1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
4 */
5
6#include <linux/kernel.h>
7#include <linux/bitops.h>
8#include <linux/err.h>
9#include <linux/delay.h>
10#include <linux/export.h>
11#include <linux/clk-provider.h>
12#include <linux/regmap.h>
13
14#include "clk-branch.h"
15
16static bool clk_branch_in_hwcg_mode(const struct clk_branch *br)
17{
18	u32 val;
19
20	if (!br->hwcg_reg)
21		return false;
22
23	regmap_read(br->clkr.regmap, br->hwcg_reg, &val);
24
25	return !!(val & BIT(br->hwcg_bit));
26}
27
28static bool clk_branch_check_halt(const struct clk_branch *br, bool enabling)
29{
30	bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
31	u32 val;
32
33	regmap_read(br->clkr.regmap, br->halt_reg, &val);
34
35	val &= BIT(br->halt_bit);
36	if (invert)
37		val = !val;
38
39	return !!val == !enabling;
40}
41
42static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
43{
44	u32 val;
45	u32 mask;
46	bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
47
48	mask = CBCR_NOC_FSM_STATUS;
49	mask |= CBCR_CLK_OFF;
50
51	regmap_read(br->clkr.regmap, br->halt_reg, &val);
52
53	if (enabling) {
54		val &= mask;
55		return (val & CBCR_CLK_OFF) == (invert ? CBCR_CLK_OFF : 0) ||
56			FIELD_GET(CBCR_NOC_FSM_STATUS, val) == FSM_STATUS_ON;
57	}
58	return (val & CBCR_CLK_OFF) == (invert ? 0 : CBCR_CLK_OFF);
59}
60
61static int clk_branch_wait(const struct clk_branch *br, bool enabling,
62		bool (check_halt)(const struct clk_branch *, bool))
63{
64	bool voted = br->halt_check & BRANCH_VOTED;
65	const char *name = clk_hw_get_name(&br->clkr.hw);
66
67	/*
68	 * Skip checking halt bit if we're explicitly ignoring the bit or the
69	 * clock is in hardware gated mode
70	 */
71	if (br->halt_check == BRANCH_HALT_SKIP || clk_branch_in_hwcg_mode(br))
72		return 0;
73
74	if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
75		udelay(10);
76	} else if (br->halt_check == BRANCH_HALT_ENABLE ||
77		   br->halt_check == BRANCH_HALT ||
78		   (enabling && voted)) {
79		int count = 200;
80
81		while (count-- > 0) {
82			if (check_halt(br, enabling))
83				return 0;
84			udelay(1);
85		}
86		WARN(1, "%s status stuck at 'o%s'", name,
87				enabling ? "ff" : "n");
88		return -EBUSY;
89	}
90	return 0;
91}
92
93static int clk_branch_toggle(struct clk_hw *hw, bool en,
94		bool (check_halt)(const struct clk_branch *, bool))
95{
96	struct clk_branch *br = to_clk_branch(hw);
97	int ret;
98
99	if (en) {
100		ret = clk_enable_regmap(hw);
101		if (ret)
102			return ret;
103	} else {
104		clk_disable_regmap(hw);
105	}
106
107	return clk_branch_wait(br, en, check_halt);
108}
109
110static int clk_branch_enable(struct clk_hw *hw)
111{
112	return clk_branch_toggle(hw, true, clk_branch_check_halt);
113}
114
115static void clk_branch_disable(struct clk_hw *hw)
116{
117	clk_branch_toggle(hw, false, clk_branch_check_halt);
118}
119
120const struct clk_ops clk_branch_ops = {
121	.enable = clk_branch_enable,
122	.disable = clk_branch_disable,
123	.is_enabled = clk_is_enabled_regmap,
124};
125EXPORT_SYMBOL_GPL(clk_branch_ops);
126
127static int clk_branch2_enable(struct clk_hw *hw)
128{
129	return clk_branch_toggle(hw, true, clk_branch2_check_halt);
130}
131
132static void clk_branch2_disable(struct clk_hw *hw)
133{
134	clk_branch_toggle(hw, false, clk_branch2_check_halt);
135}
136
137const struct clk_ops clk_branch2_ops = {
138	.enable = clk_branch2_enable,
139	.disable = clk_branch2_disable,
140	.is_enabled = clk_is_enabled_regmap,
141};
142EXPORT_SYMBOL_GPL(clk_branch2_ops);
143
144const struct clk_ops clk_branch2_aon_ops = {
145	.enable = clk_branch2_enable,
146	.is_enabled = clk_is_enabled_regmap,
147};
148EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
149
150const struct clk_ops clk_branch_simple_ops = {
151	.enable = clk_enable_regmap,
152	.disable = clk_disable_regmap,
153	.is_enabled = clk_is_enabled_regmap,
154};
155EXPORT_SYMBOL_GPL(clk_branch_simple_ops);
156