xref: /openbmc/linux/drivers/clk/clk-moxart.c (revision b96fc2f3)
1 /*
2  * MOXA ART SoCs clock driver.
3  *
4  * Copyright (C) 2013 Jonas Jensen
5  *
6  * Jonas Jensen <jonas.jensen@gmail.com>
7  *
8  * This file is licensed under the terms of the GNU General Public
9  * License version 2.  This program is licensed "as is" without any
10  * warranty of any kind, whether express or implied.
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/clk-provider.h>
15 #include <linux/io.h>
16 #include <linux/of_address.h>
17 #include <linux/clkdev.h>
18 
19 static void __init moxart_of_pll_clk_init(struct device_node *node)
20 {
21 	static void __iomem *base;
22 	struct clk *clk, *ref_clk;
23 	unsigned int mul;
24 	const char *name = node->name;
25 	const char *parent_name;
26 
27 	of_property_read_string(node, "clock-output-names", &name);
28 	parent_name = of_clk_get_parent_name(node, 0);
29 
30 	base = of_iomap(node, 0);
31 	if (!base) {
32 		pr_err("%s: of_iomap failed\n", node->full_name);
33 		return;
34 	}
35 
36 	mul = readl(base + 0x30) >> 3 & 0x3f;
37 	iounmap(base);
38 
39 	ref_clk = of_clk_get(node, 0);
40 	if (IS_ERR(ref_clk)) {
41 		pr_err("%s: of_clk_get failed\n", node->full_name);
42 		return;
43 	}
44 
45 	clk = clk_register_fixed_factor(NULL, name, parent_name, 0, mul, 1);
46 	if (IS_ERR(clk)) {
47 		pr_err("%s: failed to register clock\n", node->full_name);
48 		return;
49 	}
50 
51 	clk_register_clkdev(clk, NULL, name);
52 	of_clk_add_provider(node, of_clk_src_simple_get, clk);
53 }
54 CLK_OF_DECLARE(moxart_pll_clock, "moxa,moxart-pll-clock",
55 	       moxart_of_pll_clk_init);
56 
57 static void __init moxart_of_apb_clk_init(struct device_node *node)
58 {
59 	static void __iomem *base;
60 	struct clk *clk, *pll_clk;
61 	unsigned int div, val;
62 	unsigned int div_idx[] = { 2, 3, 4, 6, 8};
63 	const char *name = node->name;
64 	const char *parent_name;
65 
66 	of_property_read_string(node, "clock-output-names", &name);
67 	parent_name = of_clk_get_parent_name(node, 0);
68 
69 	base = of_iomap(node, 0);
70 	if (!base) {
71 		pr_err("%s: of_iomap failed\n", node->full_name);
72 		return;
73 	}
74 
75 	val = readl(base + 0xc) >> 4 & 0x7;
76 	iounmap(base);
77 
78 	if (val > 4)
79 		val = 0;
80 	div = div_idx[val] * 2;
81 
82 	pll_clk = of_clk_get(node, 0);
83 	if (IS_ERR(pll_clk)) {
84 		pr_err("%s: of_clk_get failed\n", node->full_name);
85 		return;
86 	}
87 
88 	clk = clk_register_fixed_factor(NULL, name, parent_name, 0, 1, div);
89 	if (IS_ERR(clk)) {
90 		pr_err("%s: failed to register clock\n", node->full_name);
91 		return;
92 	}
93 
94 	clk_register_clkdev(clk, NULL, name);
95 	of_clk_add_provider(node, of_clk_src_simple_get, clk);
96 }
97 CLK_OF_DECLARE(moxart_apb_clock, "moxa,moxart-apb-clock",
98 	       moxart_of_apb_clk_init);
99