1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright 2014 Chen-Yu Tsai
4 *
5 * Chen-Yu Tsai <wens@csie.org>
6 */
7
8#include <linux/clk.h>
9#include <linux/clk-provider.h>
10#include <linux/io.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/of_address.h>
14
15#define SUN8I_MBUS_ENABLE	31
16#define SUN8I_MBUS_MUX_SHIFT	24
17#define SUN8I_MBUS_MUX_MASK	0x3
18#define SUN8I_MBUS_DIV_SHIFT	0
19#define SUN8I_MBUS_DIV_WIDTH	3
20#define SUN8I_MBUS_MAX_PARENTS	4
21
22static DEFINE_SPINLOCK(sun8i_a23_mbus_lock);
23
24static void __init sun8i_a23_mbus_setup(struct device_node *node)
25{
26	int num_parents = of_clk_get_parent_count(node);
27	const char **parents;
28	const char *clk_name = node->name;
29	struct resource res;
30	struct clk_divider *div;
31	struct clk_gate *gate;
32	struct clk_mux *mux;
33	struct clk *clk;
34	void __iomem *reg;
35	int err;
36
37	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
38	if (!parents)
39		return;
40
41	reg = of_io_request_and_map(node, 0, of_node_full_name(node));
42	if (IS_ERR(reg)) {
43		pr_err("Could not get registers for sun8i-mbus-clk\n");
44		goto err_free_parents;
45	}
46
47	div = kzalloc(sizeof(*div), GFP_KERNEL);
48	if (!div)
49		goto err_unmap;
50
51	mux = kzalloc(sizeof(*mux), GFP_KERNEL);
52	if (!mux)
53		goto err_free_div;
54
55	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
56	if (!gate)
57		goto err_free_mux;
58
59	of_property_read_string(node, "clock-output-names", &clk_name);
60	of_clk_parent_fill(node, parents, num_parents);
61
62	gate->reg = reg;
63	gate->bit_idx = SUN8I_MBUS_ENABLE;
64	gate->lock = &sun8i_a23_mbus_lock;
65
66	div->reg = reg;
67	div->shift = SUN8I_MBUS_DIV_SHIFT;
68	div->width = SUN8I_MBUS_DIV_WIDTH;
69	div->lock = &sun8i_a23_mbus_lock;
70
71	mux->reg = reg;
72	mux->shift = SUN8I_MBUS_MUX_SHIFT;
73	mux->mask = SUN8I_MBUS_MUX_MASK;
74	mux->lock = &sun8i_a23_mbus_lock;
75
76	/* The MBUS clocks needs to be always enabled */
77	clk = clk_register_composite(NULL, clk_name, parents, num_parents,
78				     &mux->hw, &clk_mux_ops,
79				     &div->hw, &clk_divider_ops,
80				     &gate->hw, &clk_gate_ops,
81				     CLK_IS_CRITICAL);
82	if (IS_ERR(clk))
83		goto err_free_gate;
84
85	err = of_clk_add_provider(node, of_clk_src_simple_get, clk);
86	if (err)
87		goto err_unregister_clk;
88
89	kfree(parents); /* parents is deep copied */
90
91	return;
92
93err_unregister_clk:
94	/* TODO: The composite clock stuff will leak a bit here. */
95	clk_unregister(clk);
96err_free_gate:
97	kfree(gate);
98err_free_mux:
99	kfree(mux);
100err_free_div:
101	kfree(div);
102err_unmap:
103	iounmap(reg);
104	of_address_to_resource(node, 0, &res);
105	release_mem_region(res.start, resource_size(&res));
106err_free_parents:
107	kfree(parents);
108}
109CLK_OF_DECLARE(sun8i_a23_mbus, "allwinner,sun8i-a23-mbus-clk", sun8i_a23_mbus_setup);
110