1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2016 Socionext Inc.
4 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
5 */
6
7#include <linux/clk-provider.h>
8#include <linux/device.h>
9#include <linux/regmap.h>
10
11#include "clk-uniphier.h"
12
13#define UNIPHIER_CLK_CPUGEAR_STAT	0	/* status */
14#define UNIPHIER_CLK_CPUGEAR_SET	4	/* set */
15#define UNIPHIER_CLK_CPUGEAR_UPD	8	/* update */
16#define   UNIPHIER_CLK_CPUGEAR_UPD_BIT	BIT(0)
17
18struct uniphier_clk_cpugear {
19	struct clk_hw hw;
20	struct regmap *regmap;
21	unsigned int regbase;
22	unsigned int mask;
23};
24
25#define to_uniphier_clk_cpugear(_hw) \
26			container_of(_hw, struct uniphier_clk_cpugear, hw)
27
28static int uniphier_clk_cpugear_set_parent(struct clk_hw *hw, u8 index)
29{
30	struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
31	int ret;
32	unsigned int val;
33
34	ret = regmap_write_bits(gear->regmap,
35				gear->regbase + UNIPHIER_CLK_CPUGEAR_SET,
36				gear->mask, index);
37	if (ret)
38		return ret;
39
40	ret = regmap_write_bits(gear->regmap,
41				gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD,
42				UNIPHIER_CLK_CPUGEAR_UPD_BIT,
43				UNIPHIER_CLK_CPUGEAR_UPD_BIT);
44	if (ret)
45		return ret;
46
47	return regmap_read_poll_timeout(gear->regmap,
48				gear->regbase + UNIPHIER_CLK_CPUGEAR_UPD,
49				val, !(val & UNIPHIER_CLK_CPUGEAR_UPD_BIT),
50				0, 1);
51}
52
53static u8 uniphier_clk_cpugear_get_parent(struct clk_hw *hw)
54{
55	struct uniphier_clk_cpugear *gear = to_uniphier_clk_cpugear(hw);
56	int num_parents = clk_hw_get_num_parents(hw);
57	int ret;
58	unsigned int val;
59
60	ret = regmap_read(gear->regmap,
61			  gear->regbase + UNIPHIER_CLK_CPUGEAR_STAT, &val);
62	if (ret)
63		return ret;
64
65	val &= gear->mask;
66
67	return val < num_parents ? val : -EINVAL;
68}
69
70static const struct clk_ops uniphier_clk_cpugear_ops = {
71	.determine_rate = __clk_mux_determine_rate,
72	.set_parent = uniphier_clk_cpugear_set_parent,
73	.get_parent = uniphier_clk_cpugear_get_parent,
74};
75
76struct clk_hw *uniphier_clk_register_cpugear(struct device *dev,
77					 struct regmap *regmap,
78					 const char *name,
79				const struct uniphier_clk_cpugear_data *data)
80{
81	struct uniphier_clk_cpugear *gear;
82	struct clk_init_data init;
83	int ret;
84
85	gear = devm_kzalloc(dev, sizeof(*gear), GFP_KERNEL);
86	if (!gear)
87		return ERR_PTR(-ENOMEM);
88
89	init.name = name;
90	init.ops = &uniphier_clk_cpugear_ops;
91	init.flags = CLK_SET_RATE_PARENT;
92	init.parent_names = data->parent_names;
93	init.num_parents = data->num_parents;
94
95	gear->regmap = regmap;
96	gear->regbase = data->regbase;
97	gear->mask = data->mask;
98	gear->hw.init = &init;
99
100	ret = devm_clk_hw_register(dev, &gear->hw);
101	if (ret)
102		return ERR_PTR(ret);
103
104	return &gear->hw;
105}
106