LXR linux/drivers/clk/sunxi-ng/ccu

   1/*
   2 * Copyright (C) 2016 Maxime Ripard
   3 * Maxime Ripard <maxime.ripard@free-electrons.com>
   4 *
   5 * This program is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU General Public License as
   7 * published by the Free Software Foundation; either version 2 of
   8 * the License, or (at your option) any later version.
   9 */
  10
  11#include <linux/clk-provider.h>
  12
  13#include "ccu_gate.h"
  14#include "ccu_mult.h"
  15
  16struct _ccu_mult {
  17        unsigned long   mult, min, max;
  18};
  19
  20static void ccu_mult_find_best(unsigned long parent, unsigned long rate,
  21                               struct _ccu_mult *mult)
  22{
  23        int _mult;
  24
  25        _mult = rate / parent;
  26        if (_mult < mult->min)
  27                _mult = mult->min;
  28
  29        if (_mult > mult->max)
  30                _mult = mult->max;
  31
  32        mult->mult = _mult;
  33}
  34
  35static unsigned long ccu_mult_round_rate(struct ccu_mux_internal *mux,
  36                                         struct clk_hw *parent,
  37                                         unsigned long *parent_rate,
  38                                         unsigned long rate,
  39                                         void *data)
  40{
  41        struct ccu_mult *cm = data;
  42        struct _ccu_mult _cm;
  43
  44        _cm.min = cm->mult.min;
  45
  46        if (cm->mult.max)
  47                _cm.max = cm->mult.max;
  48        else
  49                _cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
  50
  51        ccu_mult_find_best(*parent_rate, rate, &_cm);
  52
  53        return *parent_rate * _cm.mult;
  54}
  55
  56static void ccu_mult_disable(struct clk_hw *hw)
  57{
  58        struct ccu_mult *cm = hw_to_ccu_mult(hw);
  59
  60        return ccu_gate_helper_disable(&cm->common, cm->enable);
  61}
  62
  63static int ccu_mult_enable(struct clk_hw *hw)
  64{
  65        struct ccu_mult *cm = hw_to_ccu_mult(hw);
  66
  67        return ccu_gate_helper_enable(&cm->common, cm->enable);
  68}
  69
  70static int ccu_mult_is_enabled(struct clk_hw *hw)
  71{
  72        struct ccu_mult *cm = hw_to_ccu_mult(hw);
  73
  74        return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
  75}
  76
  77static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
  78                                        unsigned long parent_rate)
  79{
  80        struct ccu_mult *cm = hw_to_ccu_mult(hw);
  81        unsigned long val;
  82        u32 reg;
  83
  84        if (ccu_frac_helper_is_enabled(&cm->common, &cm->frac))
  85                return ccu_frac_helper_read_rate(&cm->common, &cm->frac);
  86
  87        reg = readl(cm->common.base + cm->common.reg);
  88        val = reg >> cm->mult.shift;
  89        val &= (1 << cm->mult.width) - 1;
  90
  91        parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
  92                                                  parent_rate);
  93
  94        return parent_rate * (val + cm->mult.offset);
  95}
  96
  97static int ccu_mult_determine_rate(struct clk_hw *hw,
  98                                struct clk_rate_request *req)
  99{
 100        struct ccu_mult *cm = hw_to_ccu_mult(hw);
 101
 102        return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
 103                                             req, ccu_mult_round_rate, cm);
 104}
 105
 106static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
 107                           unsigned long parent_rate)
 108{
 109        struct ccu_mult *cm = hw_to_ccu_mult(hw);
 110        struct _ccu_mult _cm;
 111        unsigned long flags;
 112        u32 reg;
 113
 114        if (ccu_frac_helper_has_rate(&cm->common, &cm->frac, rate)) {
 115                ccu_frac_helper_enable(&cm->common, &cm->frac);
 116
 117                return ccu_frac_helper_set_rate(&cm->common, &cm->frac,
 118                                                rate, cm->lock);
 119        } else {
 120                ccu_frac_helper_disable(&cm->common, &cm->frac);
 121        }
 122
 123        parent_rate = ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
 124                                                  parent_rate);
 125
 126        _cm.min = cm->mult.min;
 127
 128        if (cm->mult.max)
 129                _cm.max = cm->mult.max;
 130        else
 131                _cm.max = (1 << cm->mult.width) + cm->mult.offset - 1;
 132
 133        ccu_mult_find_best(parent_rate, rate, &_cm);
 134
 135        spin_lock_irqsave(cm->common.lock, flags);
 136
 137        reg = readl(cm->common.base + cm->common.reg);
 138        reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
 139        reg |= ((_cm.mult - cm->mult.offset) << cm->mult.shift);
 140
 141        writel(reg, cm->common.base + cm->common.reg);
 142
 143        spin_unlock_irqrestore(cm->common.lock, flags);
 144
 145        ccu_helper_wait_for_lock(&cm->common, cm->lock);
 146
 147        return 0;
 148}
 149
 150static u8 ccu_mult_get_parent(struct clk_hw *hw)
 151{
 152        struct ccu_mult *cm = hw_to_ccu_mult(hw);
 153
 154        return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
 155}
 156
 157static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
 158{
 159        struct ccu_mult *cm = hw_to_ccu_mult(hw);
 160
 161        return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
 162}
 163
 164const struct clk_ops ccu_mult_ops = {
 165        .disable        = ccu_mult_disable,
 166        .enable         = ccu_mult_enable,
 167        .is_enabled     = ccu_mult_is_enabled,
 168
 169        .get_parent     = ccu_mult_get_parent,
 170        .set_parent     = ccu_mult_set_parent,
 171
 172        .determine_rate = ccu_mult_determine_rate,
 173        .recalc_rate    = ccu_mult_recalc_rate,
 174        .set_rate       = ccu_mult_set_rate,
 175};
 176