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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2018 NXP.
* Dong Aisheng <aisheng.dong@nxp.com>
*/
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"
struct clk_divider_gate {
struct clk_divider divider;
u32 cached_val;
};
static inline struct clk_divider_gate *to_clk_divider_gate(struct clk_hw *hw)
{
struct clk_divider *div = to_clk_divider(hw);
return container_of(div, struct clk_divider_gate, divider);
}
static unsigned long clk_divider_gate_recalc_rate_ro(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider *div = to_clk_divider(hw);
unsigned int val;
val = readl(div->reg) >> div->shift;
val &= clk_div_mask(div->width);
if (!val)
return 0;
return divider_recalc_rate(hw, parent_rate, val, div->table,
div->flags, div->width);
}
static unsigned long clk_divider_gate_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
struct clk_divider *div = to_clk_divider(hw);
unsigned long flags = 0;
unsigned int val;
spin_lock_irqsave(div->lock, flags);
if (!clk_hw_is_enabled(hw)) {
val = div_gate->cached_val;
} else {
val = readl(div->reg) >> div->shift;
val &= clk_div_mask(div->width);
}
spin_unlock_irqrestore(div->lock, flags);
if (!val)
return 0;
return divider_recalc_rate(hw, parent_rate, val, div->table,
div->flags, div->width);
}
static long clk_divider_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
return clk_divider_ops.round_rate(hw, rate, prate);
}
static int clk_divider_gate_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
struct clk_divider *div = to_clk_divider(hw);
unsigned long flags = 0;
int value;
u32 val;
value = divider_get_val(rate, parent_rate, div->table,
div->width, div->flags);
if (value < 0)
return value;
spin_lock_irqsave(div->lock, flags);
if (clk_hw_is_enabled(hw)) {
val = readl(div->reg);
val &= ~(clk_div_mask(div->width) << div->shift);
val |= (u32)value << div->shift;
writel(val, div->reg);
} else {
div_gate->cached_val = value;
}
spin_unlock_irqrestore(div->lock, flags);
return 0;
}
static int clk_divider_enable(struct clk_hw *hw)
{
struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
struct clk_divider *div = to_clk_divider(hw);
unsigned long flags = 0;
u32 val;
if (!div_gate->cached_val) {
pr_err("%s: no valid preset rate\n", clk_hw_get_name(hw));
return -EINVAL;
}
spin_lock_irqsave(div->lock, flags);
/* restore div val */
val = readl(div->reg);
val |= div_gate->cached_val << div->shift;
writel(val, div->reg);
spin_unlock_irqrestore(div->lock, flags);
return 0;
}
static void clk_divider_disable(struct clk_hw *hw)
{
struct clk_divider_gate *div_gate = to_clk_divider_gate(hw);
struct clk_divider *div = to_clk_divider(hw);
unsigned long flags = 0;
u32 val;
spin_lock_irqsave(div->lock, flags);
/* store the current div val */
val = readl(div->reg) >> div->shift;
val &= clk_div_mask(div->width);
div_gate->cached_val = val;
writel(0, div->reg);
spin_unlock_irqrestore(div->lock, flags);
}
static int clk_divider_is_enabled(struct clk_hw *hw)
{
struct clk_divider *div = to_clk_divider(hw);
u32 val;
val = readl(div->reg) >> div->shift;
val &= clk_div_mask(div->width);
return val ? 1 : 0;
}
static const struct clk_ops clk_divider_gate_ro_ops = {
.recalc_rate = clk_divider_gate_recalc_rate_ro,
.round_rate = clk_divider_round_rate,
};
static const struct clk_ops clk_divider_gate_ops = {
.recalc_rate = clk_divider_gate_recalc_rate,
.round_rate = clk_divider_round_rate,
.set_rate = clk_divider_gate_set_rate,
.enable = clk_divider_enable,
.disable = clk_divider_disable,
.is_enabled = clk_divider_is_enabled,
};
/*
* NOTE: In order to resue the most code from the common divider,
* we also design our divider following the way that provids an extra
* clk_divider_flags, however it's fixed to CLK_DIVIDER_ONE_BASED by
* default as our HW is. Besides that it supports only CLK_DIVIDER_READ_ONLY
* flag which can be specified by user flexibly.
*/
struct clk_hw *imx_clk_divider_gate(const char *name, const char *parent_name,
unsigned long flags, void __iomem *reg,
u8 shift, u8 width, u8 clk_divider_flags,
const struct clk_div_table *table,
spinlock_t *lock)
{
struct clk_init_data init;
struct clk_divider_gate *div_gate;
struct clk_hw *hw;
u32 val;
int ret;
div_gate = kzalloc(sizeof(*div_gate), GFP_KERNEL);
if (!div_gate)
return ERR_PTR(-ENOMEM);
init.name = name;
if (clk_divider_flags & CLK_DIVIDER_READ_ONLY)
init.ops = &clk_divider_gate_ro_ops;
else
init.ops = &clk_divider_gate_ops;
init.flags = flags;
init.parent_names = parent_name ? &parent_name : NULL;
init.num_parents = parent_name ? 1 : 0;
div_gate->divider.reg = reg;
div_gate->divider.shift = shift;
div_gate->divider.width = width;
div_gate->divider.lock = lock;
div_gate->divider.table = table;
div_gate->divider.hw.init = &init;
div_gate->divider.flags = CLK_DIVIDER_ONE_BASED | clk_divider_flags;
/* cache gate status */
val = readl(reg) >> shift;
val &= clk_div_mask(width);
div_gate->cached_val = val;
hw = &div_gate->divider.hw;
ret = clk_hw_register(NULL, hw);
if (ret) {
kfree(div_gate);
hw = ERR_PTR(ret);
}
return hw;
}
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