/*
* 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/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_debug("clockdomain: _autodep_lookup: powerdomain %s "
"does not exist\n", autodep->pwrdm_name);
WARN_ON(1);
return;
}
autodep->pwrdm = pwrdm;
return;
}
/*
* _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_name; autodep++) {
if (!autodep->pwrdm)
continue;
pr_debug("clockdomain: adding %s sleepdep/wkdep for "
"pwrdm %s\n", autodep->pwrdm_name,
clkdm->pwrdm->name);
pwrdm_add_sleepdep(clkdm->pwrdm, autodep->pwrdm);
pwrdm_add_wkdep(clkdm->pwrdm, autodep->pwrdm);
}
}
/*
* _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_name; autodep++) {
if (!autodep->pwrdm)
continue;
pr_debug("clockdomain: removing %s sleepdep/wkdep for "
"pwrdm %s\n", autodep->pwrdm_name,
clkdm->pwrdm->name);
pwrdm_del_sleepdep(clkdm->pwrdm, autodep->pwrdm);
pwrdm_del_wkdep(clkdm->pwrdm, autodep->pwrdm);
}
}
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_name; 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_debug("clockdomain: clkdm_register %s: powerdomain %s "
"does not exist\n", clkdm->name, clkdm->pwrdm_name);
return -EINVAL;
}
clkdm->pwrdm = 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, 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 pointer
* @name: name of clockdomain
*
* Find a registered clockdomain by its name. Returns a pointer to the
* struct clockdomain if found, or NULL otherwise.
*/
struct clockdomain *clkdm_lookup(const char *name)
{
struct clockdomain *clkdm, *temp_clkdm;
if (!name)
return NULL;
clkdm = NULL;
mutex_lock(&clkdm_mutex);
list_for_each_entry(temp_clkdm, &clkdm_list, node) {
if (!strcmp(name, temp_clkdm->name)) {
clkdm = temp_clkdm;
break;
}
}
mutex_unlock(&clkdm_mutex);
return clkdm;
}
/**
* clkdm_for_each - call function on each registered clockdomain
* @fn: callback function *
*
* Call the supplied function for each registered clockdomain.
* The callback function can return anything but 0 to bail
* out early from the iterator. The callback function is called with
* the clkdm_mutex held, so no clockdomain structure manipulation
* functions should be called from the callback, although hardware
* clockdomain control functions are fine. Returns the last return
* value of the callback function, which should be 0 for success or
* anything else to indicate failure; or -EINVAL if the function pointer
* is null.
*/
int clkdm_for_each(int (*fn)(struct clockdomain *clkdm))
{
struct clockdomain *clkdm;
int ret = 0;
if (!fn)
return -EINVAL;
mutex_lock(&clkdm_mutex);
list_for_each_entry(clkdm, &clkdm_list, node) {
ret = (*fn)(clkdm);
if (ret)
break;
}
mutex_unlock(&clkdm_mutex);
return ret;
}
/**
* clkdm_get_pwrdm - return a ptr to the pwrdm that this clkdm resides in
* @clkdm: struct clockdomain *
*
* Return a pointer to the struct powerdomain that the specified clockdomain
* 'clkdm' exists in, or returns NULL if clkdm argument is NULL.
*/
struct powerdomain *clkdm_get_pwrdm(struct clockdomain *clkdm)
{
if (!clkdm)
return NULL;
return clkdm->pwrdm;
}
/* Hardware clockdomain control */
/**
* omap2_clkdm_clktrctrl_read - read the clkdm's current state transition mode
* @clk: struct clk * of a clockdomain
*
* Return the clockdomain's current state transition mode from the
* corresponding domain CM_CLKSTCTRL register. Returns -EINVAL if clk
* is NULL or the current mode upon success.
*/
static int omap2_clkdm_clktrctrl_read(struct clockdomain *clkdm)
{
u32 v;
if (!clkdm)
return -EINVAL;
v = cm_read_mod_reg(clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
v &= clkdm->clktrctrl_mask;
v >>= __ffs(clkdm->clktrctrl_mask);
return v;
}
/**
* omap2_clkdm_sleep - force clockdomain sleep transition
* @clkdm: struct clockdomain *
*
* Instruct the CM to force a sleep transition on the specified
* clockdomain 'clkdm'. Returns -EINVAL if clk is NULL or if
* clockdomain does not support software-initiated sleep; 0 upon
* success.
*/
int omap2_clkdm_sleep(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!(clkdm->flags & CLKDM_CAN_FORCE_SLEEP)) {
pr_debug("clockdomain: %s does not support forcing "
"sleep via software\n", clkdm->name);
return -EINVAL;
}
pr_debug("clockdomain: forcing sleep on %s\n", clkdm->name);
if (cpu_is_omap24xx()) {
cm_set_mod_reg_bits(OMAP24XX_FORCESTATE,
clkdm->pwrdm->prcm_offs, PM_PWSTCTRL);
} else if (cpu_is_omap34xx()) {
u32 v = (OMAP34XX_CLKSTCTRL_FORCE_SLEEP <<
__ffs(clkdm->clktrctrl_mask));
cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
} else {
BUG();
};
return 0;
}
/**
* omap2_clkdm_wakeup - force clockdomain wakeup transition
* @clkdm: struct clockdomain *
*
* Instruct the CM to force a wakeup transition on the specified
* clockdomain 'clkdm'. Returns -EINVAL if clkdm is NULL or if the
* clockdomain does not support software-controlled wakeup; 0 upon
* success.
*/
int omap2_clkdm_wakeup(struct clockdomain *clkdm)
{
if (!clkdm)
return -EINVAL;
if (!(clkdm->flags & CLKDM_CAN_FORCE_WAKEUP)) {
pr_debug("clockdomain: %s does not support forcing "
"wakeup via software\n", clkdm->name);
return -EINVAL;
}
pr_debug("clockdomain: forcing wakeup on %s\n", clkdm->name);
if (cpu_is_omap24xx()) {
cm_clear_mod_reg_bits(OMAP24XX_FORCESTATE,
clkdm->pwrdm->prcm_offs, PM_PWSTCTRL);
} else if (cpu_is_omap34xx()) {
u32 v = (OMAP34XX_CLKSTCTRL_FORCE_WAKEUP <<
__ffs(clkdm->clktrctrl_mask));
cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask, v,
clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
} else {
BUG();
};
return 0;
}
/**
* omap2_clkdm_allow_idle - enable hwsup idle transitions for clkdm
* @clkdm: struct clockdomain *
*
* Allow the hardware to automatically switch the clockdomain into
* active or idle states, as needed by downstream clocks. If the
* clockdomain has any downstream clocks enabled in the clock
* framework, wkdep/sleepdep autodependencies are added; this is so
* device drivers can read and write to the device. No return value.
*/
void omap2_clkdm_allow_idle(struct clockdomain *clkdm)
{
u32 v;
if (!clkdm)
return;
if (!(clkdm->flags & CLKDM_CAN_ENABLE_AUTO)) {
pr_debug("clock: automatic idle transitions cannot be enabled "
"on clockdomain %s\n", clkdm->name);
return;
}
pr_debug("clockdomain: enabling automatic idle transitions for %s\n",
clkdm->name);
if (atomic_read(&clkdm->usecount) > 0)
_clkdm_add_autodeps(clkdm);
if (cpu_is_omap24xx())
v = OMAP24XX_CLKSTCTRL_ENABLE_AUTO;
else if (cpu_is_omap34xx())
v = OMAP34XX_CLKSTCTRL_ENABLE_AUTO;
else
BUG();
cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
v << __ffs(clkdm->clktrctrl_mask),
clkdm->pwrdm->prcm_offs,
CM_CLKSTCTRL);
}
/**
* omap2_clkdm_deny_idle - disable hwsup idle transitions for clkdm
* @clkdm: struct clockdomain *
*
* Prevent the hardware from automatically switching the clockdomain
* into inactive or idle states. If the clockdomain has downstream
* clocks enabled in the clock framework, wkdep/sleepdep
* autodependencies are removed. No return value.
*/
void omap2_clkdm_deny_idle(struct clockdomain *clkdm)
{
u32 v;
if (!clkdm)
return;
if (!(clkdm->flags & CLKDM_CAN_DISABLE_AUTO)) {
pr_debug("clockdomain: automatic idle transitions cannot be "
"disabled on %s\n", clkdm->name);
return;
}
pr_debug("clockdomain: disabling automatic idle transitions for %s\n",
clkdm->name);
if (cpu_is_omap24xx())
v = OMAP24XX_CLKSTCTRL_DISABLE_AUTO;
else if (cpu_is_omap34xx())
v = OMAP34XX_CLKSTCTRL_DISABLE_AUTO;
else
BUG();
cm_rmw_mod_reg_bits(clkdm->clktrctrl_mask,
v << __ffs(clkdm->clktrctrl_mask),
clkdm->pwrdm->prcm_offs, CM_CLKSTCTRL);
if (atomic_read(&clkdm->usecount) > 0)
_clkdm_del_autodeps(clkdm);
}
/* Clockdomain-to-clock framework interface code */
/**
* omap2_clkdm_clk_enable - add an enabled downstream clock to this clkdm
* @clkdm: struct clockdomain *
* @clk: struct clk * of the enabled downstream clock
*
* Increment the usecount of this clockdomain 'clkdm' and ensure that
* it is awake. Intended to be called by clk_enable() code. If the
* clockdomain is in software-supervised idle mode, force the
* clockdomain to wake. If the clockdomain is in hardware-supervised
* idle mode, add clkdm-pwrdm autodependencies, to ensure that devices
* in the clockdomain can be read from/written to by on-chip processors.
* Returns -EINVAL if passed null pointers; returns 0 upon success or
* if the clockdomain is in hwsup idle mode.
*/
int omap2_clkdm_clk_enable(struct clockdomain *clkdm, struct clk *clk)
{
int v;
/*
* XXX Rewrite this code to maintain a list of enabled
* downstream clocks for debugging purposes?
*/
if (!clkdm || !clk)
return -EINVAL;
if (atomic_inc_return(&clkdm->usecount) > 1)
return 0;
/* Clockdomain now has one enabled downstream clock */
pr_debug("clockdomain: clkdm %s: clk %s now enabled\n", clkdm->name,
clk->name);
v = omap2_clkdm_clktrctrl_read(clkdm);
if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
(cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
_clkdm_add_autodeps(clkdm);
else
omap2_clkdm_wakeup(clkdm);
return 0;
}
/**
* omap2_clkdm_clk_disable - remove an enabled downstream clock from this clkdm
* @clkdm: struct clockdomain *
* @clk: struct clk * of the disabled downstream clock
*
* Decrement the usecount of this clockdomain 'clkdm'. Intended to be
* called by clk_disable() code. If the usecount goes to 0, put the
* clockdomain to sleep (software-supervised mode) or remove the
* clkdm-pwrdm autodependencies (hardware-supervised mode). Returns
* -EINVAL if passed null pointers; -ERANGE if the clkdm usecount
* underflows and debugging is enabled; or returns 0 upon success or
* if the clockdomain is in hwsup idle mode.
*/
int omap2_clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
{
int v;
/*
* XXX Rewrite this code to maintain a list of enabled
* downstream clocks for debugging purposes?
*/
if (!clkdm || !clk)
return -EINVAL;
#ifdef DEBUG
if (atomic_read(&clkdm->usecount) == 0) {
WARN_ON(1); /* underflow */
return -ERANGE;
}
#endif
if (atomic_dec_return(&clkdm->usecount) > 0)
return 0;
/* All downstream clocks of this clockdomain are now disabled */
pr_debug("clockdomain: clkdm %s: clk %s now disabled\n", clkdm->name,
clk->name);
v = omap2_clkdm_clktrctrl_read(clkdm);
if ((cpu_is_omap34xx() && v == OMAP34XX_CLKSTCTRL_ENABLE_AUTO) ||
(cpu_is_omap24xx() && v == OMAP24XX_CLKSTCTRL_ENABLE_AUTO))
_clkdm_del_autodeps(clkdm);
else
omap2_clkdm_sleep(clkdm);
return 0;
}
