linux/arch/arm/mach-omap2/clkt34xx_dpll3m2.c
Tony Lindgren bf027ca137 ARM: OMAP: Split sram.h to local headers and minimal shared header
Most of the defines are specific to omap1 and omap2+,
and should be in the local headers. Only minimal function
prototypes need to be shared.

As discussed on linux-arm-kernel, we want to avoid
relative includes for the arch/arm/*omap* shared code:

http://www.spinics.net/lists/linux-omap/msg80520.html

So this patch re-adds a minimal plat/sram.h.

The new plat/sram.h must not be included from drivers,
that will break build for omap2+ CONFIG_MULTIPLATFORM.

Note that this patch temporarily adds two more
relative includes; Those will be removed in the
following patch.

Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-31 10:14:13 -07:00

120 lines
3.1 KiB
C

/*
* 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 "clock.h"
#include "clock3xxx.h"
#include "clock34xx.h"
#include "sdrc.h"
#include "sram.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;
unsigned long clkrate;
if (!clk || !rate)
return -EINVAL;
validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
if (validrate != rate)
return -EINVAL;
sdrcrate = __clk_get_rate(sdrc_ick_p);
clkrate = __clk_get_rate(clk);
if (rate > clkrate)
sdrcrate <<= ((rate / clkrate) >> 1);
else
sdrcrate >>= ((clkrate / 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 = __clk_get_rate(arm_fck_p) / 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",
clkrate, 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 > clkrate,
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 > clkrate,
sdrc_cs0->rfr_ctrl, sdrc_cs0->actim_ctrla,
sdrc_cs0->actim_ctrlb, sdrc_cs0->mr,
0, 0, 0, 0);
clk->rate = rate;
return 0;
}