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e848c2ea | 1 | // SPDX-License-Identifier: GPL-2.0 |
311accb6 YS |
2 | /* |
3 | * Renesas R-Car USB2.0 clock selector | |
4 | * | |
5 | * Copyright (C) 2017 Renesas Electronics Corp. | |
6 | * | |
7 | * Based on renesas-cpg-mssr.c | |
8 | * | |
9 | * Copyright (C) 2015 Glider bvba | |
311accb6 YS |
10 | */ |
11 | ||
12 | #include <linux/clk.h> | |
13 | #include <linux/clk-provider.h> | |
14 | #include <linux/device.h> | |
15 | #include <linux/init.h> | |
62e59c4e | 16 | #include <linux/io.h> |
311accb6 YS |
17 | #include <linux/module.h> |
18 | #include <linux/of_device.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/pm.h> | |
21 | #include <linux/pm_runtime.h> | |
22 | #include <linux/slab.h> | |
23 | ||
24 | #define USB20_CLKSET0 0x00 | |
25 | #define CLKSET0_INTCLK_EN BIT(11) | |
26 | #define CLKSET0_PRIVATE BIT(0) | |
27 | #define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE) | |
28 | ||
29 | struct usb2_clock_sel_priv { | |
30 | void __iomem *base; | |
31 | struct clk_hw hw; | |
32 | bool extal; | |
33 | bool xtal; | |
34 | }; | |
35 | #define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw) | |
36 | ||
37 | static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv) | |
38 | { | |
39 | u16 val = readw(priv->base + USB20_CLKSET0); | |
40 | ||
41 | pr_debug("%s: enter %d %d %x\n", __func__, | |
42 | priv->extal, priv->xtal, val); | |
43 | ||
44 | if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY) | |
45 | writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0); | |
46 | } | |
47 | ||
48 | static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv) | |
49 | { | |
50 | if (priv->extal && !priv->xtal) | |
51 | writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0); | |
52 | } | |
53 | ||
54 | static int usb2_clock_sel_enable(struct clk_hw *hw) | |
55 | { | |
56 | usb2_clock_sel_enable_extal_only(to_priv(hw)); | |
57 | ||
58 | return 0; | |
59 | } | |
60 | ||
61 | static void usb2_clock_sel_disable(struct clk_hw *hw) | |
62 | { | |
63 | usb2_clock_sel_disable_extal_only(to_priv(hw)); | |
64 | } | |
65 | ||
66 | /* | |
67 | * This module seems a mux, but this driver assumes a gate because | |
68 | * ehci/ohci platform drivers don't support clk_set_parent() for now. | |
69 | * If this driver acts as a gate, ehci/ohci-platform drivers don't need | |
70 | * any modification. | |
71 | */ | |
72 | static const struct clk_ops usb2_clock_sel_clock_ops = { | |
73 | .enable = usb2_clock_sel_enable, | |
74 | .disable = usb2_clock_sel_disable, | |
75 | }; | |
76 | ||
77 | static const struct of_device_id rcar_usb2_clock_sel_match[] = { | |
78 | { .compatible = "renesas,rcar-gen3-usb2-clock-sel" }, | |
79 | { } | |
80 | }; | |
81 | ||
82 | static int rcar_usb2_clock_sel_suspend(struct device *dev) | |
83 | { | |
84 | struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); | |
85 | ||
86 | usb2_clock_sel_disable_extal_only(priv); | |
87 | pm_runtime_put(dev); | |
88 | ||
89 | return 0; | |
90 | } | |
91 | ||
92 | static int rcar_usb2_clock_sel_resume(struct device *dev) | |
93 | { | |
94 | struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); | |
95 | ||
96 | pm_runtime_get_sync(dev); | |
97 | usb2_clock_sel_enable_extal_only(priv); | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | static int rcar_usb2_clock_sel_remove(struct platform_device *pdev) | |
103 | { | |
104 | struct device *dev = &pdev->dev; | |
105 | struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev); | |
106 | ||
107 | of_clk_del_provider(dev->of_node); | |
108 | clk_hw_unregister(&priv->hw); | |
109 | pm_runtime_put(dev); | |
110 | pm_runtime_disable(dev); | |
111 | ||
112 | return 0; | |
113 | } | |
114 | ||
115 | static int rcar_usb2_clock_sel_probe(struct platform_device *pdev) | |
116 | { | |
117 | struct device *dev = &pdev->dev; | |
118 | struct device_node *np = dev->of_node; | |
119 | struct usb2_clock_sel_priv *priv; | |
120 | struct resource *res; | |
121 | struct clk *clk; | |
122 | struct clk_init_data init; | |
123 | ||
124 | priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | |
125 | if (!priv) | |
126 | return -ENOMEM; | |
127 | ||
128 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
129 | priv->base = devm_ioremap_resource(dev, res); | |
130 | if (IS_ERR(priv->base)) | |
131 | return PTR_ERR(priv->base); | |
132 | ||
133 | pm_runtime_enable(dev); | |
134 | pm_runtime_get_sync(dev); | |
135 | ||
136 | clk = devm_clk_get(dev, "usb_extal"); | |
137 | if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { | |
138 | priv->extal = !!clk_get_rate(clk); | |
139 | clk_disable_unprepare(clk); | |
140 | } | |
141 | clk = devm_clk_get(dev, "usb_xtal"); | |
142 | if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { | |
143 | priv->xtal = !!clk_get_rate(clk); | |
144 | clk_disable_unprepare(clk); | |
145 | } | |
146 | ||
147 | if (!priv->extal && !priv->xtal) { | |
148 | dev_err(dev, "This driver needs usb_extal or usb_xtal\n"); | |
149 | return -ENOENT; | |
150 | } | |
151 | ||
152 | platform_set_drvdata(pdev, priv); | |
153 | dev_set_drvdata(dev, priv); | |
154 | ||
155 | init.name = "rcar_usb2_clock_sel"; | |
156 | init.ops = &usb2_clock_sel_clock_ops; | |
157 | init.flags = 0; | |
158 | init.parent_names = NULL; | |
159 | init.num_parents = 0; | |
160 | priv->hw.init = &init; | |
161 | ||
162 | clk = clk_register(NULL, &priv->hw); | |
163 | if (IS_ERR(clk)) | |
164 | return PTR_ERR(clk); | |
165 | ||
166 | return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); | |
167 | } | |
168 | ||
169 | static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { | |
170 | .suspend = rcar_usb2_clock_sel_suspend, | |
171 | .resume = rcar_usb2_clock_sel_resume, | |
172 | }; | |
173 | ||
174 | static struct platform_driver rcar_usb2_clock_sel_driver = { | |
175 | .driver = { | |
176 | .name = "rcar-usb2-clock-sel", | |
177 | .of_match_table = rcar_usb2_clock_sel_match, | |
178 | .pm = &rcar_usb2_clock_sel_pm_ops, | |
179 | }, | |
180 | .probe = rcar_usb2_clock_sel_probe, | |
181 | .remove = rcar_usb2_clock_sel_remove, | |
182 | }; | |
183 | builtin_platform_driver(rcar_usb2_clock_sel_driver); | |
184 | ||
185 | MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver"); | |
186 | MODULE_LICENSE("GPL v2"); |