xref: /linux/drivers/clk/sunxi/clk-sun8i-mbus.c (revision bfd5bb6f90af092aa345b15cd78143956a13c2a8)
1 /*
2  * Copyright 2014 Chen-Yu Tsai
3  *
4  * Chen-Yu Tsai <wens@csie.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  */
16 
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <linux/of_address.h>
22 
23 #define SUN8I_MBUS_ENABLE	31
24 #define SUN8I_MBUS_MUX_SHIFT	24
25 #define SUN8I_MBUS_MUX_MASK	0x3
26 #define SUN8I_MBUS_DIV_SHIFT	0
27 #define SUN8I_MBUS_DIV_WIDTH	3
28 #define SUN8I_MBUS_MAX_PARENTS	4
29 
30 static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
31 
32 static void __init sun8i_a23_mbus_setup(struct device_node *node)
33 {
34 	int num_parents = of_clk_get_parent_count(node);
35 	const char **parents;
36 	const char *clk_name = node->name;
37 	struct resource res;
38 	struct clk_divider *div;
39 	struct clk_gate *gate;
40 	struct clk_mux *mux;
41 	struct clk *clk;
42 	void __iomem *reg;
43 	int err;
44 
45 	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
46 	if (!parents)
47 		return;
48 
49 	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
50 	if (IS_ERR(reg)) {
51 		pr_err("Could not get registers for sun8i-mbus-clk\n");
52 		goto err_free_parents;
53 	}
54 
55 	div = kzalloc(sizeof(*div), GFP_KERNEL);
56 	if (!div)
57 		goto err_unmap;
58 
59 	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
60 	if (!mux)
61 		goto err_free_div;
62 
63 	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
64 	if (!gate)
65 		goto err_free_mux;
66 
67 	of_property_read_string(node, "clock-output-names", &clk_name);
68 	of_clk_parent_fill(node, parents, num_parents);
69 
70 	gate->reg = reg;
71 	gate->bit_idx = SUN8I_MBUS_ENABLE;
72 	gate->lock = &sun8i_a23_mbus_lock;
73 
74 	div->reg = reg;
75 	div->shift = SUN8I_MBUS_DIV_SHIFT;
76 	div->width = SUN8I_MBUS_DIV_WIDTH;
77 	div->lock = &sun8i_a23_mbus_lock;
78 
79 	mux->reg = reg;
80 	mux->shift = SUN8I_MBUS_MUX_SHIFT;
81 	mux->mask = SUN8I_MBUS_MUX_MASK;
82 	mux->lock = &sun8i_a23_mbus_lock;
83 
84 	/* The MBUS clocks needs to be always enabled */
85 	clk = clk_register_composite(NULL, clk_name, parents, num_parents,
86 				     &mux->hw, &clk_mux_ops,
87 				     &div->hw, &clk_divider_ops,
88 				     &gate->hw, &clk_gate_ops,
89 				     CLK_IS_CRITICAL);
90 	if (IS_ERR(clk))
91 		goto err_free_gate;
92 
93 	err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
94 	if (err)
95 		goto err_unregister_clk;
96 
97 	kfree(parents); /* parents is deep copied */
98 
99 	return;
100 
101 err_unregister_clk:
102 	/* TODO: The composite clock stuff will leak a bit here. */
103 	clk_unregister(clk);
104 err_free_gate:
105 	kfree(gate);
106 err_free_mux:
107 	kfree(mux);
108 err_free_div:
109 	kfree(div);
110 err_unmap:
111 	iounmap(reg);
112 	of_address_to_resource(node, 0, &res);
113 	release_mem_region(res.start, resource_size(&res));
114 err_free_parents:
115 	kfree(parents);
116 }
117 CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);
118