Initial import

1 files changed, 232 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/dpll44xx.c b/arch/arm/mach-omap2/dpll44xx.c
new file mode 100644
index 000000000..f231be05b
--- /dev/null
+++ b/arch/arm/mach-omap2/dpll44xx.c
@@ -0,0 +1,232 @@
+/*
+ * OMAP4-specific DPLL control functions
+ *
+ * Copyright (C) 2011 Texas Instruments, Inc.
+ * Rajendra Nayak
+ *
+ * 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/kernel.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/bitops.h>
+
+#include "clock.h"
+
+/*
+ * Maximum DPLL input frequency (FINT) and output frequency (FOUT) that
+ * can supported when using the DPLL low-power mode. Frequencies are
+ * defined in OMAP4430/60 Public TRM section 3.6.3.3.2 "Enable Control,
+ * Status, and Low-Power Operation Mode".
+ */
+#define OMAP4_DPLL_LP_FINT_MAX	1000000
+#define OMAP4_DPLL_LP_FOUT_MAX	100000000
+
+/*
+ * Bitfield declarations
+ */
+#define OMAP4430_DPLL_CLKOUT_GATE_CTRL_MASK		(1 << 8)
+#define OMAP4430_DPLL_CLKOUTX2_GATE_CTRL_MASK		(1 << 10)
+#define OMAP4430_DPLL_REGM4XEN_MASK			(1 << 11)
+
+/* Static rate multiplier for OMAP4 REGM4XEN clocks */
+#define OMAP4430_REGM4XEN_MULT				4
+
+void omap4_dpllmx_allow_gatectrl(struct clk_hw_omap *clk)
+{
+	u32 v;
+	u32 mask;
+
+	if (!clk || !clk->clksel_reg)
+		return;
+
+	mask = clk->flags & CLOCK_CLKOUTX2 ?
+			OMAP4430_DPLL_CLKOUTX2_GATE_CTRL_MASK :
+			OMAP4430_DPLL_CLKOUT_GATE_CTRL_MASK;
+
+	v = omap2_clk_readl(clk, clk->clksel_reg);
+	/* Clear the bit to allow gatectrl */
+	v &= ~mask;
+	omap2_clk_writel(v, clk, clk->clksel_reg);
+}
+
+void omap4_dpllmx_deny_gatectrl(struct clk_hw_omap *clk)
+{
+	u32 v;
+	u32 mask;
+
+	if (!clk || !clk->clksel_reg)
+		return;
+
+	mask = clk->flags & CLOCK_CLKOUTX2 ?
+			OMAP4430_DPLL_CLKOUTX2_GATE_CTRL_MASK :
+			OMAP4430_DPLL_CLKOUT_GATE_CTRL_MASK;
+
+	v = omap2_clk_readl(clk, clk->clksel_reg);
+	/* Set the bit to deny gatectrl */
+	v |= mask;
+	omap2_clk_writel(v, clk, clk->clksel_reg);
+}
+
+const struct clk_hw_omap_ops clkhwops_omap4_dpllmx = {
+	.allow_idle	= omap4_dpllmx_allow_gatectrl,
+	.deny_idle      = omap4_dpllmx_deny_gatectrl,
+};
+
+/**
+ * omap4_dpll_lpmode_recalc - compute DPLL low-power setting
+ * @dd: pointer to the dpll data structure
+ *
+ * Calculates if low-power mode can be enabled based upon the last
+ * multiplier and divider values calculated. If low-power mode can be
+ * enabled, then the bit to enable low-power mode is stored in the
+ * last_rounded_lpmode variable. This implementation is based upon the
+ * criteria for enabling low-power mode as described in the OMAP4430/60
+ * Public TRM section 3.6.3.3.2 "Enable Control, Status, and Low-Power
+ * Operation Mode".
+ */
+static void omap4_dpll_lpmode_recalc(struct dpll_data *dd)
+{
+	long fint, fout;
+
+	fint = __clk_get_rate(dd->clk_ref) / (dd->last_rounded_n + 1);
+	fout = fint * dd->last_rounded_m;
+
+	if ((fint < OMAP4_DPLL_LP_FINT_MAX) && (fout < OMAP4_DPLL_LP_FOUT_MAX))
+		dd->last_rounded_lpmode = 1;
+	else
+		dd->last_rounded_lpmode = 0;
+}
+
+/**
+ * omap4_dpll_regm4xen_recalc - compute DPLL rate, considering REGM4XEN bit
+ * @clk: struct clk * of the DPLL to compute the rate for
+ *
+ * Compute the output rate for the OMAP4 DPLL represented by @clk.
+ * Takes the REGM4XEN bit into consideration, which is needed for the
+ * OMAP4 ABE DPLL.  Returns the DPLL's output rate (before M-dividers)
+ * upon success, or 0 upon error.
+ */
+unsigned long omap4_dpll_regm4xen_recalc(struct clk_hw *hw,
+			unsigned long parent_rate)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	u32 v;
+	unsigned long rate;
+	struct dpll_data *dd;
+
+	if (!clk || !clk->dpll_data)
+		return 0;
+
+	dd = clk->dpll_data;
+
+	rate = omap2_get_dpll_rate(clk);
+
+	/* regm4xen adds a multiplier of 4 to DPLL calculations */
+	v = omap2_clk_readl(clk, dd->control_reg);
+	if (v & OMAP4430_DPLL_REGM4XEN_MASK)
+		rate *= OMAP4430_REGM4XEN_MULT;
+
+	return rate;
+}
+
+/**
+ * omap4_dpll_regm4xen_round_rate - round DPLL rate, considering REGM4XEN bit
+ * @clk: struct clk * of the DPLL to round a rate for
+ * @target_rate: the desired rate of the DPLL
+ *
+ * Compute the rate that would be programmed into the DPLL hardware
+ * for @clk if set_rate() were to be provided with the rate
+ * @target_rate.  Takes the REGM4XEN bit into consideration, which is
+ * needed for the OMAP4 ABE DPLL.  Returns the rounded rate (before
+ * M-dividers) upon success, -EINVAL if @clk is null or not a DPLL, or
+ * ~0 if an error occurred in omap2_dpll_round_rate().
+ */
+long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw,
+				    unsigned long target_rate,
+				    unsigned long *parent_rate)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *dd;
+	long r;
+
+	if (!clk || !clk->dpll_data)
+		return -EINVAL;
+
+	dd = clk->dpll_data;
+
+	dd->last_rounded_m4xen = 0;
+
+	/*
+	 * First try to compute the DPLL configuration for
+	 * target rate without using the 4X multiplier.
+	 */
+	r = omap2_dpll_round_rate(hw, target_rate, NULL);
+	if (r != ~0)
+		goto out;
+
+	/*
+	 * If we did not find a valid DPLL configuration, try again, but
+	 * this time see if using the 4X multiplier can help. Enabling the
+	 * 4X multiplier is equivalent to dividing the target rate by 4.
+	 */
+	r = omap2_dpll_round_rate(hw, target_rate / OMAP4430_REGM4XEN_MULT,
+				  NULL);
+	if (r == ~0)
+		return r;
+
+	dd->last_rounded_rate *= OMAP4430_REGM4XEN_MULT;
+	dd->last_rounded_m4xen = 1;
+
+out:
+	omap4_dpll_lpmode_recalc(dd);
+
+	return dd->last_rounded_rate;
+}
+
+/**
+ * omap4_dpll_regm4xen_determine_rate - determine rate for a DPLL
+ * @hw: pointer to the clock to determine rate for
+ * @rate: target rate for the DPLL
+ * @best_parent_rate: pointer for returning best parent rate
+ * @best_parent_clk: pointer for returning best parent clock
+ *
+ * Determines which DPLL mode to use for reaching a desired rate.
+ * Checks whether the DPLL shall be in bypass or locked mode, and if
+ * locked, calculates the M,N values for the DPLL via round-rate.
+ * Returns a positive clock rate with success, negative error value
+ * in failure.
+ */
+long omap4_dpll_regm4xen_determine_rate(struct clk_hw *hw, unsigned long rate,
+					unsigned long min_rate,
+					unsigned long max_rate,
+					unsigned long *best_parent_rate,
+					struct clk_hw **best_parent_clk)
+{
+	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+	struct dpll_data *dd;
+
+	if (!hw || !rate)
+		return -EINVAL;
+
+	dd = clk->dpll_data;
+	if (!dd)
+		return -EINVAL;
+
+	if (__clk_get_rate(dd->clk_bypass) == rate &&
+	    (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
+		*best_parent_clk = __clk_get_hw(dd->clk_bypass);
+	} else {
+		rate = omap4_dpll_regm4xen_round_rate(hw, rate,
+						      best_parent_rate);
+		*best_parent_clk = __clk_get_hw(dd->clk_ref);
+	}
+
+	*best_parent_rate = rate;
+
+	return rate;
+}