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// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on clk-super.c
* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
*
* Based on older tegra20-cpufreq driver by Colin Cross <ccross@google.com>
* Copyright (C) 2010 Google, Inc.
*
* Author: Dmitry Osipenko <digetx@gmail.com>
* Copyright (C) 2019 GRATE-DRIVER project
*/
#include <linux/bits.h>
#include <linux/clk-provider.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "clk.h"
#define PLLP_INDEX 4
#define PLLX_INDEX 8
#define SUPER_CDIV_ENB BIT(31)
#define TSENSOR_SLOWDOWN BIT(23)
static struct tegra_clk_super_mux *cclk_super;
static bool cclk_on_pllx;
static u8 cclk_super_get_parent(struct clk_hw *hw)
{
return tegra_clk_super_ops.get_parent(hw);
}
static int cclk_super_set_parent(struct clk_hw *hw, u8 index)
{
return tegra_clk_super_ops.set_parent(hw, index);
}
static int cclk_super_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
return tegra_clk_super_ops.set_rate(hw, rate, parent_rate);
}
static unsigned long cclk_super_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
u32 val = readl_relaxed(super->reg);
unsigned int div2;
/* check whether thermal throttling is active */
if (val & TSENSOR_SLOWDOWN)
div2 = 1;
else
div2 = 0;
if (cclk_super_get_parent(hw) == PLLX_INDEX)
return parent_rate >> div2;
return tegra_clk_super_ops.recalc_rate(hw, parent_rate) >> div2;
}
static int cclk_super_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_hw *pllp_hw = clk_hw_get_parent_by_index(hw, PLLP_INDEX);
struct clk_hw *pllx_hw = clk_hw_get_parent_by_index(hw, PLLX_INDEX);
struct tegra_clk_super_mux *super = to_clk_super_mux(hw);
unsigned long pllp_rate;
long rate = req->rate;
if (WARN_ON_ONCE(!pllp_hw || !pllx_hw))
return -EINVAL;
/*
* Switch parent to PLLP for all CCLK rates that are suitable for PLLP.
* PLLX will be disabled in this case, saving some power.
*/
pllp_rate = clk_hw_get_rate(pllp_hw);
if (rate <= pllp_rate) {
if (super->flags & TEGRA20_SUPER_CLK)
rate = pllp_rate;
else
rate = tegra_clk_super_ops.round_rate(hw, rate,
&pllp_rate);
req->best_parent_rate = pllp_rate;
req->best_parent_hw = pllp_hw;
req->rate = rate;
} else {
rate = clk_hw_round_rate(pllx_hw, rate);
req->best_parent_rate = rate;
req->best_parent_hw = pllx_hw;
req->rate = rate;
}
if (WARN_ON_ONCE(rate <= 0))
return -EINVAL;
return 0;
}
static const struct clk_ops tegra_cclk_super_ops = {
.get_parent = cclk_super_get_parent,
.set_parent = cclk_super_set_parent,
.set_rate = cclk_super_set_rate,
.recalc_rate = cclk_super_recalc_rate,
.determine_rate = cclk_super_determine_rate,
};
static const struct clk_ops tegra_cclk_super_mux_ops = {
.get_parent = cclk_super_get_parent,
.set_parent = cclk_super_set_parent,
.determine_rate = cclk_super_determine_rate,
};
struct clk *tegra_clk_register_super_cclk(const char *name,
const char * const *parent_names, u8 num_parents,
unsigned long flags, void __iomem *reg, u8 clk_super_flags,
spinlock_t *lock)
{
struct tegra_clk_super_mux *super;
struct clk *clk;
struct clk_init_data init;
u32 val;
if (WARN_ON(cclk_super))
return ERR_PTR(-EBUSY);
super = kzalloc(sizeof(*super), GFP_KERNEL);
if (!super)
return ERR_PTR(-ENOMEM);
init.name = name;
init.flags = flags;
init.parent_names = parent_names;
init.num_parents = num_parents;
super->reg = reg;
super->lock = lock;
super->width = 4;
super->flags = clk_super_flags;
super->hw.init = &init;
if (super->flags & TEGRA20_SUPER_CLK) {
init.ops = &tegra_cclk_super_mux_ops;
} else {
init.ops = &tegra_cclk_super_ops;
super->frac_div.reg = reg + 4;
super->frac_div.shift = 16;
super->frac_div.width = 8;
super->frac_div.frac_width = 1;
super->frac_div.lock = lock;
super->div_ops = &tegra_clk_frac_div_ops;
}
/*
* Tegra30+ has the following CPUG clock topology:
*
* +---+ +-------+ +-+ +-+ +-+
* PLLP+->+ +->+DIVIDER+->+0| +-------->+0| ------------->+0|
* | | +-------+ | | | +---+ | | | | |
* PLLC+->+MUX| | +->+ | S | | +->+ | +->+CPU
* ... | | | | | | K | | | | +-------+ | |
* PLLX+->+-->+------------>+1| +->+ I +->+1| +->+ DIV2 +->+1|
* +---+ +++ | P | +++ |SKIPPER| +++
* ^ | P | ^ +-------+ ^
* | | E | | |
* PLLX_SEL+--+ | R | | OVERHEAT+--+
* +---+ |
* |
* SUPER_CDIV_ENB+--+
*
* Tegra20 is similar, but simpler. It doesn't have the divider and
* thermal DIV2 skipper.
*
* At least for now we're not going to use clock-skipper, hence let's
* ensure that it is disabled.
*/
val = readl_relaxed(reg + 4);
val &= ~SUPER_CDIV_ENB;
writel_relaxed(val, reg + 4);
clk = clk_register(NULL, &super->hw);
if (IS_ERR(clk))
kfree(super);
else
cclk_super = super;
return clk;
}
int tegra_cclk_pre_pllx_rate_change(void)
{
if (IS_ERR_OR_NULL(cclk_super))
return -EINVAL;
if (cclk_super_get_parent(&cclk_super->hw) == PLLX_INDEX)
cclk_on_pllx = true;
else
cclk_on_pllx = false;
/*
* CPU needs to be temporarily re-parented away from PLLX if PLLX
* changes its rate. PLLP is a safe parent for CPU on all Tegra SoCs.
*/
if (cclk_on_pllx)
cclk_super_set_parent(&cclk_super->hw, PLLP_INDEX);
return 0;
}
void tegra_cclk_post_pllx_rate_change(void)
{
if (cclk_on_pllx)
cclk_super_set_parent(&cclk_super->hw, PLLX_INDEX);
}
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