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/*
* TI clock autoidle support
*
* Copyright (C) 2013 Texas Instruments, Inc.
*
* Tero Kristo <t-kristo@ti.com>
*
* 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.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#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>
struct clk_ti_autoidle {
void __iomem *reg;
u8 shift;
u8 flags;
const char *name;
struct list_head node;
};
#define AUTOIDLE_LOW 0x1
static LIST_HEAD(autoidle_clks);
static void ti_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 ti_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);
}
/**
* of_ti_clk_allow_autoidle_all - enable autoidle for all clocks
*
* Enables hardware autoidle for all registered DT clocks, which have
* the feature.
*/
void of_ti_clk_allow_autoidle_all(void)
{
struct clk_ti_autoidle *c;
list_for_each_entry(c, &autoidle_clks, node)
ti_allow_autoidle(c);
}
/**
* of_ti_clk_deny_autoidle_all - disable autoidle for all clocks
*
* Disables hardware autoidle for all registered DT clocks, which have
* the feature.
*/
void of_ti_clk_deny_autoidle_all(void)
{
struct clk_ti_autoidle *c;
list_for_each_entry(c, &autoidle_clks, node)
ti_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;
/* 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 = node->name;
clk->reg = ti_clk_get_reg_addr(node, 0);
if (IS_ERR(clk->reg)) {
kfree(clk);
return -EINVAL;
}
if (of_property_read_bool(node, "ti,invert-autoidle-bit"))
clk->flags |= AUTOIDLE_LOW;
list_add(&clk->node, &autoidle_clks);
return 0;
}
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