path: root/arch/arm/mach-omap2/clockdomain.c

/*
 * OMAP2/3 clockdomain framework functions
 *
 * Copyright (C) 2008 Texas Instruments, Inc.
 * Copyright (C) 2008 Nokia Corporation
 *
 * Written by Paul Walmsley and Jouni Högander
 *
 * 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.
 */
#ifdef CONFIG_OMAP_DEBUG_CLOCKDOMAIN
#  define DEBUG
#endif

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/limits.h>
#include <linux/err.h>

#include <linux/io.h>

#include <linux/bitops.h>

#include <mach/clock.h>

#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"

#include <mach/powerdomain.h>
#include <mach/clockdomain.h>

/* clkdm_list contains all registered struct clockdomains */
static LIST_HEAD(clkdm_list);

/* clkdm_mutex protects clkdm_list add and del ops */
static DEFINE_MUTEX(clkdm_mutex);

/* array of powerdomain deps to be added/removed when clkdm in hwsup mode */
static struct clkdm_pwrdm_autodep *autodeps;


/* Private functions */

/*
 * _autodep_lookup - resolve autodep pwrdm names to pwrdm pointers; store
 * @autodep: struct clkdm_pwrdm_autodep * to resolve
 *
 * Resolve autodep powerdomain names to powerdomain pointers via
 * pwrdm_lookup() and store the pointers in the autodep structure.  An
 * "autodep" is a powerdomain sleep/wakeup dependency that is
 * automatically added and removed whenever clocks in the associated
 * clockdomain are enabled or disabled (respectively) when the
 * clockdomain is in hardware-supervised mode.	Meant to be called
 * once at clockdomain layer initialization, since these should remain
 * fixed for a particular architecture.  No return value.
 */
static void _autodep_lookup(struct clkdm_pwrdm_autodep *autodep)
{
	struct powerdomain *pwrdm;

	if (!autodep)
		return;

	if (!omap_chip_is(autodep->omap_chip))
		return;

	pwrdm = pwrdm_lookup(autodep->pwrdm.name);
	if (!pwrdm) {
		pr_err("clockdomain: autodeps: powerdomain %s does not exist\n",
			 autodep->pwrdm.name);
		pwrdm = ERR_PTR(-ENOENT);
	}
	autodep->pwrdm.ptr = pwrdm;
}

/*
 * _clkdm_add_autodeps - add auto sleepdeps/wkdeps to clkdm upon clock enable
 * @clkdm: struct clockdomain *
 *
 * Add the "autodep" sleep & wakeup dependencies to clockdomain 'clkdm'
 * in hardware-supervised mode.  Meant to be called from clock framework
 * when a clock inside clockdomain 'clkdm' is enabled.	No return value.
 */
static void _clkdm_add_autodeps(struct clockdomain *clkdm)
{
	struct clkdm_pwrdm_autodep *autodep;

	for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
		if (IS_ERR(autodep->pwrdm.ptr))
			continue;

		if (!omap_chip_is(autodep->omap_chip))
			continue;

		pr_debug("clockdomain: adding %s sleepdep/wkdep for "
			 "pwrdm %s\n", autodep->pwrdm.ptr->name,
			 clkdm->pwrdm.ptr->name);

		pwrdm_add_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
		pwrdm_add_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
	}
}

/*
 * _clkdm_add_autodeps - remove auto sleepdeps/wkdeps from clkdm
 * @clkdm: struct clockdomain *
 *
 * Remove the "autodep" sleep & wakeup dependencies from clockdomain 'clkdm'
 * in hardware-supervised mode.  Meant to be called from clock framework
 * when a clock inside clockdomain 'clkdm' is disabled.  No return value.
 */
static void _clkdm_del_autodeps(struct clockdomain *clkdm)
{
	struct clkdm_pwrdm_autodep *autodep;

	for (autodep = autodeps; autodep->pwrdm.ptr; autodep++) {
		if (IS_ERR(autodep->pwrdm.ptr))
			continue;

		if (!omap_chip_is(autodep->omap_chip))
			continue;

		pr_debug("clockdomain: removing %s sleepdep/wkdep for "
			 "pwrdm %s\n", autodep->pwrdm.ptr->name,
			 clkdm->pwrdm.ptr->name);

		pwrdm_del_sleepdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
		pwrdm_del_wkdep(clkdm->pwrdm.ptr, autodep->pwrdm.ptr);
	}
}

/*
 * _omap2_clkdm_set_hwsup - set the hwsup idle transition bit
 * @clkdm: struct clockdomain *
 * @enable: int 0 to disable, 1 to enable
 *
 * Internal helper for actually switching the bit that controls hwsup
 * idle transitions for clkdm.
 */
static void _omap2_clkdm_set_hwsup(struct clockdomain *clkdm, int enable)
{
	u32 v;

	if (cpu_is_omap24xx()) {
		if (enable)
			v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
		else
			v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
	} else if (cpu_is_omap34xx()) {
		if (enable)
			v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
		else
			v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
	} else {
		BUG();
	}

	cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
			    v << __ffs(clkdm->clktrctrl_mask),
			    clkdm->pwrdm.ptr->prcm_offs, CM_CLKSTCTRL);
}

static struct clockdomain *_clkdm_lookup(const char *name)
{
	struct clockdomain *clkdm, *temp_clkdm;

	if (!name)
		return NULL;

	clkdm = NULL;

	list_for_each_entry(temp_clkdm, &clkdm_list, node) {
		if (!strcmp(name, temp_clkdm->name)) {
			clkdm = temp_clkdm;
			break;
		}
	}

	return clkdm;
}


/* Public functions */

/**
 * clkdm_init - set up the clockdomain layer
 * @clkdms: optional pointer to an array of clockdomains to register
 * @init_autodeps: optional pointer to an array of autodeps to register
 *
 * Set up internal state.  If a pointer to an array of clockdomains
 * was supplied, loop through the list of clockdomains, register all
 * that are available on the current platform.	Similarly, if a
 * pointer to an array of clockdomain-powerdomain autodependencies was
 * provided, register those.  No return value.
 */
void clkdm_init(struct clockdomain **clkdms,
		struct clkdm_pwrdm_autodep *init_autodeps)
{
	struct clockdomain **c = NULL;
	struct clkdm_pwrdm_autodep *autodep = NULL;

	if (clkdms)
		for (c = clkdms; *c; c++)
			clkdm_register(*c);

	autodeps = init_autodeps;
	if (autodeps)
		for (autodep = autodeps; autodep->pwrdm.ptr; autodep++)
			_autodep_lookup(autodep);
}

/**
 * clkdm_register - register a clockdomain
 * @clkdm: struct clockdomain * to register
 *
 * Adds a clockdomain to the internal clockdomain list.
 * Returns -EINVAL if given a null pointer, -EEXIST if a clockdomain is
 * already registered by the provided name, or 0 upon success.
 */
int clkdm_register(struct clockdomain *clkdm)
{
	int ret = -EINVAL;
	struct powerdomain *pwrdm;

	if (!clkdm || !clkdm->name)
		return -EINVAL;

	if (!omap_chip_is(clkdm->omap_chip))
		return -EINVAL;

	pwrdm = pwrdm_lookup(clkdm->pwrdm.name);
	if (!pwrdm) {
		pr_err("clockdomain: %s: powerdomain %s does not exist\n",
			clkdm->name, clkdm->pwrdm.name);
		return -EINVAL;
	}
	clkdm->pwrdm.ptr = pwrdm;

	mutex_lock(&clkdm_mutex);
	/* Verify that the clockdomain is not already registered */
	if (_clkdm_lookup(clkdm->name)) {
		ret = -EEXIST;
		goto cr_unlock;
	}

	list_add(&clkdm->node, &clkdm_list);

	pwrdm_add_clkdm(pwrdm, clkdm);

	pr_debug("clockdomain: registered %s\n", clkdm->name);
	ret = 0;

cr_unlock:
	mutex_unlock(&clkdm_mutex);

	return ret;
}

/**
 * clkdm_unregister - unregister a clockdomain
 * @clkdm: struct clockdomain * to unregister
 *
 * Removes a clockdomain from the internal clockdomain list.  Returns
 * -EINVAL if clkdm argument is NULL.
 */
int clkdm_unregister(struct clockdomain *clkdm)
{
	if (!clkdm)
		return -EINVAL;

	pwrdm_del_clkdm(clkdm->pwrdm.ptr, clkdm);

	mutex_lock(&clkdm_mutex);
	list_del(&clkdm->node);
	mutex_unlock(&clkdm_mutex);

	pr_debug("clockdomain: unregistered %s\n", clkdm->name);

	return 0;
}

/**
 * clkdm_lookup - look up a clockdomain by name, return a po