113 строки
2.5 KiB
C
113 строки
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* clk-h32mx.c
|
|
*
|
|
* Copyright (C) 2014 Atmel
|
|
*
|
|
* Alexandre Belloni <alexandre.belloni@free-electrons.com>
|
|
*/
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/clkdev.h>
|
|
#include <linux/clk/at91_pmc.h>
|
|
#include <linux/of.h>
|
|
#include <linux/regmap.h>
|
|
#include <linux/mfd/syscon.h>
|
|
|
|
#include "pmc.h"
|
|
|
|
#define H32MX_MAX_FREQ 90000000
|
|
|
|
struct clk_sama5d4_h32mx {
|
|
struct clk_hw hw;
|
|
struct regmap *regmap;
|
|
};
|
|
|
|
#define to_clk_sama5d4_h32mx(hw) container_of(hw, struct clk_sama5d4_h32mx, hw)
|
|
|
|
static unsigned long clk_sama5d4_h32mx_recalc_rate(struct clk_hw *hw,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw);
|
|
unsigned int mckr;
|
|
|
|
regmap_read(h32mxclk->regmap, AT91_PMC_MCKR, &mckr);
|
|
if (mckr & AT91_PMC_H32MXDIV)
|
|
return parent_rate / 2;
|
|
|
|
if (parent_rate > H32MX_MAX_FREQ)
|
|
pr_warn("H32MX clock is too fast\n");
|
|
return parent_rate;
|
|
}
|
|
|
|
static long clk_sama5d4_h32mx_round_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long *parent_rate)
|
|
{
|
|
unsigned long div;
|
|
|
|
if (rate > *parent_rate)
|
|
return *parent_rate;
|
|
div = *parent_rate / 2;
|
|
if (rate < div)
|
|
return div;
|
|
|
|
if (rate - div < *parent_rate - rate)
|
|
return div;
|
|
|
|
return *parent_rate;
|
|
}
|
|
|
|
static int clk_sama5d4_h32mx_set_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct clk_sama5d4_h32mx *h32mxclk = to_clk_sama5d4_h32mx(hw);
|
|
u32 mckr = 0;
|
|
|
|
if (parent_rate != rate && (parent_rate / 2) != rate)
|
|
return -EINVAL;
|
|
|
|
if ((parent_rate / 2) == rate)
|
|
mckr = AT91_PMC_H32MXDIV;
|
|
|
|
regmap_update_bits(h32mxclk->regmap, AT91_PMC_MCKR,
|
|
AT91_PMC_H32MXDIV, mckr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct clk_ops h32mx_ops = {
|
|
.recalc_rate = clk_sama5d4_h32mx_recalc_rate,
|
|
.round_rate = clk_sama5d4_h32mx_round_rate,
|
|
.set_rate = clk_sama5d4_h32mx_set_rate,
|
|
};
|
|
|
|
struct clk_hw * __init
|
|
at91_clk_register_h32mx(struct regmap *regmap, const char *name,
|
|
const char *parent_name)
|
|
{
|
|
struct clk_sama5d4_h32mx *h32mxclk;
|
|
struct clk_init_data init;
|
|
int ret;
|
|
|
|
h32mxclk = kzalloc(sizeof(*h32mxclk), GFP_KERNEL);
|
|
if (!h32mxclk)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
init.name = name;
|
|
init.ops = &h32mx_ops;
|
|
init.parent_names = parent_name ? &parent_name : NULL;
|
|
init.num_parents = parent_name ? 1 : 0;
|
|
init.flags = CLK_SET_RATE_GATE;
|
|
|
|
h32mxclk->hw.init = &init;
|
|
h32mxclk->regmap = regmap;
|
|
|
|
ret = clk_hw_register(NULL, &h32mxclk->hw);
|
|
if (ret) {
|
|
kfree(h32mxclk);
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
return &h32mxclk->hw;
|
|
}
|