drivers/clk/sunxi-ng/ccu_mult.c

   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
  16 static void ccu_mult_find_best(unsigned long parent, unsigned long rate,
  17                                unsigned int max_n, unsigned int *n)
  18 {
  19         *n = rate / parent;
  20 }
  21
  22 static unsigned long ccu_mult_round_rate(struct ccu_mux_internal *mux,
  23                                         unsigned long parent_rate,
  24                                         unsigned long rate,
  25                                         void *data)
  26 {
  27         struct ccu_mult *cm = data;
  28         unsigned int n;
  29
  30         ccu_mult_find_best(parent_rate, rate, 1 << cm->mult.width, &n);
  31
  32         return parent_rate * n;
  33 }
  34
  35 static void ccu_mult_disable(struct clk_hw *hw)
  36 {
  37         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  38
  39         return ccu_gate_helper_disable(&cm->common, cm->enable);
  40 }
  41
  42 static int ccu_mult_enable(struct clk_hw *hw)
  43 {
  44         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  45
  46         return ccu_gate_helper_enable(&cm->common, cm->enable);
  47 }
  48
  49 static int ccu_mult_is_enabled(struct clk_hw *hw)
  50 {
  51         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  52
  53         return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
  54 }
  55
  56 static unsigned long ccu_mult_recalc_rate(struct clk_hw *hw,
  57                                         unsigned long parent_rate)
  58 {
  59         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  60         unsigned long val;
  61         u32 reg;
  62
  63         reg = readl(cm->common.base + cm->common.reg);
  64         val = reg >> cm->mult.shift;
  65         val &= (1 << cm->mult.width) - 1;
  66
  67         ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
  68                                                 &parent_rate);
  69
  70         return parent_rate * (val + 1);
  71 }
  72
  73 static int ccu_mult_determine_rate(struct clk_hw *hw,
  74                                 struct clk_rate_request *req)
  75 {
  76         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  77
  78         return ccu_mux_helper_determine_rate(&cm->common, &cm->mux,
  79                                              req, ccu_mult_round_rate, cm);
  80 }
  81
  82 static int ccu_mult_set_rate(struct clk_hw *hw, unsigned long rate,
  83                            unsigned long parent_rate)
  84 {
  85         struct ccu_mult *cm = hw_to_ccu_mult(hw);
  86         unsigned long flags;
  87         unsigned int n;
  88         u32 reg;
  89
  90         ccu_mux_helper_adjust_parent_for_prediv(&cm->common, &cm->mux, -1,
  91                                                 &parent_rate);
  92
  93         ccu_mult_find_best(parent_rate, rate, 1 << cm->mult.width, &n);
  94
  95         spin_lock_irqsave(cm->common.lock, flags);
  96
  97         reg = readl(cm->common.base + cm->common.reg);
  98         reg &= ~GENMASK(cm->mult.width + cm->mult.shift - 1, cm->mult.shift);
  99
 100         writel(reg | ((n - 1) << cm->mult.shift),
 101                cm->common.base + cm->common.reg);
 102
 103         spin_unlock_irqrestore(cm->common.lock, flags);
 104
 105         return 0;
 106 }
 107
 108 static u8 ccu_mult_get_parent(struct clk_hw *hw)
 109 {
 110         struct ccu_mult *cm = hw_to_ccu_mult(hw);
 111
 112         return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
 113 }
 114
 115 static int ccu_mult_set_parent(struct clk_hw *hw, u8 index)
 116 {
 117         struct ccu_mult *cm = hw_to_ccu_mult(hw);
 118
 119         return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
 120 }
 121
 122 const struct clk_ops ccu_mult_ops = {
 123         .disable        = ccu_mult_disable,
 124         .enable         = ccu_mult_enable,
 125         .is_enabled     = ccu_mult_is_enabled,
 126
 127         .get_parent     = ccu_mult_get_parent,
 128         .set_parent     = ccu_mult_set_parent,
 129
 130         .determine_rate = ccu_mult_determine_rate,
 131         .recalc_rate    = ccu_mult_recalc_rate,
 132         .set_rate       = ccu_mult_set_rate,
 133 };