xref: /openbmc/linux/drivers/clk/actions/owl-mux.c (revision 0c874100)
1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // OWL mux clock driver
4 //
5 // Copyright (c) 2014 Actions Semi Inc.
6 // Author: David Liu <liuwei@actions-semi.com>
7 //
8 // Copyright (c) 2018 Linaro Ltd.
9 // Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
10 
11 #include <linux/clk-provider.h>
12 #include <linux/regmap.h>
13 
14 #include "owl-mux.h"
15 
16 u8 owl_mux_helper_get_parent(const struct owl_clk_common *common,
17 			     const struct owl_mux_hw *mux_hw)
18 {
19 	u32 reg;
20 	u8 parent;
21 
22 	regmap_read(common->regmap, mux_hw->reg, &reg);
23 	parent = reg >> mux_hw->shift;
24 	parent &= BIT(mux_hw->width) - 1;
25 
26 	return parent;
27 }
28 
29 static u8 owl_mux_get_parent(struct clk_hw *hw)
30 {
31 	struct owl_mux *mux = hw_to_owl_mux(hw);
32 
33 	return owl_mux_helper_get_parent(&mux->common, &mux->mux_hw);
34 }
35 
36 int owl_mux_helper_set_parent(const struct owl_clk_common *common,
37 			      struct owl_mux_hw *mux_hw, u8 index)
38 {
39 	u32 reg;
40 
41 	regmap_read(common->regmap, mux_hw->reg, &reg);
42 	reg &= ~GENMASK(mux_hw->width + mux_hw->shift - 1, mux_hw->shift);
43 	regmap_write(common->regmap, mux_hw->reg,
44 			reg | (index << mux_hw->shift));
45 
46 	return 0;
47 }
48 
49 static int owl_mux_set_parent(struct clk_hw *hw, u8 index)
50 {
51 	struct owl_mux *mux = hw_to_owl_mux(hw);
52 
53 	return owl_mux_helper_set_parent(&mux->common, &mux->mux_hw, index);
54 }
55 
56 const struct clk_ops owl_mux_ops = {
57 	.get_parent = owl_mux_get_parent,
58 	.set_parent = owl_mux_set_parent,
59 	.determine_rate = __clk_mux_determine_rate,
60 };
61