mirror of https://gitee.com/openkylin/linux.git
134 lines
3.1 KiB
C
134 lines
3.1 KiB
C
/*
|
|
* 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;
|
|
}
|