1 | // SPDX-License-Identifier: GPL-2.0 |
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 |
10 | */ |
11 | |
12 | #include <linux/clk.h> |
13 | #include <linux/clk-provider.h> |
14 | #include <linux/device.h> |
15 | #include <linux/init.h> |
16 | #include <linux/io.h> |
17 | #include <linux/module.h> |
18 | #include <linux/platform_device.h> |
19 | #include <linux/pm.h> |
20 | #include <linux/pm_runtime.h> |
21 | #include <linux/reset.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 | static const struct clk_bulk_data rcar_usb2_clocks[] = { |
30 | { .id = "ehci_ohci" , }, |
31 | { .id = "hs-usb-if" , }, |
32 | }; |
33 | |
34 | struct usb2_clock_sel_priv { |
35 | void __iomem *base; |
36 | struct clk_hw hw; |
37 | struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)]; |
38 | struct reset_control *rsts; |
39 | bool extal; |
40 | bool xtal; |
41 | }; |
42 | #define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw) |
43 | |
44 | static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv) |
45 | { |
46 | u16 val = readw(addr: priv->base + USB20_CLKSET0); |
47 | |
48 | pr_debug("%s: enter %d %d %x\n" , __func__, |
49 | priv->extal, priv->xtal, val); |
50 | |
51 | if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY) |
52 | writew(CLKSET0_EXTAL_ONLY, addr: priv->base + USB20_CLKSET0); |
53 | } |
54 | |
55 | static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv) |
56 | { |
57 | if (priv->extal && !priv->xtal) |
58 | writew(CLKSET0_PRIVATE, addr: priv->base + USB20_CLKSET0); |
59 | } |
60 | |
61 | static int usb2_clock_sel_enable(struct clk_hw *hw) |
62 | { |
63 | struct usb2_clock_sel_priv *priv = to_priv(hw); |
64 | int ret; |
65 | |
66 | ret = reset_control_deassert(rstc: priv->rsts); |
67 | if (ret) |
68 | return ret; |
69 | |
70 | ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), clks: priv->clks); |
71 | if (ret) { |
72 | reset_control_assert(rstc: priv->rsts); |
73 | return ret; |
74 | } |
75 | |
76 | usb2_clock_sel_enable_extal_only(priv); |
77 | |
78 | return 0; |
79 | } |
80 | |
81 | static void usb2_clock_sel_disable(struct clk_hw *hw) |
82 | { |
83 | struct usb2_clock_sel_priv *priv = to_priv(hw); |
84 | |
85 | usb2_clock_sel_disable_extal_only(priv); |
86 | |
87 | clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), clks: priv->clks); |
88 | reset_control_assert(rstc: priv->rsts); |
89 | } |
90 | |
91 | /* |
92 | * This module seems a mux, but this driver assumes a gate because |
93 | * ehci/ohci platform drivers don't support clk_set_parent() for now. |
94 | * If this driver acts as a gate, ehci/ohci-platform drivers don't need |
95 | * any modification. |
96 | */ |
97 | static const struct clk_ops usb2_clock_sel_clock_ops = { |
98 | .enable = usb2_clock_sel_enable, |
99 | .disable = usb2_clock_sel_disable, |
100 | }; |
101 | |
102 | static const struct of_device_id rcar_usb2_clock_sel_match[] = { |
103 | { .compatible = "renesas,rcar-gen3-usb2-clock-sel" }, |
104 | { } |
105 | }; |
106 | |
107 | static int rcar_usb2_clock_sel_suspend(struct device *dev) |
108 | { |
109 | struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); |
110 | |
111 | usb2_clock_sel_disable_extal_only(priv); |
112 | pm_runtime_put(dev); |
113 | |
114 | return 0; |
115 | } |
116 | |
117 | static int rcar_usb2_clock_sel_resume(struct device *dev) |
118 | { |
119 | struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); |
120 | |
121 | pm_runtime_get_sync(dev); |
122 | usb2_clock_sel_enable_extal_only(priv); |
123 | |
124 | return 0; |
125 | } |
126 | |
127 | static void rcar_usb2_clock_sel_remove(struct platform_device *pdev) |
128 | { |
129 | struct device *dev = &pdev->dev; |
130 | |
131 | of_clk_del_provider(np: dev->of_node); |
132 | pm_runtime_put(dev); |
133 | pm_runtime_disable(dev); |
134 | } |
135 | |
136 | static int rcar_usb2_clock_sel_probe(struct platform_device *pdev) |
137 | { |
138 | struct device *dev = &pdev->dev; |
139 | struct device_node *np = dev->of_node; |
140 | struct usb2_clock_sel_priv *priv; |
141 | struct clk *clk; |
142 | struct clk_init_data init = {}; |
143 | int ret; |
144 | |
145 | priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL); |
146 | if (!priv) |
147 | return -ENOMEM; |
148 | |
149 | priv->base = devm_platform_ioremap_resource(pdev, index: 0); |
150 | if (IS_ERR(ptr: priv->base)) |
151 | return PTR_ERR(ptr: priv->base); |
152 | |
153 | memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks)); |
154 | ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), clks: priv->clks); |
155 | if (ret < 0) |
156 | return ret; |
157 | |
158 | priv->rsts = devm_reset_control_array_get_shared(dev); |
159 | if (IS_ERR(ptr: priv->rsts)) |
160 | return PTR_ERR(ptr: priv->rsts); |
161 | |
162 | clk = devm_clk_get(dev, id: "usb_extal" ); |
163 | if (!IS_ERR(ptr: clk) && !clk_prepare_enable(clk)) { |
164 | priv->extal = !!clk_get_rate(clk); |
165 | clk_disable_unprepare(clk); |
166 | } |
167 | clk = devm_clk_get(dev, id: "usb_xtal" ); |
168 | if (!IS_ERR(ptr: clk) && !clk_prepare_enable(clk)) { |
169 | priv->xtal = !!clk_get_rate(clk); |
170 | clk_disable_unprepare(clk); |
171 | } |
172 | |
173 | if (!priv->extal && !priv->xtal) { |
174 | dev_err(dev, "This driver needs usb_extal or usb_xtal\n" ); |
175 | return -ENOENT; |
176 | } |
177 | |
178 | pm_runtime_enable(dev); |
179 | pm_runtime_get_sync(dev); |
180 | platform_set_drvdata(pdev, data: priv); |
181 | dev_set_drvdata(dev, data: priv); |
182 | |
183 | init.name = "rcar_usb2_clock_sel" ; |
184 | init.ops = &usb2_clock_sel_clock_ops; |
185 | priv->hw.init = &init; |
186 | |
187 | ret = devm_clk_hw_register(dev, hw: &priv->hw); |
188 | if (ret) |
189 | goto pm_put; |
190 | |
191 | ret = of_clk_add_hw_provider(np, get: of_clk_hw_simple_get, data: &priv->hw); |
192 | if (ret) |
193 | goto pm_put; |
194 | |
195 | return 0; |
196 | |
197 | pm_put: |
198 | pm_runtime_put(dev); |
199 | pm_runtime_disable(dev); |
200 | return ret; |
201 | } |
202 | |
203 | static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { |
204 | .suspend = rcar_usb2_clock_sel_suspend, |
205 | .resume = rcar_usb2_clock_sel_resume, |
206 | }; |
207 | |
208 | static struct platform_driver rcar_usb2_clock_sel_driver = { |
209 | .driver = { |
210 | .name = "rcar-usb2-clock-sel" , |
211 | .of_match_table = rcar_usb2_clock_sel_match, |
212 | .pm = &rcar_usb2_clock_sel_pm_ops, |
213 | }, |
214 | .probe = rcar_usb2_clock_sel_probe, |
215 | .remove_new = rcar_usb2_clock_sel_remove, |
216 | }; |
217 | builtin_platform_driver(rcar_usb2_clock_sel_driver); |
218 | |
219 | MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver" ); |
220 | MODULE_LICENSE("GPL v2" ); |
221 | |