122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
/*
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* OMAP34xx M2 divider clock code
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*
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* Copyright (C) 2007-2008 Texas Instruments, Inc.
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* Copyright (C) 2007-2010 Nokia Corporation
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*
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* Paul Walmsley
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* 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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#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 <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 "clock3xxx.h"
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#include "clock34xx.h"
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#include "sdrc.h"
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#define CYCLES_PER_MHZ 1000000
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/*
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* CORE DPLL (DPLL3) M2 divider rate programming functions
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*
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* These call into SRAM code to do the actual CM writes, since the SDRAM
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* is clocked from DPLL3.
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*/
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/**
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* omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider
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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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* Program the DPLL M2 divider with the rounded target rate. Returns
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* -EINVAL upon error, or 0 upon success.
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*/
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int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate)
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{
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u32 new_div = 0;
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u32 unlock_dll = 0;
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u32 c;
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unsigned long validrate, sdrcrate, _mpurate;
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struct omap_sdrc_params *sdrc_cs0;
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struct omap_sdrc_params *sdrc_cs1;
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int ret;
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if (!clk || !rate)
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return -EINVAL;
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validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
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if (validrate != rate)
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return -EINVAL;
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sdrcrate = sdrc_ick_p->rate;
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if (rate > clk->rate)
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sdrcrate <<= ((rate / clk->rate) >> 1);
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else
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sdrcrate >>= ((clk->rate / rate) >> 1);
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ret = omap2_sdrc_get_params(sdrcrate, &sdrc_cs0, &sdrc_cs1);
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if (ret)
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return -EINVAL;
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if (sdrcrate < MIN_SDRC_DLL_LOCK_FREQ) {
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pr_debug("clock: will unlock SDRC DLL\n");
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unlock_dll = 1;
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}
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/*
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* XXX This only needs to be done when the CPU frequency changes
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*/
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_mpurate = arm_fck_p->rate / CYCLES_PER_MHZ;
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c = (_mpurate << SDRC_MPURATE_SCALE) >> SDRC_MPURATE_BASE_SHIFT;
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c += 1; /* for safety */
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c *= SDRC_MPURATE_LOOPS;
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c >>= SDRC_MPURATE_SCALE;
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if (c == 0)
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c = 1;
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pr_debug("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate,
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validrate);
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pr_debug("clock: SDRC CS0 timing params used:"
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" RFR %08x CTRLA %08x CTRLB %08x MR %08x\n",
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sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
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sdrc_cs0->actim_ctrlb, sdrc_cs0->mr);
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if (sdrc_cs1)
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pr_debug("clock: SDRC CS1 timing params used: "
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" RFR %08x CTRLA %08x CTRLB %08x MR %08x\n",
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sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla,
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sdrc_cs1->actim_ctrlb, sdrc_cs1->mr);
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if (sdrc_cs1)
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omap3_configure_core_dpll(
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new_div, unlock_dll, c, rate > clk->rate,
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sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
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sdrc_cs0->actim_ctrlb, sdrc_cs0->mr,
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sdrc_cs1->rfr_ctrl, sdrc_cs1->actim_ctrla,
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sdrc_cs1->actim_ctrlb, sdrc_cs1->mr);
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else
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omap3_configure_core_dpll(
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new_div, unlock_dll, c, rate > clk->rate,
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sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
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sdrc_cs0->actim_ctrlb, sdrc_cs0->mr,
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0, 0, 0, 0);
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return 0;
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}
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