--- /dev/null
+/*
+ * 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 <linux/clk/ti.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 BIT(8)
+#define OMAP4430_DPLL_CLKOUTX2_GATE_CTRL_MASK BIT(10)
+#define OMAP4430_DPLL_REGM4XEN_MASK BIT(11)
+
+/* Static rate multiplier for OMAP4 REGM4XEN clocks */
+#define OMAP4430_REGM4XEN_MULT 4
+
+static 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 = ti_clk_ll_ops->clk_readl(clk->clksel_reg);
+ /* Clear the bit to allow gatectrl */
+ v &= ~mask;
+ ti_clk_ll_ops->clk_writel(v, clk->clksel_reg);
+}
+
+static 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 = ti_clk_ll_ops->clk_readl(clk->clksel_reg);
+ /* Set the bit to deny gatectrl */
+ v |= mask;
+ ti_clk_ll_ops->clk_writel(v, 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 = ti_clk_ll_ops->clk_readl(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
+ * @req: target rate request
+ *
+ * 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 0 on success and a negative error value otherwise.
+ */
+int omap4_dpll_regm4xen_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ struct clk_hw_omap *clk = to_clk_hw_omap(hw);
+ struct dpll_data *dd;
+
+ if (!req->rate)
+ return -EINVAL;
+
+ dd = clk->dpll_data;
+ if (!dd)
+ return -EINVAL;
+
+ if (clk_get_rate(dd->clk_bypass) == req->rate &&
+ (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
+ req->best_parent_hw = __clk_get_hw(dd->clk_bypass);
+ } else {
+ req->rate = omap4_dpll_regm4xen_round_rate(hw, req->rate,
+ &req->best_parent_rate);
+ req->best_parent_hw = __clk_get_hw(dd->clk_ref);
+ }
+
+ req->best_parent_rate = req->rate;
+
+ return 0;
+}
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