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1// SPDX-License-Identifier: GPL-2.02/*3 * Renesas R-Car USB2.0 clock selector4 *5 * Copyright (C) 2017 Renesas Electronics Corp.6 *7 * Based on renesas-cpg-mssr.c8 *9 * Copyright (C) 2015 Glider bvba10 */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 0x0025#define CLKSET0_INTCLK_EN BIT(11)26#define CLKSET0_PRIVATE BIT(0)27#define CLKSET0_EXTAL_ONLY (CLKSET0_INTCLK_EN | CLKSET0_PRIVATE)28 29static const struct clk_bulk_data rcar_usb2_clocks[] = {30 { .id = "ehci_ohci", },31 { .id = "hs-usb-if", },32};33 34struct 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 44static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv)45{46 u16 val = readw(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, priv->base + USB20_CLKSET0);53}54 55static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv)56{57 if (priv->extal && !priv->xtal)58 writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0);59}60 61static 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(priv->rsts);67 if (ret)68 return ret;69 70 ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks);71 if (ret) {72 reset_control_assert(priv->rsts);73 return ret;74 }75 76 usb2_clock_sel_enable_extal_only(priv);77 78 return 0;79}80 81static 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), priv->clks);88 reset_control_assert(priv->rsts);89}90 91/*92 * This module seems a mux, but this driver assumes a gate because93 * 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 need95 * any modification.96 */97static const struct clk_ops usb2_clock_sel_clock_ops = {98 .enable = usb2_clock_sel_enable,99 .disable = usb2_clock_sel_disable,100};101 102static const struct of_device_id rcar_usb2_clock_sel_match[] = {103 { .compatible = "renesas,rcar-gen3-usb2-clock-sel" },104 { }105};106 107static 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 117static 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 127static void rcar_usb2_clock_sel_remove(struct platform_device *pdev)128{129 struct device *dev = &pdev->dev;130 131 of_clk_del_provider(dev->of_node);132 pm_runtime_put(dev);133 pm_runtime_disable(dev);134}135 136static 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, sizeof(*priv), GFP_KERNEL);146 if (!priv)147 return -ENOMEM;148 149 priv->base = devm_platform_ioremap_resource(pdev, 0);150 if (IS_ERR(priv->base))151 return PTR_ERR(priv->base);152 153 memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks));154 ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->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(priv->rsts))160 return PTR_ERR(priv->rsts);161 162 clk = devm_clk_get(dev, "usb_extal");163 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {164 priv->extal = !!clk_get_rate(clk);165 clk_disable_unprepare(clk);166 }167 clk = devm_clk_get(dev, "usb_xtal");168 if (!IS_ERR(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, priv);181 dev_set_drvdata(dev, 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, &priv->hw);188 if (ret)189 goto pm_put;190 191 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);192 if (ret)193 goto pm_put;194 195 return 0;196 197pm_put:198 pm_runtime_put(dev);199 pm_runtime_disable(dev);200 return ret;201}202 203static 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 208static 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 = rcar_usb2_clock_sel_remove,216};217builtin_platform_driver(rcar_usb2_clock_sel_driver);218 219MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver");220MODULE_LICENSE("GPL v2");221