xref: /linux/drivers/clk/zynqmp/clk-mux-zynqmp.c (revision e91158f1be5b157329ab8f21f86728d591c8f747)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Zynq UltraScale+ MPSoC mux
4  *
5  *  Copyright (C) 2016-2018 Xilinx
6  */
7 
8 #include <linux/clk-provider.h>
9 #include <linux/slab.h>
10 #include "clk-zynqmp.h"
11 
12 /*
13  * DOC: basic adjustable multiplexer clock that cannot gate
14  *
15  * Traits of this clock:
16  * prepare - clk_prepare only ensures that parents are prepared
17  * enable - clk_enable only ensures that parents are enabled
18  * rate - rate is only affected by parent switching.  No clk_set_rate support
19  * parent - parent is adjustable through clk_set_parent
20  */
21 
22 /**
23  * struct zynqmp_clk_mux - multiplexer clock
24  *
25  * @hw:		handle between common and hardware-specific interfaces
26  * @flags:	hardware-specific flags
27  * @clk_id:	Id of clock
28  */
29 struct zynqmp_clk_mux {
30 	struct clk_hw hw;
31 	u8 flags;
32 	u32 clk_id;
33 };
34 
35 #define to_zynqmp_clk_mux(_hw) container_of(_hw, struct zynqmp_clk_mux, hw)
36 
37 /**
38  * zynqmp_clk_mux_get_parent() - Get parent of clock
39  * @hw:		handle between common and hardware-specific interfaces
40  *
41  * Return: Parent index
42  */
43 static u8 zynqmp_clk_mux_get_parent(struct clk_hw *hw)
44 {
45 	struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
46 	const char *clk_name = clk_hw_get_name(hw);
47 	u32 clk_id = mux->clk_id;
48 	u32 val;
49 	int ret;
50 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
51 
52 	ret = eemi_ops->clock_getparent(clk_id, &val);
53 
54 	if (ret)
55 		pr_warn_once("%s() getparent failed for clock: %s, ret = %d\n",
56 			     __func__, clk_name, ret);
57 
58 	return val;
59 }
60 
61 /**
62  * zynqmp_clk_mux_set_parent() - Set parent of clock
63  * @hw:		handle between common and hardware-specific interfaces
64  * @index:	Parent index
65  *
66  * Return: 0 on success else error+reason
67  */
68 static int zynqmp_clk_mux_set_parent(struct clk_hw *hw, u8 index)
69 {
70 	struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
71 	const char *clk_name = clk_hw_get_name(hw);
72 	u32 clk_id = mux->clk_id;
73 	int ret;
74 	const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
75 
76 	ret = eemi_ops->clock_setparent(clk_id, index);
77 
78 	if (ret)
79 		pr_warn_once("%s() set parent failed for clock: %s, ret = %d\n",
80 			     __func__, clk_name, ret);
81 
82 	return ret;
83 }
84 
85 static const struct clk_ops zynqmp_clk_mux_ops = {
86 	.get_parent = zynqmp_clk_mux_get_parent,
87 	.set_parent = zynqmp_clk_mux_set_parent,
88 	.determine_rate = __clk_mux_determine_rate,
89 };
90 
91 static const struct clk_ops zynqmp_clk_mux_ro_ops = {
92 	.get_parent = zynqmp_clk_mux_get_parent,
93 };
94 
95 /**
96  * zynqmp_clk_register_mux() - Register a mux table with the clock
97  *			       framework
98  * @name:		Name of this clock
99  * @clk_id:		Id of this clock
100  * @parents:		Name of this clock's parents
101  * @num_parents:	Number of parents
102  * @nodes:		Clock topology node
103  *
104  * Return: clock hardware of the registered clock mux
105  */
106 struct clk_hw *zynqmp_clk_register_mux(const char *name, u32 clk_id,
107 				       const char * const *parents,
108 				       u8 num_parents,
109 				       const struct clock_topology *nodes)
110 {
111 	struct zynqmp_clk_mux *mux;
112 	struct clk_hw *hw;
113 	struct clk_init_data init;
114 	int ret;
115 
116 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
117 	if (!mux)
118 		return ERR_PTR(-ENOMEM);
119 
120 	init.name = name;
121 	if (nodes->type_flag & CLK_MUX_READ_ONLY)
122 		init.ops = &zynqmp_clk_mux_ro_ops;
123 	else
124 		init.ops = &zynqmp_clk_mux_ops;
125 	init.flags = nodes->flag;
126 	init.parent_names = parents;
127 	init.num_parents = num_parents;
128 	mux->flags = nodes->type_flag;
129 	mux->hw.init = &init;
130 	mux->clk_id = clk_id;
131 
132 	hw = &mux->hw;
133 	ret = clk_hw_register(NULL, hw);
134 	if (ret) {
135 		kfree(hw);
136 		hw = ERR_PTR(ret);
137 	}
138 
139 	return hw;
140 }
141