drivers/clk/qcom/reset.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
   4  */
   5
   6 #include <linux/bitops.h>
   7 #include <linux/export.h>
   8 #include <linux/regmap.h>
   9 #include <linux/reset-controller.h>
  10 #include <linux/delay.h>
  11
  12 #include "reset.h"
  13
  14 static int qcom_reset(struct reset_controller_dev *rcdev, unsigned long id)
  15 {
  16         struct qcom_reset_controller *rst = to_qcom_reset_controller(rcdev);
  17
  18         rcdev->ops->assert(rcdev, id);
  19         fsleep(rst->reset_map[id].udelay ?: 1); /* use 1 us as default */
  20
  21         rcdev->ops->deassert(rcdev, id);
  22         return 0;
  23 }
  24
  25 static int qcom_reset_set_assert(struct reset_controller_dev *rcdev,
  26                                  unsigned long id, bool assert)
  27 {
  28         struct qcom_reset_controller *rst;
  29         const struct qcom_reset_map *map;
  30         u32 mask;
  31
  32         rst = to_qcom_reset_controller(rcdev);
  33         map = &rst->reset_map[id];
  34         mask = map->bitmask ? map->bitmask : BIT(map->bit);
  35
  36         regmap_update_bits(rst->regmap, map->reg, mask, assert ? mask : 0);
  37
  38         /* Read back the register to ensure write completion, ignore the value */
  39         regmap_read(rst->regmap, map->reg, &mask);
  40
  41         return 0;
  42 }
  43
  44 static int qcom_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
  45 {
  46         return qcom_reset_set_assert(rcdev, id, true);
  47 }
  48
  49 static int qcom_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
  50 {
  51         return qcom_reset_set_assert(rcdev, id, false);
  52 }
  53
  54 const struct reset_control_ops qcom_reset_ops = {
  55         .reset = qcom_reset,
  56         .assert = qcom_reset_assert,
  57         .deassert = qcom_reset_deassert,
  58 };
  59 EXPORT_SYMBOL_GPL(qcom_reset_ops);