OMAP2/3 clock: split, rename omap2_wait_clock_ready()

Some OMAP2/3 hardware modules have CM_IDLEST attributes that are not
handled by the current omap2_wait_clock_ready() code.  In preparation
for patches that fix the unusual devices, rename the function
omap2_wait_clock_ready() to omap2_wait_module_ready() and split it
into three parts:

1. A clkops-specific companion clock return function (by default,
   omap2_clk_dflt_find_companion())

2. A clkops-specific CM_IDLEST register address and bit shift return
   function (by default, omap2_clk_dflt_find_idlest())

3. Code to wait for the CM to indicate that the module is ready
   (omap2_cm_wait_idlest())

Clocks can now specify their own custom find_companion() and find_idlest()
functions; used in subsequent patches.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
This commit is contained in:
Paul Walmsley 2009-07-24 19:44:03 -06:00 committed by paul
parent df56556e57
commit 72350b29a4
5 changed files with 135 additions and 81 deletions

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@ -27,6 +27,7 @@
#include <mach/clock.h>
#include <mach/clockdomain.h>
#include <mach/cpu.h>
#include <mach/prcm.h>
#include <asm/div64.h>
#include <mach/sdrc.h>
@ -38,8 +39,6 @@
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
#define MAX_CLOCK_ENABLE_WAIT 100000
/* DPLL rate rounding: minimum DPLL multiplier, divider values */
#define DPLL_MIN_MULTIPLIER 1
#define DPLL_MIN_DIVIDER 1
@ -274,83 +273,97 @@ unsigned long omap2_fixed_divisor_recalc(struct clk *clk)
}
/**
* omap2_wait_clock_ready - wait for clock to enable
* @reg: physical address of clock IDLEST register
* @mask: value to mask against to determine if the clock is active
* @name: name of the clock (for printk)
* omap2_clk_dflt_find_companion - find companion clock to @clk
* @clk: struct clk * to find the companion clock of
* @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
* @other_bit: u8 ** to return the companion clock bit shift in
*
* Returns 1 if the clock enabled in time, or 0 if it failed to enable
* in roughly MAX_CLOCK_ENABLE_WAIT microseconds.
*/
int omap2_wait_clock_ready(void __iomem *reg, u32 mask, const char *name)
{
int i = 0;
int ena = 0;
/*
* 24xx uses 0 to indicate not ready, and 1 to indicate ready.
* 34xx reverses this, just to keep us on our toes
*/
if (cpu_mask & (RATE_IN_242X | RATE_IN_243X))
ena = mask;
else if (cpu_mask & RATE_IN_343X)
ena = 0;
/* Wait for lock */
while (((__raw_readl(reg) & mask) != ena) &&
(i++ < MAX_CLOCK_ENABLE_WAIT)) {
udelay(1);
}
if (i <= MAX_CLOCK_ENABLE_WAIT)
pr_debug("Clock %s stable after %d loops\n", name, i);
else
printk(KERN_ERR "Clock %s didn't enable in %d tries\n",
name, MAX_CLOCK_ENABLE_WAIT);
return (i < MAX_CLOCK_ENABLE_WAIT) ? 1 : 0;
};
/*
* Note: We don't need special code here for INVERT_ENABLE
* for the time being since INVERT_ENABLE only applies to clocks enabled by
* Note: We don't need special code here for INVERT_ENABLE for the
* time being since INVERT_ENABLE only applies to clocks enabled by
* CM_CLKEN_PLL
*
* Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes it's
* just a matter of XORing the bits.
*
* Some clocks don't have companion clocks. For example, modules with
* only an interface clock (such as MAILBOXES) don't have a companion
* clock. Right now, this code relies on the hardware exporting a bit
* in the correct companion register that indicates that the
* nonexistent 'companion clock' is active. Future patches will
* associate this type of code with per-module data structures to
* avoid this issue, and remove the casts. No return value.
*/
static void omap2_clk_wait_ready(struct clk *clk)
void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
u8 *other_bit)
{
void __iomem *reg, *other_reg, *st_reg;
u32 bit;
/*
* REVISIT: This code is pretty ugly. It would be nice to generalize
* it and pull it into struct clk itself somehow.
*/
reg = clk->enable_reg;
u32 r;
/*
* Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes
* it's just a matter of XORing the bits.
*/
other_reg = (void __iomem *)((u32)reg ^ (CM_FCLKEN ^ CM_ICLKEN));
r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
/* Check if both functional and interface clocks
* are running. */
bit = 1 << clk->enable_bit;
if (!(__raw_readl(other_reg) & bit))
return;
st_reg = (void __iomem *)(((u32)other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
omap2_wait_clock_ready(st_reg, bit, clk->name);
*other_reg = (__force void __iomem *)r;
*other_bit = clk->enable_bit;
}
static int omap2_dflt_clk_enable(struct clk *clk)
/**
* omap2_clk_dflt_find_idlest - find CM_IDLEST reg va, bit shift for @clk
* @clk: struct clk * to find IDLEST info for
* @idlest_reg: void __iomem ** to return the CM_IDLEST va in
* @idlest_bit: u8 ** to return the CM_IDLEST bit shift in
*
* Return the CM_IDLEST register address and bit shift corresponding
* to the module that "owns" this clock. This default code assumes
* that the CM_IDLEST bit shift is the CM_*CLKEN bit shift, and that
* the IDLEST register address ID corresponds to the CM_*CLKEN
* register address ID (e.g., that CM_FCLKEN2 corresponds to
* CM_IDLEST2). This is not true for all modules. No return value.
*/
void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg,
u8 *idlest_bit)
{
u32 r;
r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
*idlest_bit = clk->enable_bit;
}
/**
* omap2_module_wait_ready - wait for an OMAP module to leave IDLE
* @clk: struct clk * belonging to the module
*
* If the necessary clocks for the OMAP hardware IP block that
* corresponds to clock @clk are enabled, then wait for the module to
* indicate readiness (i.e., to leave IDLE). This code does not
* belong in the clock code and will be moved in the medium term to
* module-dependent code. No return value.
*/
static void omap2_module_wait_ready(struct clk *clk)
{
void __iomem *companion_reg, *idlest_reg;
u8 other_bit, idlest_bit;
/* Not all modules have multiple clocks that their IDLEST depends on */
if (clk->ops->find_companion) {
clk->ops->find_companion(clk, &companion_reg, &other_bit);
if (!(__raw_readl(companion_reg) & (1 << other_bit)))
return;
}
clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit);
omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), clk->name);
}
int omap2_dflt_clk_enable(struct clk *clk)
{
u32 v;
if (unlikely(clk->enable_reg == NULL)) {
printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
pr_err("clock.c: Enable for %s without enable code\n",
clk->name);
return 0; /* REVISIT: -EINVAL */
}
@ -363,26 +376,13 @@ static int omap2_dflt_clk_enable(struct clk *clk)
__raw_writel(v, clk->enable_reg);
v = __raw_readl(clk->enable_reg); /* OCP barrier */
if (clk->ops->find_idlest)
omap2_module_wait_ready(clk);
return 0;
}
static int omap2_dflt_clk_enable_wait(struct clk *clk)
{
int ret;
if (!clk->enable_reg) {
printk(KERN_ERR "clock.c: Enable for %s without enable code\n",
clk->name);
return 0; /* REVISIT: -EINVAL */
}
ret = omap2_dflt_clk_enable(clk);
if (ret == 0)
omap2_clk_wait_ready(clk);
return ret;
}
static void omap2_dflt_clk_disable(struct clk *clk)
void omap2_dflt_clk_disable(struct clk *clk)
{
u32 v;
@ -406,8 +406,10 @@ static void omap2_dflt_clk_disable(struct clk *clk)
}
const struct clkops clkops_omap2_dflt_wait = {
.enable = omap2_dflt_clk_enable_wait,
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
.find_companion = omap2_clk_dflt_find_companion,
.find_idlest = omap2_clk_dflt_find_idlest,
};
const struct clkops clkops_omap2_dflt = {

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@ -65,6 +65,12 @@ int omap2_clksel_set_rate(struct clk *clk, unsigned long rate);
u32 omap2_get_dpll_rate(struct clk *clk);
int omap2_wait_clock_ready(void __iomem *reg, u32 cval, const char *name);
void omap2_clk_prepare_for_reboot(void);
int omap2_dflt_clk_enable(struct clk *clk);
void omap2_dflt_clk_disable(struct clk *clk);
void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
u8 *other_bit);
void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg,
u8 *idlest_bit);
extern const struct clkops clkops_omap2_dflt_wait;
extern const struct clkops clkops_omap2_dflt;

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@ -17,6 +17,7 @@
#include <linux/init.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <mach/common.h>
#include <mach/prcm.h>
@ -28,6 +29,8 @@
static void __iomem *prm_base;
static void __iomem *cm_base;
#define MAX_MODULE_ENABLE_WAIT 100000
u32 omap_prcm_get_reset_sources(void)
{
/* XXX This presumably needs modification for 34XX */
@ -120,6 +123,46 @@ u32 cm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
}
EXPORT_SYMBOL(cm_rmw_mod_reg_bits);
/**
* omap2_cm_wait_idlest - wait for IDLEST bit to indicate module readiness
* @reg: physical address of module IDLEST register
* @mask: value to mask against to determine if the module is active
* @name: name of the clock (for printk)
*
* Returns 1 if the module indicated readiness in time, or 0 if it
* failed to enable in roughly MAX_MODULE_ENABLE_WAIT microseconds.
*/
int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, const char *name)
{
int i = 0;
int ena = 0;
/*
* 24xx uses 0 to indicate not ready, and 1 to indicate ready.
* 34xx reverses this, just to keep us on our toes
*/
if (cpu_is_omap24xx())
ena = mask;
else if (cpu_is_omap34xx())
ena = 0;
else
BUG();
/* Wait for lock */
while (((__raw_readl(reg) & mask) != ena) &&
(i++ < MAX_MODULE_ENABLE_WAIT))
udelay(1);
if (i < MAX_MODULE_ENABLE_WAIT)
pr_debug("cm: Module associated with clock %s ready after %d "
"loops\n", name, i);
else
pr_err("cm: Module associated with clock %s didn't enable in "
"%d tries\n", name, MAX_MODULE_ENABLE_WAIT);
return (i < MAX_MODULE_ENABLE_WAIT) ? 1 : 0;
};
void __init omap2_set_globals_prcm(struct omap_globals *omap2_globals)
{
prm_base = omap2_globals->prm;

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@ -20,6 +20,8 @@ struct clockdomain;
struct clkops {
int (*enable)(struct clk *);
void (*disable)(struct clk *);
void (*find_idlest)(struct clk *, void __iomem **, u8 *);
void (*find_companion)(struct clk *, void __iomem **, u8 *);
};
#if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3) || \

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@ -25,6 +25,7 @@
u32 omap_prcm_get_reset_sources(void);
void omap_prcm_arch_reset(char mode);
int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, const char *name);
#endif