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clk: sunxi-ng: Add N-K-factor clock support
Introduce support for clocks that use a combination of two linear multipliers. Signed-off-by: Maxime Ripard <[email protected]> Signed-off-by: Michael Turquette <[email protected]> Link: lkml.kernel.org/r/[email protected]
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/* | ||
* Copyright (C) 2016 Maxime Ripard | ||
* Maxime Ripard <[email protected]> | ||
* | ||
* This program is free software; you can redistribute it and/or | ||
* modify it under the terms of the GNU General Public License as | ||
* published by the Free Software Foundation; either version 2 of | ||
* the License, or (at your option) any later version. | ||
*/ | ||
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#include <linux/clk-provider.h> | ||
#include <linux/rational.h> | ||
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#include "ccu_gate.h" | ||
#include "ccu_nk.h" | ||
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void ccu_nk_find_best(unsigned long parent, unsigned long rate, | ||
unsigned int max_n, unsigned int max_k, | ||
unsigned int *n, unsigned int *k) | ||
{ | ||
unsigned long best_rate = 0; | ||
unsigned int best_k = 0, best_n = 0; | ||
unsigned int _k, _n; | ||
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for (_k = 1; _k <= max_k; _k++) { | ||
for (_n = 1; _n <= max_n; _n++) { | ||
unsigned long tmp_rate = parent * _n * _k; | ||
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if (tmp_rate > rate) | ||
continue; | ||
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if ((rate - tmp_rate) < (rate - best_rate)) { | ||
best_rate = tmp_rate; | ||
best_k = _k; | ||
best_n = _n; | ||
} | ||
} | ||
} | ||
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*k = best_k; | ||
*n = best_n; | ||
} | ||
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static void ccu_nk_disable(struct clk_hw *hw) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
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return ccu_gate_helper_disable(&nk->common, nk->enable); | ||
} | ||
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static int ccu_nk_enable(struct clk_hw *hw) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
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return ccu_gate_helper_enable(&nk->common, nk->enable); | ||
} | ||
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static int ccu_nk_is_enabled(struct clk_hw *hw) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
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return ccu_gate_helper_is_enabled(&nk->common, nk->enable); | ||
} | ||
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static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw, | ||
unsigned long parent_rate) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
unsigned long rate, n, k; | ||
u32 reg; | ||
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reg = readl(nk->common.base + nk->common.reg); | ||
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n = reg >> nk->n.shift; | ||
n &= (1 << nk->n.width) - 1; | ||
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k = reg >> nk->k.shift; | ||
k &= (1 << nk->k.width) - 1; | ||
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rate = parent_rate * (n + 1) * (k + 1); | ||
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if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) | ||
rate /= nk->fixed_post_div; | ||
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return rate; | ||
} | ||
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static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate, | ||
unsigned long *parent_rate) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
unsigned int n, k; | ||
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if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) | ||
rate *= nk->fixed_post_div; | ||
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ccu_nk_find_best(*parent_rate, rate, | ||
1 << nk->n.width, 1 << nk->k.width, | ||
&n, &k); | ||
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rate = *parent_rate * n * k; | ||
if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) | ||
rate = rate / nk->fixed_post_div; | ||
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return rate; | ||
} | ||
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static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate, | ||
unsigned long parent_rate) | ||
{ | ||
struct ccu_nk *nk = hw_to_ccu_nk(hw); | ||
unsigned long flags; | ||
unsigned int n, k; | ||
u32 reg; | ||
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if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV) | ||
rate = rate * nk->fixed_post_div; | ||
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ccu_nk_find_best(parent_rate, rate, | ||
1 << nk->n.width, 1 << nk->k.width, | ||
&n, &k); | ||
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spin_lock_irqsave(nk->common.lock, flags); | ||
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reg = readl(nk->common.base + nk->common.reg); | ||
reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift); | ||
reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift); | ||
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writel(reg | ((k - 1) << nk->k.shift) | ((n - 1) << nk->n.shift), | ||
nk->common.base + nk->common.reg); | ||
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spin_unlock_irqrestore(nk->common.lock, flags); | ||
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ccu_helper_wait_for_lock(&nk->common, nk->lock); | ||
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return 0; | ||
} | ||
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const struct clk_ops ccu_nk_ops = { | ||
.disable = ccu_nk_disable, | ||
.enable = ccu_nk_enable, | ||
.is_enabled = ccu_nk_is_enabled, | ||
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.recalc_rate = ccu_nk_recalc_rate, | ||
.round_rate = ccu_nk_round_rate, | ||
.set_rate = ccu_nk_set_rate, | ||
}; |
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/* | ||
* Copyright (c) 2016 Maxime Ripard. All rights reserved. | ||
* | ||
* This software is licensed under the terms of the GNU General Public | ||
* License version 2, as published by the Free Software Foundation, and | ||
* may be copied, distributed, and modified under those terms. | ||
* | ||
* This program is distributed in the hope that it will be useful, | ||
* but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
* GNU General Public License for more details. | ||
*/ | ||
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#ifndef _CCU_NK_H_ | ||
#define _CCU_NK_H_ | ||
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#include <linux/clk-provider.h> | ||
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#include "ccu_common.h" | ||
#include "ccu_div.h" | ||
#include "ccu_mult.h" | ||
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/* | ||
* struct ccu_nk - Definition of an N-K clock | ||
* | ||
* Clocks based on the formula parent * N * K | ||
*/ | ||
struct ccu_nk { | ||
u16 reg; | ||
u32 enable; | ||
u32 lock; | ||
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struct _ccu_mult n; | ||
struct _ccu_mult k; | ||
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unsigned int fixed_post_div; | ||
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struct ccu_common common; | ||
}; | ||
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#define SUNXI_CCU_NK_WITH_GATE_LOCK_POSTDIV(_struct, _name, _parent, _reg, \ | ||
_nshift, _nwidth, \ | ||
_kshift, _kwidth, \ | ||
_gate, _lock, _postdiv, \ | ||
_flags) \ | ||
struct ccu_nk _struct = { \ | ||
.enable = _gate, \ | ||
.lock = _lock, \ | ||
.k = _SUNXI_CCU_MULT(_kshift, _kwidth), \ | ||
.n = _SUNXI_CCU_MULT(_nshift, _nwidth), \ | ||
.fixed_post_div = _postdiv, \ | ||
.common = { \ | ||
.reg = _reg, \ | ||
.features = CCU_FEATURE_FIXED_POSTDIV, \ | ||
.hw.init = CLK_HW_INIT(_name, \ | ||
_parent, \ | ||
&ccu_nk_ops, \ | ||
_flags), \ | ||
}, \ | ||
} | ||
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static inline struct ccu_nk *hw_to_ccu_nk(struct clk_hw *hw) | ||
{ | ||
struct ccu_common *common = hw_to_ccu_common(hw); | ||
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return container_of(common, struct ccu_nk, common); | ||
} | ||
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extern const struct clk_ops ccu_nk_ops; | ||
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#endif /* _CCU_NK_H_ */ |