1 files changed, 409 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt_clksel.c b/arch/arm/mach-omap2/clkt_clksel.c
new file mode 100644
index 00000000000..e50812dd03f
--- /dev/null
+++ b/arch/arm/mach-omap2/clkt_clksel.c
@@ -0,0 +1,409 @@
+/*
+ * clkt_clksel.c - OMAP2/3/4 clksel clock functions
+ *
+ * Copyright (C) 2005-2008 Texas Instruments, Inc.
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Contacts:
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Paul Walmsley
+ *
+ * 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.
+ *
+ * XXX At some point these clksel clocks should be split into
+ * "divider" clocks and "mux" clocks to better match the hardware.
+ *
+ * XXX Currently these clocks are only used in the OMAP2/3/4 code, but
+ * many of the OMAP1 clocks should be convertible to use this
+ * mechanism.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/clock.h>
+
+#include "clock.h"
+#include "cm.h"
+#include "cm-regbits-24xx.h"
+#include "cm-regbits-34xx.h"
+
+/* Private functions */
+
+/**
+ * _omap2_get_clksel_by_parent - return clksel struct for a given clk & parent
+ * @clk: OMAP struct clk ptr to inspect
+ * @src_clk: OMAP struct clk ptr of the parent clk to search for
+ *
+ * Scan the struct clksel array associated with the clock to find
+ * the element associated with the supplied parent clock address.
+ * Returns a pointer to the struct clksel on success or NULL on error.
+ */
+static const struct clksel *_omap2_get_clksel_by_parent(struct clk *clk,
+							struct clk *src_clk)
+{
+	const struct clksel *clks;
+
+	if (!clk->clksel)
+		return NULL;
+
+	for (clks = clk->clksel; clks->parent; clks++) {
+		if (clks->parent == src_clk)
+			break; /* Found the requested parent */
+	}
+
+	if (!clks->parent) {
+		printk(KERN_ERR "clock: Could not find parent clock %s in "
+		       "clksel array of clock %s\n", src_clk->name,
+		       clk->name);
+		return NULL;
+	}
+
+	return clks;
+}
+
+/*
+ * Converts encoded control register address into a full address
+ * On error, the return value (parent_div) will be 0.
+ */
+static u32 _omap2_clksel_get_src_field(struct clk *src_clk, struct clk *clk,
+				       u32 *field_val)
+{
+	const struct clksel *clks;
+	const struct clksel_rate *clkr;
+
+	clks = _omap2_get_clksel_by_parent(clk, src_clk);
+	if (!clks)
+		return 0;
+
+	for (clkr = clks->rates; clkr->div; clkr++) {
+		if (clkr->flags & cpu_mask && clkr->flags & DEFAULT_RATE)
+			break; /* Found the default rate for this platform */
+	}
+
+	if (!clkr->div) {
+		printk(KERN_ERR "clock: Could not find default rate for "
+		       "clock %s parent %s\n", clk->name,
+		       src_clk->parent->name);
+		return 0;
+	}
+
+	/* Should never happen.  Add a clksel mask to the struct clk. */
+	WARN_ON(clk->clksel_mask == 0);
+
+	*field_val = clkr->val;
+
+	return clkr->div;
+}
+
+
+/* Public functions */
+
+/**
+ * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
+ * @clk: OMAP clock struct ptr to use
+ *
+ * Given a pointer to a source-selectable struct clk, read the hardware
+ * register and determine what its parent is currently set to.  Update the
+ * clk->parent field with the appropriate clk ptr.
+ */
+void omap2_init_clksel_parent(struct clk *clk)
+{
+	const struct clksel *clks;
+	const struct clksel_rate *clkr;
+	u32 r, found = 0;
+
+	if (!clk->clksel)
+		return;
+
+	r = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
+	r >>= __ffs(clk->clksel_mask);
+
+	for (clks = clk->clksel; clks->parent && !found; clks++) {
+		for (clkr = clks->rates; clkr->div && !found; clkr++) {
+			if ((clkr->flags & cpu_mask) && (clkr->val == r)) {
+				if (clk->parent != clks->parent) {
+					pr_debug("clock: inited %s parent "
+						 "to %s (was %s)\n",
+						 clk->name, clks->parent->name,
+						 ((clk->parent) ?
+						  clk->parent->name : "NULL"));
+					clk_reparent(clk, clks->parent);
+				};
+				found = 1;
+			}
+		}
+	}
+
+	if (!found)
+		printk(KERN_ERR "clock: init parent: could not find "
+		       "regval %0x for clock %s\n", r,  clk->name);
+
+	return;
+}
+
+/*
+ * Used for clocks that are part of CLKSEL_xyz governed clocks.
+ * REVISIT: Maybe change to use clk->enable() functions like on omap1?
+ */
+unsigned long omap2_clksel_recalc(struct clk *clk)
+{
+	unsigned long rate;
+	u32 div = 0;
+
+	pr_debug("clock: recalc'ing clksel clk %s\n", clk->name);
+
+	div = omap2_clksel_get_divisor(clk);
+	if (div == 0)
+		return clk->rate;
+
+	rate = clk->parent->rate / div;
+
+	pr_debug("clock: new clock rate is %ld (div %d)\n", rate, div);
+
+	return rate;
+}
+
+/**
+ * omap2_clksel_round_rate_div - find divisor for the given clock and rate
+ * @clk: OMAP struct clk to use
+ * @target_rate: desired clock rate
+ * @new_div: ptr to where we should store the divisor
+ *
+ * Finds 'best' divider value in an array based on the source and target
+ * rates.  The divider array must be sorted with smallest divider first.
+ * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
+ * they are only settable as part of virtual_prcm set.
+ *
+ * Returns the rounded clock rate or returns 0xffffffff on error.
+ */
+u32 omap2_clksel_round_rate_div(struct clk *clk, unsigned long target_rate,
+				u32 *new_div)
+{
+	unsigned long test_rate;
+	const struct clksel *clks;
+	const struct clksel_rate *clkr;
+	u32 last_div = 0;
+
+	pr_debug("clock: clksel_round_rate_div: %s target_rate %ld\n",
+		 clk->name, target_rate);
+
+	*new_div = 1;
+
+	clks = _omap2_get_clksel_by_parent(clk, clk->parent);
+	if (!clks)
+		return ~0;
+
+	for (clkr = clks->rates; clkr->div; clkr++) {
+		if (!(clkr->flags & cpu_mask))
+			continue;
+
+		/* Sanity check */
+		if (clkr->div <= last_div)
+			pr_err("clock: clksel_rate table not sorted "
+			       "for clock %s", clk->name);
+
+		last_div = clkr->div;
+
+		test_rate = clk->parent->rate / clkr->div;
+
+		if (test_rate <= target_rate)
+			break; /* found it */
+	}
+
+	if (!clkr->div) {
+		pr_err("clock: Could not find divisor for target "
+		       "rate %ld for clock %s parent %s\n", target_rate,
+		       clk->name, clk->parent->name);
+		return ~0;
+	}
+
+	*new_div = clkr->div;
+
+	pr_debug("clock: new_div = %d, new_rate = %ld\n", *new_div,
+		 (clk->parent->rate / clkr->div));
+
+	return clk->parent->rate / clkr->div;
+}
+
+/**
+ * omap2_clksel_round_rate - find rounded rate for the given clock and rate
+ * @clk: OMAP struct clk to use
+ * @target_rate: desired clock rate
+ *
+ * Compatibility wrapper for OMAP clock framework
+ * Finds best target rate based on the source clock and possible dividers.
+ * rates. The divider array must be sorted with smallest divider first.
+ * Note that this will not work for clocks which are part of CONFIG_PARTICIPANT,
+ * they are only settable as part of virtual_prcm set.
+ *
+ * Returns the rounded clock rate or returns 0xffffffff on error.
+ */
+long omap2_clksel_round_rate(struct clk *clk, unsigned long target_rate)
+{
+	u32 new_div;
+
+	return omap2_clksel_round_rate_div(clk, target_rate, &new_div);
+}
+
+
+/* Given a clock and a rate apply a clock specific rounding function */
+long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	if (clk->round_rate)
+		return clk->round_rate(clk, rate);
+
+	return clk->rate;
+}
+
+/**
+ * omap2_clksel_to_divisor() - turn clksel field value into integer divider
+ * @clk: OMAP struct clk to use
+ * @field_val: register field value to find
+ *
+ * Given a struct clk of a rate-selectable clksel clock, and a register field
+ * value to search for, find the corresponding clock divisor.  The register
+ * field value should be pre-masked and shifted down so the LSB is at bit 0
+ * before calling.  Returns 0 on error
+ */
+u32 omap2_clksel_to_divisor(struct clk *clk, u32 field_val)
+{
+	const struct clksel *clks;
+	const struct clksel_rate *clkr;
+
+	clks = _omap2_get_clksel_by_parent(clk, clk->parent);
+	if (!clks)
+		return 0;
+
+	for (clkr = clks->rates; clkr->div; clkr++) {
+		if ((clkr->flags & cpu_mask) && (clkr->val == field_val))
+			break;
+	}
+
+	if (!clkr->div) {
+		printk(KERN_ERR "clock: Could not find fieldval %d for "
+		       "clock %s parent %s\n", field_val, clk->name,
+		       clk->parent->name);
+		return 0;
+	}
+
+	return clkr->div;
+}
+
+/**
+ * omap2_divisor_to_clksel() - turn clksel integer divisor into a field value
+ * @clk: OMAP struct clk to use
+ * @div: integer divisor to search for
+ *
+ * Given a struct clk of a rate-selectable clksel clock, and a clock divisor,
+ * find the corresponding register field value.  The return register value is
+ * the value before left-shifting.  Returns ~0 on error
+ */
+u32 omap2_divisor_to_clksel(struct clk *clk, u32 div)
+{
+	const struct clksel *clks;
+	const struct clksel_rate *clkr;
+
+	/* should never happen */
+	WARN_ON(div == 0);
+
+	clks = _omap2_get_clksel_by_parent(clk, clk->parent);
+	if (!clks)
+		return ~0;
+
+	for (clkr = clks->rates; clkr->div; clkr++) {
+		if ((clkr->flags & cpu_mask) && (clkr->div == div))
+			break;
+	}
+
+	if (!clkr->div) {
+		printk(KERN_ERR "clock: Could not find divisor %d for "
+		       "clock %s parent %s\n", div, clk->name,
+		       clk->parent->name);
+		return ~0;
+	}
+
+	return clkr->val;
+}
+
+/**
+ * omap2_clksel_get_divisor - get current divider applied to parent clock.
+ * @clk: OMAP struct clk to use.
+ *
+ * Returns the integer divisor upon success or 0 on error.
+ */
+u32 omap2_clksel_get_divisor(struct clk *clk)
+{
+	u32 v;
+
+	if (!clk->clksel_mask)
+		return 0;
+
+	v = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
+	v >>= __ffs(clk->clksel_mask);
+
+	return omap2_clksel_to_divisor(clk, v);
+}
+
+int omap2_clksel_set_rate(struct clk *clk, unsigned long rate)
+{
+	u32 v, field_val, validrate, new_div = 0;
+
+	if (!clk->clksel_mask)
+		return -EINVAL;
+
+	validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
+	if (validrate != rate)
+		return -EINVAL;
+
+	field_val = omap2_divisor_to_clksel(clk, new_div);
+	if (field_val == ~0)
+		return -EINVAL;
+
+	v = __raw_readl(clk->clksel_reg);
+	v &= ~clk->clksel_mask;
+	v |= field_val << __ffs(clk->clksel_mask);
+	__raw_writel(v, clk->clksel_reg);
+	v = __raw_readl(clk->clksel_reg); /* OCP barrier */
+
+	clk->rate = clk->parent->rate / new_div;
+
+	return 0;
+}
+
+int omap2_clksel_set_parent(struct clk *clk, struct clk *new_parent)
+{
+	u32 field_val, v, parent_div;
+
+	if (!clk->clksel)
+		return -EINVAL;
+
+	parent_div = _omap2_clksel_get_src_field(new_parent, clk, &field_val);
+	if (!parent_div)
+		return -EINVAL;
+
+	/* Set new source value (previous dividers if any in effect) */
+	v = __raw_readl(clk->clksel_reg);
+	v &= ~clk->clksel_mask;
+	v |= field_val << __ffs(clk->clksel_mask);
+	__raw_writel(v, clk->clksel_reg);
+	v = __raw_readl(clk->clksel_reg);    /* OCP barrier */
+
+	clk_reparent(clk, new_parent);
+
+	/* CLKSEL clocks follow their parents' rates, divided by a divisor */
+	clk->rate = new_parent->rate;
+
+	if (parent_div > 0)
+		clk->rate /= parent_div;
+
+	pr_debug("clock: set parent of %s to %s (new rate %ld)\n",
+		 clk->name, clk->parent->name, clk->rate);
+
+	return 0;
+}