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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include "clk.h"
#define pll_out_override(p) (BIT((p->shift - 6)))
#define div_mask(d) ((1 << (d->width)) - 1)
#define get_mul(d) (1 << d->frac_width)
#define get_max_div(d) div_mask(d)
#define PERIPH_CLK_UART_DIV_ENB BIT(24)
static int get_div(struct tegra_clk_frac_div *divider, unsigned long rate,
unsigned long parent_rate)
{
int div;
div = div_frac_get(rate, parent_rate, divider->width,
divider->frac_width, divider->flags);
if (div < 0)
return 0;
return div;
}
static unsigned long clk_frac_div_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct tegra_clk_frac_div *divider = to_clk_frac_div(hw);
u32 reg;
int div, mul;
u64 rate = parent_rate;
reg = readl_relaxed(divider->reg);
if ((divider->flags & TEGRA_DIVIDER_UART) &&
!(reg & PERIPH_CLK_UART_DIV_ENB))
return rate;
div = (reg >> divider->shift) & div_mask(divider);
mul = get_mul(divider);
div += mul;
rate *= mul;
rate += div - 1;
do_div(rate, div);
return rate;
}
static long clk_frac_div_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct tegra_clk_frac_div *divider = to_clk_frac_div(hw);
int div, mul;
unsigned long output_rate = *prate;
if (!rate)
return output_rate;
div = get_div(divider, rate, output_rate);
if (div < 0)
return *prate;
mul = get_mul(divider);
return DIV_ROUND_UP(output_rate * mul, div + mul);
}
static int clk_frac_div_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct tegra_clk_frac_div *divider = to_clk_frac_div(hw);
int div;
unsigned long flags = 0;
u32 val;
div = get_div(divider, rate, parent_rate);
if (div < 0)
return div;
if (divider->lock)
spin_lock_irqsave(divider->lock, flags);
val = readl_relaxed(divider->reg);
val &= ~(div_mask(divider) << divider->shift);
val |= div << divider->shift;
if (divider->flags & TEGRA_DIVIDER_UART) {
if (div)
val |= PERIPH_CLK_UART_DIV_ENB;
else
val &= ~PERIPH_CLK_UART_DIV_ENB;
}
if (divider->flags & TEGRA_DIVIDER_FIXED)
val |= pll_out_override(divider);
writel_relaxed(val, divider->reg);
if (divider->lock)
spin_unlock_irqrestore(divider->lock, flags);
return 0;
}
static void clk_divider_restore_context(struct clk_hw *hw)
{
struct clk_hw *parent = clk_hw_get_parent(hw);
unsigned long parent_rate = clk_hw_get_rate(parent);
unsigned long rate = clk_hw_get_rate(hw);
if (clk_frac_div_set_rate(hw, rate, parent_rate) < 0)
WARN_ON(1);
}
const struct clk_ops tegra_clk_frac_div_ops = {
.recalc_rate = clk_frac_div_recalc_rate,
.set_rate = clk_frac_div_set_rate,
.round_rate = clk_frac_div_round_rate,
.restore_context = clk_divider_restore_context,
};
struct clk *tegra_clk_register_divider(const char *name,
const char *parent_name, void __iomem *reg,
unsigned long flags, u8 clk_divider_flags, u8 shift, u8 width,
u8 frac_width, spinlock_t *lock)
{
struct tegra_clk_frac_div *divider;
struct clk *clk;
struct clk_init_data init;
divider = kzalloc(sizeof(*divider), GFP_KERNEL);
if (!divider) {
pr_err("%s: could not allocate fractional divider clk\n",
__func__);
return ERR_PTR(-ENOMEM);
}
init.name = name;
init.ops = &tegra_clk_frac_div_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
divider->reg = reg;
divider->shift = shift;
divider->width = width;
divider->frac_width = frac_width;
divider->lock = lock;
divider->flags = clk_divider_flags;
/* Data in .init is copied by clk_register(), so stack variable OK */
divider->hw.init = &init;
clk = clk_register(NULL, ÷r->hw);
if (IS_ERR(clk))
kfree(divider);
return clk;
}
static const struct clk_div_table mc_div_table[] = {
{ .val = 0, .div = 2 },
{ .val = 1, .div = 1 },
{ .val = 0, .div = 0 },
};
struct clk *tegra_clk_register_mc(const char *name, const char *parent_name,
void __iomem *reg, spinlock_t *lock)
{
return clk_register_divider_table(NULL, name, parent_name,
CLK_IS_CRITICAL,
reg, 16, 1, CLK_DIVIDER_READ_ONLY,
mc_div_table, lock);
}
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