drivers/clk/sprd/gate.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Spreadtrum gate clock driver
   4 //
   5 // Copyright (C) 2017 Spreadtrum, Inc.
   6 // Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
   7
   8 #include <linux/clk-provider.h>
   9 #include <linux/regmap.h>
  10
  11 #include "gate.h"
  12
  13 static void clk_gate_toggle(const struct sprd_gate *sg, bool en)
  14 {
  15         const struct sprd_clk_common *common = &sg->common;
  16         unsigned int reg;
  17         bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? true : false;
  18
  19         set ^= en;
  20
  21         regmap_read(common->regmap, common->reg, &reg);
  22
  23         if (set)
  24                 reg |= sg->enable_mask;
  25         else
  26                 reg &= ~sg->enable_mask;
  27
  28         regmap_write(common->regmap, common->reg, reg);
  29 }
  30
  31 static void clk_sc_gate_toggle(const struct sprd_gate *sg, bool en)
  32 {
  33         const struct sprd_clk_common *common = &sg->common;
  34         bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
  35         unsigned int offset;
  36
  37         set ^= en;
  38
  39         /*
  40          * Each set/clear gate clock has three registers:
  41          * common->reg                  - base register
  42          * common->reg + offset         - set register
  43          * common->reg + 2 * offset     - clear register
  44          */
  45         offset = set ? sg->sc_offset : sg->sc_offset * 2;
  46
  47         regmap_write(common->regmap, common->reg + offset,
  48                           sg->enable_mask);
  49 }
  50
  51 static void sprd_gate_disable(struct clk_hw *hw)
  52 {
  53         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  54
  55         clk_gate_toggle(sg, false);
  56 }
  57
  58 static int sprd_gate_enable(struct clk_hw *hw)
  59 {
  60         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  61
  62         clk_gate_toggle(sg, true);
  63
  64         return 0;
  65 }
  66
  67 static void sprd_sc_gate_disable(struct clk_hw *hw)
  68 {
  69         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  70
  71         clk_sc_gate_toggle(sg, false);
  72 }
  73
  74 static int sprd_sc_gate_enable(struct clk_hw *hw)
  75 {
  76         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  77
  78         clk_sc_gate_toggle(sg, true);
  79
  80         return 0;
  81 }
  82
  83 static int sprd_pll_sc_gate_prepare(struct clk_hw *hw)
  84 {
  85         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  86
  87         clk_sc_gate_toggle(sg, true);
  88         udelay(sg->udelay);
  89
  90         return 0;
  91 }
  92
  93 static int sprd_gate_is_enabled(struct clk_hw *hw)
  94 {
  95         struct sprd_gate *sg = hw_to_sprd_gate(hw);
  96         struct sprd_clk_common *common = &sg->common;
  97         struct clk_hw *parent;
  98         unsigned int reg;
  99
 100         if (sg->flags & SPRD_GATE_NON_AON) {
 101                 parent = clk_hw_get_parent(hw);
 102                 if (!parent || !clk_hw_is_enabled(parent))
 103                         return 0;
 104         }
 105
 106         regmap_read(common->regmap, common->reg, &reg);
 107
 108         if (sg->flags & CLK_GATE_SET_TO_DISABLE)
 109                 reg ^= sg->enable_mask;
 110
 111         reg &= sg->enable_mask;
 112
 113         return reg ? 1 : 0;
 114 }
 115
 116 const struct clk_ops sprd_gate_ops = {
 117         .disable        = sprd_gate_disable,
 118         .enable         = sprd_gate_enable,
 119         .is_enabled     = sprd_gate_is_enabled,
 120 };
 121 EXPORT_SYMBOL_GPL(sprd_gate_ops);
 122
 123 const struct clk_ops sprd_sc_gate_ops = {
 124         .disable        = sprd_sc_gate_disable,
 125         .enable         = sprd_sc_gate_enable,
 126         .is_enabled     = sprd_gate_is_enabled,
 127 };
 128 EXPORT_SYMBOL_GPL(sprd_sc_gate_ops);
 129
 130 const struct clk_ops sprd_pll_sc_gate_ops = {
 131         .unprepare      = sprd_sc_gate_disable,
 132         .prepare        = sprd_pll_sc_gate_prepare,
 133         .is_enabled     = sprd_gate_is_enabled,
 134 };
 135 EXPORT_SYMBOL_GPL(sprd_pll_sc_gate_ops);