539 lines
13 KiB
C
539 lines
13 KiB
C
/*
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* OMAP3/4 - specific DPLL control functions
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*
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* Copyright (C) 2009 Texas Instruments, Inc.
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* Copyright (C) 2009 Nokia Corporation
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*
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* Written by Paul Walmsley
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* Testing and integration fixes by Jouni Högander
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*
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* Parts of this code are based on code written by
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* Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/list.h>
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#include <linux/errno.h>
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#include <linux/delay.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/limits.h>
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#include <linux/bitops.h>
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#include <plat/cpu.h>
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#include <plat/clock.h>
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#include <plat/sram.h>
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#include <asm/div64.h>
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#include <asm/clkdev.h>
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#include "clock.h"
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#include "prm.h"
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#include "prm-regbits-34xx.h"
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#include "cm.h"
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#include "cm-regbits-34xx.h"
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/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
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#define DPLL_AUTOIDLE_DISABLE 0x0
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#define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
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#define MAX_DPLL_WAIT_TRIES 1000000
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/**
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* omap3_dpll_recalc - recalculate DPLL rate
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* @clk: DPLL struct clk
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*
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* Recalculate and propagate the DPLL rate.
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*/
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unsigned long omap3_dpll_recalc(struct clk *clk)
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{
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return omap2_get_dpll_rate(clk);
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}
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/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
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static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
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{
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const struct dpll_data *dd;
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u32 v;
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dd = clk->dpll_data;
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v = __raw_readl(dd->control_reg);
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v &= ~dd->enable_mask;
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v |= clken_bits << __ffs(dd->enable_mask);
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__raw_writel(v, dd->control_reg);
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}
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/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
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static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
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{
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const struct dpll_data *dd;
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int i = 0;
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int ret = -EINVAL;
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dd = clk->dpll_data;
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state <<= __ffs(dd->idlest_mask);
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while (((__raw_readl(dd->idlest_reg) & dd->idlest_mask) != state) &&
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i < MAX_DPLL_WAIT_TRIES) {
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i++;
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udelay(1);
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}
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if (i == MAX_DPLL_WAIT_TRIES) {
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printk(KERN_ERR "clock: %s failed transition to '%s'\n",
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clk->name, (state) ? "locked" : "bypassed");
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} else {
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pr_debug("clock: %s transition to '%s' in %d loops\n",
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clk->name, (state) ? "locked" : "bypassed", i);
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ret = 0;
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}
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return ret;
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}
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/* From 3430 TRM ES2 4.7.6.2 */
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static u16 _omap3_dpll_compute_freqsel(struct clk *clk, u8 n)
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{
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unsigned long fint;
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u16 f = 0;
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fint = clk->dpll_data->clk_ref->rate / n;
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pr_debug("clock: fint is %lu\n", fint);
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if (fint >= 750000 && fint <= 1000000)
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f = 0x3;
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else if (fint > 1000000 && fint <= 1250000)
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f = 0x4;
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else if (fint > 1250000 && fint <= 1500000)
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f = 0x5;
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else if (fint > 1500000 && fint <= 1750000)
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f = 0x6;
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else if (fint > 1750000 && fint <= 2100000)
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f = 0x7;
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else if (fint > 7500000 && fint <= 10000000)
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f = 0xB;
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else if (fint > 10000000 && fint <= 12500000)
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f = 0xC;
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else if (fint > 12500000 && fint <= 15000000)
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f = 0xD;
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else if (fint > 15000000 && fint <= 17500000)
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f = 0xE;
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else if (fint > 17500000 && fint <= 21000000)
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f = 0xF;
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else
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pr_debug("clock: unknown freqsel setting for %d\n", n);
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return f;
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}
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/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
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/*
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* _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
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* @clk: pointer to a DPLL struct clk
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*
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* Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
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* readiness before returning. Will save and restore the DPLL's
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* autoidle state across the enable, per the CDP code. If the DPLL
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* locked successfully, return 0; if the DPLL did not lock in the time
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* allotted, or DPLL3 was passed in, return -EINVAL.
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*/
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static int _omap3_noncore_dpll_lock(struct clk *clk)
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{
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u8 ai;
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int r;
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pr_debug("clock: locking DPLL %s\n", clk->name);
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ai = omap3_dpll_autoidle_read(clk);
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omap3_dpll_deny_idle(clk);
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_omap3_dpll_write_clken(clk, DPLL_LOCKED);
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r = _omap3_wait_dpll_status(clk, 1);
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if (ai)
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omap3_dpll_allow_idle(clk);
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return r;
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}
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/*
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* _omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
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* @clk: pointer to a DPLL struct clk
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*
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* Instructs a non-CORE DPLL to enter low-power bypass mode. In
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* bypass mode, the DPLL's rate is set equal to its parent clock's
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* rate. Waits for the DPLL to report readiness before returning.
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* Will save and restore the DPLL's autoidle state across the enable,
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* per the CDP code. If the DPLL entered bypass mode successfully,
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* return 0; if the DPLL did not enter bypass in the time allotted, or
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* DPLL3 was passed in, or the DPLL does not support low-power bypass,
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* return -EINVAL.
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*/
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static int _omap3_noncore_dpll_bypass(struct clk *clk)
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{
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int r;
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u8 ai;
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if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
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return -EINVAL;
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pr_debug("clock: configuring DPLL %s for low-power bypass\n",
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clk->name);
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ai = omap3_dpll_autoidle_read(clk);
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_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
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r = _omap3_wait_dpll_status(clk, 0);
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if (ai)
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omap3_dpll_allow_idle(clk);
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else
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omap3_dpll_deny_idle(clk);
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return r;
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}
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/*
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* _omap3_noncore_dpll_stop - instruct a DPLL to stop
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* @clk: pointer to a DPLL struct clk
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*
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* Instructs a non-CORE DPLL to enter low-power stop. Will save and
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* restore the DPLL's autoidle state across the stop, per the CDP
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* code. If DPLL3 was passed in, or the DPLL does not support
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* low-power stop, return -EINVAL; otherwise, return 0.
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*/
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static int _omap3_noncore_dpll_stop(struct clk *clk)
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{
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u8 ai;
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if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
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return -EINVAL;
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pr_debug("clock: stopping DPLL %s\n", clk->name);
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ai = omap3_dpll_autoidle_read(clk);
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_omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
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if (ai)
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omap3_dpll_allow_idle(clk);
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else
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omap3_dpll_deny_idle(clk);
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return 0;
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}
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/**
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* omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
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* @clk: pointer to a DPLL struct clk
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*
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* Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
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* The choice of modes depends on the DPLL's programmed rate: if it is
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* the same as the DPLL's parent clock, it will enter bypass;
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* otherwise, it will enter lock. This code will wait for the DPLL to
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* indicate readiness before returning, unless the DPLL takes too long
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* to enter the target state. Intended to be used as the struct clk's
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* enable function. If DPLL3 was passed in, or the DPLL does not
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* support low-power stop, or if the DPLL took too long to enter
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* bypass or lock, return -EINVAL; otherwise, return 0.
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*/
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int omap3_noncore_dpll_enable(struct clk *clk)
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{
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int r;
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struct dpll_data *dd;
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dd = clk->dpll_data;
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if (!dd)
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return -EINVAL;
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if (clk->rate == dd->clk_bypass->rate) {
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WARN_ON(clk->parent != dd->clk_bypass);
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r = _omap3_noncore_dpll_bypass(clk);
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} else {
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WARN_ON(clk->parent != dd->clk_ref);
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r = _omap3_noncore_dpll_lock(clk);
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}
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/*
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*FIXME: this is dubious - if clk->rate has changed, what about
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* propagating?
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*/
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if (!r)
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clk->rate = omap2_get_dpll_rate(clk);
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return r;
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}
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/**
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* omap3_noncore_dpll_disable - instruct a DPLL to enter low-power stop
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* @clk: pointer to a DPLL struct clk
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*
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* Instructs a non-CORE DPLL to enter low-power stop. This function is
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* intended for use in struct clkops. No return value.
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*/
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void omap3_noncore_dpll_disable(struct clk *clk)
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{
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_omap3_noncore_dpll_stop(clk);
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}
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/* Non-CORE DPLL rate set code */
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/*
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* omap3_noncore_dpll_program - set non-core DPLL M,N values directly
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* @clk: struct clk * of DPLL to set
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* @m: DPLL multiplier to set
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* @n: DPLL divider to set
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* @freqsel: FREQSEL value to set
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*
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* Program the DPLL with the supplied M, N values, and wait for the DPLL to
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* lock.. Returns -EINVAL upon error, or 0 upon success.
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*/
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int omap3_noncore_dpll_program(struct clk *clk, u16 m, u8 n, u16 freqsel)
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{
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struct dpll_data *dd = clk->dpll_data;
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u32 v;
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/* 3430 ES2 TRM: 4.7.6.9 DPLL Programming Sequence */
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_omap3_noncore_dpll_bypass(clk);
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/* Set jitter correction */
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if (!cpu_is_omap44xx()) {
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v = __raw_readl(dd->control_reg);
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v &= ~dd->freqsel_mask;
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v |= freqsel << __ffs(dd->freqsel_mask);
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__raw_writel(v, dd->control_reg);
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}
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/* Set DPLL multiplier, divider */
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v = __raw_readl(dd->mult_div1_reg);
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v &= ~(dd->mult_mask | dd->div1_mask);
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v |= m << __ffs(dd->mult_mask);
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v |= (n - 1) << __ffs(dd->div1_mask);
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__raw_writel(v, dd->mult_div1_reg);
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/* We let the clock framework set the other output dividers later */
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/* REVISIT: Set ramp-up delay? */
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_omap3_noncore_dpll_lock(clk);
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return 0;
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}
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/**
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* omap3_noncore_dpll_set_rate - set non-core DPLL rate
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* @clk: struct clk * of DPLL to set
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* @rate: rounded target rate
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*
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* Set the DPLL CLKOUT to the target rate. If the DPLL can enter
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* low-power bypass, and the target rate is the bypass source clock
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* rate, then configure the DPLL for bypass. Otherwise, round the
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* target rate if it hasn't been done already, then program and lock
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* the DPLL. Returns -EINVAL upon error, or 0 upon success.
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*/
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int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate)
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{
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struct clk *new_parent = NULL;
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u16 freqsel = 0;
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struct dpll_data *dd;
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int ret;
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if (!clk || !rate)
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return -EINVAL;
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dd = clk->dpll_data;
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if (!dd)
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return -EINVAL;
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if (rate == omap2_get_dpll_rate(clk))
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return 0;
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/*
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* Ensure both the bypass and ref clocks are enabled prior to
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* doing anything; we need the bypass clock running to reprogram
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* the DPLL.
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*/
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omap2_clk_enable(dd->clk_bypass);
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omap2_clk_enable(dd->clk_ref);
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if (dd->clk_bypass->rate == rate &&
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(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
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pr_debug("clock: %s: set rate: entering bypass.\n", clk->name);
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ret = _omap3_noncore_dpll_bypass(clk);
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if (!ret)
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new_parent = dd->clk_bypass;
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} else {
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if (dd->last_rounded_rate != rate)
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omap2_dpll_round_rate(clk, rate);
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if (dd->last_rounded_rate == 0)
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return -EINVAL;
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/* No freqsel on OMAP4 */
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if (!cpu_is_omap44xx()) {
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freqsel = _omap3_dpll_compute_freqsel(clk,
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dd->last_rounded_n);
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if (!freqsel)
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WARN_ON(1);
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}
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pr_debug("clock: %s: set rate: locking rate to %lu.\n",
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clk->name, rate);
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ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
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dd->last_rounded_n, freqsel);
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if (!ret)
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new_parent = dd->clk_ref;
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}
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if (!ret) {
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/*
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* Switch the parent clock in the heirarchy, and make sure
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* that the new parent's usecount is correct. Note: we
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* enable the new parent before disabling the old to avoid
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* any unnecessary hardware disable->enable transitions.
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*/
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if (clk->usecount) {
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omap2_clk_enable(new_parent);
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omap2_clk_disable(clk->parent);
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}
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clk_reparent(clk, new_parent);
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clk->rate = rate;
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}
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omap2_clk_disable(dd->clk_ref);
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omap2_clk_disable(dd->clk_bypass);
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return 0;
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}
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/* DPLL autoidle read/set code */
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/**
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* omap3_dpll_autoidle_read - read a DPLL's autoidle bits
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* @clk: struct clk * of the DPLL to read
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*
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* Return the DPLL's autoidle bits, shifted down to bit 0. Returns
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* -EINVAL if passed a null pointer or if the struct clk does not
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* appear to refer to a DPLL.
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*/
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u32 omap3_dpll_autoidle_read(struct clk *clk)
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{
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const struct dpll_data *dd;
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u32 v;
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if (!clk || !clk->dpll_data)
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return -EINVAL;
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dd = clk->dpll_data;
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v = __raw_readl(dd->autoidle_reg);
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v &= dd->autoidle_mask;
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v >>= __ffs(dd->autoidle_mask);
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return v;
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}
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/**
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* omap3_dpll_allow_idle - enable DPLL autoidle bits
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* @clk: struct clk * of the DPLL to operate on
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*
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* Enable DPLL automatic idle control. This automatic idle mode
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* switching takes effect only when the DPLL is locked, at least on
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* OMAP3430. The DPLL will enter low-power stop when its downstream
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* clocks are gated. No return value.
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*/
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void omap3_dpll_allow_idle(struct clk *clk)
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{
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const struct dpll_data *dd;
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u32 v;
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if (!clk || !clk->dpll_data)
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return;
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dd = clk->dpll_data;
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/*
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* REVISIT: CORE DPLL can optionally enter low-power bypass
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* by writing 0x5 instead of 0x1. Add some mechanism to
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* optionally enter this mode.
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*/
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v = __raw_readl(dd->autoidle_reg);
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v &= ~dd->autoidle_mask;
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v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
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__raw_writel(v, dd->autoidle_reg);
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}
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/**
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* omap3_dpll_deny_idle - prevent DPLL from automatically idling
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* @clk: struct clk * of the DPLL to operate on
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*
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* Disable DPLL automatic idle control. No return value.
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*/
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void omap3_dpll_deny_idle(struct clk *clk)
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{
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const struct dpll_data *dd;
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u32 v;
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if (!clk || !clk->dpll_data)
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return;
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dd = clk->dpll_data;
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v = __raw_readl(dd->autoidle_reg);
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v &= ~dd->autoidle_mask;
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v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
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__raw_writel(v, dd->autoidle_reg);
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}
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/* Clock control for DPLL outputs */
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/**
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* omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
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* @clk: DPLL output struct clk
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*
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* Using parent clock DPLL data, look up DPLL state. If locked, set our
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* rate to the dpll_clk * 2; otherwise, just use dpll_clk.
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*/
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unsigned long omap3_clkoutx2_recalc(struct clk *clk)
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{
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const struct dpll_data *dd;
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unsigned long rate;
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u32 v;
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struct clk *pclk;
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/* Walk up the parents of clk, looking for a DPLL */
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pclk = clk->parent;
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while (pclk && !pclk->dpll_data)
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pclk = pclk->parent;
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/* clk does not have a DPLL as a parent? */
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WARN_ON(!pclk);
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dd = pclk->dpll_data;
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WARN_ON(!dd->enable_mask);
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v = __raw_readl(dd->control_reg) & dd->enable_mask;
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v >>= __ffs(dd->enable_mask);
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if (v != OMAP3XXX_EN_DPLL_LOCKED)
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rate = clk->parent->rate;
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else
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rate = clk->parent->rate * 2;
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return rate;
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}
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