drivers/clk/sunxi-ng/ccu_gate.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2016 Maxime Ripard
   4  * Maxime Ripard <maxime.ripard@free-electrons.com>
   5  */
   6
   7 #include <linux/clk-provider.h>
   8 #include <linux/io.h>
   9
  10 #include "ccu_gate.h"
  11
  12 void ccu_gate_helper_disable(struct ccu_common *common, u32 gate)
  13 {
  14         unsigned long flags;
  15         u32 reg;
  16
  17         if (!gate)
  18                 return;
  19
  20         spin_lock_irqsave(common->lock, flags);
  21
  22         reg = readl(common->base + common->reg);
  23         writel(reg & ~gate, common->base + common->reg);
  24
  25         spin_unlock_irqrestore(common->lock, flags);
  26 }
  27 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_disable, SUNXI_CCU);
  28
  29 static void ccu_gate_disable(struct clk_hw *hw)
  30 {
  31         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  32
  33         return ccu_gate_helper_disable(&cg->common, cg->enable);
  34 }
  35
  36 int ccu_gate_helper_enable(struct ccu_common *common, u32 gate)
  37 {
  38         unsigned long flags;
  39         u32 reg;
  40
  41         if (!gate)
  42                 return 0;
  43
  44         spin_lock_irqsave(common->lock, flags);
  45
  46         reg = readl(common->base + common->reg);
  47         writel(reg | gate, common->base + common->reg);
  48
  49         spin_unlock_irqrestore(common->lock, flags);
  50
  51         return 0;
  52 }
  53 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_enable, SUNXI_CCU);
  54
  55 static int ccu_gate_enable(struct clk_hw *hw)
  56 {
  57         struct ccu_gate *cg = hw_to_ccu_gate(hw);
  58
  59         return ccu_gate_helper_enable(&cg->common, cg->enable);
  60 }
  61
  62 int ccu_gate_helper_is_enabled(struct ccu_common *common, u32 gate)
  63 {
  64         if (!gate)
  65                 return 1;
  66
  67         return readl(common->base + common->reg) & gate;
  68 }
  69 EXPORT_SYMBOL_NS_GPL(ccu_gate_helper_is_enabled, SUNXI_CCU);
  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 };
 130 EXPORT_SYMBOL_NS_GPL(ccu_gate_ops, SUNXI_CCU);