e66f81bbd7
The factors we've seen so far all had an offset of one. However, on the earlier Allwinner SoCs, some factors could have no offset at all, meaning that the value computed to reach the rate we want to use was the one we had to program in the registers. Implement an additional field for the factors that can have such an offset (linears, not based on a power of two) to specify that offset. This offset is not linked to the extremums that can be specified in those structures too. The minimum and maximum are representing the range of values we can use to try to compute the best rate. The offset comes later on when we want to set the best value in the registers. Acked-by: Chen-Yu Tsai <wens@csie.org> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
159 lines
3.8 KiB
C
159 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_mult.h"
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struct _ccu_mult {
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unsigned long mult, min, max;
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};
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static void ccu_mult_find_best(unsigned long parent, unsigned long rate,
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struct _ccu_mult *mult)
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{
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int _mult;
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_mult = rate / parent;
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if (_mult < mult->min)
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_mult = mult->min;
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if (_mult > mult->max)
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_mult = mult->max;
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mult->mult = _mult;
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}
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static unsigned long ccu_mult_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_mult *cm = data;
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struct _ccu_mult _cm;
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_cm.min = 1;
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_cm.max = 1 << cm->mult.width;
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ccu_mult_find_best(parent_rate, rate, &_cm);
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return parent_rate * _cm.mult;
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}
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static void ccu_mult_disable(struct clk_hw *hw)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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return ccu_gate_helper_disable(&cm->common, cm->enable);
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}
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static int ccu_mult_enable(struct clk_hw *hw)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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return ccu_gate_helper_enable(&cm->common, cm->enable);
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}
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static int ccu_mult_is_enabled(struct clk_hw *hw)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
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}
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static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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unsigned long val;
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u32 reg;
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if (ccu_frac_helper_is_enabled(&cm->common, &cm->frac))
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return ccu_frac_helper_read_rate(&cm->common, &cm->frac);
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reg = readl(cm->common.base + cm->common.reg);
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val = reg >> cm->mult.shift;
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val &= (1 << cm->mult.width) - 1;
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ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
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&parent_rate);
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return parent_rate * (val + cm->mult.offset);
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}
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static int ccu_mult_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_mult *cm = hw_to_ccu_mult(hw);
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return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
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req, ccu_mult_round_rate, cm);
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}
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static int ccu_mult_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_mult *cm = hw_to_ccu_mult(hw);
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struct _ccu_mult _cm;
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unsigned long flags;
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u32 reg;
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if (ccu_frac_helper_has_rate(&cm->common, &cm->frac, rate))
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return ccu_frac_helper_set_rate(&cm->common, &cm->frac, rate);
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else
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ccu_frac_helper_disable(&cm->common, &cm->frac);
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ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
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&parent_rate);
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_cm.min = cm->mult.min;
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_cm.max = 1 << cm->mult.width;
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ccu_mult_find_best(parent_rate, rate, &_cm);
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spin_lock_irqsave(cm->common.lock, flags);
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reg = readl(cm->common.base + cm->common.reg);
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reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
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reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);
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writel(reg, cm->common.base + cm->common.reg);
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spin_unlock_irqrestore(cm->common.lock, flags);
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return 0;
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}
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static u8 ccu_mult_get_parent(struct clk_hw *hw)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
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}
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static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
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{
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struct ccu_mult *cm = hw_to_ccu_mult(hw);
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return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
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}
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const struct clk_ops ccu_mult_ops = {
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.disable = ccu_mult_disable,
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.enable = ccu_mult_enable,
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.is_enabled = ccu_mult_is_enabled,
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.get_parent = ccu_mult_get_parent,
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.set_parent = ccu_mult_set_parent,
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.determine_rate = ccu_mult_determine_rate,
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.recalc_rate = ccu_mult_recalc_rate,
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.set_rate = ccu_mult_set_rate,
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};
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