1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Zynq UltraScale+ MPSoC clock controller
4  *
5  *  Copyright (C) 2016-2018 Xilinx
6  *
7  * Gated clock implementation
8  */
9 
10 #include <linux/clk-provider.h>
11 #include <linux/slab.h>
12 #include "clk-zynqmp.h"
13 
14 /**
15  * struct zynqmp_clk_gate - gating clock
16  * @hw:		handle between common and hardware-specific interfaces
17  * @flags:	hardware-specific flags
18  * @clk_id:	Id of clock
19  */
20 struct zynqmp_clk_gate {
21 	struct clk_hw hw;
22 	u8 flags;
23 	u32 clk_id;
24 };
25 
26 #define to_zynqmp_clk_gate(_hw) container_of(_hw, struct zynqmp_clk_gate, hw)
27 
28 /**
29  * zynqmp_clk_gate_enable() - Enable clock
30  * @hw:		handle between common and hardware-specific interfaces
31  *
32  * Return: 0 on success else error code
33  */
34 static int zynqmp_clk_gate_enable(struct clk_hw *hw)
35 {
36 	struct zynqmp_clk_gate *gate = to_zynqmp_clk_gate(hw);
37 	const char *clk_name = clk_hw_get_name(hw);
38 	u32 clk_id = gate->clk_id;
39 	int ret;
40 
41 	ret = zynqmp_pm_clock_enable(clk_id);
42 
43 	if (ret)
44 		pr_debug("%s() clock enable failed for %s (id %d), ret = %d\n",
45 			 __func__, clk_name, clk_id, ret);
46 
47 	return ret;
48 }
49 
50 /*
51  * zynqmp_clk_gate_disable() - Disable clock
52  * @hw:		handle between common and hardware-specific interfaces
53  */
54 static void zynqmp_clk_gate_disable(struct clk_hw *hw)
55 {
56 	struct zynqmp_clk_gate *gate = to_zynqmp_clk_gate(hw);
57 	const char *clk_name = clk_hw_get_name(hw);
58 	u32 clk_id = gate->clk_id;
59 	int ret;
60 
61 	ret = zynqmp_pm_clock_disable(clk_id);
62 
63 	if (ret)
64 		pr_debug("%s() clock disable failed for %s (id %d), ret = %d\n",
65 			 __func__, clk_name, clk_id, ret);
66 }
67 
68 /**
69  * zynqmp_clk_gate_is_enabled() - Check clock state
70  * @hw:		handle between common and hardware-specific interfaces
71  *
72  * Return: 1 if enabled, 0 if disabled else error code
73  */
74 static int zynqmp_clk_gate_is_enabled(struct clk_hw *hw)
75 {
76 	struct zynqmp_clk_gate *gate = to_zynqmp_clk_gate(hw);
77 	const char *clk_name = clk_hw_get_name(hw);
78 	u32 clk_id = gate->clk_id;
79 	int state, ret;
80 
81 	ret = zynqmp_pm_clock_getstate(clk_id, &state);
82 	if (ret) {
83 		pr_debug("%s() clock get state failed for %s, ret = %d\n",
84 			 __func__, clk_name, ret);
85 		return -EIO;
86 	}
87 
88 	return state ? 1 : 0;
89 }
90 
91 static const struct clk_ops zynqmp_clk_gate_ops = {
92 	.enable = zynqmp_clk_gate_enable,
93 	.disable = zynqmp_clk_gate_disable,
94 	.is_enabled = zynqmp_clk_gate_is_enabled,
95 };
96 
97 /**
98  * zynqmp_clk_register_gate() - Register a gate clock with the clock framework
99  * @name:		Name of this clock
100  * @clk_id:		Id of this clock
101  * @parents:		Name of this clock's parents
102  * @num_parents:	Number of parents
103  * @nodes:		Clock topology node
104  *
105  * Return: clock hardware of the registered clock gate
106  */
107 struct clk_hw *zynqmp_clk_register_gate(const char *name, u32 clk_id,
108 					const char * const *parents,
109 					u8 num_parents,
110 					const struct clock_topology *nodes)
111 {
112 	struct zynqmp_clk_gate *gate;
113 	struct clk_hw *hw;
114 	int ret;
115 	struct clk_init_data init;
116 
117 	/* allocate the gate */
118 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
119 	if (!gate)
120 		return ERR_PTR(-ENOMEM);
121 
122 	init.name = name;
123 	init.ops = &zynqmp_clk_gate_ops;
124 
125 	init.flags = zynqmp_clk_map_common_ccf_flags(nodes->flag);
126 
127 	init.parent_names = parents;
128 	init.num_parents = 1;
129 
130 	/* struct clk_gate assignments */
131 	gate->flags = nodes->type_flag;
132 	gate->hw.init = &init;
133 	gate->clk_id = clk_id;
134 
135 	hw = &gate->hw;
136 	ret = clk_hw_register(NULL, hw);
137 	if (ret) {
138 		kfree(gate);
139 		hw = ERR_PTR(ret);
140 	}
141 
142 	return hw;
143 }
144