clk-krait.c
// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018, The Linux Foundation. All rights reserved.
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/clk-provider.h>
#include <linux/spinlock.h>
#include <asm/krait-l2-accessors.h>
#include "clk-krait.h"
/* Secondary and primary muxes share the same cp15 register */
static DEFINE_SPINLOCK(krait_clock_reg_lock);
#define LPL_SHIFT 8
#define SECCLKAGD BIT(4)
static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel)
{
unsigned long flags;
u32 regval;
spin_lock_irqsave(&krait_clock_reg_lock, flags);
regval = krait_get_l2_indirect_reg(mux->offset);
/* apq/ipq8064 Errata: disable sec_src clock gating during switch. */
if (mux->disable_sec_src_gating) {
regval |= SECCLKAGD;
krait_set_l2_indirect_reg(mux->offset, regval);
}
regval &= ~(mux->mask << mux->shift);
regval |= (sel & mux->mask) << mux->shift;
if (mux->lpl) {
regval &= ~(mux->mask << (mux->shift + LPL_SHIFT));
regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT);
}
krait_set_l2_indirect_reg(mux->offset, regval);
/* apq/ipq8064 Errata: re-enabled sec_src clock gating. */
if (mux->disable_sec_src_gating) {
regval &= ~SECCLKAGD;
krait_set_l2_indirect_reg(mux->offset, regval);
}
/* Wait for switch to complete. */
mb();
udelay(1);
/*
* Unlock now to make sure the mux register is not
* modified while switching to the new parent.
*/
spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
}
static int krait_mux_set_parent(struct clk_hw *hw, u8 index)
{
struct krait_mux_clk *mux = to_krait_mux_clk(hw);
u32 sel;
sel = clk_mux_index_to_val(mux->parent_map, 0, index);
mux->en_mask = sel;
/* Don't touch mux if CPU is off as it won't work */
if (__clk_is_enabled(hw->clk))
__krait_mux_set_sel(mux, sel);
mux->reparent = true;
return 0;
}
static u8 krait_mux_get_parent(struct clk_hw *hw)
{
struct krait_mux_clk *mux = to_krait_mux_clk(hw);
u32 sel;
sel = krait_get_l2_indirect_reg(mux->offset);
sel >>= mux->shift;
sel &= mux->mask;
mux->en_mask = sel;
return clk_mux_val_to_index(hw, mux->parent_map, 0, sel);
}
const struct clk_ops krait_mux_clk_ops = {
.set_parent = krait_mux_set_parent,
.get_parent = krait_mux_get_parent,
.determine_rate = __clk_mux_determine_rate_closest,
};
EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
/* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */
static int krait_div2_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
{
req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), req->rate * 2);
req->rate = DIV_ROUND_UP(req->best_parent_rate, 2);
return 0;
}
static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct krait_div2_clk *d = to_krait_div2_clk(hw);
unsigned long flags;
u32 val;
u32 mask = BIT(d->width) - 1;
if (d->lpl)
mask = mask << (d->shift + LPL_SHIFT) | mask << d->shift;
else
mask <<= d->shift;
spin_lock_irqsave(&krait_clock_reg_lock, flags);
val = krait_get_l2_indirect_reg(d->offset);
val &= ~mask;
krait_set_l2_indirect_reg(d->offset, val);
spin_unlock_irqrestore(&krait_clock_reg_lock, flags);
return 0;
}
static unsigned long
krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
struct krait_div2_clk *d = to_krait_div2_clk(hw);
u32 mask = BIT(d->width) - 1;
u32 div;
div = krait_get_l2_indirect_reg(d->offset);
div >>= d->shift;
div &= mask;
div = (div + 1) * 2;
return DIV_ROUND_UP(parent_rate, div);
}
const struct clk_ops krait_div2_clk_ops = {
.determine_rate = krait_div2_determine_rate,
.set_rate = krait_div2_set_rate,
.recalc_rate = krait_div2_recalc_rate,
};
EXPORT_SYMBOL_GPL(krait_div2_clk_ops);