arch/arm/mach-omap2/clock3xxx.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/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/err.h>

#include <plat/cpu.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 */

/* REVISIT: Move this init stuff out into clock.c */

/*
 * Switch the MPU rate if specified on cmdline.
 * We cannot do this early until cmdline is parsed.
 */
static int __init omap3xxx_clk_arch_init(void)
{
	struct clk *osc_sys_ck, *dpll1_ck, *arm_fck, *core_ck;
	unsigned long osc_sys_rate;
	bool err = 0;

	if (!cpu_is_omap34xx())
		return 0;

	if (!mpurate)
		return -EINVAL;

	/* XXX test these for success */
	dpll1_ck = clk_get(NULL, "dpll1_ck");
	if (WARN(IS_ERR(dpll1_ck), "Failed to get dpll1_ck.\n"))
		err = 1;

	arm_fck = clk_get(NULL, "arm_fck");
	if (WARN(IS_ERR(arm_fck), "Failed to get arm_fck.\n"))
		err = 1;

	core_ck = clk_get(NULL, "core_ck");
	if (WARN(IS_ERR(core_ck), "Failed to get core_ck.\n"))
		err = 1;

	osc_sys_ck = clk_get(NULL, "osc_sys_ck");
	if (WARN(IS_ERR(osc_sys_ck), "Failed to get osc_sys_ck.\n"))
		err = 1;

	if (err)
		return -ENOENT;

	/* REVISIT: not yet ready for 343x */
	if (clk_set_rate(dpll1_ck, mpurate))
		printk(KERN_ERR "*** Unable to set MPU rate\n");

	recalculate_root_clocks();

	osc_sys_rate = clk_get_rate(osc_sys_ck);

	pr_info("Switched to new clocking rate (Crystal/Core/MPU): "
		"%ld.%01ld/%ld/%ld MHz\n",
		(osc_sys_rate / 1000000),
		((osc_sys_rate / 100000) % 10),
		(clk_get_rate(core_ck) / 1000000),
		(clk_get_rate(arm_fck) / 1000000));

	calibrate_delay();

	return 0;
}
arch_initcall(omap3xxx_clk_arch_init);