drivers/clk/mediatek/reset.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2014 MediaTek Inc.
   4  */
   5
   6 #include <linux/mfd/syscon.h>
   7 #include <linux/module.h>
   8 #include <linux/of.h>
   9 #include <linux/platform_device.h>
  10 #include <linux/regmap.h>
  11 #include <linux/reset-controller.h>
  12 #include <linux/slab.h>
  13
  14 #include "clk-mtk.h"
  15
  16 struct mtk_reset {
  17         struct regmap *regmap;
  18         int regofs;
  19         struct reset_controller_dev rcdev;
  20 };
  21
  22 static int mtk_reset_assert_set_clr(struct reset_controller_dev *rcdev,
  23         unsigned long id)
  24 {
  25         struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  26         unsigned int reg = data->regofs + ((id / 32) << 4);
  27
  28         return regmap_write(data->regmap, reg, 1);
  29 }
  30
  31 static int mtk_reset_deassert_set_clr(struct reset_controller_dev *rcdev,
  32         unsigned long id)
  33 {
  34         struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  35         unsigned int reg = data->regofs + ((id / 32) << 4) + 0x4;
  36
  37         return regmap_write(data->regmap, reg, 1);
  38 }
  39
  40 static int mtk_reset_assert(struct reset_controller_dev *rcdev,
  41                               unsigned long id)
  42 {
  43         struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  44
  45         return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
  46                         BIT(id % 32), ~0);
  47 }
  48
  49 static int mtk_reset_deassert(struct reset_controller_dev *rcdev,
  50                                 unsigned long id)
  51 {
  52         struct mtk_reset *data = container_of(rcdev, struct mtk_reset, rcdev);
  53
  54         return regmap_update_bits(data->regmap, data->regofs + ((id / 32) << 2),
  55                         BIT(id % 32), 0);
  56 }
  57
  58 static int mtk_reset(struct reset_controller_dev *rcdev,
  59                               unsigned long id)
  60 {
  61         int ret;
  62
  63         ret = mtk_reset_assert(rcdev, id);
  64         if (ret)
  65                 return ret;
  66
  67         return mtk_reset_deassert(rcdev, id);
  68 }
  69
  70 static int mtk_reset_set_clr(struct reset_controller_dev *rcdev,
  71         unsigned long id)
  72 {
  73         int ret;
  74
  75         ret = mtk_reset_assert_set_clr(rcdev, id);
  76         if (ret)
  77                 return ret;
  78         return mtk_reset_deassert_set_clr(rcdev, id);
  79 }
  80
  81 static const struct reset_control_ops mtk_reset_ops = {
  82         .assert = mtk_reset_assert,
  83         .deassert = mtk_reset_deassert,
  84         .reset = mtk_reset,
  85 };
  86
  87 static const struct reset_control_ops mtk_reset_ops_set_clr = {
  88         .assert = mtk_reset_assert_set_clr,
  89         .deassert = mtk_reset_deassert_set_clr,
  90         .reset = mtk_reset_set_clr,
  91 };
  92
  93 static void mtk_register_reset_controller_common(struct device_node *np,
  94                         unsigned int num_regs, int regofs,
  95                         const struct reset_control_ops *reset_ops)
  96 {
  97         struct mtk_reset *data;
  98         int ret;
  99         struct regmap *regmap;
 100
 101         regmap = syscon_node_to_regmap(np);
 102         if (IS_ERR(regmap)) {
 103                 pr_err("Cannot find regmap for %pOF: %ld\n", np,
 104                                 PTR_ERR(regmap));
 105                 return;
 106         }
 107
 108         data = kzalloc(sizeof(*data), GFP_KERNEL);
 109         if (!data)
 110                 return;
 111
 112         data->regmap = regmap;
 113         data->regofs = regofs;
 114         data->rcdev.owner = THIS_MODULE;
 115         data->rcdev.nr_resets = num_regs * 32;
 116         data->rcdev.ops = reset_ops;
 117         data->rcdev.of_node = np;
 118
 119         ret = reset_controller_register(&data->rcdev);
 120         if (ret) {
 121                 pr_err("could not register reset controller: %d\n", ret);
 122                 kfree(data);
 123                 return;
 124         }
 125 }
 126
 127 void mtk_register_reset_controller(struct device_node *np,
 128         unsigned int num_regs, int regofs)
 129 {
 130         mtk_register_reset_controller_common(np, num_regs, regofs,
 131                 &mtk_reset_ops);
 132 }
 133
 134 void mtk_register_reset_controller_set_clr(struct device_node *np,
 135         unsigned int num_regs, int regofs)
 136 {
 137         mtk_register_reset_controller_common(np, num_regs, regofs,
 138                 &mtk_reset_ops_set_clr);
 139 }