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
42 #define BRANCH_CLK_OFF BIT(31)
43 #define BRANCH_NOC_FSM_STATUS_SHIFT 28
44 #define BRANCH_NOC_FSM_STATUS_MASK 0x7
45 #define BRANCH_NOC_FSM_STATUS_ON (0x2 << BRANCH_NOC_FSM_STATUS_SHIFT)
46
clk_branch2_check_halt(const struct clk_branch * br,bool enabling)47 static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
48 {
49 u32 val;
50 u32 mask;
51
52 mask = BRANCH_NOC_FSM_STATUS_MASK << BRANCH_NOC_FSM_STATUS_SHIFT;
53 mask |= BRANCH_CLK_OFF;
54
55 regmap_read(br->clkr.regmap, br->halt_reg, &val);
56
57 if (enabling) {
58 val &= mask;
59 return (val & BRANCH_CLK_OFF) == 0 ||
60 val == BRANCH_NOC_FSM_STATUS_ON;
61 } else {
62 return val & BRANCH_CLK_OFF;
63 }
64 }
65
clk_branch_wait(const struct clk_branch * br,bool enabling,bool (check_halt)(const struct clk_branch *,bool))66 static int clk_branch_wait(const struct clk_branch *br, bool enabling,
67 bool (check_halt)(const struct clk_branch *, bool))
68 {
69 bool voted = br->halt_check & BRANCH_VOTED;
70 const char *name = clk_hw_get_name(&br->clkr.hw);
71
72 /*
73 * Skip checking halt bit if we're explicitly ignoring the bit or the
74 * clock is in hardware gated mode
75 */
76 if (br->halt_check == BRANCH_HALT_SKIP || clk_branch_in_hwcg_mode(br))
77 return 0;
78
79 if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
80 udelay(10);
81 } else if (br->halt_check == BRANCH_HALT_ENABLE ||
82 br->halt_check == BRANCH_HALT ||
83 (enabling && voted)) {
84 int count = 200;
85
86 while (count-- > 0) {
87 if (check_halt(br, enabling))
88 return 0;
89 udelay(1);
90 }
91 WARN(1, "%s status stuck at 'o%s'", name,
92 enabling ? "ff" : "n");
93 return -EBUSY;
94 }
95 return 0;
96 }
97
clk_branch_toggle(struct clk_hw * hw,bool en,bool (check_halt)(const struct clk_branch *,bool))98 static int clk_branch_toggle(struct clk_hw *hw, bool en,
99 bool (check_halt)(const struct clk_branch *, bool))
100 {
101 struct clk_branch *br = to_clk_branch(hw);
102 int ret;
103
104 if (en) {
105 ret = clk_enable_regmap(hw);
106 if (ret)
107 return ret;
108 } else {
109 clk_disable_regmap(hw);
110 }
111
112 return clk_branch_wait(br, en, check_halt);
113 }
114
clk_branch_enable(struct clk_hw * hw)115 static int clk_branch_enable(struct clk_hw *hw)
116 {
117 return clk_branch_toggle(hw, true, clk_branch_check_halt);
118 }
119
clk_branch_disable(struct clk_hw * hw)120 static void clk_branch_disable(struct clk_hw *hw)
121 {
122 clk_branch_toggle(hw, false, clk_branch_check_halt);
123 }
124
125 const struct clk_ops clk_branch_ops = {
126 .enable = clk_branch_enable,
127 .disable = clk_branch_disable,
128 .is_enabled = clk_is_enabled_regmap,
129 };
130 EXPORT_SYMBOL_GPL(clk_branch_ops);
131
clk_branch2_enable(struct clk_hw * hw)132 static int clk_branch2_enable(struct clk_hw *hw)
133 {
134 return clk_branch_toggle(hw, true, clk_branch2_check_halt);
135 }
136
clk_branch2_disable(struct clk_hw * hw)137 static void clk_branch2_disable(struct clk_hw *hw)
138 {
139 clk_branch_toggle(hw, false, clk_branch2_check_halt);
140 }
141
142 const struct clk_ops clk_branch2_ops = {
143 .enable = clk_branch2_enable,
144 .disable = clk_branch2_disable,
145 .is_enabled = clk_is_enabled_regmap,
146 };
147 EXPORT_SYMBOL_GPL(clk_branch2_ops);
148
149 const struct clk_ops clk_branch2_aon_ops = {
150 .enable = clk_branch2_enable,
151 .is_enabled = clk_is_enabled_regmap,
152 };
153 EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
154
155 const struct clk_ops clk_branch_simple_ops = {
156 .enable = clk_enable_regmap,
157 .disable = clk_disable_regmap,
158 .is_enabled = clk_is_enabled_regmap,
159 };
160 EXPORT_SYMBOL_GPL(clk_branch_simple_ops);
161