1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Clock driver for the ARM Integrator/IM-PD1 board
4  * Copyright (C) 2012-2013 Linus Walleij
5  */
6 #include <linux/clk-provider.h>
7 #include <linux/clkdev.h>
8 #include <linux/err.h>
9 #include <linux/io.h>
10 #include <linux/platform_device.h>
11 #include <linux/module.h>
12 #include <linux/mfd/syscon.h>
13 #include <linux/regmap.h>
14 
15 #include "icst.h"
16 #include "clk-icst.h"
17 
18 #define IMPD1_OSC1	0x00
19 #define IMPD1_OSC2	0x04
20 #define IMPD1_LOCK	0x08
21 
22 /*
23  * There are two VCO's on the IM-PD1
24  */
25 
26 static const struct icst_params impd1_vco1_params = {
27 	.ref		= 24000000,	/* 24 MHz */
28 	.vco_max	= ICST525_VCO_MAX_3V,
29 	.vco_min	= ICST525_VCO_MIN,
30 	.vd_min		= 12,
31 	.vd_max		= 519,
32 	.rd_min		= 3,
33 	.rd_max		= 120,
34 	.s2div		= icst525_s2div,
35 	.idx2s		= icst525_idx2s,
36 };
37 
38 static const struct clk_icst_desc impd1_icst1_desc = {
39 	.params = &impd1_vco1_params,
40 	.vco_offset = IMPD1_OSC1,
41 	.lock_offset = IMPD1_LOCK,
42 };
43 
44 static const struct icst_params impd1_vco2_params = {
45 	.ref		= 24000000,	/* 24 MHz */
46 	.vco_max	= ICST525_VCO_MAX_3V,
47 	.vco_min	= ICST525_VCO_MIN,
48 	.vd_min		= 12,
49 	.vd_max		= 519,
50 	.rd_min		= 3,
51 	.rd_max		= 120,
52 	.s2div		= icst525_s2div,
53 	.idx2s		= icst525_idx2s,
54 };
55 
56 static const struct clk_icst_desc impd1_icst2_desc = {
57 	.params = &impd1_vco2_params,
58 	.vco_offset = IMPD1_OSC2,
59 	.lock_offset = IMPD1_LOCK,
60 };
61 
62 static int integrator_impd1_clk_spawn(struct device *dev,
63 				      struct device_node *parent,
64 				      struct device_node *np)
65 {
66 	struct regmap *map;
67 	struct clk *clk = ERR_PTR(-EINVAL);
68 	const char *name = np->name;
69 	const char *parent_name;
70 	const struct clk_icst_desc *desc;
71 	int ret;
72 
73 	map = syscon_node_to_regmap(parent);
74 	if (IS_ERR(map)) {
75 		pr_err("no regmap for syscon IM-PD1 ICST clock parent\n");
76 		return PTR_ERR(map);
77 	}
78 
79 	if (of_device_is_compatible(np, "arm,impd1-vco1")) {
80 		desc = &impd1_icst1_desc;
81 	} else if (of_device_is_compatible(np, "arm,impd1-vco2")) {
82 		desc = &impd1_icst2_desc;
83 	} else {
84 		dev_err(dev, "not a clock node %s\n", name);
85 		return -ENODEV;
86 	}
87 
88 	of_property_read_string(np, "clock-output-names", &name);
89 	parent_name = of_clk_get_parent_name(np, 0);
90 	clk = icst_clk_setup(NULL, desc, name, parent_name, map,
91 			     ICST_INTEGRATOR_IM_PD1);
92 	if (!IS_ERR(clk)) {
93 		of_clk_add_provider(np, of_clk_src_simple_get, clk);
94 		ret = 0;
95 	} else {
96 		dev_err(dev, "error setting up IM-PD1 ICST clock\n");
97 		ret = PTR_ERR(clk);
98 	}
99 
100 	return ret;
101 }
102 
103 static int integrator_impd1_clk_probe(struct platform_device *pdev)
104 {
105 	struct device *dev = &pdev->dev;
106 	struct device_node *np = dev->of_node;
107 	struct device_node *child;
108 	int ret = 0;
109 
110 	for_each_available_child_of_node(np, child) {
111 		ret = integrator_impd1_clk_spawn(dev, np, child);
112 		if (ret)
113 			break;
114 	}
115 
116 	return ret;
117 }
118 
119 static const struct of_device_id impd1_syscon_match[] = {
120 	{ .compatible = "arm,im-pd1-syscon", },
121 	{}
122 };
123 MODULE_DEVICE_TABLE(of, impd1_syscon_match);
124 
125 static struct platform_driver impd1_clk_driver = {
126 	.driver = {
127 		.name = "impd1-clk",
128 		.of_match_table = impd1_syscon_match,
129 	},
130 	.probe  = integrator_impd1_clk_probe,
131 };
132 builtin_platform_driver(impd1_clk_driver);
133 
134 MODULE_AUTHOR("Linus Walleij <linusw@kernel.org>");
135 MODULE_DESCRIPTION("Arm IM-PD1 module clock driver");
136 MODULE_LICENSE("GPL v2");
137