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 on success or number of parents in case of error
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 
51 	ret = zynqmp_pm_clock_getparent(clk_id, &val);
52 
53 	if (ret) {
54 		pr_debug("%s() getparent failed for clock: %s, ret = %d\n",
55 			 __func__, clk_name, ret);
56 		/*
57 		 * clk_core_get_parent_by_index() takes num_parents as incorrect
58 		 * index which is exactly what I want to return here
59 		 */
60 		return clk_hw_get_num_parents(hw);
61 	}
62 
63 	return val;
64 }
65 
66 /**
67  * zynqmp_clk_mux_set_parent() - Set parent of clock
68  * @hw:		handle between common and hardware-specific interfaces
69  * @index:	Parent index
70  *
71  * Return: 0 on success else error+reason
72  */
73 static int zynqmp_clk_mux_set_parent(struct clk_hw *hw, u8 index)
74 {
75 	struct zynqmp_clk_mux *mux = to_zynqmp_clk_mux(hw);
76 	const char *clk_name = clk_hw_get_name(hw);
77 	u32 clk_id = mux->clk_id;
78 	int ret;
79 
80 	ret = zynqmp_pm_clock_setparent(clk_id, index);
81 
82 	if (ret)
83 		pr_debug("%s() set parent failed for clock: %s, ret = %d\n",
84 			 __func__, clk_name, ret);
85 
86 	return ret;
87 }
88 
89 static const struct clk_ops zynqmp_clk_mux_ops = {
90 	.get_parent = zynqmp_clk_mux_get_parent,
91 	.set_parent = zynqmp_clk_mux_set_parent,
92 	.determine_rate = __clk_mux_determine_rate,
93 };
94 
95 static const struct clk_ops zynqmp_clk_mux_ro_ops = {
96 	.get_parent = zynqmp_clk_mux_get_parent,
97 };
98 
99 static inline unsigned long zynqmp_clk_map_mux_ccf_flags(
100 				       const u32 zynqmp_type_flag)
101 {
102 	unsigned long ccf_flag = 0;
103 
104 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_INDEX_ONE)
105 		ccf_flag |= CLK_MUX_INDEX_ONE;
106 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_INDEX_BIT)
107 		ccf_flag |= CLK_MUX_INDEX_BIT;
108 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_HIWORD_MASK)
109 		ccf_flag |= CLK_MUX_HIWORD_MASK;
110 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_READ_ONLY)
111 		ccf_flag |= CLK_MUX_READ_ONLY;
112 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_ROUND_CLOSEST)
113 		ccf_flag |= CLK_MUX_ROUND_CLOSEST;
114 	if (zynqmp_type_flag & ZYNQMP_CLK_MUX_BIG_ENDIAN)
115 		ccf_flag |= CLK_MUX_BIG_ENDIAN;
116 
117 	return ccf_flag;
118 }
119 
120 /**
121  * zynqmp_clk_register_mux() - Register a mux table with the clock
122  *			       framework
123  * @name:		Name of this clock
124  * @clk_id:		Id of this clock
125  * @parents:		Name of this clock's parents
126  * @num_parents:	Number of parents
127  * @nodes:		Clock topology node
128  *
129  * Return: clock hardware of the registered clock mux
130  */
131 struct clk_hw *zynqmp_clk_register_mux(const char *name, u32 clk_id,
132 				       const char * const *parents,
133 				       u8 num_parents,
134 				       const struct clock_topology *nodes)
135 {
136 	struct zynqmp_clk_mux *mux;
137 	struct clk_hw *hw;
138 	struct clk_init_data init;
139 	int ret;
140 
141 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
142 	if (!mux)
143 		return ERR_PTR(-ENOMEM);
144 
145 	init.name = name;
146 	if (nodes->type_flag & CLK_MUX_READ_ONLY)
147 		init.ops = &zynqmp_clk_mux_ro_ops;
148 	else
149 		init.ops = &zynqmp_clk_mux_ops;
150 
151 	init.flags = zynqmp_clk_map_common_ccf_flags(nodes->flag);
152 
153 	init.parent_names = parents;
154 	init.num_parents = num_parents;
155 	mux->flags = zynqmp_clk_map_mux_ccf_flags(nodes->type_flag);
156 	mux->hw.init = &init;
157 	mux->clk_id = clk_id;
158 
159 	hw = &mux->hw;
160 	ret = clk_hw_register(NULL, hw);
161 	if (ret) {
162 		kfree(mux);
163 		hw = ERR_PTR(ret);
164 	}
165 
166 	return hw;
167 }
168