linux/drivers/clk/at91/clk-h32mx.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

113 lines
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;
}