168 lines
4.5 KiB
C
168 lines
4.5 KiB
C
/*
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* OMAP2xxx DVFS virtual clock functions
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*
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* Copyright (C) 2005-2008 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 <plat/cpu.h>
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#include <plat/clock.h>
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#include <plat/sram.h>
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#include <plat/sdrc.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_3xxx.h"
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#include "cm-regbits-24xx.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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* 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 *clk)
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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 *clk, unsigned long 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 != sclk->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 *clk, unsigned long rate)
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{
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u32 cur_rate, done_rate, bypass = 0, tmp;
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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 != sclk->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(dclk);
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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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/* MPU divider */
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omap2_cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
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/* dsp + iva1 div(2420), iva2.1(2430) */
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omap2_cm_write_mod_reg(prcm->cm_clksel_dsp,
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OMAP24XX_DSP_MOD, CM_CLKSEL);
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omap2_cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
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/* Major subsystem dividers */
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tmp = omap2_cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
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omap2_cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD,
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CM_CLKSEL1);
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if (cpu_is_omap2430())
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omap2_cm_write_mod_reg(prcm->cm_clksel_mdm,
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OMAP2430_MDM_MOD, CM_CLKSEL);
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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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