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 #include <linux/io.h>
  13
  14 #include "ccu_gate.h"
  15
  16 void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
  17 {
  18         unsigned long flags;
  19         u32 reg;
  20
  21         if (!gate)
  22                 return;
  23
  24         spin_lock_irqsave(common->lock, flags);
  25
  26         reg = readl(common->base + common->reg);
  27         writel(reg & ~gate, common->base + common->reg);
  28
  29         spin_unlock_irqrestore(common->lock, flags);
  30 }
  31
  32 static void ccu_gate_disable(struct clk_hw *hw)
  33 {
  34         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  35
  36         return ccu_gate_helper_disable(&cg->common, cg->enable);
  37 }
  38
  39 int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
  40 {
  41         unsigned long flags;
  42         u32 reg;
  43
  44         if (!gate)
  45                 return 0;
  46
  47         spin_lock_irqsave(common->lock, flags);
  48
  49         reg = readl(common->base + common->reg);
  50         writel(reg | gate, common->base + common->reg);
  51
  52         spin_unlock_irqrestore(common->lock, flags);
  53
  54         return 0;
  55 }
  56
  57 static int ccu_gate_enable(struct clk_hw *hw)
  58 {
  59         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  60
  61         return ccu_gate_helper_enable(&cg->common, cg->enable);
  62 }
  63
  64 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
  65 {
  66         if (!gate)
  67                 return 1;
  68
  69         return readl(common->base + common->reg) & gate;
  70 }
  71
  72 static int ccu_gate_is_enabled(struct clk_hw *hw)
  73 {
  74         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  75
  76         return ccu_gate_helper_is_enabled(&cg->common, cg->enable);
  77 }
  78
  79 static unsigned long ccu_gate_recalc_rate(struct clk_hw *hw,
  80                                           unsigned long parent_rate)
  81 {
  82         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  83         unsigned long rate = parent_rate;
  84
  85         if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
  86                 rate /= cg->common.prediv;
  87
  88         return rate;
  89 }
  90
  91 static long ccu_gate_round_rate(struct clk_hw *hw, unsigned long rate,
  92                                 unsigned long *prate)
  93 {
  94         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  95         int div = 1;
  96
  97         if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
  98                 div = cg->common.prediv;
  99
 100         if (clk_hw_get_flags(hw) & CLK_SET_RATE_PARENT) {
 101                 unsigned long best_parent = rate;
 102
 103                 if (cg->common.features & CCU_FEATURE_ALL_PREDIV)
 104                         best_parent *= div;
 105                 *prate = clk_hw_round_rate(clk_hw_get_parent(hw), best_parent);
 106         }
 107
 108         return *prate / div;
 109 }
 110
 111 static int ccu_gate_set_rate(struct clk_hw *hw, unsigned long rate,
 112                              unsigned long parent_rate)
 113 {
 114         /*
 115          * We must report success but we can do so unconditionally because
 116          * clk_factor_round_rate returns values that ensure this call is a
 117          * nop.
 118          */
 119
 120         return 0;
 121 }
 122
 123 const struct clk_ops ccu_gate_ops = {
 124         .disable        = ccu_gate_disable,
 125         .enable         = ccu_gate_enable,
 126         .is_enabled     = ccu_gate_is_enabled,
 127         .round_rate     = ccu_gate_round_rate,
 128         .set_rate       = ccu_gate_set_rate,
 129         .recalc_rate    = ccu_gate_recalc_rate,
 130 };