The clock and clkdev for this are added manually. Signed-off-by: Tero Kristo <t-kristo@ti.com>
		
			
				
	
	
		
			263 lines
		
	
	
	
		
			6.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			263 lines
		
	
	
	
		
			6.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * OMAP2xxx DVFS virtual clock functions
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 *
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 * Copyright (C) 2005-2008, 2012 Texas Instruments, Inc.
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 * Copyright (C) 2004-2010 Nokia Corporation
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 *
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 * Contacts:
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 * Richard Woodruff <r-woodruff2@ti.com>
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 * Paul Walmsley
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 *
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 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
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 * Gordon McNutt and RidgeRun, Inc.
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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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 * XXX Some of this code should be replaceable by the upcoming OPP layer
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 * code.  However, some notion of "rate set" is probably still necessary
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 * for OMAP2xxx at least.  Rate sets should be generalized so they can be
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 * used for any OMAP chip, not just OMAP2xxx.  In particular, Richard Woodruff
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 * has in the past expressed a preference to use rate sets for OPP changes,
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 * rather than dynamically recalculating the clock tree, so if someone wants
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 * this badly enough to write the code to handle it, we should support it
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 * as an option.
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 */
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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#include <linux/cpufreq.h>
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#include <linux/slab.h>
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#include "soc.h"
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#include "clock.h"
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#include "clock2xxx.h"
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#include "opp2xxx.h"
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#include "cm2xxx.h"
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#include "cm-regbits-24xx.h"
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#include "sdrc.h"
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#include "sram.h"
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const struct prcm_config *curr_prcm_set;
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const struct prcm_config *rate_table;
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/*
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 * sys_ck_rate: the rate of the external high-frequency clock
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 * oscillator on the board.  Set by the SoC-specific clock init code.
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 * Once set during a boot, will not change.
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 */
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static unsigned long sys_ck_rate;
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/**
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 * omap2_table_mpu_recalc - just return the MPU speed
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 * @clk: virt_prcm_set struct clk
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 *
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 * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
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 */
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unsigned long omap2_table_mpu_recalc(struct clk_hw *clk,
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				     unsigned long parent_rate)
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{
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	return curr_prcm_set->mpu_speed;
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}
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/*
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 * Look for a rate equal or less than the target rate given a configuration set.
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 *
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 * What's not entirely clear is "which" field represents the key field.
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 * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
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 * just uses the ARM rates.
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 */
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long omap2_round_to_table_rate(struct clk_hw *hw, unsigned long rate,
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			       unsigned long *parent_rate)
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{
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	const struct prcm_config *ptr;
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	long highest_rate;
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	highest_rate = -EINVAL;
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	for (ptr = rate_table; ptr->mpu_speed; ptr++) {
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		if (!(ptr->flags & cpu_mask))
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			continue;
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		if (ptr->xtal_speed != sys_ck_rate)
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			continue;
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		highest_rate = ptr->mpu_speed;
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		/* Can check only after xtal frequency check */
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		if (ptr->mpu_speed <= rate)
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			break;
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	}
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	return highest_rate;
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}
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/* Sets basic clocks based on the specified rate */
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int omap2_select_table_rate(struct clk_hw *hw, unsigned long rate,
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			    unsigned long parent_rate)
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{
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	u32 cur_rate, done_rate, bypass = 0;
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	const struct prcm_config *prcm;
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	unsigned long found_speed = 0;
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	unsigned long flags;
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	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
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		if (!(prcm->flags & cpu_mask))
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			continue;
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		if (prcm->xtal_speed != sys_ck_rate)
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			continue;
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		if (prcm->mpu_speed <= rate) {
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			found_speed = prcm->mpu_speed;
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			break;
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		}
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	}
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	if (!found_speed) {
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		printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
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		       rate / 1000000);
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		return -EINVAL;
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	}
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	curr_prcm_set = prcm;
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	cur_rate = omap2xxx_clk_get_core_rate();
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	if (prcm->dpll_speed == cur_rate / 2) {
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		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL, 1);
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	} else if (prcm->dpll_speed == cur_rate * 2) {
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		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
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	} else if (prcm->dpll_speed != cur_rate) {
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		local_irq_save(flags);
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		if (prcm->dpll_speed == prcm->xtal_speed)
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			bypass = 1;
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		if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
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		    CORE_CLK_SRC_DPLL_X2)
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			done_rate = CORE_CLK_SRC_DPLL_X2;
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		else
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			done_rate = CORE_CLK_SRC_DPLL;
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		omap2xxx_cm_set_mod_dividers(prcm->cm_clksel_mpu,
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					     prcm->cm_clksel_dsp,
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					     prcm->cm_clksel_gfx,
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					     prcm->cm_clksel1_core,
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					     prcm->cm_clksel_mdm);
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		/* x2 to enter omap2xxx_sdrc_init_params() */
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		omap2xxx_sdrc_reprogram(CORE_CLK_SRC_DPLL_X2, 1);
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		omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
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			       bypass);
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		omap2xxx_sdrc_init_params(omap2xxx_sdrc_dll_is_unlocked());
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		omap2xxx_sdrc_reprogram(done_rate, 0);
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		local_irq_restore(flags);
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	}
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	return 0;
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}
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/**
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 * omap2xxx_clkt_vps_check_bootloader_rate - determine which of the rate
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 * table sets matches the current CORE DPLL hardware rate
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 *
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 * Check the MPU rate set by bootloader.  Sets the 'curr_prcm_set'
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 * global to point to the active rate set when found; otherwise, sets
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 * it to NULL.  No return value;
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 */
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void omap2xxx_clkt_vps_check_bootloader_rates(void)
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{
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	const struct prcm_config *prcm = NULL;
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	unsigned long rate;
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	rate = omap2xxx_clk_get_core_rate();
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	for (prcm = rate_table; prcm->mpu_speed; prcm++) {
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		if (!(prcm->flags & cpu_mask))
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			continue;
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		if (prcm->xtal_speed != sys_ck_rate)
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			continue;
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		if (prcm->dpll_speed <= rate)
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			break;
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	}
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	curr_prcm_set = prcm;
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}
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/**
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 * omap2xxx_clkt_vps_late_init - store a copy of the sys_ck rate
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 *
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 * Store a copy of the sys_ck rate for later use by the OMAP2xxx DVFS
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 * code.  (The sys_ck rate does not -- or rather, must not -- change
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 * during kernel runtime.)  Must be called after we have a valid
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 * sys_ck rate, but before the virt_prcm_set clock rate is
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 * recalculated.  No return value.
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 */
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void omap2xxx_clkt_vps_late_init(void)
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{
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	struct clk *c;
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	c = clk_get(NULL, "sys_ck");
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	if (IS_ERR(c)) {
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		WARN(1, "could not locate sys_ck\n");
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	} else {
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		sys_ck_rate = clk_get_rate(c);
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		clk_put(c);
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	}
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}
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#ifdef CONFIG_OF
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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static const struct clk_ops virt_prcm_set_ops = {
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	.recalc_rate	= &omap2_table_mpu_recalc,
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	.set_rate	= &omap2_select_table_rate,
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	.round_rate	= &omap2_round_to_table_rate,
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};
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/**
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 * omap2xxx_clkt_vps_init - initialize virt_prcm_set clock
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 *
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 * Does a manual init for the virtual prcm DVFS clock for OMAP2. This
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 * function is called only from omap2 DT clock init, as the virtual
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 * node is not modelled in the DT clock data.
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 */
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void omap2xxx_clkt_vps_init(void)
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{
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	struct clk_init_data init = { NULL };
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	struct clk_hw_omap *hw = NULL;
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	struct clk *clk;
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	const char *parent_name = "mpu_ck";
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	struct clk_lookup *lookup = NULL;
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	omap2xxx_clkt_vps_late_init();
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	omap2xxx_clkt_vps_check_bootloader_rates();
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	hw = kzalloc(sizeof(*hw), GFP_KERNEL);
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	lookup = kzalloc(sizeof(*lookup), GFP_KERNEL);
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	if (!hw || !lookup)
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		goto cleanup;
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	init.name = "virt_prcm_set";
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	init.ops = &virt_prcm_set_ops;
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	init.parent_names = &parent_name;
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	init.num_parents = 1;
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	hw->hw.init = &init;
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	clk = clk_register(NULL, &hw->hw);
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	lookup->dev_id = NULL;
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	lookup->con_id = "cpufreq_ck";
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	lookup->clk = clk;
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	clkdev_add(lookup);
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	return;
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cleanup:
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	kfree(hw);
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	kfree(lookup);
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}
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#endif
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