xref: /openbmc/linux/drivers/clk/sunxi/clk-a10-hosc.c (revision bc5aa3a0)
1 /*
2  * Copyright 2013 Emilio López
3  *
4  * Emilio López <emilio@elopez.com.ar>
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-provider.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/slab.h>
21 
22 #define SUNXI_OSC24M_GATE	0
23 
24 static DEFINE_SPINLOCK(hosc_lock);
25 
26 static void __init sun4i_osc_clk_setup(struct device_node *node)
27 {
28 	struct clk *clk;
29 	struct clk_fixed_rate *fixed;
30 	struct clk_gate *gate;
31 	const char *clk_name = node->name;
32 	u32 rate;
33 
34 	if (of_property_read_u32(node, "clock-frequency", &rate))
35 		return;
36 
37 	/* allocate fixed-rate and gate clock structs */
38 	fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL);
39 	if (!fixed)
40 		return;
41 	gate = kzalloc(sizeof(struct clk_gate), GFP_KERNEL);
42 	if (!gate)
43 		goto err_free_fixed;
44 
45 	of_property_read_string(node, "clock-output-names", &clk_name);
46 
47 	/* set up gate and fixed rate properties */
48 	gate->reg = of_iomap(node, 0);
49 	gate->bit_idx = SUNXI_OSC24M_GATE;
50 	gate->lock = &hosc_lock;
51 	fixed->fixed_rate = rate;
52 
53 	clk = clk_register_composite(NULL, clk_name,
54 			NULL, 0,
55 			NULL, NULL,
56 			&fixed->hw, &clk_fixed_rate_ops,
57 			&gate->hw, &clk_gate_ops, 0);
58 
59 	if (IS_ERR(clk))
60 		goto err_free_gate;
61 
62 	of_clk_add_provider(node, of_clk_src_simple_get, clk);
63 
64 	return;
65 
66 err_free_gate:
67 	kfree(gate);
68 err_free_fixed:
69 	kfree(fixed);
70 }
71 CLK_OF_DECLARE(sun4i_osc, "allwinner,sun4i-a10-osc-clk", sun4i_osc_clk_setup);
72