1 /*
2  * Marvell Armada 37xx SoC Time Base Generator clocks
3  *
4  * Copyright (C) 2016 Marvell
5  *
6  * Gregory CLEMENT <gregory.clement@free-electrons.com>
7  *
8  * This file is licensed under the terms of the GNU General Public
9  * License version 2 or later. This program is licensed "as is"
10  * without any warranty of any kind, whether express or implied.
11  */
12 
13 #include <linux/clk-provider.h>
14 #include <linux/clk.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 
20 #define NUM_TBG	    4
21 
22 #define TBG_CTRL0		0x4
23 #define TBG_CTRL1		0x8
24 #define TBG_CTRL7		0x20
25 #define TBG_CTRL8		0x30
26 
27 #define TBG_DIV_MASK		0x1FF
28 
29 #define TBG_A_REFDIV		0
30 #define TBG_B_REFDIV		16
31 
32 #define TBG_A_FBDIV		2
33 #define TBG_B_FBDIV		18
34 
35 #define TBG_A_VCODIV_SE		0
36 #define TBG_B_VCODIV_SE		16
37 
38 #define TBG_A_VCODIV_DIFF	1
39 #define TBG_B_VCODIV_DIFF	17
40 
41 struct tbg_def {
42 	char *name;
43 	u32 refdiv_offset;
44 	u32 fbdiv_offset;
45 	u32 vcodiv_reg;
46 	u32 vcodiv_offset;
47 };
48 
49 static const struct tbg_def tbg[NUM_TBG] = {
50 	{"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
51 	{"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
52 	{"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
53 	{"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
54 };
55 
56 static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
57 {
58 	u32 val;
59 
60 	val = readl(reg + TBG_CTRL0);
61 
62 	return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
63 }
64 
65 static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
66 {
67 	u32 val;
68 	unsigned int div;
69 
70 	val = readl(reg + TBG_CTRL7);
71 
72 	div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
73 	if (div == 0)
74 		div = 1;
75 	val = readl(reg + ptbg->vcodiv_reg);
76 
77 	div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);
78 
79 	return div;
80 }
81 
82 
83 static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
84 {
85 	struct device_node *np = pdev->dev.of_node;
86 	struct clk_hw_onecell_data *hw_tbg_data;
87 	struct device *dev = &pdev->dev;
88 	const char *parent_name;
89 	struct resource *res;
90 	struct clk *parent;
91 	void __iomem *reg;
92 	int i, ret;
93 
94 	hw_tbg_data = devm_kzalloc(&pdev->dev, sizeof(*hw_tbg_data)
95 				   + sizeof(*hw_tbg_data->hws) * NUM_TBG,
96 				   GFP_KERNEL);
97 	if (!hw_tbg_data)
98 		return -ENOMEM;
99 	hw_tbg_data->num = NUM_TBG;
100 	platform_set_drvdata(pdev, hw_tbg_data);
101 
102 	parent = devm_clk_get(dev, NULL);
103 	if (IS_ERR(parent)) {
104 		dev_err(dev, "Could get the clock parent\n");
105 		return -EINVAL;
106 	}
107 	parent_name = __clk_get_name(parent);
108 
109 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
110 	reg = devm_ioremap_resource(dev, res);
111 	if (IS_ERR(reg))
112 		return PTR_ERR(reg);
113 
114 	for (i = 0; i < NUM_TBG; i++) {
115 		const char *name;
116 		unsigned int mult, div;
117 
118 		name = tbg[i].name;
119 		mult = tbg_get_mult(reg, &tbg[i]);
120 		div = tbg_get_div(reg, &tbg[i]);
121 		hw_tbg_data->hws[i] = clk_hw_register_fixed_factor(NULL, name,
122 						parent_name, 0, mult, div);
123 		if (IS_ERR(hw_tbg_data->hws[i]))
124 			dev_err(dev, "Can't register TBG clock %s\n", name);
125 	}
126 
127 	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_tbg_data);
128 
129 	return ret;
130 }
131 
132 static int armada_3700_tbg_clock_remove(struct platform_device *pdev)
133 {
134 	int i;
135 	struct clk_hw_onecell_data *hw_tbg_data = platform_get_drvdata(pdev);
136 
137 	of_clk_del_provider(pdev->dev.of_node);
138 	for (i = 0; i < hw_tbg_data->num; i++)
139 		clk_hw_unregister_fixed_factor(hw_tbg_data->hws[i]);
140 
141 	return 0;
142 }
143 
144 static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
145 	{ .compatible = "marvell,armada-3700-tbg-clock", },
146 	{ }
147 };
148 
149 static struct platform_driver armada_3700_tbg_clock_driver = {
150 	.probe = armada_3700_tbg_clock_probe,
151 	.remove = armada_3700_tbg_clock_remove,
152 	.driver		= {
153 		.name	= "marvell-armada-3700-tbg-clock",
154 		.of_match_table = armada_3700_tbg_clock_of_match,
155 	},
156 };
157 
158 builtin_platform_driver(armada_3700_tbg_clock_driver);
159