ccu_nm.c
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/*
* Copyright (C) 2016 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.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/rational.h>
#include "ccu_frac.h"
#include "ccu_gate.h"
#include "ccu_nm.h"
static void ccu_nm_disable(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_disable(&nm->common, nm->enable);
}
static int ccu_nm_enable(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_enable(&nm->common, nm->enable);
}
static int ccu_nm_is_enabled(struct clk_hw *hw)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
return ccu_gate_helper_is_enabled(&nm->common, nm->enable);
}
static unsigned long ccu_nm_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
unsigned long n, m;
u32 reg;
if (ccu_frac_helper_is_enabled(&nm->common, &nm->frac))
return ccu_frac_helper_read_rate(&nm->common, &nm->frac);
reg = readl(nm->common.base + nm->common.reg);
n = reg >> nm->n.shift;
n &= (1 << nm->n.width) - 1;
m = reg >> nm->m.shift;
m &= (1 << nm->m.width) - 1;
return parent_rate * (n + 1) / (m + 1);
}
static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
unsigned long max_n, max_m;
unsigned long n, m;
max_n = 1 << nm->n.width;
max_m = nm->m.max ?: 1 << nm->m.width;
rational_best_approximation(rate, *parent_rate, max_n, max_m, &n, &m);
return *parent_rate * n / m;
}
static int ccu_nm_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct ccu_nm *nm = hw_to_ccu_nm(hw);
unsigned long flags;
unsigned long max_n, max_m;
unsigned long n, m;
u32 reg;
if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate))
return ccu_frac_helper_set_rate(&nm->common, &nm->frac, rate);
else
ccu_frac_helper_disable(&nm->common, &nm->frac);
max_n = 1 << nm->n.width;
max_m = nm->m.max ?: 1 << nm->m.width;
rational_best_approximation(rate, parent_rate, max_n, max_m, &n, &m);
spin_lock_irqsave(nm->common.lock, flags);
reg = readl(nm->common.base + nm->common.reg);
reg &= ~GENMASK(nm->n.width + nm->n.shift - 1, nm->n.shift);
reg &= ~GENMASK(nm->m.width + nm->m.shift - 1, nm->m.shift);
writel(reg | ((m - 1) << nm->m.shift) | ((n - 1) << nm->n.shift),
nm->common.base + nm->common.reg);
spin_unlock_irqrestore(nm->common.lock, flags);
ccu_helper_wait_for_lock(&nm->common, nm->lock);
return 0;
}
const struct clk_ops ccu_nm_ops = {
.disable = ccu_nm_disable,
.enable = ccu_nm_enable,
.is_enabled = ccu_nm_is_enabled,
.recalc_rate = ccu_nm_recalc_rate,
.round_rate = ccu_nm_round_rate,
.set_rate = ccu_nm_set_rate,
};