1 // SPDX-License-Identifier: GPL-2.0
3 * Renesas R-Car USB2.0 clock selector
5 * Copyright (C) 2017 Renesas Electronics Corp.
7 * Based on renesas-cpg-mssr.c
9 * Copyright (C) 2015 Glider bvba
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/device.h>
15 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/of_device.h>
19 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/reset.h>
23 #include <linux/slab.h>
25 #define USB20_CLKSET0 0x00
26 #define CLKSET0_INTCLK_EN BIT(11)
27 #define CLKSET0_PRIVATE BIT(0)
28 #define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE)
30 static const struct clk_bulk_data rcar_usb2_clocks[] = {
31 { .id = "ehci_ohci", },
32 { .id = "hs-usb-if", },
35 struct usb2_clock_sel_priv {
38 struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)];
39 struct reset_control *rsts;
43 #define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw)
45 static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv)
47 u16 val = readw(priv->base + USB20_CLKSET0);
49 pr_debug("%s: enter %d %d %x\n", __func__,
50 priv->extal, priv->xtal, val);
52 if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY)
53 writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0);
56 static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv)
58 if (priv->extal && !priv->xtal)
59 writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0);
62 static int usb2_clock_sel_enable(struct clk_hw *hw)
64 struct usb2_clock_sel_priv *priv = to_priv(hw);
67 ret = reset_control_deassert(priv->rsts);
71 ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);
73 reset_control_assert(priv->rsts);
77 usb2_clock_sel_enable_extal_only(priv);
82 static void usb2_clock_sel_disable(struct clk_hw *hw)
84 struct usb2_clock_sel_priv *priv = to_priv(hw);
86 usb2_clock_sel_disable_extal_only(priv);
88 clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), priv->clks);
89 reset_control_assert(priv->rsts);
93 * This module seems a mux, but this driver assumes a gate because
94 * ehci/ohci platform drivers don't support clk_set_parent() for now.
95 * If this driver acts as a gate, ehci/ohci-platform drivers don't need
98 static const struct clk_ops usb2_clock_sel_clock_ops = {
99 .enable = usb2_clock_sel_enable,
100 .disable = usb2_clock_sel_disable,
103 static const struct of_device_id rcar_usb2_clock_sel_match[] = {
104 { .compatible = "renesas,rcar-gen3-usb2-clock-sel" },
108 static int rcar_usb2_clock_sel_suspend(struct device *dev)
110 struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
112 usb2_clock_sel_disable_extal_only(priv);
118 static int rcar_usb2_clock_sel_resume(struct device *dev)
120 struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev);
122 pm_runtime_get_sync(dev);
123 usb2_clock_sel_enable_extal_only(priv);
128 static int rcar_usb2_clock_sel_remove(struct platform_device *pdev)
130 struct device *dev = &pdev->dev;
132 of_clk_del_provider(dev->of_node);
134 pm_runtime_disable(dev);
139 static int rcar_usb2_clock_sel_probe(struct platform_device *pdev)
141 struct device *dev = &pdev->dev;
142 struct device_node *np = dev->of_node;
143 struct usb2_clock_sel_priv *priv;
145 struct clk_init_data init = {};
148 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
152 priv->base = devm_platform_ioremap_resource(pdev, 0);
153 if (IS_ERR(priv->base))
154 return PTR_ERR(priv->base);
156 memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks));
157 ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), priv->clks);
161 priv->rsts = devm_reset_control_array_get_shared(dev);
162 if (IS_ERR(priv->rsts))
163 return PTR_ERR(priv->rsts);
165 clk = devm_clk_get(dev, "usb_extal");
166 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
167 priv->extal = !!clk_get_rate(clk);
168 clk_disable_unprepare(clk);
170 clk = devm_clk_get(dev, "usb_xtal");
171 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
172 priv->xtal = !!clk_get_rate(clk);
173 clk_disable_unprepare(clk);
176 if (!priv->extal && !priv->xtal) {
177 dev_err(dev, "This driver needs usb_extal or usb_xtal\n");
181 pm_runtime_enable(dev);
182 pm_runtime_get_sync(dev);
183 platform_set_drvdata(pdev, priv);
184 dev_set_drvdata(dev, priv);
186 init.name = "rcar_usb2_clock_sel";
187 init.ops = &usb2_clock_sel_clock_ops;
188 priv->hw.init = &init;
190 ret = devm_clk_hw_register(NULL, &priv->hw);
194 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
202 pm_runtime_disable(dev);
206 static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = {
207 .suspend = rcar_usb2_clock_sel_suspend,
208 .resume = rcar_usb2_clock_sel_resume,
211 static struct platform_driver rcar_usb2_clock_sel_driver = {
213 .name = "rcar-usb2-clock-sel",
214 .of_match_table = rcar_usb2_clock_sel_match,
215 .pm = &rcar_usb2_clock_sel_pm_ops,
217 .probe = rcar_usb2_clock_sel_probe,
218 .remove = rcar_usb2_clock_sel_remove,
220 builtin_platform_driver(rcar_usb2_clock_sel_driver);
222 MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver");
223 MODULE_LICENSE("GPL v2");