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
  16static 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
  22static 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
  35static 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
  42static 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
  49static 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
  56static 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
  73static 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
  82static 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
 108static 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
 115static 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
 122const 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};
 134