xref: /linux/drivers/clk/imx/clk-gate-exclusive.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2014 Freescale Semiconductor, Inc.
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/err.h>
8 #include <linux/io.h>
9 #include <linux/slab.h>
10 #include "clk.h"
11 
12 /**
13  * struct clk_gate_exclusive - i.MX specific gate clock which is mutually
14  * exclusive with other gate clocks
15  *
16  * @gate: the parent class
17  * @exclusive_mask: mask of gate bits which are mutually exclusive to this
18  *	gate clock
19  *
20  * The imx exclusive gate clock is a subclass of basic clk_gate
21  * with an addtional mask to indicate which other gate bits in the same
22  * register is mutually exclusive to this gate clock.
23  */
24 struct clk_gate_exclusive {
25 	struct clk_gate gate;
26 	u32 exclusive_mask;
27 };
28 
29 static int clk_gate_exclusive_enable(struct clk_hw *hw)
30 {
31 	struct clk_gate *gate = to_clk_gate(hw);
32 	struct clk_gate_exclusive *exgate = container_of(gate,
33 					struct clk_gate_exclusive, gate);
34 	u32 val = readl(gate->reg);
35 
36 	if (val & exgate->exclusive_mask)
37 		return -EBUSY;
38 
39 	return clk_gate_ops.enable(hw);
40 }
41 
42 static void clk_gate_exclusive_disable(struct clk_hw *hw)
43 {
44 	clk_gate_ops.disable(hw);
45 }
46 
47 static int clk_gate_exclusive_is_enabled(struct clk_hw *hw)
48 {
49 	return clk_gate_ops.is_enabled(hw);
50 }
51 
52 static const struct clk_ops clk_gate_exclusive_ops = {
53 	.enable = clk_gate_exclusive_enable,
54 	.disable = clk_gate_exclusive_disable,
55 	.is_enabled = clk_gate_exclusive_is_enabled,
56 };
57 
58 struct clk_hw *imx_clk_hw_gate_exclusive(const char *name, const char *parent,
59 	 void __iomem *reg, u8 shift, u32 exclusive_mask)
60 {
61 	struct clk_gate_exclusive *exgate;
62 	struct clk_gate *gate;
63 	struct clk_hw *hw;
64 	struct clk_init_data init;
65 	int ret;
66 
67 	if (exclusive_mask == 0)
68 		return ERR_PTR(-EINVAL);
69 
70 	exgate = kzalloc(sizeof(*exgate), GFP_KERNEL);
71 	if (!exgate)
72 		return ERR_PTR(-ENOMEM);
73 	gate = &exgate->gate;
74 
75 	init.name = name;
76 	init.ops = &clk_gate_exclusive_ops;
77 	init.flags = CLK_SET_RATE_PARENT;
78 	init.parent_names = parent ? &parent : NULL;
79 	init.num_parents = parent ? 1 : 0;
80 
81 	gate->reg = reg;
82 	gate->bit_idx = shift;
83 	gate->lock = &imx_ccm_lock;
84 	gate->hw.init = &init;
85 	exgate->exclusive_mask = exclusive_mask;
86 
87 	hw = &gate->hw;
88 
89 	ret = clk_hw_register(NULL, hw);
90 	if (ret) {
91 		kfree(gate);
92 		return ERR_PTR(ret);
93 	}
94 
95 	return hw;
96 }
97