blob: 0c38ca96c840ad596017b60f3d0801ae973a74c1 [file] [log] [blame]
/*
* 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/export.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/clk-private.h>
#include <asm/cpu.h>
#include <trace/events/power.h>
#include "soc.h"
#include "clockdomain.h"
#include "clock.h"
#include "cm.h"
#include "cm2xxx.h"
#include "cm3xxx.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
#include "common.h"
/*
* MAX_MODULE_ENABLE_WAIT: maximum of number of microseconds to wait
* for a module to indicate that it is no longer in idle
*/
#define MAX_MODULE_ENABLE_WAIT 100000
u16 cpu_mask;
/*
* clkdm_control: if true, then when a clock is enabled in the
* hardware, its clockdomain will first be enabled; and when a clock
* is disabled in the hardware, its clockdomain will be disabled
* afterwards.
*/
static bool clkdm_control = true;
static LIST_HEAD(clk_hw_omap_clocks);
/*
* Used for clocks that have the same value as the parent clock,
* divided by some factor
*/
unsigned long omap_fixed_divisor_recalc(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_hw_omap *oclk;
if (!hw) {
pr_warn("%s: hw is NULL\n", __func__);
return -EINVAL;
}
oclk = to_clk_hw_omap(hw);
WARN_ON(!oclk->fixed_div);
return parent_rate / oclk->fixed_div;
}
/*
* OMAP2+ specific clock functions
*/
/* Private functions */
/**
* _wait_idlest_generic - wait for a module to leave the idle state
* @reg: virtual address of module IDLEST register
* @mask: value to mask against to determine if the module is active
* @idlest: idle state indicator (0 or 1) for the clock
* @name: name of the clock (for printk)
*
* Wait for a module to leave idle, where its idle-status register is
* not inside the CM module. Returns 1 if the module left idle
* promptly, or 0 if the module did not leave idle before the timeout
* elapsed. XXX Deprecated - should be moved into drivers for the
* individual IP block that the IDLEST register exists in.
*/
static int _wait_idlest_generic(void __iomem *reg, u32 mask, u8 idlest,
const char *name)
{
int i = 0, ena = 0;
ena = (idlest) ? 0 : mask;
omap_test_timeout(((__raw_readl(reg) & mask) == ena),
MAX_MODULE_ENABLE_WAIT, i);
if (i < MAX_MODULE_ENABLE_WAIT)
pr_debug("omap clock: module associated with clock %s ready after %d loops\n",
name, i);
else
pr_err("omap clock: 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;
};
/**
* _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_hw_omap *clk)
{
void __iomem *companion_reg, *idlest_reg;
u8 other_bit, idlest_bit, idlest_val, idlest_reg_id;
s16 prcm_mod;
int r;
/* 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);
r = cm_split_idlest_reg(idlest_reg, &prcm_mod, &idlest_reg_id);
if (r) {
/* IDLEST register not in the CM module */
_wait_idlest_generic(idlest_reg, (1 << idlest_bit), idlest_val,
__clk_get_name(clk->hw.clk));
} else {
cm_wait_module_ready(prcm_mod, idlest_reg_id, idlest_bit);
};
}
/* 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_hw *hw)
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
struct clockdomain *clkdm;
const char *clk_name;
if (!clk->clkdm_name)
return;
clk_name = __clk_get_name(hw->clk);
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_disable_clkdm_control - disable clkdm control on clk enable/disable
*
* Prevent the OMAP clock code from calling into the clockdomain code
* when a hardware clock in that clockdomain is enabled or disabled.
* Intended to be called at init time from omap*_clk_init(). No
* return value.
*/
void __init omap2_clk_disable_clkdm_control(void)
{
clkdm_control = false;
}
/**
* 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_hw_omap *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_hw_omap *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();
}
/**
* omap2_dflt_clk_enable - enable a clock in the hardware
* @hw: struct clk_hw * of the clock to enable
*
* Enable the clock @hw in the hardware. We first call into the OMAP
* clockdomain code to "enable" the corresponding clockdomain if this
* is the first enabled user of the clockdomain. Then program the
* hardware to enable the clock. Then wait for the IP block that uses
* this clock to leave idle (if applicable). Returns the error value
* from clkdm_clk_enable() if it terminated with an error, or -EINVAL
* if @hw has a null clock enable_reg, or zero upon success.
*/
int omap2_dflt_clk_enable(struct clk_hw *hw)
{
struct clk_hw_omap *clk;
u32 v;
int ret = 0;
clk = to_clk_hw_omap(hw);
if (clkdm_control && clk->clkdm) {
ret = clkdm_clk_enable(clk->clkdm, hw->clk);
if (ret) {
WARN(1, "%s: could not enable %s's clockdomain %s: %d\n",
__func__, __clk_get_name(hw->clk),
clk->clkdm->name, ret);
return ret;
}
}
if (unlikely(clk->enable_reg == NULL)) {
pr_err("%s: %s missing enable_reg\n", __func__,
__clk_get_name(hw->clk));
ret = -EINVAL;
goto err;
}
/* FIXME should not have INVERT_ENABLE bit here */
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 && clk->ops->find_idlest)
_omap2_module_wait_ready(clk);
return 0;
err:
if (clkdm_control && clk->clkdm)
clkdm_clk_disable(clk->clkdm, hw->clk);
return ret;
}
/**
* omap2_dflt_clk_disable - disable a clock in the hardware
* @hw: struct clk_hw * of the clock to disable
*
* Disable the clock @hw in the hardware, and call into the OMAP
* clockdomain code to "disable" the corresponding clockdomain if all
* clocks/hwmods in that clockdomain are now disabled. No return
* value.
*/
void omap2_dflt_clk_disable(struct clk_hw *hw)
{
struct clk_hw_omap *clk;
u32 v;
clk = to_clk_hw_omap(hw);
if (!clk->enable_reg) {
/*
* 'independent' here refers to a clock which is not
* controlled by its parent.
*/
pr_err("%s: independent clock %s has no enable_reg\n",
__func__, __clk_get_name(hw->clk));
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 */
if (clkdm_control && clk->clkdm)
clkdm_clk_disable(clk->clkdm, hw->clk);
}
/**
* omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
* @hw: struct clk_hw * of the clock being enabled
*
* Increment the usecount of the clockdomain of the clock pointed to
* by @hw; if the usecount is 1, the clockdomain will be "enabled."
* Only needed for clocks that don't use omap2_dflt_clk_enable() as
* their enable function pointer. Passes along the return value of
* clkdm_clk_enable(), -EINVAL if @hw is not associated with a
* clockdomain, or 0 if clock framework-based clockdomain control is
* not implemented.
*/
int omap2_clkops_enable_clkdm(struct clk_hw *hw)
{
struct clk_hw_omap *clk;
int ret = 0;
clk = to_clk_hw_omap(hw);
if (unlikely(!clk->clkdm)) {
pr_err("%s: %s: no clkdm set ?!\n", __func__,
__clk_get_name(hw->clk));
return -EINVAL;
}
if (unlikely(clk->enable_reg))
pr_err("%s: %s: should use dflt_clk_enable ?!\n", __func__,
__clk_get_name(hw->clk));
if (!clkdm_control) {
pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
__func__, __clk_get_name(hw->clk));
return 0;
}
ret = clkdm_clk_enable(clk->clkdm, hw->clk);
WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
__func__, __clk_get_name(hw->clk), clk->clkdm->name, ret);
return ret;
}
/**
* omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
* @hw: struct clk_hw * of the clock being disabled
*
* Decrement the usecount of the clockdomain of the clock pointed to
* by @hw; if the usecount is 0, the clockdomain will be "disabled."
* Only needed for clocks that don't use omap2_dflt_clk_disable() as their
* disable function pointer. No return value.
*/
void omap2_clkops_disable_clkdm(struct clk_hw *hw)
{
struct clk_hw_omap *clk;
clk = to_clk_hw_omap(hw);
if (unlikely(!clk->clkdm)) {
pr_err("%s: %s: no clkdm set ?!\n", __func__,
__clk_get_name(hw->clk));
return;
}
if (unlikely(clk->enable_reg))
pr_err("%s: %s: should use dflt_clk_disable ?!\n", __func__,
__clk_get_name(hw->clk));
if (!clkdm_control) {
pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
__func__, __clk_get_name(hw->clk));
return;
}
clkdm_clk_disable(clk->clkdm, hw->clk);
}
/**
* omap2_dflt_clk_is_enabled - is clock enabled in the hardware?
* @hw: struct clk_hw * to check
*
* Return 1 if the clock represented by @hw is enabled in the
* hardware, or 0 otherwise. Intended for use in the struct
* clk_ops.is_enabled function pointer.
*/
int omap2_dflt_clk_is_enabled(struct clk_hw *hw)
{
struct clk_hw_omap *clk = to_clk_hw_omap(hw);
u32 v;
v = __raw_readl(clk->enable_reg);
if (clk->flags & INVERT_ENABLE)
v ^= BIT(clk->enable_bit);
v &= BIT(clk->enable_bit);
return v ? 1 : 0;
}
static int __initdata mpurate;
/*
* By default we use the rate set by the bootloader.
* You can override this with mpurate= cmdline option.
*/
static int __init omap_clk_setup(char *str)
{
get_option(&str, &mpurate);
if (!mpurate)
return 1;
if (mpurate < 1000)
mpurate *= 1000000;
return 1;
}
__setup("mpurate=", omap_clk_setup);
/**
* omap2_init_clk_hw_omap_clocks - initialize an OMAP clock
* @clk: struct clk * to initialize
*
* Add an OMAP clock @clk to the internal list of OMAP clocks. Used
* temporarily for autoidle handling, until this support can be
* integrated into the common clock framework code in some way. No
* return value.
*/
void omap2_init_clk_hw_omap_clocks(struct clk *clk)
{
struct clk_hw_omap *c;
if (__clk_get_flags(clk) & CLK_IS_BASIC)
return;
c = to_clk_hw_omap(__clk_get_hw(clk));
list_add(&c->node, &clk_hw_omap_clocks);
}
/**
* omap2_clk_enable_autoidle_all - enable autoidle on all OMAP clocks that
* support it
*
* Enable clock autoidle on all OMAP clocks that have allow_idle
* function pointers associated with them. This function is intended
* to be temporary until support for this is added to the common clock
* code. Returns 0.
*/
int omap2_clk_enable_autoidle_all(void)
{
struct clk_hw_omap *c;
list_for_each_entry(c, &clk_hw_omap_clocks, node)
if (c->ops && c->ops->allow_idle)
c->ops->allow_idle(c);
return 0;
}
/**
* omap2_clk_disable_autoidle_all - disable autoidle on all OMAP clocks that
* support it
*
* Disable clock autoidle on all OMAP clocks that have allow_idle
* function pointers associated with them. This function is intended
* to be temporary until support for this is added to the common clock
* code. Returns 0.
*/
int omap2_clk_disable_autoidle_all(void)
{
struct clk_hw_omap *c;
list_for_each_entry(c, &clk_hw_omap_clocks, node)
if (c->ops && c->ops->deny_idle)
c->ops->deny_idle(c);
return 0;
}
/**
* omap2_clk_enable_init_clocks - prepare & enable a list of clocks
* @clk_names: ptr to an array of strings of clock names to enable
* @num_clocks: number of clock names in @clk_names
*
* Prepare and enable a list of clocks, named by @clk_names. No
* return value. XXX Deprecated; only needed until these clocks are
* properly claimed and enabled by the drivers or core code that uses
* them. XXX What code disables & calls clk_put on these clocks?
*/
void omap2_clk_enable_init_clocks(const char **clk_names, u8 num_clocks)
{
struct clk *init_clk;
int i;
for (i = 0; i < num_clocks; i++) {
init_clk = clk_get(NULL, clk_names[i]);
clk_prepare_enable(init_clk);
}
}
const struct clk_hw_omap_ops clkhwops_wait = {
.find_idlest = omap2_clk_dflt_find_idlest,
.find_companion = omap2_clk_dflt_find_companion,
};
/**
* omap_clocks_register - register an array of omap_clk
* @ocs: pointer to an array of omap_clk to register
*/
void __init omap_clocks_register(struct omap_clk oclks[], int cnt)
{
struct omap_clk *c;
for (c = oclks; c < oclks + cnt; c++) {
clkdev_add(&c->lk);
if (!__clk_init(NULL, c->lk.clk))
omap2_init_clk_hw_omap_clocks(c->lk.clk);
}
}
/**
* 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 (r < 0) {
WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
mpurate_ck_name, mpurate, r);
clk_put(mpurate_ck);
return -EINVAL;
}
calibrate_delay();
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));
}