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/delay.h>
8 #include <linux/io.h>
9 #include <linux/reset-controller.h>
10
11 #include "ccu_reset.h"
12
ccu_reset_assert(struct reset_controller_dev * rcdev,unsigned long id)13 static int ccu_reset_assert(struct reset_controller_dev *rcdev,
14 unsigned long id)
15 {
16 struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
17 const struct ccu_reset_map *map = &ccu->reset_map[id];
18 unsigned long flags;
19 u32 reg;
20
21 spin_lock_irqsave(ccu->lock, flags);
22
23 reg = readl(ccu->base + map->reg);
24 writel(reg & ~map->bit, ccu->base + map->reg);
25
26 spin_unlock_irqrestore(ccu->lock, flags);
27
28 return 0;
29 }
30
ccu_reset_deassert(struct reset_controller_dev * rcdev,unsigned long id)31 static int ccu_reset_deassert(struct reset_controller_dev *rcdev,
32 unsigned long id)
33 {
34 struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
35 const struct ccu_reset_map *map = &ccu->reset_map[id];
36 unsigned long flags;
37 u32 reg;
38
39 spin_lock_irqsave(ccu->lock, flags);
40
41 reg = readl(ccu->base + map->reg);
42 writel(reg | map->bit, ccu->base + map->reg);
43
44 spin_unlock_irqrestore(ccu->lock, flags);
45
46 return 0;
47 }
48
ccu_reset_reset(struct reset_controller_dev * rcdev,unsigned long id)49 static int ccu_reset_reset(struct reset_controller_dev *rcdev,
50 unsigned long id)
51 {
52 ccu_reset_assert(rcdev, id);
53 udelay(10);
54 ccu_reset_deassert(rcdev, id);
55
56 return 0;
57 }
58
ccu_reset_status(struct reset_controller_dev * rcdev,unsigned long id)59 static int ccu_reset_status(struct reset_controller_dev *rcdev,
60 unsigned long id)
61 {
62 struct ccu_reset *ccu = rcdev_to_ccu_reset(rcdev);
63 const struct ccu_reset_map *map = &ccu->reset_map[id];
64
65 /*
66 * The reset control API expects 0 if reset is not asserted,
67 * which is the opposite of what our hardware uses.
68 */
69 return !(map->bit & readl(ccu->base + map->reg));
70 }
71
72 const struct reset_control_ops ccu_reset_ops = {
73 .assert = ccu_reset_assert,
74 .deassert = ccu_reset_deassert,
75 .reset = ccu_reset_reset,
76 .status = ccu_reset_status,
77 };
78
