linux/arch/arm/mach-omap2/clock.c
Paul Walmsley 6041c27f51 OMAP2+: clock: reduce the amount of standard debugging while disabling unused clocks
Reduce the amount of debugging generated by default when unused clocks
are being disabled by the clock code.  The previous code would only
generate debug-level messages, but some people who wished to run
production kernels with debug-level messages enabled reported that the
large number of clock disable messages were slowing boot.  Now to
enable clock-by-clock disable messages, DEBUG needs to be defined in
mach-omap2/clock.c.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tuukka Tikkanen <tuukka.tikkanen@nokia.com>
Cc: Tim Bird <tim.bird@am.sony.com>
2010-10-08 11:40:20 -06:00

508 lines
14 KiB
C

/*
* linux/arch/arm/mach-omap2/clock.c
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
* Copyright (C) 2004-2010 Nokia Corporation
*
* Contacts:
* Richard Woodruff <r-woodruff2@ti.com>
* Paul Walmsley
*
* 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/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <plat/clock.h>
#include <plat/clockdomain.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
#include "clock.h"
#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
u8 cpu_mask;
/*
* OMAP2+ specific clock functions
*/
/* Private functions */
/**
* _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, idlest_val;
/* 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, &idlest_val);
omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), idlest_val,
clk->name);
}
/* Public functions */
/**
* omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
* @clk: OMAP clock struct ptr to use
*
* Convert a clockdomain name stored in a struct clk 'clk' into a
* clockdomain pointer, and save it into the struct clk. Intended to be
* called during clk_register(). No return value.
*/
void omap2_init_clk_clkdm(struct clk *clk)
{
struct clockdomain *clkdm;
if (!clk->clkdm_name)
return;
clkdm = clkdm_lookup(clk->clkdm_name);
if (clkdm) {
pr_debug("clock: associated clk %s to clkdm %s\n",
clk->name, clk->clkdm_name);
clk->clkdm = clkdm;
} else {
pr_debug("clock: could not associate clk %s to "
"clkdm %s\n", clk->name, clk->clkdm_name);
}
}
/**
* 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
*
* 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.
*/
void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
u8 *other_bit)
{
u32 r;
/*
* Convert CM_ICLKEN* <-> CM_FCLKEN*. This conversion assumes
* it's just a matter of XORing the bits.
*/
r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
*other_reg = (__force void __iomem *)r;
*other_bit = clk->enable_bit;
}
/**
* 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
* @idlest_val: u8 * to return the idle status indicator
*
* 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, u8 *idlest_val)
{
u32 r;
r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
*idlest_reg = (__force void __iomem *)r;
*idlest_bit = clk->enable_bit;
/*
* 24xx uses 0 to indicate not ready, and 1 to indicate ready.
* 34xx reverses this, just to keep us on our toes
* AM35xx uses both, depending on the module.
*/
if (cpu_is_omap24xx())
*idlest_val = OMAP24XX_CM_IDLEST_VAL;
else if (cpu_is_omap34xx())
*idlest_val = OMAP34XX_CM_IDLEST_VAL;
else
BUG();
}
int omap2_dflt_clk_enable(struct clk *clk)
{
u32 v;
if (unlikely(clk->enable_reg == NULL)) {
pr_err("clock.c: Enable for %s without enable code\n",
clk->name);
return 0; /* REVISIT: -EINVAL */
}
v = __raw_readl(clk->enable_reg);
if (clk->flags & INVERT_ENABLE)
v &= ~(1 << clk->enable_bit);
else
v |= (1 << clk->enable_bit);
__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;
}
void omap2_dflt_clk_disable(struct clk *clk)
{
u32 v;
if (!clk->enable_reg) {
/*
* 'Independent' here refers to a clock which is not
* controlled by its parent.
*/
printk(KERN_ERR "clock: clk_disable called on independent "
"clock %s which has no enable_reg\n", clk->name);
return;
}
v = __raw_readl(clk->enable_reg);
if (clk->flags & INVERT_ENABLE)
v |= (1 << clk->enable_bit);
else
v &= ~(1 << clk->enable_bit);
__raw_writel(v, clk->enable_reg);
/* No OCP barrier needed here since it is a disable operation */
}
const struct clkops clkops_omap2_dflt_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 = {
.enable = omap2_dflt_clk_enable,
.disable = omap2_dflt_clk_disable,
};
/**
* omap2_clk_disable - disable a clock, if the system is not using it
* @clk: struct clk * to disable
*
* Decrements the usecount on struct clk @clk. If there are no users
* left, call the clkops-specific clock disable function to disable it
* in hardware. If the clock is part of a clockdomain (which they all
* should be), request that the clockdomain be disabled. (It too has
* a usecount, and so will not be disabled in the hardware until it no
* longer has any users.) If the clock has a parent clock (most of
* them do), then call ourselves, recursing on the parent clock. This
* can cause an entire branch of the clock tree to be powered off by
* simply disabling one clock. Intended to be called with the clockfw_lock
* spinlock held. No return value.
*/
void omap2_clk_disable(struct clk *clk)
{
if (clk->usecount == 0) {
WARN(1, "clock: %s: omap2_clk_disable() called, but usecount "
"already 0?", clk->name);
return;
}
pr_debug("clock: %s: decrementing usecount\n", clk->name);
clk->usecount--;
if (clk->usecount > 0)
return;
pr_debug("clock: %s: disabling in hardware\n", clk->name);
clk->ops->disable(clk);
if (clk->clkdm)
omap2_clkdm_clk_disable(clk->clkdm, clk);
if (clk->parent)
omap2_clk_disable(clk->parent);
}
/**
* omap2_clk_enable - request that the system enable a clock
* @clk: struct clk * to enable
*
* Increments the usecount on struct clk @clk. If there were no users
* previously, then recurse up the clock tree, enabling all of the
* clock's parents and all of the parent clockdomains, and finally,
* enabling @clk's clockdomain, and @clk itself. Intended to be
* called with the clockfw_lock spinlock held. Returns 0 upon success
* or a negative error code upon failure.
*/
int omap2_clk_enable(struct clk *clk)
{
int ret;
pr_debug("clock: %s: incrementing usecount\n", clk->name);
clk->usecount++;
if (clk->usecount > 1)
return 0;
pr_debug("clock: %s: enabling in hardware\n", clk->name);
if (clk->parent) {
ret = omap2_clk_enable(clk->parent);
if (ret) {
WARN(1, "clock: %s: could not enable parent %s: %d\n",
clk->name, clk->parent->name, ret);
goto oce_err1;
}
}
if (clk->clkdm) {
ret = omap2_clkdm_clk_enable(clk->clkdm, clk);
if (ret) {
WARN(1, "clock: %s: could not enable clockdomain %s: "
"%d\n", clk->name, clk->clkdm->name, ret);
goto oce_err2;
}
}
ret = clk->ops->enable(clk);
if (ret) {
WARN(1, "clock: %s: could not enable: %d\n", clk->name, ret);
goto oce_err3;
}
return 0;
oce_err3:
if (clk->clkdm)
omap2_clkdm_clk_disable(clk->clkdm, clk);
oce_err2:
if (clk->parent)
omap2_clk_disable(clk->parent);
oce_err1:
clk->usecount--;
return ret;
}
/* Given a clock and a rate apply a clock specific rounding function */
long omap2_clk_round_rate(struct clk *clk, unsigned long rate)
{
if (clk->round_rate)
return clk->round_rate(clk, rate);
return clk->rate;
}
/* Set the clock rate for a clock source */
int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
{
int ret = -EINVAL;
pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);
/* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
if (clk->set_rate)
ret = clk->set_rate(clk, rate);
return ret;
}
int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
{
if (!clk->clksel)
return -EINVAL;
if (clk->parent == new_parent)
return 0;
return omap2_clksel_set_parent(clk, new_parent);
}
/* OMAP3/4 non-CORE DPLL clkops */
#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
const struct clkops clkops_omap3_noncore_dpll_ops = {
.enable = omap3_noncore_dpll_enable,
.disable = omap3_noncore_dpll_disable,
};
#endif
/*
* OMAP2+ clock reset and init functions
*/
#ifdef CONFIG_OMAP_RESET_CLOCKS
void omap2_clk_disable_unused(struct clk *clk)
{
u32 regval32, v;
v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0;
regval32 = __raw_readl(clk->enable_reg);
if ((regval32 & (1 << clk->enable_bit)) == v)
return;
pr_debug("Disabling unused clock \"%s\"\n", clk->name);
if (cpu_is_omap34xx()) {
omap2_clk_enable(clk);
omap2_clk_disable(clk);
} else {
clk->ops->disable(clk);
}
if (clk->clkdm != NULL)
pwrdm_clkdm_state_switch(clk->clkdm);
}
#endif
/**
* omap2_clk_switch_mpurate_at_boot - switch ARM MPU rate by boot-time argument
* @mpurate_ck_name: clk name of the clock to change rate
*
* Change the ARM MPU clock rate to the rate specified on the command
* line, if one was specified. @mpurate_ck_name should be
* "virt_prcm_set" on OMAP2xxx and "dpll1_ck" on OMAP34xx/OMAP36xx.
* XXX Does not handle voltage scaling - on OMAP2xxx this is currently
* handled by the virt_prcm_set clock, but this should be handled by
* the OPP layer. XXX This is intended to be handled by the OPP layer
* code in the near future and should be removed from the clock code.
* Returns -EINVAL if 'mpurate' is zero or if clk_set_rate() rejects
* the rate, -ENOENT if the struct clk referred to by @mpurate_ck_name
* cannot be found, or 0 upon success.
*/
int __init omap2_clk_switch_mpurate_at_boot(const char *mpurate_ck_name)
{
struct clk *mpurate_ck;
int r;
if (!mpurate)
return -EINVAL;
mpurate_ck = clk_get(NULL, mpurate_ck_name);
if (WARN(IS_ERR(mpurate_ck), "Failed to get %s.\n", mpurate_ck_name))
return -ENOENT;
r = clk_set_rate(mpurate_ck, mpurate);
if (IS_ERR_VALUE(r)) {
WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
mpurate_ck->name, mpurate, r);
return -EINVAL;
}
calibrate_delay();
recalculate_root_clocks();
clk_put(mpurate_ck);
return 0;
}
/**
* omap2_clk_print_new_rates - print summary of current clock tree rates
* @hfclkin_ck_name: clk name for the off-chip HF oscillator
* @core_ck_name: clk name for the on-chip CORE_CLK
* @mpu_ck_name: clk name for the ARM MPU clock
*
* Prints a short message to the console with the HFCLKIN oscillator
* rate, the rate of the CORE clock, and the rate of the ARM MPU clock.
* Called by the boot-time MPU rate switching code. XXX This is intended
* to be handled by the OPP layer code in the near future and should be
* removed from the clock code. No return value.
*/
void __init omap2_clk_print_new_rates(const char *hfclkin_ck_name,
const char *core_ck_name,
const char *mpu_ck_name)
{
struct clk *hfclkin_ck, *core_ck, *mpu_ck;
unsigned long hfclkin_rate;
mpu_ck = clk_get(NULL, mpu_ck_name);
if (WARN(IS_ERR(mpu_ck), "clock: failed to get %s.\n", mpu_ck_name))
return;
core_ck = clk_get(NULL, core_ck_name);
if (WARN(IS_ERR(core_ck), "clock: failed to get %s.\n", core_ck_name))
return;
hfclkin_ck = clk_get(NULL, hfclkin_ck_name);
if (WARN(IS_ERR(hfclkin_ck), "Failed to get %s.\n", hfclkin_ck_name))
return;
hfclkin_rate = clk_get_rate(hfclkin_ck);
pr_info("Switched to new clocking rate (Crystal/Core/MPU): "
"%ld.%01ld/%ld/%ld MHz\n",
(hfclkin_rate / 1000000),
((hfclkin_rate / 100000) % 10),
(clk_get_rate(core_ck) / 1000000),
(clk_get_rate(mpu_ck) / 1000000));
}
/* Common data */
struct clk_functions omap2_clk_functions = {
.clk_enable = omap2_clk_enable,
.clk_disable = omap2_clk_disable,
.clk_round_rate = omap2_clk_round_rate,
.clk_set_rate = omap2_clk_set_rate,
.clk_set_parent = omap2_clk_set_parent,
.clk_disable_unused = omap2_clk_disable_unused,
#ifdef CONFIG_CPU_FREQ
/* These will be removed when the OPP code is integrated */
.clk_init_cpufreq_table = omap2_clk_init_cpufreq_table,
.clk_exit_cpufreq_table = omap2_clk_exit_cpufreq_table,
#endif
};