linux/arch/arm/mach-omap2/clkt2xxx_osc.c

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/*
* OMAP2xxx osc_clk-specific clock code
*
* 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/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/io.h>
#include "clock.h"
#include "clock2xxx.h"
#include "prm2xxx_3xxx.h"
#include "prm-regbits-24xx.h"
/*
* XXX This does not actually enable the osc_ck, since the osc_ck must
* be running for this function to be called. Instead, this function
* is used to disable an autoidle mode on the osc_ck. The existing
* clk_enable/clk_disable()-based usecounting for osc_ck should be
* replaced with autoidle-based usecounting.
*/
int omap2_enable_osc_ck(struct clk_hw *clk)
{
u32 pcc;
pcc = __raw_readl(prcm_clksrc_ctrl);
__raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
return 0;
}
/*
* XXX This does not actually disable the osc_ck, since doing so would
* immediately halt the system. Instead, this function is used to
* enable an autoidle mode on the osc_ck. The existing
* clk_enable/clk_disable()-based usecounting for osc_ck should be
* replaced with autoidle-based usecounting.
*/
void omap2_disable_osc_ck(struct clk_hw *clk)
{
u32 pcc;
pcc = __raw_readl(prcm_clksrc_ctrl);
__raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
}
unsigned long omap2_osc_clk_recalc(struct clk_hw *clk,
unsigned long parent_rate)
{
return omap2xxx_get_apll_clkin() * omap2xxx_get_sysclkdiv();
}