xref: /linux/drivers/clk/imx/clk-busy.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright 2012 Freescale Semiconductor, Inc.
4  * Copyright 2012 Linaro Ltd.
5  */
6 
7 #include <linux/clk.h>
8 #include <linux/clk-provider.h>
9 #include <linux/io.h>
10 #include <linux/slab.h>
11 #include <linux/jiffies.h>
12 #include <linux/err.h>
13 #include "clk.h"
14 
15 static int clk_busy_wait(void __iomem *reg, u8 shift)
16 {
17 	unsigned long timeout = jiffies + msecs_to_jiffies(10);
18 
19 	while (readl_relaxed(reg) & (1 << shift))
20 		if (time_after(jiffies, timeout))
21 			return -ETIMEDOUT;
22 
23 	return 0;
24 }
25 
26 struct clk_busy_divider {
27 	struct clk_divider div;
28 	const struct clk_ops *div_ops;
29 	void __iomem *reg;
30 	u8 shift;
31 };
32 
33 static inline struct clk_busy_divider *to_clk_busy_divider(struct clk_hw *hw)
34 {
35 	struct clk_divider *div = to_clk_divider(hw);
36 
37 	return container_of(div, struct clk_busy_divider, div);
38 }
39 
40 static unsigned long clk_busy_divider_recalc_rate(struct clk_hw *hw,
41 						  unsigned long parent_rate)
42 {
43 	struct clk_busy_divider *busy = to_clk_busy_divider(hw);
44 
45 	return busy->div_ops->recalc_rate(&busy->div.hw, parent_rate);
46 }
47 
48 static long clk_busy_divider_round_rate(struct clk_hw *hw, unsigned long rate,
49 					unsigned long *prate)
50 {
51 	struct clk_busy_divider *busy = to_clk_busy_divider(hw);
52 
53 	return busy->div_ops->round_rate(&busy->div.hw, rate, prate);
54 }
55 
56 static int clk_busy_divider_set_rate(struct clk_hw *hw, unsigned long rate,
57 		unsigned long parent_rate)
58 {
59 	struct clk_busy_divider *busy = to_clk_busy_divider(hw);
60 	int ret;
61 
62 	ret = busy->div_ops->set_rate(&busy->div.hw, rate, parent_rate);
63 	if (!ret)
64 		ret = clk_busy_wait(busy->reg, busy->shift);
65 
66 	return ret;
67 }
68 
69 static const struct clk_ops clk_busy_divider_ops = {
70 	.recalc_rate = clk_busy_divider_recalc_rate,
71 	.round_rate = clk_busy_divider_round_rate,
72 	.set_rate = clk_busy_divider_set_rate,
73 };
74 
75 struct clk *imx_clk_busy_divider(const char *name, const char *parent_name,
76 				 void __iomem *reg, u8 shift, u8 width,
77 				 void __iomem *busy_reg, u8 busy_shift)
78 {
79 	struct clk_busy_divider *busy;
80 	struct clk *clk;
81 	struct clk_init_data init;
82 
83 	busy = kzalloc(sizeof(*busy), GFP_KERNEL);
84 	if (!busy)
85 		return ERR_PTR(-ENOMEM);
86 
87 	busy->reg = busy_reg;
88 	busy->shift = busy_shift;
89 
90 	busy->div.reg = reg;
91 	busy->div.shift = shift;
92 	busy->div.width = width;
93 	busy->div.lock = &imx_ccm_lock;
94 	busy->div_ops = &clk_divider_ops;
95 
96 	init.name = name;
97 	init.ops = &clk_busy_divider_ops;
98 	init.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL;
99 	init.parent_names = &parent_name;
100 	init.num_parents = 1;
101 
102 	busy->div.hw.init = &init;
103 
104 	clk = clk_register(NULL, &busy->div.hw);
105 	if (IS_ERR(clk))
106 		kfree(busy);
107 
108 	return clk;
109 }
110 
111 struct clk_busy_mux {
112 	struct clk_mux mux;
113 	const struct clk_ops *mux_ops;
114 	void __iomem *reg;
115 	u8 shift;
116 };
117 
118 static inline struct clk_busy_mux *to_clk_busy_mux(struct clk_hw *hw)
119 {
120 	struct clk_mux *mux = to_clk_mux(hw);
121 
122 	return container_of(mux, struct clk_busy_mux, mux);
123 }
124 
125 static u8 clk_busy_mux_get_parent(struct clk_hw *hw)
126 {
127 	struct clk_busy_mux *busy = to_clk_busy_mux(hw);
128 
129 	return busy->mux_ops->get_parent(&busy->mux.hw);
130 }
131 
132 static int clk_busy_mux_set_parent(struct clk_hw *hw, u8 index)
133 {
134 	struct clk_busy_mux *busy = to_clk_busy_mux(hw);
135 	int ret;
136 
137 	ret = busy->mux_ops->set_parent(&busy->mux.hw, index);
138 	if (!ret)
139 		ret = clk_busy_wait(busy->reg, busy->shift);
140 
141 	return ret;
142 }
143 
144 static const struct clk_ops clk_busy_mux_ops = {
145 	.get_parent = clk_busy_mux_get_parent,
146 	.set_parent = clk_busy_mux_set_parent,
147 };
148 
149 struct clk *imx_clk_busy_mux(const char *name, void __iomem *reg, u8 shift,
150 			     u8 width, void __iomem *busy_reg, u8 busy_shift,
151 			     const char * const *parent_names, int num_parents)
152 {
153 	struct clk_busy_mux *busy;
154 	struct clk *clk;
155 	struct clk_init_data init;
156 
157 	busy = kzalloc(sizeof(*busy), GFP_KERNEL);
158 	if (!busy)
159 		return ERR_PTR(-ENOMEM);
160 
161 	busy->reg = busy_reg;
162 	busy->shift = busy_shift;
163 
164 	busy->mux.reg = reg;
165 	busy->mux.shift = shift;
166 	busy->mux.mask = BIT(width) - 1;
167 	busy->mux.lock = &imx_ccm_lock;
168 	busy->mux_ops = &clk_mux_ops;
169 
170 	init.name = name;
171 	init.ops = &clk_busy_mux_ops;
172 	init.flags = CLK_IS_CRITICAL;
173 	init.parent_names = parent_names;
174 	init.num_parents = num_parents;
175 
176 	busy->mux.hw.init = &init;
177 
178 	clk = clk_register(NULL, &busy->mux.hw);
179 	if (IS_ERR(clk))
180 		kfree(busy);
181 
182 	return clk;
183 }
184