/*
* 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;
}
/* 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;
printk(KERN_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
};
