xref: /openbmc/linux/drivers/clk/imx/clk-busy.c (revision fb574682)
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_hw *imx_clk_hw_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_hw *hw;
81 	struct clk_init_data init;
82 	int ret;
83 
84 	busy = kzalloc(sizeof(*busy), GFP_KERNEL);
85 	if (!busy)
86 		return ERR_PTR(-ENOMEM);
87 
88 	busy->reg = busy_reg;
89 	busy->shift = busy_shift;
90 
91 	busy->div.reg = reg;
92 	busy->div.shift = shift;
93 	busy->div.width = width;
94 	busy->div.lock = &imx_ccm_lock;
95 	busy->div_ops = &clk_divider_ops;
96 
97 	init.name = name;
98 	init.ops = &clk_busy_divider_ops;
99 	init.flags = CLK_SET_RATE_PARENT | CLK_IS_CRITICAL;
100 	init.parent_names = &parent_name;
101 	init.num_parents = 1;
102 
103 	busy->div.hw.init = &init;
104 
105 	hw = &busy->div.hw;
106 
107 	ret = clk_hw_register(NULL, hw);
108 	if (ret) {
109 		kfree(busy);
110 		return ERR_PTR(ret);
111 	}
112 
113 	return hw;
114 }
115 
116 struct clk_busy_mux {
117 	struct clk_mux mux;
118 	const struct clk_ops *mux_ops;
119 	void __iomem *reg;
120 	u8 shift;
121 };
122 
123 static inline struct clk_busy_mux *to_clk_busy_mux(struct clk_hw *hw)
124 {
125 	struct clk_mux *mux = to_clk_mux(hw);
126 
127 	return container_of(mux, struct clk_busy_mux, mux);
128 }
129 
130 static u8 clk_busy_mux_get_parent(struct clk_hw *hw)
131 {
132 	struct clk_busy_mux *busy = to_clk_busy_mux(hw);
133 
134 	return busy->mux_ops->get_parent(&busy->mux.hw);
135 }
136 
137 static int clk_busy_mux_set_parent(struct clk_hw *hw, u8 index)
138 {
139 	struct clk_busy_mux *busy = to_clk_busy_mux(hw);
140 	int ret;
141 
142 	ret = busy->mux_ops->set_parent(&busy->mux.hw, index);
143 	if (!ret)
144 		ret = clk_busy_wait(busy->reg, busy->shift);
145 
146 	return ret;
147 }
148 
149 static const struct clk_ops clk_busy_mux_ops = {
150 	.get_parent = clk_busy_mux_get_parent,
151 	.set_parent = clk_busy_mux_set_parent,
152 };
153 
154 struct clk_hw *imx_clk_hw_busy_mux(const char *name, void __iomem *reg, u8 shift,
155 			     u8 width, void __iomem *busy_reg, u8 busy_shift,
156 			     const char * const *parent_names, int num_parents)
157 {
158 	struct clk_busy_mux *busy;
159 	struct clk_hw *hw;
160 	struct clk_init_data init;
161 	int ret;
162 
163 	busy = kzalloc(sizeof(*busy), GFP_KERNEL);
164 	if (!busy)
165 		return ERR_PTR(-ENOMEM);
166 
167 	busy->reg = busy_reg;
168 	busy->shift = busy_shift;
169 
170 	busy->mux.reg = reg;
171 	busy->mux.shift = shift;
172 	busy->mux.mask = BIT(width) - 1;
173 	busy->mux.lock = &imx_ccm_lock;
174 	busy->mux_ops = &clk_mux_ops;
175 
176 	init.name = name;
177 	init.ops = &clk_busy_mux_ops;
178 	init.flags = CLK_IS_CRITICAL;
179 	init.parent_names = parent_names;
180 	init.num_parents = num_parents;
181 
182 	busy->mux.hw.init = &init;
183 
184 	hw = &busy->mux.hw;
185 
186 	ret = clk_hw_register(NULL, hw);
187 	if (ret) {
188 		kfree(busy);
189 		return ERR_PTR(ret);
190 	}
191 
192 	return hw;
193 }
194