xref: /openbmc/linux/drivers/clk/sprd/mux.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Spreadtrum multiplexer clock driver
4 //
5 // Copyright (C) 2017 Spreadtrum, Inc.
6 // Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
7 
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/regmap.h>
11 
12 #include "mux.h"
13 
14 u8 sprd_mux_helper_get_parent(const struct sprd_clk_common *common,
15 			      const struct sprd_mux_ssel *mux)
16 {
17 	unsigned int reg;
18 	u8 parent;
19 	int num_parents;
20 	int i;
21 
22 	regmap_read(common->regmap, common->reg, &reg);
23 	parent = reg >> mux->shift;
24 	parent &= (1 << mux->width) - 1;
25 
26 	if (!mux->table)
27 		return parent;
28 
29 	num_parents = clk_hw_get_num_parents(&common->hw);
30 
31 	for (i = 0; i < num_parents - 1; i++)
32 		if (parent >= mux->table[i] && parent < mux->table[i + 1])
33 			return i;
34 
35 	return num_parents - 1;
36 }
37 EXPORT_SYMBOL_GPL(sprd_mux_helper_get_parent);
38 
39 static u8 sprd_mux_get_parent(struct clk_hw *hw)
40 {
41 	struct sprd_mux *cm = hw_to_sprd_mux(hw);
42 
43 	return sprd_mux_helper_get_parent(&cm->common, &cm->mux);
44 }
45 
46 int sprd_mux_helper_set_parent(const struct sprd_clk_common *common,
47 			       const struct sprd_mux_ssel *mux,
48 			       u8 index)
49 {
50 	unsigned int reg;
51 
52 	if (mux->table)
53 		index = mux->table[index];
54 
55 	regmap_read(common->regmap, common->reg, &reg);
56 	reg &= ~GENMASK(mux->width + mux->shift - 1, mux->shift);
57 	regmap_write(common->regmap, common->reg,
58 			  reg | (index << mux->shift));
59 
60 	return 0;
61 }
62 EXPORT_SYMBOL_GPL(sprd_mux_helper_set_parent);
63 
64 static int sprd_mux_set_parent(struct clk_hw *hw, u8 index)
65 {
66 	struct sprd_mux *cm = hw_to_sprd_mux(hw);
67 
68 	return sprd_mux_helper_set_parent(&cm->common, &cm->mux, index);
69 }
70 
71 const struct clk_ops sprd_mux_ops = {
72 	.get_parent = sprd_mux_get_parent,
73 	.set_parent = sprd_mux_set_parent,
74 	.determine_rate = __clk_mux_determine_rate,
75 };
76 EXPORT_SYMBOL_GPL(sprd_mux_ops);
77