121 строка
2.6 KiB
C
121 строка
2.6 KiB
C
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/*
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* OMAP2xxx APLL clock control 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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#undef DEBUG
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#include <linux/kernel.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/prcm.h>
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#include "clock.h"
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#include "clock2xxx.h"
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#include "cm.h"
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#include "cm-regbits-24xx.h"
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/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
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#define EN_APLL_STOPPED 0
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#define EN_APLL_LOCKED 3
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/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
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#define APLLS_CLKIN_19_2MHZ 0
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#define APLLS_CLKIN_13MHZ 2
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#define APLLS_CLKIN_12MHZ 3
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/* Private functions */
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/* Enable an APLL if off */
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static int omap2_clk_apll_enable(struct clk *clk, u32 status_mask)
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{
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u32 cval, apll_mask;
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apll_mask = EN_APLL_LOCKED << clk->enable_bit;
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cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
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if ((cval & apll_mask) == apll_mask)
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return 0; /* apll already enabled */
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cval &= ~apll_mask;
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cval |= apll_mask;
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cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
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omap2_cm_wait_idlest(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), status_mask,
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clk->name);
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/*
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* REVISIT: Should we return an error code if omap2_wait_clock_ready()
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* fails?
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*/
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return 0;
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}
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static int omap2_clk_apll96_enable(struct clk *clk)
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{
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return omap2_clk_apll_enable(clk, OMAP24XX_ST_96M_APLL);
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}
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static int omap2_clk_apll54_enable(struct clk *clk)
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{
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return omap2_clk_apll_enable(clk, OMAP24XX_ST_54M_APLL);
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}
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/* Stop APLL */
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static void omap2_clk_apll_disable(struct clk *clk)
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{
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u32 cval;
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cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
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cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
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cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
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}
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/* Public data */
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const struct clkops clkops_apll96 = {
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.enable = omap2_clk_apll96_enable,
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.disable = omap2_clk_apll_disable,
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};
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const struct clkops clkops_apll54 = {
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.enable = omap2_clk_apll54_enable,
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.disable = omap2_clk_apll_disable,
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};
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/* Public functions */
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u32 omap2xxx_get_apll_clkin(void)
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{
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u32 aplls, srate = 0;
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aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
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aplls &= OMAP24XX_APLLS_CLKIN_MASK;
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aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;
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if (aplls == APLLS_CLKIN_19_2MHZ)
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srate = 19200000;
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else if (aplls == APLLS_CLKIN_13MHZ)
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srate = 13000000;
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else if (aplls == APLLS_CLKIN_12MHZ)
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srate = 12000000;
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return srate;
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}
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