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
clk_branch_in_hwcg_mode(const struct clk_branch * br)16 static 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
clk_branch_check_halt(const struct clk_branch * br,bool enabling)28 static 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
clk_branch2_check_halt(const struct clk_branch * br,bool enabling)42 static 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
clk_branch_wait(const struct clk_branch * br,bool enabling,bool (check_halt)(const struct clk_branch *,bool))61 static 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
clk_branch_toggle(struct clk_hw * hw,bool en,bool (check_halt)(const struct clk_branch *,bool))93 static 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
clk_branch_enable(struct clk_hw * hw)110 static int clk_branch_enable(struct clk_hw *hw)
111 {
112 return clk_branch_toggle(hw, true, clk_branch_check_halt);
113 }
114
clk_branch_disable(struct clk_hw * hw)115 static void clk_branch_disable(struct clk_hw *hw)
116 {
117 clk_branch_toggle(hw, false, clk_branch_check_halt);
118 }
119
120 const struct clk_ops clk_branch_ops = {
121 .enable = clk_branch_enable,
122 .disable = clk_branch_disable,
123 .is_enabled = clk_is_enabled_regmap,
124 };
125 EXPORT_SYMBOL_GPL(clk_branch_ops);
126
clk_branch2_enable(struct clk_hw * hw)127 static int clk_branch2_enable(struct clk_hw *hw)
128 {
129 return clk_branch_toggle(hw, true, clk_branch2_check_halt);
130 }
131
clk_branch2_disable(struct clk_hw * hw)132 static void clk_branch2_disable(struct clk_hw *hw)
133 {
134 clk_branch_toggle(hw, false, clk_branch2_check_halt);
135 }
136
137 const struct clk_ops clk_branch2_ops = {
138 .enable = clk_branch2_enable,
139 .disable = clk_branch2_disable,
140 .is_enabled = clk_is_enabled_regmap,
141 };
142 EXPORT_SYMBOL_GPL(clk_branch2_ops);
143
144 const struct clk_ops clk_branch2_aon_ops = {
145 .enable = clk_branch2_enable,
146 .is_enabled = clk_is_enabled_regmap,
147 };
148 EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
149
150 const 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 };
155 EXPORT_SYMBOL_GPL(clk_branch_simple_ops);
156