drivers/clk/sunxi-ng/ccu_gate.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
  15 void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
  16 {
  17         unsigned long flags;
  18         u32 reg;
  19
  20         if (!gate)
  21                 return;
  22
  23         spin_lock_irqsave(common->lock, flags);
  24
  25         reg = readl(common->base + common->reg);
  26         writel(reg & ~gate, common->base + common->reg);
  27
  28         spin_unlock_irqrestore(common->lock, flags);
  29 }
  30
  31 static void ccu_gate_disable(struct clk_hw *hw)
  32 {
  33         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  34
  35         return ccu_gate_helper_disable(&cg->common, cg->enable);
  36 }
  37
  38 int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
  39 {
  40         unsigned long flags;
  41         u32 reg;
  42
  43         if (!gate)
  44                 return 0;
  45
  46         spin_lock_irqsave(common->lock, flags);
  47
  48         reg = readl(common->base + common->reg);
  49         writel(reg | gate, common->base + common->reg);
  50
  51         spin_unlock_irqrestore(common->lock, flags);
  52
  53         return 0;
  54 }
  55
  56 static int ccu_gate_enable(struct clk_hw *hw)
  57 {
  58         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  59
  60         return ccu_gate_helper_enable(&cg->common, cg->enable);
  61 }
  62
  63 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
  64 {
  65         if (!gate)
  66                 return 1;
  67
  68         return readl(common->base + common->reg) & gate;
  69 }
  70
  71 static int ccu_gate_is_enabled(struct clk_hw *hw)
  72 {
  73         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  74
  75         return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
  76 }
  77
  78 static unsigned long ccu_gate_recalc_rate(struct clk_hw *hw,
  79                                           unsigned long parent_rate)
  80 {
  81         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  82         unsigned long rate = parent_rate;
  83
  84         if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
  85                 rate /= cg->common.prediv;
  86
  87         return rate;
  88 }
  89
  90 static long ccu_gate_round_rate(struct clk_hw *hw, unsigned long rate,
  91                                 unsigned long *prate)
  92 {
  93         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  94         int div = 1;
  95
  96         if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
  97                 div = cg->common.prediv;
  98
  99         if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
 100                 unsigned long best_parent = rate;
 101
 102                 if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
 103                         best_parent *= div;
 104                 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
 105         }
 106
 107         return *prate / div;
 108 }
 109
 110 static int ccu_gate_set_rate(struct clk_hw *hw, unsigned long rate,
 111                              unsigned long parent_rate)
 112 {
 113         /*
 114          * We must report success but we can do so unconditionally because
 115          * clk_factor_round_rate returns values that ensure this call is a
 116          * nop.
 117          */
 118
 119         return 0;
 120 }
 121
 122 const struct clk_ops ccu_gate_ops = {
 123         .disable        = ccu_gate_disable,
 124         .enable         = ccu_gate_enable,
 125         .is_enabled     = ccu_gate_is_enabled,
 126         .round_rate     = ccu_gate_round_rate,
 127         .set_rate       = ccu_gate_set_rate,
 128         .recalc_rate    = ccu_gate_recalc_rate,
 129 };