ARM: OMAP4: PM: Move DPLL control apis to dpll.c

This patch moves all the dpll control api's to a
common file dpll.c. This is in preperation of omap4
support wherein most of these api's can be reused.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>

1 files changed, 532 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/dpll.c b/arch/arm/mach-omap2/dpll.c
new file mode 100644
index 000000000000..a39fe9d8c278
--- /dev/null
+++ b/arch/arm/mach-omap2/dpll.c
@@ -0,0 +1,532 @@
+/*
+ * OMAP3/4 - specific DPLL control functions
+ *
+ * Copyright (C) 2009 Texas Instruments, Inc.
+ * Copyright (C) 2009 Nokia Corporation
+ *
+ * Written by Paul Walmsley
+ * Testing and integration fixes by Jouni Högander
+ *
+ * Parts of this code are based on code written by
+ * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/limits.h>
+#include <linux/bitops.h>
+
+#include <mach/cpu.h>
+#include <mach/clock.h>
+#include <mach/sram.h>
+#include <asm/div64.h>
+#include <asm/clkdev.h>
+
+#include "clock.h"
+#include "prm.h"
+#include "prm-regbits-34xx.h"
+#include "cm.h"
+#include "cm-regbits-34xx.h"
+
+/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
+#define DPLL_AUTOIDLE_DISABLE                   0x0
+#define DPLL_AUTOIDLE_LOW_POWER_STOP            0x1
+
+#define MAX_DPLL_WAIT_TRIES             1000000
+
+
+/**
+ * omap3_dpll_recalc - recalculate DPLL rate
+ * @clk: DPLL struct clk
+ *
+ * Recalculate and propagate the DPLL rate.
+ */
+unsigned long omap3_dpll_recalc(struct clk *clk)
+{
+        return omap2_get_dpll_rate(clk);
+}
+
+/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
+static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
+{
+        const struct dpll_data *dd;
+        u32 v;
+
+        dd = clk->dpll_data;
+
+        v = __raw_readl(dd->control_reg);
+        v &= ~dd->enable_mask;
+        v |= clken_bits << __ffs(dd->enable_mask);
+        __raw_writel(v, dd->control_reg);
+}
+
+/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
+static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
+{
+        const struct dpll_data *dd;
+        int i = 0;
+        int ret = -EINVAL;
+
+        dd = clk->dpll_data;
+
+        state <<= __ffs(dd->idlest_mask);
+
+        while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
+               i < MAX_DPLL_WAIT_TRIES) {
+                i++;
+                udelay(1);
+        }
+
+        if (i == MAX_DPLL_WAIT_TRIES) {
+                printk(KERN_ERR "clock: %s failed transition to '%s'\n",
+                       clk->name, (state) ? "locked" : "bypassed");
+        } else {
+                pr_debug("clock: %s transition to '%s' in %d loops\n",
+                         clk->name, (state) ? "locked" : "bypassed", i);
+
+                ret = 0;
+        }
+
+        return ret;
+}
+
+/* From 3430 TRM ES2 4.7.6.2 */
+static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
+{
+        unsigned long fint;
+        u16 f = 0;
+
+        fint = clk->dpll_data->clk_ref->rate / n;
+
+        pr_debug("clock: fint is %lu\n", fint);
+
+        if (fint >= 750000 && fint <= 1000000)
+                f = 0x3;
+        else if (fint > 1000000 && fint <= 1250000)
+                f = 0x4;
+        else if (fint > 1250000 && fint <= 1500000)
+                f = 0x5;
+        else if (fint > 1500000 && fint <= 1750000)
+                f = 0x6;
+        else if (fint > 1750000 && fint <= 2100000)
+                f = 0x7;
+        else if (fint > 7500000 && fint <= 10000000)
+                f = 0xB;
+        else if (fint > 10000000 && fint <= 12500000)
+                f = 0xC;
+        else if (fint > 12500000 && fint <= 15000000)
+                f = 0xD;
+        else if (fint > 15000000 && fint <= 17500000)
+                f = 0xE;
+        else if (fint > 17500000 && fint <= 21000000)
+                f = 0xF;
+        else
+                pr_debug("clock: unknown freqsel setting for %d\n", n);
+
+        return f;
+}
+
+/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
+
+/*
+ * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to lock.  Waits for the DPLL to report
+ * readiness before returning.  Will save and restore the DPLL's
+ * autoidle state across the enable, per the CDP code.  If the DPLL
+ * locked successfully, return 0; if the DPLL did not lock in the time
+ * allotted, or DPLL3 was passed in, return -EINVAL.
+ */
+static int _omap3_noncore_dpll_lock(struct clk *clk)
+{
+        u8 ai;
+        int r;
+
+        pr_debug("clock: locking DPLL %s\n", clk->name);
+
+        ai = omap3_dpll_autoidle_read(clk);
+
+        omap3_dpll_deny_idle(clk);
+
+        _omap3_dpll_write_clken(clk, DPLL_LOCKED);
+
+        r = _omap3_wait_dpll_status(clk, 1);
+
+        if (ai)
+                omap3_dpll_allow_idle(clk);
+
+        return r;
+}
+
+/*
+ * _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enter low-power bypass mode.  In
+ * bypass mode, the DPLL's rate is set equal to its parent clock's
+ * rate.  Waits for the DPLL to report readiness before returning.
+ * Will save and restore the DPLL's autoidle state across the enable,
+ * per the CDP code.  If the DPLL entered bypass mode successfully,
+ * return 0; if the DPLL did not enter bypass in the time allotted, or
+ * DPLL3 was passed in, or the DPLL does not support low-power bypass,
+ * return -EINVAL.
+ */
+static int _omap3_noncore_dpll_bypass(struct clk *clk)
+{
+        int r;
+        u8 ai;
+
+        if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
+                return -EINVAL;
+
+        pr_debug("clock: configuring DPLL %s for low-power bypass\n",
+                 clk->name);
+
+        ai = omap3_dpll_autoidle_read(clk);
+
+        _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
+
+        r = _omap3_wait_dpll_status(clk, 0);
+
+        if (ai)
+                omap3_dpll_allow_idle(clk);
+        else
+                omap3_dpll_deny_idle(clk);
+
+        return r;
+}
+
+/*
+ * _omap3_noncore_dpll_stop - instruct a DPLL to stop
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enter low-power stop. Will save and
+ * restore the DPLL's autoidle state across the stop, per the CDP
+ * code.  If DPLL3 was passed in, or the DPLL does not support
+ * low-power stop, return -EINVAL; otherwise, return 0.
+ */
+static int _omap3_noncore_dpll_stop(struct clk *clk)
+{
+        u8 ai;
+
+        if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
+                return -EINVAL;
+
+        pr_debug("clock: stopping DPLL %s\n", clk->name);
+
+        ai = omap3_dpll_autoidle_read(clk);
+
+        _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
+
+        if (ai)
+                omap3_dpll_allow_idle(clk);
+        else
+                omap3_dpll_deny_idle(clk);
+
+        return 0;
+}
+
+/**
+ * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
+ * The choice of modes depends on the DPLL's programmed rate: if it is
+ * the same as the DPLL's parent clock, it will enter bypass;
+ * otherwise, it will enter lock.  This code will wait for the DPLL to
+ * indicate readiness before returning, unless the DPLL takes too long
+ * to enter the target state.  Intended to be used as the struct clk's
+ * enable function.  If DPLL3 was passed in, or the DPLL does not
+ * support low-power stop, or if the DPLL took too long to enter
+ * bypass or lock, return -EINVAL; otherwise, return 0.
+ */
+int omap3_noncore_dpll_enable(struct clk *clk)
+{
+        int r;
+        struct dpll_data *dd;
+
+        dd = clk->dpll_data;
+        if (!dd)
+                return -EINVAL;
+
+        if (clk->rate == dd->clk_bypass->rate) {
+                WARN_ON(clk->parent != dd->clk_bypass);
+                r = _omap3_noncore_dpll_bypass(clk);
+        } else {
+                WARN_ON(clk->parent != dd->clk_ref);
+                r = _omap3_noncore_dpll_lock(clk);
+        }
+        /*
+         *FIXME: this is dubious - if clk->rate has changed, what about
+         * propagating?
+         */
+        if (!r)
+                clk->rate = omap2_get_dpll_rate(clk);
+
+        return r;
+}
+
+/**
+ * omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enter low-power stop.  This function is
+ * intended for use in struct clkops.  No return value.
+ */
+void omap3_noncore_dpll_disable(struct clk *clk)
+{
+        _omap3_noncore_dpll_stop(clk);
+}
+
+
+/* Non-CORE DPLL rate set code */
+
+/*
+ * omap3_noncore_dpll_program - set non-core DPLL M,N values directly
+ * @clk: struct clk * of DPLL to set
+ * @m: DPLL multiplier to set
+ * @n: DPLL divider to set
+ * @freqsel: FREQSEL value to set
+ *
+ * Program the DPLL with the supplied M, N values, and wait for the DPLL to
+ * lock..  Returns -EINVAL upon error, or 0 upon success.
+ */
+int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
+{
+        struct dpll_data *dd = clk->dpll_data;
+        u32 v;
+
+        /* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
+        _omap3_noncore_dpll_bypass(clk);
+
+        /* Set jitter correction */
+        v = __raw_readl(dd->control_reg);
+        v &= ~dd->freqsel_mask;
+        v |= freqsel << __ffs(dd->freqsel_mask);
+        __raw_writel(v, dd->control_reg);
+
+        /* Set DPLL multiplier, divider */
+        v = __raw_readl(dd->mult_div1_reg);
+        v &= ~(dd->mult_mask | dd->div1_mask);
+        v |= m << __ffs(dd->mult_mask);
+        v |= (n - 1) << __ffs(dd->div1_mask);
+        __raw_writel(v, dd->mult_div1_reg);
+
+        /* We let the clock framework set the other output dividers later */
+
+        /* REVISIT: Set ramp-up delay? */
+
+        _omap3_noncore_dpll_lock(clk);
+
+        return 0;
+}
+
+/**
+ * omap3_noncore_dpll_set_rate - set non-core DPLL rate
+ * @clk: struct clk * of DPLL to set
+ * @rate: rounded target rate
+ *
+ * Set the DPLL CLKOUT to the target rate.  If the DPLL can enter
+ * low-power bypass, and the target rate is the bypass source clock
+ * rate, then configure the DPLL for bypass.  Otherwise, round the
+ * target rate if it hasn't been done already, then program and lock
+ * the DPLL.  Returns -EINVAL upon error, or 0 upon success.
+ */
+int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
+{
+        struct clk *new_parent = NULL;
+        u16 freqsel;
+        struct dpll_data *dd;
+        int ret;
+
+        if (!clk || !rate)
+                return -EINVAL;
+
+        dd = clk->dpll_data;
+        if (!dd)
+                return -EINVAL;
+
+        if (rate == omap2_get_dpll_rate(clk))
+                return 0;
+
+        /*
+         * Ensure both the bypass and ref clocks are enabled prior to
+         * doing anything; we need the bypass clock running to reprogram
+         * the DPLL.
+         */
+        omap2_clk_enable(dd->clk_bypass);
+        omap2_clk_enable(dd->clk_ref);
+
+        if (dd->clk_bypass->rate == rate &&
+            (clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
+                pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);
+
+                ret = _omap3_noncore_dpll_bypass(clk);
+                if (!ret)
+                        new_parent = dd->clk_bypass;
+        } else {
+                if (dd->last_rounded_rate != rate)
+                        omap2_dpll_round_rate(clk, rate);
+
+                if (dd->last_rounded_rate == 0)
+                        return -EINVAL;
+
+                freqsel = _omap3_dpll_compute_freqsel(clk, dd->last_rounded_n);
+                if (!freqsel)
+                        WARN_ON(1);
+
+                pr_debug("clock: %s: set rate: locking rate to %lu.\n",
+                         clk->name, rate);
+
+                ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
+                                                 dd->last_rounded_n, freqsel);
+                if (!ret)
+                        new_parent = dd->clk_ref;
+        }
+        if (!ret) {
+                /*
+                 * Switch the parent clock in the heirarchy, and make sure
+                 * that the new parent's usecount is correct.  Note: we
+                 * enable the new parent before disabling the old to avoid
+                 * any unnecessary hardware disable->enable transitions.
+                 */
+                if (clk->usecount) {
+                        omap2_clk_enable(new_parent);
+                        omap2_clk_disable(clk->parent);
+                }
+                clk_reparent(clk, new_parent);
+                clk->rate = rate;
+        }
+        omap2_clk_disable(dd->clk_ref);
+        omap2_clk_disable(dd->clk_bypass);
+
+        return 0;
+}
+
+/* DPLL autoidle read/set code */
+
+/**
+ * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
+ * @clk: struct clk * of the DPLL to read
+ *
+ * Return the DPLL's autoidle bits, shifted down to bit 0.  Returns
+ * -EINVAL if passed a null pointer or if the struct clk does not
+ * appear to refer to a DPLL.
+ */
+u32 omap3_dpll_autoidle_read(struct clk *clk)
+{
+        const struct dpll_data *dd;
+        u32 v;
+
+        if (!clk || !clk->dpll_data)
+                return -EINVAL;
+
+        dd = clk->dpll_data;
+
+        v = __raw_readl(dd->autoidle_reg);
+        v &= dd->autoidle_mask;
+        v >>= __ffs(dd->autoidle_mask);
+
+        return v;
+}
+
+/**
+ * omap3_dpll_allow_idle - enable DPLL autoidle bits
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Enable DPLL automatic idle control.  This automatic idle mode
+ * switching takes effect only when the DPLL is locked, at least on
+ * OMAP3430.  The DPLL will enter low-power stop when its downstream
+ * clocks are gated.  No return value.
+ */
+void omap3_dpll_allow_idle(struct clk *clk)
+{
+        const struct dpll_data *dd;
+        u32 v;
+
+        if (!clk || !clk->dpll_data)
+                return;
+
+        dd = clk->dpll_data;
+
+        /*
+         * REVISIT: CORE DPLL can optionally enter low-power bypass
+         * by writing 0x5 instead of 0x1.  Add some mechanism to
+         * optionally enter this mode.
+         */
+        v = __raw_readl(dd->autoidle_reg);
+        v &= ~dd->autoidle_mask;
+        v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
+        __raw_writel(v, dd->autoidle_reg);
+}
+
+/**
+ * omap3_dpll_deny_idle - prevent DPLL from automatically idling
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Disable DPLL automatic idle control.  No return value.
+ */
+void omap3_dpll_deny_idle(struct clk *clk)
+{
+        const struct dpll_data *dd;
+        u32 v;
+
+        if (!clk || !clk->dpll_data)
+                return;
+
+        dd = clk->dpll_data;
+
+        v = __raw_readl(dd->autoidle_reg);
+        v &= ~dd->autoidle_mask;
+        v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
+        __raw_writel(v, dd->autoidle_reg);
+
+}
+
+/* Clock control for DPLL outputs */
+
+/**
+ * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
+ * @clk: DPLL output struct clk
+ *
+ * Using parent clock DPLL data, look up DPLL state.  If locked, set our
+ * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
+ */
+unsigned long omap3_clkoutx2_recalc(struct clk *clk)
+{
+        const struct dpll_data *dd;
+        unsigned long rate;
+        u32 v;
+        struct clk *pclk;
+
+        /* Walk up the parents of clk, looking for a DPLL */
+        pclk = clk->parent;
+        while (pclk && !pclk->dpll_data)
+                pclk = pclk->parent;
+
+        /* clk does not have a DPLL as a parent? */
+        WARN_ON(!pclk);
+
+        dd = pclk->dpll_data;
+
+        WARN_ON(!dd->enable_mask);
+
+        v = __raw_readl(dd->control_reg) & dd->enable_mask;
+        v >>= __ffs(dd->enable_mask);
+        if (v != OMAP3XXX_EN_DPLL_LOCKED)
+                rate = clk->parent->rate;
+        else
+                rate = clk->parent->rate * 2;
+        return rate;
+}