linux/drivers/clk/at91/clk-slow.c

112 lines
2.5 KiB
C

/*
* drivers/clk/at91/clk-slow.c
*
* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#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"
struct clk_sam9260_slow {
struct clk_hw hw;
struct regmap *regmap;
};
#define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
{
struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
unsigned int status;
regmap_read(slowck->regmap, AT91_PMC_SR, &status);
return status & AT91_PMC_OSCSEL ? 1 : 0;
}
static const struct clk_ops sam9260_slow_ops = {
.get_parent = clk_sam9260_slow_get_parent,
};
static struct clk_hw * __init
at91_clk_register_sam9260_slow(struct regmap *regmap,
const char *name,
const char **parent_names,
int num_parents)
{
struct clk_sam9260_slow *slowck;
struct clk_hw *hw;
struct clk_init_data init;
int ret;
if (!name)
return ERR_PTR(-EINVAL);
if (!parent_names || !num_parents)
return ERR_PTR(-EINVAL);
slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
if (!slowck)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &sam9260_slow_ops;
init.parent_names = parent_names;
init.num_parents = num_parents;
init.flags = 0;
slowck->hw.init = &init;
slowck->regmap = regmap;
hw = &slowck->hw;
ret = clk_hw_register(NULL, &slowck->hw);
if (ret) {
kfree(slowck);
hw = ERR_PTR(ret);
}
return hw;
}
static void __init of_at91sam9260_clk_slow_setup(struct device_node *np)
{
struct clk_hw *hw;
const char *parent_names[2];
unsigned int num_parents;
const char *name = np->name;
struct regmap *regmap;
num_parents = of_clk_get_parent_count(np);
if (num_parents != 2)
return;
of_clk_parent_fill(np, parent_names, num_parents);
regmap = syscon_node_to_regmap(of_get_parent(np));
if (IS_ERR(regmap))
return;
of_property_read_string(np, "clock-output-names", &name);
hw = at91_clk_register_sam9260_slow(regmap, name, parent_names,
num_parents);
if (IS_ERR(hw))
return;
of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
}
CLK_OF_DECLARE(at91sam9260_clk_slow, "atmel,at91sam9260-clk-slow",
of_at91sam9260_clk_slow_setup);