = clk->set_rate(clk, rate);
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	if (ret == 0) {
+		if (clk->recalc)
+			clk->rate = clk->recalc(clk);
+		propagate_rate(clk);
+	}
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	unsigned long flags;
+
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	/* Cannot change parent on enabled clock */
+	if (WARN_ON(clk->usecount))
+		return -EINVAL;
+
+	mutex_lock(&clocks_mutex);
+	clk->parent = parent;
+	list_del_init(&clk->childnode);
+	list_add(&clk->childnode, &clk->parent->children);
+	mutex_unlock(&clocks_mutex);
+
+	spin_lock_irqsave(&clockfw_lock, flags);
+	if (clk->recalc)
+		clk->rate = clk->recalc(clk);
+	propagate_rate(clk);
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+int clk_register(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return -EINVAL;
+
+	if (WARN(clk->parent && !clk->parent->rate,
+			"CLK: %s parent %s has no rate!\n",
+			clk->name, clk->parent->name))
+		return -EINVAL;
+
+	INIT_LIST_HEAD(&clk->children);
+
+	mutex_lock(&clocks_mutex);
+	list_add_tail(&clk->node, &clocks);
+	if (clk->parent)
+		list_add_tail(&clk->childnode, &clk->parent->children);
+	mutex_unlock(&clocks_mutex);
+
+	/* If rate is already set, use it */
+	if (clk->rate)
+		return 0;
+
+	/* Else, see if there is a way to calculate it */
+	if (clk->recalc)
+		clk->rate = clk->recalc(clk);
+
+	/* Otherwise, default to parent rate */
+	else if (clk->parent)
+		clk->rate = clk->parent->rate;
+
+	return 0;
+}
+EXPORT_SYMBOL(clk_register);
+
+void clk_unregister(struct clk *clk)
+{
+	if (clk == NULL || IS_ERR(clk))
+		return;
+
+	mutex_lock(&clocks_mutex);
+	list_del(&clk->node);
+	list_del(&clk->childnode);
+	mutex_unlock(&clocks_mutex);
+}
+EXPORT_SYMBOL(clk_unregister);
+
+#ifdef CONFIG_DAVINCI_RESET_CLOCKS
+/*
+ * Disable any unused clocks left on by the bootloader
+ */
+static int __init clk_disable_unused(void)
+{
+	struct clk *ck;
+
+	spin_lock_irq(&clockfw_lock);
+	list_for_each_entry(ck, &clocks, node) {
+		if (ck->usecount > 0)
+			continue;
+		if (!(ck->flags & CLK_PSC))
+			continue;
+
+		/* ignore if in Disabled or SwRstDisable states */
+		if (!davinci_psc_is_clk_active(ck->gpsc, ck->lpsc))
+			continue;
+
+		pr_debug("Clocks: disable unused %s\n", ck->name);
+
+		davinci_psc_config(ck->domain, ck->gpsc, ck->lpsc,
+				false, ck->flags);
+	}
+	spin_unlock_irq(&clockfw_lock);
+
+	return 0;
+}
+late_initcall(clk_disable_unused);
+#endif
+
+static unsigned long clk_sysclk_recalc(struct clk *clk)
+{
+	u32 v, plldiv;
+	struct pll_data *pll;
+	unsigned long rate = clk->rate;
+
+	/* If this is the PLL base clock, no more calculations needed */
+	if (clk->pll_data)
+		return rate;
+
+	if (WARN_ON(!clk->parent))
+		return rate;
+
+	rate = clk->parent->rate;
+
+	/* Otherwise, the parent must be a PLL */
+	if (WARN_ON(!clk->parent->pll_data))
+		return rate;
+
+	pll = clk->parent->pll_data;
+
+	/* If pre-PLL, source clock is before the multiplier and divider(s) */
+	if (clk->flags & PRE_PLL)
+		rate = pll->input_rate;
+
+	if (!clk->div_reg)
+		return rate;
+
+	v = __raw_readl(pll->base + clk->div_reg);
+	if (v & PLLDIV_EN) {
+		plldiv = (v & pll->div_ratio_mask) + 1;
+		if (plldiv)
+			rate /= plldiv;
+	}
+
+	return rate;
+}
+
+int davinci_set_sysclk_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned v;
+	struct pll_data *pll;
+	unsigned long input;
+	unsigned ratio = 0;
+
+	/* If this is the PLL base clock, wrong function to call */
+	if (clk->pll_data)
+		return -EINVAL;
+
+	/* There must be a parent... */
+	if (WARN_ON(!clk->parent))
+		return -EINVAL;
+
+	/* ... the parent must be a PLL... */
+	if (WARN_ON(!clk->parent->pll_data))
+		return -EINVAL;
+
+	/* ... and this clock must have a divider. */
+	if (WARN_ON(!clk->div_reg))
+		return -EINVAL;
+
+	pll = clk->parent->pll_data;
+
+	input = clk->parent->rate;
+
+	/* If pre-PLL, source clock is before the multiplier and divider(s) */
+	if (clk->flags & PRE_PLL)
+		input = pll->input_rate;
+
+	if (input > rate) {
+		/*
+		 * Can afford to provide an output little higher than requested
+		 * only if maximum rate supported by hardware on this sysclk
+		 * is known.
+		 */
+		if (clk->maxrate) {
+			ratio = DIV_ROUND_CLOSEST(input, rate);
+			if (input / ratio > clk->maxrate)
+				ratio = 0;
+		}
+
+		if (ratio == 0)
+			ratio = DIV_ROUND_UP(input, rate);
+
+		ratio--;
+	}
+
+	if (ratio > pll->div_ratio_mask)
+		return -EINVAL;
+
+	do {
+		v = __raw_readl(pll->base + PLLSTAT);
+	} while (v & PLLSTAT_GOSTAT);
+
+	v = __raw_readl(pll->base + clk->div_reg);
+	v &= ~pll->div_ratio_mask;
+	v |= ratio | PLLDIV_EN;
+	__raw_writel(v, pll->base + clk->div_reg);
+
+	v = __raw_readl(pll->base + PLLCMD);
+	v |= PLLCMD_GOSET;
+	__raw_writel(v, pll->base + PLLCMD);
+
+	do {
+		v = __raw_readl(pll->base + PLLSTAT);
+	} while (v & PLLSTAT_GOSTAT);
+
+	return 0;
+}
+EXPORT_SYMBOL(davinci_set_sysclk_rate);
+
+static unsigned long clk_leafclk_recalc(struct clk *clk)
+{
+	if (WARN_ON(!clk->parent))
+		return clk->rate;
+
+	return clk->parent->rate;
+}
+
+int davinci_simple_set_rate(struct clk *clk, unsigned long rate)
+{
+	clk->rate = rate;
+	return 0;
+}
+
+static unsigned long clk_pllclk_recalc(struct clk *clk)
+{
+	u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
+	u8 bypass;
+	struct pll_data *pll = clk->pll_data;
+	unsigned long rate = clk->rate;
+
+	ctrl = __raw_readl(pll->base + PLLCTL);
+	rate = pll->input_rate = clk->parent->rate;
+
+	if (ctrl & PLLCTL_PLLEN) {
+		bypass = 0;
+		mult = __raw_readl(pll->base + PLLM);
+		if (cpu_is_davinci_dm365())
+			mult = 2 * (mult & PLLM_PLLM_MASK);
+		else
+			mult = (mult & PLLM_PLLM_MASK) + 1;
+	} else
+		bypass = 1;
+
+	if (pll->flags & PLL_HAS_PREDIV) {
+		prediv = __raw_readl(pll->base + PREDIV);
+		if (prediv & PLLDIV_EN)
+			prediv = (prediv & pll->div_ratio_mask) + 1;
+		else
+			prediv = 1;
+	}
+
+	/* pre-divider is fixed, but (some?) chips won't report that */
+	if (cpu_is_davinci_dm355() && pll->num == 1)
+		prediv = 8;
+
+	if (pll->flags & PLL_HAS_POSTDIV) {
+		postdiv = __raw_readl(pll->base + POSTDIV);
+		if (postdiv & PLLDIV_EN)
+			postdiv = (postdiv & pll->div_ratio_mask) + 1;
+		else
+			postdiv = 1;
+	}
+
+	if (!bypass) {
+		rate /= prediv;
+		rate *= mult;
+		rate /= postdiv;
+	}
+
+	pr_debug("PLL%d: input = %lu MHz [ ",
+		 pll->num, clk->parent->rate / 1000000);
+	if (bypass)
+		pr_debug("bypass ");
+	if (prediv > 1)
+		pr_debug("/ %d ", prediv);
+	if (mult > 1)
+		pr_debug("* %d ", mult);
+	if (postdiv > 1)
+		pr_debug("/ %d ", postdiv);
+	pr_debug("] --> %lu MHz output.\n", rate / 1000000);
+
+	return rate;
+}
+
+/**
+ * davinci_set_pllrate - set the output rate of a given PLL.
+ *
+ * Note: Currently tested to work with OMAP-L138 only.
+ *
+ * @pll: pll whose rate needs to be changed.
+ * @prediv: The pre divider value. Passing 0 disables the pre-divider.
+ * @pllm: The multiplier value. Passing 0 leads to multiply-by-one.
+ * @postdiv: The post divider value. Passing 0 disables the post-divider.
+ */
+int davinci_set_pllrate(struct pll_data *pll, unsigned int prediv,
+					unsigned int mult, unsigned int postdiv)
+{
+	u32 ctrl;
+	unsigned int locktime;
+	unsigned long flags;
+
+	if (pll->base == NULL)
+		return -EINVAL;
+
+	/*
+	 *  PLL lock time required per OMAP-L138 datasheet is
+	 * (2000 * prediv)/sqrt(pllm) OSCIN cycles. We approximate sqrt(pllm)
+	 * as 4 and OSCIN cycle as 25 MHz.
+	 */
+	if (prediv) {
+		locktime = ((2000 * prediv) / 100);
+		prediv = (prediv - 1) | PLLDIV_EN;
+	} else {
+		locktime = PLL_LOCK_TIME;
+	}
+	if (postdiv)
+		postdiv = (postdiv - 1) | PLLDIV_EN;
+	if (mult)
+		mult = mult - 1;
+
+	/* Protect against simultaneous calls to PLL setting seqeunce */
+	spin_lock_irqsave(&clockfw_lock, flags);
+
+	ctrl = __raw_readl(pll->base + PLLCTL);
+
+	/* Switch the PLL to bypass mode */
+	ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
+	__raw_writel(ctrl, pll->base + PLLCTL);
+
+	udelay(PLL_BYPASS_TIME);
+
+	/* Reset and enable PLL */
+	ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS);
+	__raw_writel(ctrl, pll->base + PLLCTL);
+
+	if (pll->flags & PLL_HAS_PREDIV)
+		__raw_writel(prediv, pll->base + PREDIV);
+
+	__raw_writel(mult, pll->base + PLLM);
+
+	if (pll->flags & PLL_HAS_POSTDIV)
+		__raw_writel(postdiv, pll->base + POSTDIV);
+
+	udelay(PLL_RESET_TIME);
+
+	/* Bring PLL out of reset */
+	ctrl |= PLLCTL_PLLRST;
+	__raw_writel(ctrl, pll->base + PLLCTL);
+
+	udelay(locktime);
+
+	/* Remove PLL from bypass mode */
+	ctrl |= PLLCTL_PLLEN;
+	__raw_writel(ctrl, pll->base + PLLCTL);
+
+	spin_unlock_irqrestore(&clockfw_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(davinci_set_pllrate);
+
+/**
+ * davinci_set_refclk_rate() - Set the reference clock rate
+ * @rate:	The new rate.
+ *
+ * Sets the reference clock rate to a given value. This will most likely
+ * result in the entire clock tree getting updated.
+ *
+ * This is used to support boards which use a reference clock different
+ * than that used by default in <soc>.c file. The reference clock rate
+ * should be updated early in the boot process; ideally soon after the
+ * clock tree has been initialized once with the default reference clock
+ * rate (davinci_common_init()).
+ *
+ * Returns 0 on success, error otherwise.
+ */
+int davinci_set_refclk_rate(unsigned long rate)
+{
+	struct clk *refclk;
+
+	refclk = clk_get(NULL, "ref");
+	if (IS_ERR(refclk)) {
+		pr_err("%s: failed to get reference clock.\n", __func__);
+		return PTR_ERR(refclk);
+	}
+
+	clk_set_rate(refclk, rate);
+
+	clk_put(refclk);
+
+	return 0;
+}
+
+int __init davinci_clk_init(struct clk_lookup *clocks)
+  {
+	struct clk_lookup *c;
+	struct clk *clk;
+	size_t num_clocks = 0;
+
+	for (c = clocks; c->clk; c++) {
+		clk = c->clk;
+
+		if (!clk->recalc) {
+
+			/* Check if clock is a PLL */
+			if (clk->pll_data)
+				clk->recalc = clk_pllclk_recalc;
+
+			/* Else, if it is a PLL-derived clock */
+			else if (clk->flags & CLK_PLL)
+				clk->recalc = clk_sysclk_recalc;
+
+			/* Otherwise, it is a leaf clock (PSC clock) */
+			else if (clk->parent)
+				clk->recalc = clk_leafclk_recalc;
+		}
+
+		if (clk->pll_data) {
+			struct pll_data *pll = clk->pll_data;
+
+			if (!pll->div_ratio_mask)
+				pll->div_ratio_mask = PLLDIV_RATIO_MASK;
+
+			if (pll->phys_base && !pll->base) {
+				pll->base = ioremap(pll->phys_base, SZ_4K);
+				WARN_ON(!pll->base);
+			}
+		}
+
+		if (clk->recalc)
+			clk->rate = clk->recalc(clk);
+
+		if (clk->lpsc)
+			clk->flags |= CLK_PSC;
+
+		clk_register(clk);
+		num_clocks++;
+
+		/* Turn on clocks that Linux doesn't otherwise manage */
+		if (clk->flags & ALWAYS_ENABLED)
+			clk_enable(clk);
+	}
+
+	clkdev_add_table(clocks, num_clocks);
+
+	return 0;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+#define CLKNAME_MAX	10		/* longest clock name */
+#define NEST_DELTA	2
+#define NEST_MAX	4
+
+static void
+dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
+{
+	char		*state;
+	char		buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
+	struct clk	*clk;
+	unsigned	i;
+
+	if (parent->flags & CLK_PLL)
+		state = "pll";
+	else if (parent->flags & CLK_PSC)
+		state = "psc";
+	else
+		state = "";
+
+	/* <nest spaces> name <pad to end> */
+	memset(buf, ' ', sizeof(buf) - 1);
+	buf[sizeof(buf) - 1] = 0;
+	i = strlen(parent->name);
+	memcpy(buf + nest, parent->name,
+			min(i, (unsigned)(sizeof(buf) - 1 - nest)));
+
+	seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
+		   buf, parent->usecount, state, clk_get_rate(parent));
+	/* REVISIT show device associations too */
+
+	/* cost is now small, but not linear... */
+	list_for_each_entry(clk, &parent->children, childnode) {
+		dump_clock(s, nest + NEST_DELTA, clk);
+	}
+}
+
+static int davinci_ck_show(struct seq_file *m, void *v)
+{
+	struct clk *clk;
+
+	/*
+	 * Show clock tree; We trust nonzero usecounts equate to PSC enables...
+	 */
+	mutex_lock(&clocks_mutex);
+	list_for_each_entry(clk, &clocks, node)
+		if (!clk->parent)
+			dump_clock(m, 0, clk);
+	mutex_unlock(&clocks_mutex);
+
+	return 0;
+}
+
+static int davinci_ck_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, davinci_ck_show, NULL);
+}
+
+static const struct file_operations davinci_ck_operations = {
+	.open		= davinci_ck_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init davinci_clk_debugfs_init(void)
+{
+	debugfs_create_file("davinci_clocks", S_IFREG | S_IRUGO, NULL, NULL,
+						&davinci_ck_operations);
+	return 0;
+
+}
+device_initcall(davinci_clk_debugfs_init);
+#endif /* CONFIG_DEBUG_FS */