// SPDX-License-Identifier: GPL-2.0-only
/*
* TI clock autoidle support
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* Tero Kristo <[email protected]>
*/
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clk/ti.h>
#include "clock.h"
struct clk_ti_autoidle {
struct clk_omap_reg reg;
u8 shift;
u8 flags;
const char *name;
struct list_head node;
};
#define AUTOIDLE_LOW 0x1
static LIST_HEAD(autoidle_clks);
/*
* we have some non-atomic read/write
* operations behind it, so lets
* take one lock for handling autoidle
* of all clocks
*/
static DEFINE_SPINLOCK(autoidle_spinlock);
static int _omap2_clk_deny_idle(struct clk_hw_omap *clk)
{
if (clk->ops && clk->ops->deny_idle) {
unsigned long irqflags;
spin_lock_irqsave(&autoidle_spinlock, irqflags);
clk->autoidle_count++;
if (clk->autoidle_count == 1)
clk->ops->deny_idle(clk);
spin_unlock_irqrestore(&autoidle_spinlock, irqflags);
}
return 0;
}
static int _omap2_clk_allow_idle(struct clk_hw_omap *clk)
{
if (clk->ops && clk->ops->allow_idle) {
unsigned long irqflags;
spin_lock_irqsave(&autoidle_spinlock, irqflags);
clk->autoidle_count--;
if (clk->autoidle_count == 0)
clk->ops->allow_idle(clk);
spin_unlock_irqrestore(&autoidle_spinlock, irqflags);
}
return 0;
}
/**
* omap2_clk_deny_idle - disable autoidle on an OMAP clock
* @clk: struct clk * to disable autoidle for
*
* Disable autoidle on an OMAP clock.
*/
int omap2_clk_deny_idle(struct clk *clk)
{
struct clk_hw *hw;
if (!clk)
return -EINVAL;
hw = __clk_get_hw(clk);
if (omap2_clk_is_hw_omap(hw)) {
struct clk_hw_omap *c = to_clk_hw_omap(hw);
return _omap2_clk_deny_idle(c);
}
return -EINVAL;
}
/**
* omap2_clk_allow_idle - enable autoidle on an OMAP clock
* @clk: struct clk * to enable autoidle for
*
* Enable autoidle on an OMAP clock.
*/
int omap2_clk_allow_idle(struct clk *clk)
{
struct clk_hw *hw;
if (!clk)
return -EINVAL;
hw = __clk_get_hw(clk);
if (omap2_clk_is_hw_omap(hw)) {
struct clk_hw_omap *c = to_clk_hw_omap(hw);
return _omap2_clk_allow_idle(c);
}
return -EINVAL;
}
static void _allow_autoidle(struct clk_ti_autoidle *clk)
{
u32 val;
val = ti_clk_ll_ops->clk_readl(&clk->reg);
if (clk->flags & AUTOIDLE_LOW)
val &= ~(1 << clk->shift);
else
val |= (1 << clk->shift);
ti_clk_ll_ops->clk_writel(val, &clk->reg);
}
static void _deny_autoidle(struct clk_ti_autoidle *clk)
{
u32 val;
val = ti_clk_ll_ops->clk_readl(&clk->reg);
if (clk->flags & AUTOIDLE_LOW)
val |= (1 << clk->shift);
else
val &= ~(1 << clk->shift);
ti_clk_ll_ops->clk_writel(val, &clk->reg);
}
/**
* _clk_generic_allow_autoidle_all - enable autoidle for all clocks
*
* Enables hardware autoidle for all registered DT clocks, which have
* the feature.
*/
static void _clk_generic_allow_autoidle_all(void)
{
struct clk_ti_autoidle *c;
list_for_each_entry(c, &autoidle_clks, node)
_allow_autoidle(c);
}
/**
* _clk_generic_deny_autoidle_all - disable autoidle for all clocks
*
* Disables hardware autoidle for all registered DT clocks, which have
* the feature.
*/
static void _clk_generic_deny_autoidle_all(void)
{
struct clk_ti_autoidle *c;
list_for_each_entry(c, &autoidle_clks, node)
_deny_autoidle(c);
}
/**
* of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock
* @node: pointer to the clock device node
*
* Checks if a clock has hardware autoidle support or not (check
* for presence of 'ti,autoidle-shift' property in the device tree
* node) and sets up the hardware autoidle feature for the clock
* if available. If autoidle is available, the clock is also added
* to the autoidle list for later processing. Returns 0 on success,
* negative error value on failure.
*/
int __init of_ti_clk_autoidle_setup(struct device_node *node)
{
u32 shift;
struct clk_ti_autoidle *clk;
int ret;
/* Check if this clock has autoidle support or not */
if (of_property_read_u32(node, "ti,autoidle-shift", &shift))
return 0;
clk = kzalloc(sizeof(*clk), GFP_KERNEL);
if (!clk)
return -ENOMEM;
clk->shift = shift;
clk->name = ti_dt_clk_name(node);
ret = ti_clk_get_reg_addr(node, 0, &clk->reg);
if (ret) {
kfree(clk);
return ret;
}
if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
clk->flags |= AUTOIDLE_LOW;
list_add(&clk->node, &autoidle_clks);
return 0;
}
/**
* 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)
{
int ret;
ret = omap2_clk_for_each(_omap2_clk_allow_idle);
if (ret)
return ret;
_clk_generic_allow_autoidle_all();
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)
{
int ret;
ret = omap2_clk_for_each(_omap2_clk_deny_idle);
if (ret)
return ret;
_clk_generic_deny_autoidle_all();
return 0;
}
Codebase Browser
linux