xref: /openbmc/linux/drivers/clk/imx/clk-fixup-mux.c (revision ca55b2fe)
1 /*
2  * Copyright (C) 2013 Freescale Semiconductor, Inc.
3  *
4  * The code contained herein is licensed under the GNU General Public
5  * License. You may obtain a copy of the GNU General Public License
6  * Version 2 or later at the following locations:
7  *
8  * http://www.opensource.org/licenses/gpl-license.html
9  * http://www.gnu.org/copyleft/gpl.html
10  */
11 
12 #include <linux/clk-provider.h>
13 #include <linux/err.h>
14 #include <linux/io.h>
15 #include <linux/slab.h>
16 #include "clk.h"
17 
18 #define to_clk_mux(_hw) container_of(_hw, struct clk_mux, hw)
19 
20 /**
21  * struct clk_fixup_mux - imx integer fixup multiplexer clock
22  * @mux: the parent class
23  * @ops: pointer to clk_ops of parent class
24  * @fixup: a hook to fixup the write value
25  *
26  * The imx fixup multiplexer clock is a subclass of basic clk_mux
27  * with an addtional fixup hook.
28  */
29 struct clk_fixup_mux {
30 	struct clk_mux mux;
31 	const struct clk_ops *ops;
32 	void (*fixup)(u32 *val);
33 };
34 
35 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
36 {
37 	struct clk_mux *mux = to_clk_mux(hw);
38 
39 	return container_of(mux, struct clk_fixup_mux, mux);
40 }
41 
42 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
43 {
44 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
45 
46 	return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
47 }
48 
49 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
50 {
51 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
52 	struct clk_mux *mux = to_clk_mux(hw);
53 	unsigned long flags = 0;
54 	u32 val;
55 
56 	spin_lock_irqsave(mux->lock, flags);
57 
58 	val = readl(mux->reg);
59 	val &= ~(mux->mask << mux->shift);
60 	val |= index << mux->shift;
61 	fixup_mux->fixup(&val);
62 	writel(val, mux->reg);
63 
64 	spin_unlock_irqrestore(mux->lock, flags);
65 
66 	return 0;
67 }
68 
69 static const struct clk_ops clk_fixup_mux_ops = {
70 	.get_parent = clk_fixup_mux_get_parent,
71 	.set_parent = clk_fixup_mux_set_parent,
72 };
73 
74 struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
75 			      u8 shift, u8 width, const char **parents,
76 			      int num_parents, void (*fixup)(u32 *val))
77 {
78 	struct clk_fixup_mux *fixup_mux;
79 	struct clk *clk;
80 	struct clk_init_data init;
81 
82 	if (!fixup)
83 		return ERR_PTR(-EINVAL);
84 
85 	fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
86 	if (!fixup_mux)
87 		return ERR_PTR(-ENOMEM);
88 
89 	init.name = name;
90 	init.ops = &clk_fixup_mux_ops;
91 	init.parent_names = parents;
92 	init.num_parents = num_parents;
93 	init.flags = 0;
94 
95 	fixup_mux->mux.reg = reg;
96 	fixup_mux->mux.shift = shift;
97 	fixup_mux->mux.mask = BIT(width) - 1;
98 	fixup_mux->mux.lock = &imx_ccm_lock;
99 	fixup_mux->mux.hw.init = &init;
100 	fixup_mux->ops = &clk_mux_ops;
101 	fixup_mux->fixup = fixup;
102 
103 	clk = clk_register(NULL, &fixup_mux->mux.hw);
104 	if (IS_ERR(clk))
105 		kfree(fixup_mux);
106 
107 	return clk;
108 }
109