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linux-next/arch/arm/mach-omap2/clock3xxx.c
Paul Walmsley 4d30e82c26 OMAP2/3 clock: combine OMAP2 & 3 boot-time MPU rate change code
The OMAP2 and OMAP3 boot-time MPU rate change code is almost
identical.  Merge them into mach-omap2/clock.c, and add kerneldoc
documentation.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
2010-02-24 17:45:15 -07:00

105 lines
2.5 KiB
C

/*
* OMAP3-specific clock framework functions
*
* 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 "clock.h"
#include "clock3xxx.h"
#include "prm.h"
#include "prm-regbits-34xx.h"
#include "cm.h"
#include "cm-regbits-34xx.h"
/*
* DPLL5_FREQ_FOR_USBHOST: USBHOST and USBTLL are the only clocks
* that are sourced by DPLL5, and both of these require this clock
* to be at 120 MHz for proper operation.
*/
#define DPLL5_FREQ_FOR_USBHOST 120000000
/* needed by omap3_core_dpll_m2_set_rate() */
struct clk *sdrc_ick_p, *arm_fck_p;
int omap3_dpll4_set_rate(struct clk *clk, unsigned long rate)
{
/*
* According to the 12-5 CDP code from TI, "Limitation 2.5"
* on 3430ES1 prevents us from changing DPLL multipliers or dividers
* on DPLL4.
*/
if (omap_rev() == OMAP3430_REV_ES1_0) {
pr_err("clock: DPLL4 cannot change rate due to "
"silicon 'Limitation 2.5' on 3430ES1.\n");
return -EINVAL;
}
return omap3_noncore_dpll_set_rate(clk, rate);
}
void __init omap3_clk_lock_dpll5(void)
{
struct clk *dpll5_clk;
struct clk *dpll5_m2_clk;
dpll5_clk = clk_get(NULL, "dpll5_ck");
clk_set_rate(dpll5_clk, DPLL5_FREQ_FOR_USBHOST);
clk_enable(dpll5_clk);
/* Enable autoidle to allow it to enter low power bypass */
omap3_dpll_allow_idle(dpll5_clk);
/* Program dpll5_m2_clk divider for no division */
dpll5_m2_clk = clk_get(NULL, "dpll5_m2_ck");
clk_enable(dpll5_m2_clk);
clk_set_rate(dpll5_m2_clk, DPLL5_FREQ_FOR_USBHOST);
clk_disable(dpll5_m2_clk);
clk_disable(dpll5_clk);
return;
}
/* Common clock code */
/*
* Switch the MPU rate if specified on cmdline. We cannot do this
* early until cmdline is parsed. XXX This should be removed from the
* clock code and handled by the OPP layer code in the near future.
*/
static int __init omap3xxx_clk_arch_init(void)
{
int ret;
if (!cpu_is_omap34xx())
return 0;
ret = omap2_clk_switch_mpurate_at_boot("dpll1_ck");
if (!ret)
omap2_clk_print_new_rates("osc_sys_ck", "arm_fck", "core_ck");
return ret;
}
arch_initcall(omap3xxx_clk_arch_init);