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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2018 NXP
*/
#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"
#define PCG_PREDIV_SHIFT 16
#define PCG_PREDIV_WIDTH 3
#define PCG_PREDIV_MAX 8
#define PCG_DIV_SHIFT 0
#define PCG_DIV_WIDTH 6
#define PCG_DIV_MAX 64
#define PCG_PCS_SHIFT 24
#define PCG_PCS_MASK 0x7
#define PCG_CGC_SHIFT 28
static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
unsigned long prediv_rate;
unsigned int prediv_value;
unsigned int div_value;
prediv_value = readl(divider->reg) >> divider->shift;
prediv_value &= clk_div_mask(divider->width);
prediv_rate = divider_recalc_rate(hw, parent_rate, prediv_value,
NULL, divider->flags,
divider->width);
div_value = readl(divider->reg) >> PCG_DIV_SHIFT;
div_value &= clk_div_mask(PCG_DIV_WIDTH);
return divider_recalc_rate(hw, prediv_rate, div_value, NULL,
divider->flags, PCG_DIV_WIDTH);
}
static int imx8m_clk_composite_compute_dividers(unsigned long rate,
unsigned long parent_rate,
int *prediv, int *postdiv)
{
int div1, div2;
int error = INT_MAX;
int ret = -EINVAL;
*prediv = 1;
*postdiv = 1;
for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) {
for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) {
int new_error = ((parent_rate / div1) / div2) - rate;
if (abs(new_error) < abs(error)) {
*prediv = div1;
*postdiv = div2;
error = new_error;
ret = 0;
}
}
}
return ret;
}
static long imx8m_clk_composite_divider_round_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long *prate)
{
int prediv_value;
int div_value;
imx8m_clk_composite_compute_dividers(rate, *prate,
&prediv_value, &div_value);
rate = DIV_ROUND_UP(*prate, prediv_value);
return DIV_ROUND_UP(rate, div_value);
}
static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long parent_rate)
{
struct clk_divider *divider = to_clk_divider(hw);
unsigned long flags = 0;
int prediv_value;
int div_value;
int ret;
u32 val;
ret = imx8m_clk_composite_compute_dividers(rate, parent_rate,
&prediv_value, &div_value);
if (ret)
return -EINVAL;
spin_lock_irqsave(divider->lock, flags);
val = readl(divider->reg);
val &= ~((clk_div_mask(divider->width) << divider->shift) |
(clk_div_mask(PCG_DIV_WIDTH) << PCG_DIV_SHIFT));
val |= (u32)(prediv_value - 1) << divider->shift;
val |= (u32)(div_value - 1) << PCG_DIV_SHIFT;
writel(val, divider->reg);
spin_unlock_irqrestore(divider->lock, flags);
return ret;
}
static const struct clk_ops imx8m_clk_composite_divider_ops = {
.recalc_rate = imx8m_clk_composite_divider_recalc_rate,
.round_rate = imx8m_clk_composite_divider_round_rate,
.set_rate = imx8m_clk_composite_divider_set_rate,
};
struct clk *imx8m_clk_composite_flags(const char *name,
const char * const *parent_names,
int num_parents, void __iomem *reg,
unsigned long flags)
{
struct clk_hw *hw = ERR_PTR(-ENOMEM), *mux_hw;
struct clk_hw *div_hw, *gate_hw;
struct clk_divider *div = NULL;
struct clk_gate *gate = NULL;
struct clk_mux *mux = NULL;
mux = kzalloc(sizeof(*mux), GFP_KERNEL);
if (!mux)
goto fail;
mux_hw = &mux->hw;
mux->reg = reg;
mux->shift = PCG_PCS_SHIFT;
mux->mask = PCG_PCS_MASK;
div = kzalloc(sizeof(*div), GFP_KERNEL);
if (!div)
goto fail;
div_hw = &div->hw;
div->reg = reg;
div->shift = PCG_PREDIV_SHIFT;
div->width = PCG_PREDIV_WIDTH;
div->lock = &imx_ccm_lock;
div->flags = CLK_DIVIDER_ROUND_CLOSEST;
gate = kzalloc(sizeof(*gate), GFP_KERNEL);
if (!gate)
goto fail;
gate_hw = &gate->hw;
gate->reg = reg;
gate->bit_idx = PCG_CGC_SHIFT;
hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
mux_hw, &clk_mux_ops, div_hw,
&imx8m_clk_composite_divider_ops,
gate_hw, &clk_gate_ops, flags);
if (IS_ERR(hw))
goto fail;
return hw->clk;
fail:
kfree(gate);
kfree(div);
kfree(mux);
return ERR_CAST(hw);
}
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