linux/arch/arm/mach-davinci/clock.c
Sekhar Nori 9a219a9ecf davinci: move PLL wait time values to clock.h
As suspend support is added, the code supporting
the suspend operation needs to bypass PLLs and
needs to access the same wait time values as the
PLL code in clock.c.

To facilitate this, move the PLL wait times to
clock.h where they can be accessed by suspend code.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2010-02-04 13:29:33 -08:00

557 lines
12 KiB
C

/*
* Clock and PLL control for DaVinci devices
*
* Copyright (C) 2006-2007 Texas Instruments.
* Copyright (C) 2008-2009 Deep Root Systems, LLC
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <mach/hardware.h>
#include <mach/psc.h>
#include <mach/cputype.h>
#include "clock.h"
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
static DEFINE_SPINLOCK(clockfw_lock);
static unsigned psc_domain(struct clk *clk)
{
return (clk->flags & PSC_DSP)
? DAVINCI_GPSC_DSPDOMAIN
: DAVINCI_GPSC_ARMDOMAIN;
}
static void __clk_enable(struct clk *clk)
{
if (clk->parent)
__clk_enable(clk->parent);
if (clk->usecount++ == 0 && (clk->flags & CLK_PSC))
davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc, 1);
}
static void __clk_disable(struct clk *clk)
{
if (WARN_ON(clk->usecount == 0))
return;
if (--clk->usecount == 0 && !(clk->flags & CLK_PLL))
davinci_psc_config(psc_domain(clk), clk->gpsc, clk->lpsc, 0);
if (clk->parent)
__clk_disable(clk->parent);
}
int clk_enable(struct clk *clk)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
spin_lock_irqsave(&clockfw_lock, flags);
__clk_enable(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return;
spin_lock_irqsave(&clockfw_lock, flags);
__clk_disable(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
long clk_round_rate(struct clk *clk, unsigned long rate)
{
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
if (clk->round_rate)
return clk->round_rate(clk, rate);
return clk->rate;
}
EXPORT_SYMBOL(clk_round_rate);
/* Propagate rate to children */
static void propagate_rate(struct clk *root)
{
struct clk *clk;
list_for_each_entry(clk, &root->children, childnode) {
if (clk->recalc)
clk->rate = clk->recalc(clk);
propagate_rate(clk);
}
}
int clk_set_rate(struct clk *clk, unsigned long rate)
{
unsigned long flags;
int ret = -EINVAL;
if (clk == NULL || IS_ERR(clk))
return ret;
spin_lock_irqsave(&clockfw_lock, flags);
if (clk->set_rate)
ret = clk->set_rate(clk, rate);
if (ret == 0) {
if (clk->recalc)
clk->rate = clk->recalc(clk);
propagate_rate(clk);
}
spin_unlock_irqrestore(&clockfw_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_set_rate);
int clk_set_parent(struct clk *clk, struct clk *parent)
{
unsigned long flags;
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
/* Cannot change parent on enabled clock */
if (WARN_ON(clk->usecount))
return -EINVAL;
mutex_lock(&clocks_mutex);
clk->parent = parent;
list_del_init(&clk->childnode);
list_add(&clk->childnode, &clk->parent->children);
mutex_unlock(&clocks_mutex);
spin_lock_irqsave(&clockfw_lock, flags);
if (clk->recalc)
clk->rate = clk->recalc(clk);
propagate_rate(clk);
spin_unlock_irqrestore(&clockfw_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_set_parent);
int clk_register(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return -EINVAL;
if (WARN(clk->parent && !clk->parent->rate,
"CLK: %s parent %s has no rate!\n",
clk->name, clk->parent->name))
return -EINVAL;
INIT_LIST_HEAD(&clk->children);
mutex_lock(&clocks_mutex);
list_add_tail(&clk->node, &clocks);
if (clk->parent)
list_add_tail(&clk->childnode, &clk->parent->children);
mutex_unlock(&clocks_mutex);
/* If rate is already set, use it */
if (clk->rate)
return 0;
/* Else, see if there is a way to calculate it */
if (clk->recalc)
clk->rate = clk->recalc(clk);
/* Otherwise, default to parent rate */
else if (clk->parent)
clk->rate = clk->parent->rate;
return 0;
}
EXPORT_SYMBOL(clk_register);
void clk_unregister(struct clk *clk)
{
if (clk == NULL || IS_ERR(clk))
return;
mutex_lock(&clocks_mutex);
list_del(&clk->node);
list_del(&clk->childnode);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clk_unregister);
#ifdef CONFIG_DAVINCI_RESET_CLOCKS
/*
* Disable any unused clocks left on by the bootloader
*/
static int __init clk_disable_unused(void)
{
struct clk *ck;
spin_lock_irq(&clockfw_lock);
list_for_each_entry(ck, &clocks, node) {
if (ck->usecount > 0)
continue;
if (!(ck->flags & CLK_PSC))
continue;
/* ignore if in Disabled or SwRstDisable states */
if (!davinci_psc_is_clk_active(ck->gpsc, ck->lpsc))
continue;
pr_info("Clocks: disable unused %s\n", ck->name);
davinci_psc_config(psc_domain(ck), ck->gpsc, ck->lpsc, 0);
}
spin_unlock_irq(&clockfw_lock);
return 0;
}
late_initcall(clk_disable_unused);
#endif
static unsigned long clk_sysclk_recalc(struct clk *clk)
{
u32 v, plldiv;
struct pll_data *pll;
unsigned long rate = clk->rate;
/* If this is the PLL base clock, no more calculations needed */
if (clk->pll_data)
return rate;
if (WARN_ON(!clk->parent))
return rate;
rate = clk->parent->rate;
/* Otherwise, the parent must be a PLL */
if (WARN_ON(!clk->parent->pll_data))
return rate;
pll = clk->parent->pll_data;
/* If pre-PLL, source clock is before the multiplier and divider(s) */
if (clk->flags & PRE_PLL)
rate = pll->input_rate;
if (!clk->div_reg)
return rate;
v = __raw_readl(pll->base + clk->div_reg);
if (v & PLLDIV_EN) {
plldiv = (v & PLLDIV_RATIO_MASK) + 1;
if (plldiv)
rate /= plldiv;
}
return rate;
}
static unsigned long clk_leafclk_recalc(struct clk *clk)
{
if (WARN_ON(!clk->parent))
return clk->rate;
return clk->parent->rate;
}
static unsigned long clk_pllclk_recalc(struct clk *clk)
{
u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
u8 bypass;
struct pll_data *pll = clk->pll_data;
unsigned long rate = clk->rate;
pll->base = IO_ADDRESS(pll->phys_base);
ctrl = __raw_readl(pll->base + PLLCTL);
rate = pll->input_rate = clk->parent->rate;
if (ctrl & PLLCTL_PLLEN) {
bypass = 0;
mult = __raw_readl(pll->base + PLLM);
if (cpu_is_davinci_dm365())
mult = 2 * (mult & PLLM_PLLM_MASK);
else
mult = (mult & PLLM_PLLM_MASK) + 1;
} else
bypass = 1;
if (pll->flags & PLL_HAS_PREDIV) {
prediv = __raw_readl(pll->base + PREDIV);
if (prediv & PLLDIV_EN)
prediv = (prediv & PLLDIV_RATIO_MASK) + 1;
else
prediv = 1;
}
/* pre-divider is fixed, but (some?) chips won't report that */
if (cpu_is_davinci_dm355() && pll->num == 1)
prediv = 8;
if (pll->flags & PLL_HAS_POSTDIV) {
postdiv = __raw_readl(pll->base + POSTDIV);
if (postdiv & PLLDIV_EN)
postdiv = (postdiv & PLLDIV_RATIO_MASK) + 1;
else
postdiv = 1;
}
if (!bypass) {
rate /= prediv;
rate *= mult;
rate /= postdiv;
}
pr_debug("PLL%d: input = %lu MHz [ ",
pll->num, clk->parent->rate / 1000000);
if (bypass)
pr_debug("bypass ");
if (prediv > 1)
pr_debug("/ %d ", prediv);
if (mult > 1)
pr_debug("* %d ", mult);
if (postdiv > 1)
pr_debug("/ %d ", postdiv);
pr_debug("] --> %lu MHz output.\n", rate / 1000000);
return rate;
}
/**
* davinci_set_pllrate - set the output rate of a given PLL.
*
* Note: Currently tested to work with OMAP-L138 only.
*
* @pll: pll whose rate needs to be changed.
* @prediv: The pre divider value. Passing 0 disables the pre-divider.
* @pllm: The multiplier value. Passing 0 leads to multiply-by-one.
* @postdiv: The post divider value. Passing 0 disables the post-divider.
*/
int davinci_set_pllrate(struct pll_data *pll, unsigned int prediv,
unsigned int mult, unsigned int postdiv)
{
u32 ctrl;
unsigned int locktime;
if (pll->base == NULL)
return -EINVAL;
/*
* PLL lock time required per OMAP-L138 datasheet is
* (2000 * prediv)/sqrt(pllm) OSCIN cycles. We approximate sqrt(pllm)
* as 4 and OSCIN cycle as 25 MHz.
*/
if (prediv) {
locktime = ((2000 * prediv) / 100);
prediv = (prediv - 1) | PLLDIV_EN;
} else {
locktime = PLL_LOCK_TIME;
}
if (postdiv)
postdiv = (postdiv - 1) | PLLDIV_EN;
if (mult)
mult = mult - 1;
ctrl = __raw_readl(pll->base + PLLCTL);
/* Switch the PLL to bypass mode */
ctrl &= ~(PLLCTL_PLLENSRC | PLLCTL_PLLEN);
__raw_writel(ctrl, pll->base + PLLCTL);
udelay(PLL_BYPASS_TIME);
/* Reset and enable PLL */
ctrl &= ~(PLLCTL_PLLRST | PLLCTL_PLLDIS);
__raw_writel(ctrl, pll->base + PLLCTL);
if (pll->flags & PLL_HAS_PREDIV)
__raw_writel(prediv, pll->base + PREDIV);
__raw_writel(mult, pll->base + PLLM);
if (pll->flags & PLL_HAS_POSTDIV)
__raw_writel(postdiv, pll->base + POSTDIV);
udelay(PLL_RESET_TIME);
/* Bring PLL out of reset */
ctrl |= PLLCTL_PLLRST;
__raw_writel(ctrl, pll->base + PLLCTL);
udelay(locktime);
/* Remove PLL from bypass mode */
ctrl |= PLLCTL_PLLEN;
__raw_writel(ctrl, pll->base + PLLCTL);
return 0;
}
EXPORT_SYMBOL(davinci_set_pllrate);
int __init davinci_clk_init(struct davinci_clk *clocks)
{
struct davinci_clk *c;
struct clk *clk;
for (c = clocks; c->lk.clk; c++) {
clk = c->lk.clk;
if (!clk->recalc) {
/* Check if clock is a PLL */
if (clk->pll_data)
clk->recalc = clk_pllclk_recalc;
/* Else, if it is a PLL-derived clock */
else if (clk->flags & CLK_PLL)
clk->recalc = clk_sysclk_recalc;
/* Otherwise, it is a leaf clock (PSC clock) */
else if (clk->parent)
clk->recalc = clk_leafclk_recalc;
}
if (clk->recalc)
clk->rate = clk->recalc(clk);
if (clk->lpsc)
clk->flags |= CLK_PSC;
clkdev_add(&c->lk);
clk_register(clk);
/* Turn on clocks that Linux doesn't otherwise manage */
if (clk->flags & ALWAYS_ENABLED)
clk_enable(clk);
}
return 0;
}
#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
static void *davinci_ck_start(struct seq_file *m, loff_t *pos)
{
return *pos < 1 ? (void *)1 : NULL;
}
static void *davinci_ck_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return NULL;
}
static void davinci_ck_stop(struct seq_file *m, void *v)
{
}
#define CLKNAME_MAX 10 /* longest clock name */
#define NEST_DELTA 2
#define NEST_MAX 4
static void
dump_clock(struct seq_file *s, unsigned nest, struct clk *parent)
{
char *state;
char buf[CLKNAME_MAX + NEST_DELTA * NEST_MAX];
struct clk *clk;
unsigned i;
if (parent->flags & CLK_PLL)
state = "pll";
else if (parent->flags & CLK_PSC)
state = "psc";
else
state = "";
/* <nest spaces> name <pad to end> */
memset(buf, ' ', sizeof(buf) - 1);
buf[sizeof(buf) - 1] = 0;
i = strlen(parent->name);
memcpy(buf + nest, parent->name,
min(i, (unsigned)(sizeof(buf) - 1 - nest)));
seq_printf(s, "%s users=%2d %-3s %9ld Hz\n",
buf, parent->usecount, state, clk_get_rate(parent));
/* REVISIT show device associations too */
/* cost is now small, but not linear... */
list_for_each_entry(clk, &parent->children, childnode) {
dump_clock(s, nest + NEST_DELTA, clk);
}
}
static int davinci_ck_show(struct seq_file *m, void *v)
{
/* Show clock tree; we know the main oscillator is first.
* We trust nonzero usecounts equate to PSC enables...
*/
mutex_lock(&clocks_mutex);
if (!list_empty(&clocks))
dump_clock(m, 0, list_first_entry(&clocks, struct clk, node));
mutex_unlock(&clocks_mutex);
return 0;
}
static const struct seq_operations davinci_ck_op = {
.start = davinci_ck_start,
.next = davinci_ck_next,
.stop = davinci_ck_stop,
.show = davinci_ck_show
};
static int davinci_ck_open(struct inode *inode, struct file *file)
{
return seq_open(file, &davinci_ck_op);
}
static const struct file_operations proc_davinci_ck_operations = {
.open = davinci_ck_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init davinci_ck_proc_init(void)
{
proc_create("davinci_clocks", 0, NULL, &proc_davinci_ck_operations);
return 0;
}
__initcall(davinci_ck_proc_init);
#endif /* CONFIG_DEBUG_PROC_FS */