xref: /openbmc/linux/drivers/clk/clk-moxart.c (revision d9fd5a71)
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 	void __iomem *base;
22 	struct clk_hw *hw;
23 	struct clk *ref_clk;
24 	unsigned int mul;
25 	const char *name = node->name;
26 	const char *parent_name;
27 
28 	of_property_read_string(node, "clock-output-names", &name);
29 	parent_name = of_clk_get_parent_name(node, 0);
30 
31 	base = of_iomap(node, 0);
32 	if (!base) {
33 		pr_err("%pOF: of_iomap failed\n", node);
34 		return;
35 	}
36 
37 	mul = readl(base + 0x30) >> 3 & 0x3f;
38 	iounmap(base);
39 
40 	ref_clk = of_clk_get(node, 0);
41 	if (IS_ERR(ref_clk)) {
42 		pr_err("%pOF: of_clk_get failed\n", node);
43 		return;
44 	}
45 
46 	hw = clk_hw_register_fixed_factor(NULL, name, parent_name, 0, mul, 1);
47 	if (IS_ERR(hw)) {
48 		pr_err("%pOF: failed to register clock\n", node);
49 		return;
50 	}
51 
52 	clk_hw_register_clkdev(hw, NULL, name);
53 	of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
54 }
55 CLK_OF_DECLARE(moxart_pll_clock, "moxa,moxart-pll-clock",
56 	       moxart_of_pll_clk_init);
57 
58 static void __init moxart_of_apb_clk_init(struct device_node *node)
59 {
60 	void __iomem *base;
61 	struct clk_hw *hw;
62 	struct clk *pll_clk;
63 	unsigned int div, val;
64 	unsigned int div_idx[] = { 2, 3, 4, 6, 8};
65 	const char *name = node->name;
66 	const char *parent_name;
67 
68 	of_property_read_string(node, "clock-output-names", &name);
69 	parent_name = of_clk_get_parent_name(node, 0);
70 
71 	base = of_iomap(node, 0);
72 	if (!base) {
73 		pr_err("%pOF: of_iomap failed\n", node);
74 		return;
75 	}
76 
77 	val = readl(base + 0xc) >> 4 & 0x7;
78 	iounmap(base);
79 
80 	if (val > 4)
81 		val = 0;
82 	div = div_idx[val] * 2;
83 
84 	pll_clk = of_clk_get(node, 0);
85 	if (IS_ERR(pll_clk)) {
86 		pr_err("%pOF: of_clk_get failed\n", node);
87 		return;
88 	}
89 
90 	hw = clk_hw_register_fixed_factor(NULL, name, parent_name, 0, 1, div);
91 	if (IS_ERR(hw)) {
92 		pr_err("%pOF: failed to register clock\n", node);
93 		return;
94 	}
95 
96 	clk_hw_register_clkdev(hw, NULL, name);
97 	of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
98 }
99 CLK_OF_DECLARE(moxart_apb_clock, "moxa,moxart-apb-clock",
100 	       moxart_of_apb_clk_init);
101