xref: /openbmc/linux/drivers/clk/qcom/reset.c (revision f0f52af4)
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);
60