Blame view

kernel/linux-imx6_3.14.28/drivers/clk/qcom/clk-branch.c 3.81 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
  /*
   * Copyright (c) 2013, The Linux Foundation. All rights reserved.
   *
   * This software is licensed under the terms of the GNU General Public
   * License version 2, as published by the Free Software Foundation, and
   * may be copied, distributed, and modified under those terms.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #include <linux/kernel.h>
  #include <linux/bitops.h>
  #include <linux/err.h>
  #include <linux/delay.h>
  #include <linux/export.h>
  #include <linux/clk-provider.h>
  #include <linux/regmap.h>
  
  #include "clk-branch.h"
  
  static bool clk_branch_in_hwcg_mode(const struct clk_branch *br)
  {
  	u32 val;
  
  	if (!br->hwcg_reg)
  		return 0;
  
  	regmap_read(br->clkr.regmap, br->hwcg_reg, &val);
  
  	return !!(val & BIT(br->hwcg_bit));
  }
  
  static bool clk_branch_check_halt(const struct clk_branch *br, bool enabling)
  {
  	bool invert = (br->halt_check == BRANCH_HALT_ENABLE);
  	u32 val;
  
  	regmap_read(br->clkr.regmap, br->halt_reg, &val);
  
  	val &= BIT(br->halt_bit);
  	if (invert)
  		val = !val;
  
  	return !!val == !enabling;
  }
  
  #define BRANCH_CLK_OFF			BIT(31)
  #define BRANCH_NOC_FSM_STATUS_SHIFT	28
  #define BRANCH_NOC_FSM_STATUS_MASK	0x7
  #define BRANCH_NOC_FSM_STATUS_ON	(0x2 << BRANCH_NOC_FSM_STATUS_SHIFT)
  
  static bool clk_branch2_check_halt(const struct clk_branch *br, bool enabling)
  {
  	u32 val;
  	u32 mask;
  
  	mask = BRANCH_NOC_FSM_STATUS_MASK << BRANCH_NOC_FSM_STATUS_SHIFT;
  	mask |= BRANCH_CLK_OFF;
  
  	regmap_read(br->clkr.regmap, br->halt_reg, &val);
  
  	if (enabling) {
  		val &= mask;
  		return (val & BRANCH_CLK_OFF) == 0 ||
  			val == BRANCH_NOC_FSM_STATUS_ON;
  	} else {
  		return val & BRANCH_CLK_OFF;
  	}
  }
  
  static int clk_branch_wait(const struct clk_branch *br, bool enabling,
  		bool (check_halt)(const struct clk_branch *, bool))
  {
  	bool voted = br->halt_check & BRANCH_VOTED;
  	const char *name = __clk_get_name(br->clkr.hw.clk);
  
  	/* Skip checking halt bit if the clock is in hardware gated mode */
  	if (clk_branch_in_hwcg_mode(br))
  		return 0;
  
  	if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) {
  		udelay(10);
  	} else if (br->halt_check == BRANCH_HALT_ENABLE ||
  		   br->halt_check == BRANCH_HALT ||
  		   (enabling && voted)) {
  		int count = 200;
  
  		while (count-- > 0) {
  			if (check_halt(br, enabling))
  				return 0;
  			udelay(1);
  		}
  		WARN(1, "%s status stuck at 'o%s'", name,
  				enabling ? "ff" : "n");
  		return -EBUSY;
  	}
  	return 0;
  }
  
  static int clk_branch_toggle(struct clk_hw *hw, bool en,
  		bool (check_halt)(const struct clk_branch *, bool))
  {
  	struct clk_branch *br = to_clk_branch(hw);
  	int ret;
  
  	if (en) {
  		ret = clk_enable_regmap(hw);
  		if (ret)
  			return ret;
  	} else {
  		clk_disable_regmap(hw);
  	}
  
  	return clk_branch_wait(br, en, check_halt);
  }
  
  static int clk_branch_enable(struct clk_hw *hw)
  {
  	return clk_branch_toggle(hw, true, clk_branch_check_halt);
  }
  
  static void clk_branch_disable(struct clk_hw *hw)
  {
  	clk_branch_toggle(hw, false, clk_branch_check_halt);
  }
  
  const struct clk_ops clk_branch_ops = {
  	.enable = clk_branch_enable,
  	.disable = clk_branch_disable,
  	.is_enabled = clk_is_enabled_regmap,
  };
  EXPORT_SYMBOL_GPL(clk_branch_ops);
  
  static int clk_branch2_enable(struct clk_hw *hw)
  {
  	return clk_branch_toggle(hw, true, clk_branch2_check_halt);
  }
  
  static void clk_branch2_disable(struct clk_hw *hw)
  {
  	clk_branch_toggle(hw, false, clk_branch2_check_halt);
  }
  
  const struct clk_ops clk_branch2_ops = {
  	.enable = clk_branch2_enable,
  	.disable = clk_branch2_disable,
  	.is_enabled = clk_is_enabled_regmap,
  };
  EXPORT_SYMBOL_GPL(clk_branch2_ops);
  
  const struct clk_ops clk_branch_simple_ops = {
  	.enable = clk_enable_regmap,
  	.disable = clk_disable_regmap,
  	.is_enabled = clk_is_enabled_regmap,
  };
  EXPORT_SYMBOL_GPL(clk_branch_simple_ops);