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87ba9e5962
Some dividers might have a maximum value that is lower than the width of the register. Add a field to _ccu_div to handle those case properly. If the field is set to 0, the code will assume that the maximum value is the maximum one that can be used with the field register width. Otherwise, we'll use whatever value has been set. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Acked-by: Chen-Yu Tsai <wens@csie.org>
161 lines
3.8 KiB
C
161 lines
3.8 KiB
C
/*
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* Copyright (C) 2016 Maxime Ripard
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* Maxime Ripard <maxime.ripard@free-electrons.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*/
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#include <linux/clk-provider.h>
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#include "ccu_gate.h"
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#include "ccu_mp.h"
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static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
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unsigned int max_m, unsigned int max_p,
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unsigned int *m, unsigned int *p)
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{
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unsigned long best_rate = 0;
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unsigned int best_m = 0, best_p = 0;
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unsigned int _m, _p;
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for (_p = 1; _p <= max_p; _p <<= 1) {
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for (_m = 1; _m <= max_m; _m++) {
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unsigned long tmp_rate = parent / _p / _m;
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if (tmp_rate > rate)
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continue;
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if ((rate - tmp_rate) < (rate - best_rate)) {
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best_rate = tmp_rate;
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best_m = _m;
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best_p = _p;
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}
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}
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}
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*m = best_m;
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*p = best_p;
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}
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static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
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unsigned long parent_rate,
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unsigned long rate,
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void *data)
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{
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struct ccu_mp *cmp = data;
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unsigned int max_m, max_p;
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unsigned int m, p;
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max_m = cmp->m.max ?: 1 << cmp->m.width;
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max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
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ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p);
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return parent_rate / p / m;
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}
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static void ccu_mp_disable(struct clk_hw *hw)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_gate_helper_disable(&cmp->common, cmp->enable);
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}
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static int ccu_mp_enable(struct clk_hw *hw)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_gate_helper_enable(&cmp->common, cmp->enable);
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}
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static int ccu_mp_is_enabled(struct clk_hw *hw)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_gate_helper_is_enabled(&cmp->common, cmp->enable);
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}
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static unsigned long ccu_mp_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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unsigned int m, p;
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u32 reg;
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reg = readl(cmp->common.base + cmp->common.reg);
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m = reg >> cmp->m.shift;
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m &= (1 << cmp->m.width) - 1;
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p = reg >> cmp->p.shift;
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p &= (1 << cmp->p.width) - 1;
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return (parent_rate >> p) / (m + 1);
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}
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static int ccu_mp_determine_rate(struct clk_hw *hw,
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struct clk_rate_request *req)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_mux_helper_determine_rate(&cmp->common, &cmp->mux,
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req, ccu_mp_round_rate, cmp);
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}
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static int ccu_mp_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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unsigned long flags;
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unsigned int max_m, max_p;
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unsigned int m, p;
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u32 reg;
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max_m = cmp->m.max ?: 1 << cmp->m.width;
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max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
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ccu_mp_find_best(parent_rate, rate, max_m, max_p, &m, &p);
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spin_lock_irqsave(cmp->common.lock, flags);
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reg = readl(cmp->common.base + cmp->common.reg);
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reg &= ~GENMASK(cmp->m.width + cmp->m.shift - 1, cmp->m.shift);
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reg &= ~GENMASK(cmp->p.width + cmp->p.shift - 1, cmp->p.shift);
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writel(reg | (ilog2(p) << cmp->p.shift) | ((m - 1) << cmp->m.shift),
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cmp->common.base + cmp->common.reg);
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spin_unlock_irqrestore(cmp->common.lock, flags);
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return 0;
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}
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static u8 ccu_mp_get_parent(struct clk_hw *hw)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_mux_helper_get_parent(&cmp->common, &cmp->mux);
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}
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static int ccu_mp_set_parent(struct clk_hw *hw, u8 index)
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{
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struct ccu_mp *cmp = hw_to_ccu_mp(hw);
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return ccu_mux_helper_set_parent(&cmp->common, &cmp->mux, index);
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}
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const struct clk_ops ccu_mp_ops = {
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.disable = ccu_mp_disable,
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.enable = ccu_mp_enable,
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.is_enabled = ccu_mp_is_enabled,
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.get_parent = ccu_mp_get_parent,
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.set_parent = ccu_mp_set_parent,
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.determine_rate = ccu_mp_determine_rate,
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.recalc_rate = ccu_mp_recalc_rate,
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.set_rate = ccu_mp_set_rate,
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};
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