]> Git Repo - J-linux.git/blob - drivers/clk/stm32/reset-stm32.c
Merge tag 'vfs-6.13-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
[J-linux.git] / drivers / clk / stm32 / reset-stm32.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) STMicroelectronics 2022 - All Rights Reserved
4  * Author: Gabriel Fernandez <[email protected]> for STMicroelectronics.
5  */
6
7 #include <linux/of.h>
8 #include <linux/platform_device.h>
9 #include <linux/regmap.h>
10 #include <linux/reset-controller.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13
14 #include "reset-stm32.h"
15
16 struct stm32_reset_data {
17         /* reset lock */
18         spinlock_t                      lock;
19         struct reset_controller_dev     rcdev;
20         void __iomem                    *membase;
21         u32                             clear_offset;
22         const struct stm32_reset_cfg    **reset_lines;
23 };
24
25 static inline struct stm32_reset_data *
26 to_stm32_reset_data(struct reset_controller_dev *rcdev)
27 {
28         return container_of(rcdev, struct stm32_reset_data, rcdev);
29 }
30
31 static const struct stm32_reset_cfg *stm32_get_reset_line(struct reset_controller_dev *rcdev,
32                                                           unsigned long id,
33                                                           struct stm32_reset_cfg *line)
34 {
35         struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
36
37         if (!data->reset_lines) {
38                 int reg_width = sizeof(u32);
39                 int bank = id / (reg_width * BITS_PER_BYTE);
40                 int offset = id % (reg_width * BITS_PER_BYTE);
41
42                 line->offset = bank * reg_width;
43                 line->bit_idx = offset;
44                 line->set_clr = (data->clear_offset ? true : false);
45
46                 return line;
47         }
48
49         return data->reset_lines[id];
50 }
51
52 static int stm32_reset_update(struct reset_controller_dev *rcdev,
53                               unsigned long id, bool assert)
54 {
55         struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
56         struct stm32_reset_cfg line_reset;
57         const struct stm32_reset_cfg *ptr_line;
58
59         ptr_line = stm32_get_reset_line(rcdev, id, &line_reset);
60         if (!ptr_line)
61                 return -EPERM;
62
63         if (ptr_line->set_clr) {
64                 void __iomem *addr;
65
66                 addr = data->membase + ptr_line->offset;
67                 if (!assert)
68                         addr += data->clear_offset;
69
70                 writel(BIT(ptr_line->bit_idx), addr);
71
72         } else {
73                 unsigned long flags;
74                 u32 reg;
75
76                 spin_lock_irqsave(&data->lock, flags);
77
78                 reg = readl(data->membase + ptr_line->offset);
79
80                 if (assert)
81                         reg |= BIT(ptr_line->bit_idx);
82                 else
83                         reg &= ~BIT(ptr_line->bit_idx);
84
85                 writel(reg, data->membase + ptr_line->offset);
86
87                 spin_unlock_irqrestore(&data->lock, flags);
88         }
89
90         return 0;
91 }
92
93 static int stm32_reset_assert(struct reset_controller_dev *rcdev,
94                               unsigned long id)
95 {
96         return stm32_reset_update(rcdev, id, true);
97 }
98
99 static int stm32_reset_deassert(struct reset_controller_dev *rcdev,
100                                 unsigned long id)
101 {
102         return stm32_reset_update(rcdev, id, false);
103 }
104
105 static int stm32_reset_status(struct reset_controller_dev *rcdev,
106                               unsigned long id)
107 {
108         struct stm32_reset_data *data = to_stm32_reset_data(rcdev);
109         struct stm32_reset_cfg line_reset;
110         const struct stm32_reset_cfg *ptr_line;
111         u32 reg;
112
113         ptr_line = stm32_get_reset_line(rcdev, id, &line_reset);
114         if (!ptr_line)
115                 return -EPERM;
116
117         reg = readl(data->membase + ptr_line->offset);
118
119         return !!(reg & BIT(ptr_line->bit_idx));
120 }
121
122 static const struct reset_control_ops stm32_reset_ops = {
123         .assert         = stm32_reset_assert,
124         .deassert       = stm32_reset_deassert,
125         .status         = stm32_reset_status,
126 };
127
128 int stm32_rcc_reset_init(struct device *dev, struct clk_stm32_reset_data *data,
129                          void __iomem *base)
130 {
131         struct stm32_reset_data *reset_data;
132
133         reset_data = kzalloc(sizeof(*reset_data), GFP_KERNEL);
134         if (!reset_data)
135                 return -ENOMEM;
136
137         spin_lock_init(&reset_data->lock);
138
139         reset_data->membase = base;
140         reset_data->rcdev.owner = THIS_MODULE;
141         reset_data->rcdev.ops = &stm32_reset_ops;
142         reset_data->rcdev.of_node = dev_of_node(dev);
143         reset_data->rcdev.nr_resets = data->nr_lines;
144         reset_data->reset_lines = data->reset_lines;
145         reset_data->clear_offset = data->clear_offset;
146
147         return reset_controller_register(&reset_data->rcdev);
148 }
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