1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2013, The Linux Foundation. All rights reserved.
4 * Copyright (c) 2023, Qualcomm Innovation Center, Inc. All rights reserved.
5 */
6
7#include <linux/kernel.h>
8#include <linux/bitops.h>
9#include <linux/err.h>
10#include <linux/delay.h>
11#include <linux/export.h>
12#include <linux/clk-provider.h>
13#include <linux/regmap.h>
14
15#include "clk-branch.h"
16
17static bool clk_branch_in_hwcg_mode(const struct clk_branch *br)
18{
19	u32 val;
20
21	if (!br->hwcg_reg)
22		return false;
23
24	regmap_read(br->clkr.regmap, br->hwcg_reg, &val);
25
26	return !!(val & BIT(br->hwcg_bit));
27}
28
29static bool clk_branch_check_halt(const struct clk_branch *br, bool enabling)
30{
31	bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
32	u32 val;
33
34	regmap_read(br->clkr.regmap, br->halt_reg, &val);
35
36	val &= BIT(br->halt_bit);
37	if (invert)
38		val = !val;
39
40	return !!val == !enabling;
41}
42
43static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
44{
45	u32 val;
46	u32 mask;
47	bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
48
49	mask = CBCR_NOC_FSM_STATUS;
50	mask |= CBCR_CLK_OFF;
51
52	regmap_read(br->clkr.regmap, br->halt_reg, &val);
53
54	if (enabling) {
55		val &= mask;
56		return (val & CBCR_CLK_OFF) == (invert ? CBCR_CLK_OFF : 0) ||
57			FIELD_GET(CBCR_NOC_FSM_STATUS, val) == FSM_STATUS_ON;
58	}
59	return (val & CBCR_CLK_OFF) == (invert ? 0 : CBCR_CLK_OFF);
60}
61
62static int clk_branch_wait(const struct clk_branch *br, bool enabling,
63		bool (check_halt)(const struct clk_branch *, bool))
64{
65	bool voted = br->halt_check & BRANCH_VOTED;
66	const char *name = clk_hw_get_name(&br->clkr.hw);
67
68	/*
69	 * Skip checking halt bit if we're explicitly ignoring the bit or the
70	 * clock is in hardware gated mode
71	 */
72	if (br->halt_check == BRANCH_HALT_SKIP || clk_branch_in_hwcg_mode(br))
73		return 0;
74
75	if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
76		udelay(10);
77	} else if (br->halt_check == BRANCH_HALT_ENABLE ||
78		   br->halt_check == BRANCH_HALT ||
79		   (enabling && voted)) {
80		int count = 200;
81
82		while (count-- > 0) {
83			if (check_halt(br, enabling))
84				return 0;
85			udelay(1);
86		}
87		WARN(1, "%s status stuck at 'o%s'", name,
88				enabling ? "ff" : "n");
89		return -EBUSY;
90	}
91	return 0;
92}
93
94static int clk_branch_toggle(struct clk_hw *hw, bool en,
95		bool (check_halt)(const struct clk_branch *, bool))
96{
97	struct clk_branch *br = to_clk_branch(hw);
98	int ret;
99
100	if (en) {
101		ret = clk_enable_regmap(hw);
102		if (ret)
103			return ret;
104	} else {
105		clk_disable_regmap(hw);
106	}
107
108	return clk_branch_wait(br, en, check_halt);
109}
110
111static int clk_branch_enable(struct clk_hw *hw)
112{
113	return clk_branch_toggle(hw, true, clk_branch_check_halt);
114}
115
116static void clk_branch_disable(struct clk_hw *hw)
117{
118	clk_branch_toggle(hw, false, clk_branch_check_halt);
119}
120
121const struct clk_ops clk_branch_ops = {
122	.enable = clk_branch_enable,
123	.disable = clk_branch_disable,
124	.is_enabled = clk_is_enabled_regmap,
125};
126EXPORT_SYMBOL_GPL(clk_branch_ops);
127
128static int clk_branch2_enable(struct clk_hw *hw)
129{
130	return clk_branch_toggle(hw, true, clk_branch2_check_halt);
131}
132
133static void clk_branch2_disable(struct clk_hw *hw)
134{
135	clk_branch_toggle(hw, false, clk_branch2_check_halt);
136}
137
138static int clk_branch2_mem_enable(struct clk_hw *hw)
139{
140	struct clk_mem_branch *mem_br = to_clk_mem_branch(hw);
141	struct clk_branch branch = mem_br->branch;
142	u32 val;
143	int ret;
144
145	regmap_update_bits(branch.clkr.regmap, mem_br->mem_enable_reg,
146			   mem_br->mem_enable_ack_mask, mem_br->mem_enable_ack_mask);
147
148	ret = regmap_read_poll_timeout(branch.clkr.regmap, mem_br->mem_ack_reg,
149				       val, val & mem_br->mem_enable_ack_mask, 0, 200);
150	if (ret) {
151		WARN(1, "%s mem enable failed\n", clk_hw_get_name(&branch.clkr.hw));
152		return ret;
153	}
154
155	return clk_branch2_enable(hw);
156}
157
158static void clk_branch2_mem_disable(struct clk_hw *hw)
159{
160	struct clk_mem_branch *mem_br = to_clk_mem_branch(hw);
161
162	regmap_update_bits(mem_br->branch.clkr.regmap, mem_br->mem_enable_reg,
163			   mem_br->mem_enable_ack_mask, 0);
164
165	return clk_branch2_disable(hw);
166}
167
168const struct clk_ops clk_branch2_mem_ops = {
169	.enable = clk_branch2_mem_enable,
170	.disable = clk_branch2_mem_disable,
171	.is_enabled = clk_is_enabled_regmap,
172};
173EXPORT_SYMBOL_GPL(clk_branch2_mem_ops);
174
175const struct clk_ops clk_branch2_ops = {
176	.enable = clk_branch2_enable,
177	.disable = clk_branch2_disable,
178	.is_enabled = clk_is_enabled_regmap,
179};
180EXPORT_SYMBOL_GPL(clk_branch2_ops);
181
182const struct clk_ops clk_branch2_aon_ops = {
183	.enable = clk_branch2_enable,
184	.is_enabled = clk_is_enabled_regmap,
185};
186EXPORT_SYMBOL_GPL(clk_branch2_aon_ops);
187
188const struct clk_ops clk_branch_simple_ops = {
189	.enable = clk_enable_regmap,
190	.disable = clk_disable_regmap,
191	.is_enabled = clk_is_enabled_regmap,
192};
193EXPORT_SYMBOL_GPL(clk_branch_simple_ops);
194