xref: /openbmc/linux/drivers/clk/mmp/reset.c (revision b2441318)
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 
mmp_of_reset_xlate(struct reset_controller_dev * rcdev,const struct of_phandle_args * reset_spec)12 static 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 
mmp_clk_reset_assert(struct reset_controller_dev * rcdev,unsigned long id)34 static 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(cell->reg);
47 	val |= cell->bits;
48 	writel(val, cell->reg);
49 
50 	if (cell->lock)
51 		spin_unlock_irqrestore(cell->lock, flags);
52 
53 	return 0;
54 }
55 
mmp_clk_reset_deassert(struct reset_controller_dev * rcdev,unsigned long id)56 static 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(cell->reg);
69 	val &= ~cell->bits;
70 	writel(val, cell->reg);
71 
72 	if (cell->lock)
73 		spin_unlock_irqrestore(cell->lock, flags);
74 
75 	return 0;
76 }
77 
78 static const struct reset_control_ops mmp_clk_reset_ops = {
79 	.assert		= mmp_clk_reset_assert,
80 	.deassert	= mmp_clk_reset_deassert,
81 };
82 
mmp_clk_reset_register(struct device_node * np,struct mmp_clk_reset_cell * cells,int nr_resets)83 void 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(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(&unit->rcdev);
100 }
101