xref: /openbmc/linux/drivers/clk/imx/clk-fixup-mux.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2013 Freescale Semiconductor, Inc.
4  */
5 
6 #include <linux/bits.h>
7 #include <linux/clk-provider.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/slab.h>
11 #include "clk.h"
12 
13 /**
14  * struct clk_fixup_mux - imx integer fixup multiplexer clock
15  * @mux: the parent class
16  * @ops: pointer to clk_ops of parent class
17  * @fixup: a hook to fixup the write value
18  *
19  * The imx fixup multiplexer clock is a subclass of basic clk_mux
20  * with an addtional fixup hook.
21  */
22 struct clk_fixup_mux {
23 	struct clk_mux mux;
24 	const struct clk_ops *ops;
25 	void (*fixup)(u32 *val);
26 };
27 
28 static inline struct clk_fixup_mux *to_clk_fixup_mux(struct clk_hw *hw)
29 {
30 	struct clk_mux *mux = to_clk_mux(hw);
31 
32 	return container_of(mux, struct clk_fixup_mux, mux);
33 }
34 
35 static u8 clk_fixup_mux_get_parent(struct clk_hw *hw)
36 {
37 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
38 
39 	return fixup_mux->ops->get_parent(&fixup_mux->mux.hw);
40 }
41 
42 static int clk_fixup_mux_set_parent(struct clk_hw *hw, u8 index)
43 {
44 	struct clk_fixup_mux *fixup_mux = to_clk_fixup_mux(hw);
45 	struct clk_mux *mux = to_clk_mux(hw);
46 	unsigned long flags;
47 	u32 val;
48 
49 	spin_lock_irqsave(mux->lock, flags);
50 
51 	val = readl(mux->reg);
52 	val &= ~(mux->mask << mux->shift);
53 	val |= index << mux->shift;
54 	fixup_mux->fixup(&val);
55 	writel(val, mux->reg);
56 
57 	spin_unlock_irqrestore(mux->lock, flags);
58 
59 	return 0;
60 }
61 
62 static const struct clk_ops clk_fixup_mux_ops = {
63 	.get_parent = clk_fixup_mux_get_parent,
64 	.set_parent = clk_fixup_mux_set_parent,
65 };
66 
67 struct clk_hw *imx_clk_hw_fixup_mux(const char *name, void __iomem *reg,
68 			      u8 shift, u8 width, const char * const *parents,
69 			      int num_parents, void (*fixup)(u32 *val))
70 {
71 	struct clk_fixup_mux *fixup_mux;
72 	struct clk_hw *hw;
73 	struct clk_init_data init;
74 	int ret;
75 
76 	if (!fixup)
77 		return ERR_PTR(-EINVAL);
78 
79 	fixup_mux = kzalloc(sizeof(*fixup_mux), GFP_KERNEL);
80 	if (!fixup_mux)
81 		return ERR_PTR(-ENOMEM);
82 
83 	init.name = name;
84 	init.ops = &clk_fixup_mux_ops;
85 	init.parent_names = parents;
86 	init.num_parents = num_parents;
87 	init.flags = 0;
88 
89 	fixup_mux->mux.reg = reg;
90 	fixup_mux->mux.shift = shift;
91 	fixup_mux->mux.mask = BIT(width) - 1;
92 	fixup_mux->mux.lock = &imx_ccm_lock;
93 	fixup_mux->mux.hw.init = &init;
94 	fixup_mux->ops = &clk_mux_ops;
95 	fixup_mux->fixup = fixup;
96 
97 	hw = &fixup_mux->mux.hw;
98 
99 	ret = clk_hw_register(NULL, hw);
100 	if (ret) {
101 		kfree(fixup_mux);
102 		return ERR_PTR(ret);
103 	}
104 
105 	return hw;
106 }
107