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/*
* OMAP2xxx APLL clock control functions
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
* Copyright (C) 2004-2010 Nokia Corporation
*
* Contacts:
* Richard Woodruff <r-woodruff2@ti.com>
* Paul Walmsley
*
* Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
* Gordon McNutt and RidgeRun, Inc.
*
* 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/clk.h>
#include <linux/io.h>
#include <plat/clock.h>
#include <plat/prcm.h>
#include "clock.h"
#include "clock2xxx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
#define EN_APLL_STOPPED 0
#define EN_APLL_LOCKED 3
/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
#define APLLS_CLKIN_19_2MHZ 0
#define APLLS_CLKIN_13MHZ 2
#define APLLS_CLKIN_12MHZ 3
/* Private functions */
/* Enable an APLL if off */
static int omap2_clk_apll_enable(struct clk *clk, u32 status_mask)
{
u32 cval, apll_mask;
apll_mask = EN_APLL_LOCKED << clk->enable_bit;
cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
if ((cval & apll_mask) == apll_mask)
return 0; /* apll already enabled */
cval &= ~apll_mask;
cval |= apll_mask;
cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
omap2_cm_wait_idlest(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), status_mask,
clk->name);
/*
* REVISIT: Should we return an error code if omap2_wait_clock_ready()
* fails?
*/
return 0;
}
static int omap2_clk_apll96_enable(struct clk *clk)
{
return omap2_clk_apll_enable(clk, OMAP24XX_ST_96M_APLL);
}
static int omap2_clk_apll54_enable(struct clk *clk)
{
return omap2_clk_apll_enable(clk, OMAP24XX_ST_54M_APLL);
}
/* Stop APLL */
static void omap2_clk_apll_disable(struct clk *clk)
{
u32 cval;
cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
}
/* Public data */
const struct clkops clkops_apll96 = {
.enable = omap2_clk_apll96_enable,
.disable = omap2_clk_apll_disable,
};
const struct clkops clkops_apll54 = {
.enable = omap2_clk_apll54_enable,
.disable = omap2_clk_apll_disable,
};
/* Public functions */
u32 omap2xxx_get_apll_clkin(void)
{
u32 aplls, srate = 0;
aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
aplls &= OMAP24XX_APLLS_CLKIN_MASK;
aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;
if (aplls == APLLS_CLKIN_19_2MHZ)
srate = 19200000;
else if (aplls == APLLS_CLKIN_13MHZ)
srate = 13000000;
else if (aplls == APLLS_CLKIN_12MHZ)
srate = 12000000;
return srate;
}
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