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