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/of_device.h> 19 #include <linux/platform_device.h> 20 #include <linux/pm.h> 21 #include <linux/pm_runtime.h> 22 #include <linux/reset.h> 23 #include <linux/slab.h> 24 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) 29 30 static const struct clk_bulk_data rcar_usb2_clocks[] = { 31 { .id = "ehci_ohci", }, 32 { .id = "hs-usb-if", }, 33 }; 34 35 struct usb2_clock_sel_priv { 36 void __iomem *base; 37 struct clk_hw hw; 38 struct clk_bulk_data clks[ARRAY_SIZE(rcar_usb2_clocks)]; 39 struct reset_control *rsts; 40 bool extal; 41 bool xtal; 42 }; 43 #define to_priv(_hw) container_of(_hw, struct usb2_clock_sel_priv, hw) 44 45 static void usb2_clock_sel_enable_extal_only(struct usb2_clock_sel_priv *priv) 46 { 47 u16 val = readw(priv->base + USB20_CLKSET0); 48 49 pr_debug("%s: enter %d %d %x\n", __func__, 50 priv->extal, priv->xtal, val); 51 52 if (priv->extal && !priv->xtal && val != CLKSET0_EXTAL_ONLY) 53 writew(CLKSET0_EXTAL_ONLY, priv->base + USB20_CLKSET0); 54 } 55 56 static void usb2_clock_sel_disable_extal_only(struct usb2_clock_sel_priv *priv) 57 { 58 if (priv->extal && !priv->xtal) 59 writew(CLKSET0_PRIVATE, priv->base + USB20_CLKSET0); 60 } 61 62 static int usb2_clock_sel_enable(struct clk_hw *hw) 63 { 64 struct usb2_clock_sel_priv *priv = to_priv(hw); 65 int ret; 66 67 ret = reset_control_deassert(priv->rsts); 68 if (ret) 69 return ret; 70 71 ret = clk_bulk_prepare_enable(ARRAY_SIZE(priv->clks), priv->clks); 72 if (ret) { 73 reset_control_assert(priv->rsts); 74 return ret; 75 } 76 77 usb2_clock_sel_enable_extal_only(priv); 78 79 return 0; 80 } 81 82 static void usb2_clock_sel_disable(struct clk_hw *hw) 83 { 84 struct usb2_clock_sel_priv *priv = to_priv(hw); 85 86 usb2_clock_sel_disable_extal_only(priv); 87 88 clk_bulk_disable_unprepare(ARRAY_SIZE(priv->clks), priv->clks); 89 reset_control_assert(priv->rsts); 90 } 91 92 /* 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 96 * any modification. 97 */ 98 static const struct clk_ops usb2_clock_sel_clock_ops = { 99 .enable = usb2_clock_sel_enable, 100 .disable = usb2_clock_sel_disable, 101 }; 102 103 static const struct of_device_id rcar_usb2_clock_sel_match[] = { 104 { .compatible = "renesas,rcar-gen3-usb2-clock-sel" }, 105 { } 106 }; 107 108 static int rcar_usb2_clock_sel_suspend(struct device *dev) 109 { 110 struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); 111 112 usb2_clock_sel_disable_extal_only(priv); 113 pm_runtime_put(dev); 114 115 return 0; 116 } 117 118 static int rcar_usb2_clock_sel_resume(struct device *dev) 119 { 120 struct usb2_clock_sel_priv *priv = dev_get_drvdata(dev); 121 122 pm_runtime_get_sync(dev); 123 usb2_clock_sel_enable_extal_only(priv); 124 125 return 0; 126 } 127 128 static int rcar_usb2_clock_sel_remove(struct platform_device *pdev) 129 { 130 struct device *dev = &pdev->dev; 131 struct usb2_clock_sel_priv *priv = platform_get_drvdata(pdev); 132 133 of_clk_del_provider(dev->of_node); 134 clk_hw_unregister(&priv->hw); 135 pm_runtime_put(dev); 136 pm_runtime_disable(dev); 137 138 return 0; 139 } 140 141 static int rcar_usb2_clock_sel_probe(struct platform_device *pdev) 142 { 143 struct device *dev = &pdev->dev; 144 struct device_node *np = dev->of_node; 145 struct usb2_clock_sel_priv *priv; 146 struct clk *clk; 147 struct clk_init_data init; 148 int ret; 149 150 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 151 if (!priv) 152 return -ENOMEM; 153 154 priv->base = devm_platform_ioremap_resource(pdev, 0); 155 if (IS_ERR(priv->base)) 156 return PTR_ERR(priv->base); 157 158 memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks)); 159 ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), priv->clks); 160 if (ret < 0) 161 return ret; 162 163 priv->rsts = devm_reset_control_array_get_shared(dev); 164 if (IS_ERR(priv->rsts)) 165 return PTR_ERR(priv->rsts); 166 167 pm_runtime_enable(dev); 168 pm_runtime_get_sync(dev); 169 170 clk = devm_clk_get(dev, "usb_extal"); 171 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { 172 priv->extal = !!clk_get_rate(clk); 173 clk_disable_unprepare(clk); 174 } 175 clk = devm_clk_get(dev, "usb_xtal"); 176 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { 177 priv->xtal = !!clk_get_rate(clk); 178 clk_disable_unprepare(clk); 179 } 180 181 if (!priv->extal && !priv->xtal) { 182 dev_err(dev, "This driver needs usb_extal or usb_xtal\n"); 183 return -ENOENT; 184 } 185 186 platform_set_drvdata(pdev, priv); 187 dev_set_drvdata(dev, priv); 188 189 init.name = "rcar_usb2_clock_sel"; 190 init.ops = &usb2_clock_sel_clock_ops; 191 init.flags = 0; 192 init.parent_names = NULL; 193 init.num_parents = 0; 194 priv->hw.init = &init; 195 196 clk = clk_register(NULL, &priv->hw); 197 if (IS_ERR(clk)) 198 return PTR_ERR(clk); 199 200 return of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); 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 = 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