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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/clk/at91_pmc.h>
#include <linux/of.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include "pmc.h"
#define SYSTEM_MAX_ID 31
#define SYSTEM_MAX_NAME_SZ 32
#define to_clk_system(hw) container_of(hw, struct clk_system, hw)
struct clk_system {
struct clk_hw hw;
struct regmap *regmap;
struct at91_clk_pms pms;
u8 id;
};
static inline int is_pck(int id)
{
return (id >= 8) && (id <= 15);
}
static inline bool clk_system_ready(struct regmap *regmap, int id)
{
unsigned int status;
regmap_read(regmap, AT91_PMC_SR, &status);
return !!(status & (1 << id));
}
static int clk_system_prepare(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
regmap_write(sys->regmap, AT91_PMC_SCER, 1 << sys->id);
if (!is_pck(sys->id))
return 0;
while (!clk_system_ready(sys->regmap, sys->id))
cpu_relax();
return 0;
}
static void clk_system_unprepare(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
regmap_write(sys->regmap, AT91_PMC_SCDR, 1 << sys->id);
}
static int clk_system_is_prepared(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
unsigned int status;
regmap_read(sys->regmap, AT91_PMC_SCSR, &status);
if (!(status & (1 << sys->id)))
return 0;
if (!is_pck(sys->id))
return 1;
regmap_read(sys->regmap, AT91_PMC_SR, &status);
return !!(status & (1 << sys->id));
}
static int clk_system_save_context(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
sys->pms.status = clk_system_is_prepared(hw);
return 0;
}
static void clk_system_restore_context(struct clk_hw *hw)
{
struct clk_system *sys = to_clk_system(hw);
if (sys->pms.status)
clk_system_prepare(&sys->hw);
}
static const struct clk_ops system_ops = {
.prepare = clk_system_prepare,
.unprepare = clk_system_unprepare,
.is_prepared = clk_system_is_prepared,
.save_context = clk_system_save_context,
.restore_context = clk_system_restore_context,
};
struct clk_hw * __init
at91_clk_register_system(struct regmap *regmap, const char *name,
const char *parent_name, u8 id)
{
struct clk_system *sys;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (!parent_name || id > SYSTEM_MAX_ID)
return ERR_PTR(-EINVAL);
sys = kzalloc(sizeof(*sys), GFP_KERNEL);
if (!sys)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &system_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
init.flags = CLK_SET_RATE_PARENT;
sys->id = id;
sys->hw.init = &init;
sys->regmap = regmap;
hw = &sys->hw;
ret = clk_hw_register(NULL, &sys->hw);
if (ret) {
kfree(sys);
hw = ERR_PTR(ret);
}
return hw;
}
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