xref: /openbmc/linux/drivers/clk/imx/clk-fixup-mux.c (revision b593bce5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2013 Freescale Semiconductor, Inc.
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/err.h>
8 #include <linux/io.h>
9 #include <linux/slab.h>
10 #include "clk.h"
11 
12 /**
13  * struct clk_fixup_mux - imx integer fixup multiplexer clock
14  * @mux: the parent class
15  * @ops: pointer to clk_ops of parent class
16  * @fixup: a hook to fixup the write value
17  *
18  * The imx fixup multiplexer clock is a subclass of basic clk_mux
19  * with an addtional fixup hook.
20  */
21 struct clk_fixup_mux {
22 	struct clk_mux mux;
23 	const struct clk_ops *ops;
24 	void (*fixup)(u32 *val);
25 };
26 
27 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
28 {
29 	struct clk_mux *mux = to_clk_mux(hw);
30 
31 	return container_of(mux, struct clk_fixup_mux, mux);
32 }
33 
34 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
35 {
36 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
37 
38 	return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
39 }
40 
41 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
42 {
43 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
44 	struct clk_mux *mux = to_clk_mux(hw);
45 	unsigned long flags = 0;
46 	u32 val;
47 
48 	spin_lock_irqsave(mux->lock, flags);
49 
50 	val = readl(mux->reg);
51 	val &= ~(mux->mask << mux->shift);
52 	val |= index << mux->shift;
53 	fixup_mux->fixup(&val);
54 	writel(val, mux->reg);
55 
56 	spin_unlock_irqrestore(mux->lock, flags);
57 
58 	return 0;
59 }
60 
61 static const struct clk_ops clk_fixup_mux_ops = {
62 	.get_parent = clk_fixup_mux_get_parent,
63 	.set_parent = clk_fixup_mux_set_parent,
64 };
65 
66 struct clk_hw *imx_clk_hw_fixup_mux(const char *name, void __iomem *reg,
67 			      u8 shift, u8 width, const char * const *parents,
68 			      int num_parents, void (*fixup)(u32 *val))
69 {
70 	struct clk_fixup_mux *fixup_mux;
71 	struct clk_hw *hw;
72 	struct clk_init_data init;
73 	int ret;
74 
75 	if (!fixup)
76 		return ERR_PTR(-EINVAL);
77 
78 	fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
79 	if (!fixup_mux)
80 		return ERR_PTR(-ENOMEM);
81 
82 	init.name = name;
83 	init.ops = &clk_fixup_mux_ops;
84 	init.parent_names = parents;
85 	init.num_parents = num_parents;
86 	init.flags = 0;
87 
88 	fixup_mux->mux.reg = reg;
89 	fixup_mux->mux.shift = shift;
90 	fixup_mux->mux.mask = BIT(width) - 1;
91 	fixup_mux->mux.lock = &imx_ccm_lock;
92 	fixup_mux->mux.hw.init = &init;
93 	fixup_mux->ops = &clk_mux_ops;
94 	fixup_mux->fixup = fixup;
95 
96 	hw = &fixup_mux->mux.hw;
97 
98 	ret = clk_hw_register(NULL, hw);
99 	if (ret) {
100 		kfree(fixup_mux);
101 		return ERR_PTR(ret);
102 	}
103 
104 	return hw;
105 }
106