1// SPDX-License-Identifier: GPL-2.0
2#include <linux/slab.h>
3#include <linux/io.h>
4#include <linux/of.h>
5#include <linux/of_address.h>
6#include <linux/reset-controller.h>
7
8#include "reset.h"
9
10#define rcdev_to_unit(rcdev) container_of(rcdev, struct mmp_clk_reset_unit, rcdev)
11
12static int mmp_of_reset_xlate(struct reset_controller_dev *rcdev,
13 const struct of_phandle_args *reset_spec)
14{
15 struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
16 struct mmp_clk_reset_cell *cell;
17 int i;
18
19 if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
20 return -EINVAL;
21
22 for (i = 0; i < rcdev->nr_resets; i++) {
23 cell = &unit->cells[i];
24 if (cell->clk_id == reset_spec->args[0])
25 break;
26 }
27
28 if (i == rcdev->nr_resets)
29 return -EINVAL;
30
31 return i;
32}
33
34static int mmp_clk_reset_assert(struct reset_controller_dev *rcdev,
35 unsigned long id)
36{
37 struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
38 struct mmp_clk_reset_cell *cell;
39 unsigned long flags = 0;
40 u32 val;
41
42 cell = &unit->cells[id];
43 if (cell->lock)
44 spin_lock_irqsave(cell->lock, flags);
45
46 val = readl(addr: cell->reg);
47 val |= cell->bits;
48 writel(val, addr: cell->reg);
49
50 if (cell->lock)
51 spin_unlock_irqrestore(lock: cell->lock, flags);
52
53 return 0;
54}
55
56static int mmp_clk_reset_deassert(struct reset_controller_dev *rcdev,
57 unsigned long id)
58{
59 struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
60 struct mmp_clk_reset_cell *cell;
61 unsigned long flags = 0;
62 u32 val;
63
64 cell = &unit->cells[id];
65 if (cell->lock)
66 spin_lock_irqsave(cell->lock, flags);
67
68 val = readl(addr: cell->reg);
69 val &= ~cell->bits;
70 writel(val, addr: cell->reg);
71
72 if (cell->lock)
73 spin_unlock_irqrestore(lock: cell->lock, flags);
74
75 return 0;
76}
77
78static const struct reset_control_ops mmp_clk_reset_ops = {
79 .assert = mmp_clk_reset_assert,
80 .deassert = mmp_clk_reset_deassert,
81};
82
83void mmp_clk_reset_register(struct device_node *np,
84 struct mmp_clk_reset_cell *cells, int nr_resets)
85{
86 struct mmp_clk_reset_unit *unit;
87
88 unit = kzalloc(size: sizeof(*unit), GFP_KERNEL);
89 if (!unit)
90 return;
91
92 unit->cells = cells;
93 unit->rcdev.of_reset_n_cells = 1;
94 unit->rcdev.nr_resets = nr_resets;
95 unit->rcdev.ops = &mmp_clk_reset_ops;
96 unit->rcdev.of_node = np;
97 unit->rcdev.of_xlate = mmp_of_reset_xlate;
98
99 reset_controller_register(rcdev: &unit->rcdev);
100}
101

source code of linux/drivers/clk/mmp/reset.c