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(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 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, 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(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 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), priv->clks); 88 reset_control_assert(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(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, 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; 196 197 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