xref: /openbmc/linux/drivers/clk/imx/clk-fixup-mux.c (revision 6d99a79c)
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 /**
19  * struct clk_fixup_mux - imx integer fixup multiplexer clock
20  * @mux: the parent class
21  * @ops: pointer to clk_ops of parent class
22  * @fixup: a hook to fixup the write value
23  *
24  * The imx fixup multiplexer clock is a subclass of basic clk_mux
25  * with an addtional fixup hook.
26  */
27 struct clk_fixup_mux {
28 	struct clk_mux mux;
29 	const struct clk_ops *ops;
30 	void (*fixup)(u32 *val);
31 };
32 
33 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
34 {
35 	struct clk_mux *mux = to_clk_mux(hw);
36 
37 	return container_of(mux, struct clk_fixup_mux, mux);
38 }
39 
40 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
41 {
42 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
43 
44 	return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
45 }
46 
47 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
48 {
49 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
50 	struct clk_mux *mux = to_clk_mux(hw);
51 	unsigned long flags = 0;
52 	u32 val;
53 
54 	spin_lock_irqsave(mux->lock, flags);
55 
56 	val = readl(mux->reg);
57 	val &= ~(mux->mask << mux->shift);
58 	val |= index << mux->shift;
59 	fixup_mux->fixup(&val);
60 	writel(val, mux->reg);
61 
62 	spin_unlock_irqrestore(mux->lock, flags);
63 
64 	return 0;
65 }
66 
67 static const struct clk_ops clk_fixup_mux_ops = {
68 	.get_parent = clk_fixup_mux_get_parent,
69 	.set_parent = clk_fixup_mux_set_parent,
70 };
71 
72 struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
73 			      u8 shift, u8 width, const char **parents,
74 			      int num_parents, void (*fixup)(u32 *val))
75 {
76 	struct clk_fixup_mux *fixup_mux;
77 	struct clk *clk;
78 	struct clk_init_data init;
79 
80 	if (!fixup)
81 		return ERR_PTR(-EINVAL);
82 
83 	fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
84 	if (!fixup_mux)
85 		return ERR_PTR(-ENOMEM);
86 
87 	init.name = name;
88 	init.ops = &clk_fixup_mux_ops;
89 	init.parent_names = parents;
90 	init.num_parents = num_parents;
91 	init.flags = 0;
92 
93 	fixup_mux->mux.reg = reg;
94 	fixup_mux->mux.shift = shift;
95 	fixup_mux->mux.mask = BIT(width) - 1;
96 	fixup_mux->mux.lock = &imx_ccm_lock;
97 	fixup_mux->mux.hw.init = &init;
98 	fixup_mux->ops = &clk_mux_ops;
99 	fixup_mux->fixup = fixup;
100 
101 	clk = clk_register(NULL, &fixup_mux->mux.hw);
102 	if (IS_ERR(clk))
103 		kfree(fixup_mux);
104 
105 	return clk;
106 }
107