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 void rcar_usb2_clock_sel_remove(struct platform_device *pdev) 129 { 130 struct device *dev = &pdev->dev; 131 132 of_clk_del_provider(dev->of_node); 133 pm_runtime_put(dev); 134 pm_runtime_disable(dev); 135 } 136 137 static int rcar_usb2_clock_sel_probe(struct platform_device *pdev) 138 { 139 struct device *dev = &pdev->dev; 140 struct device_node *np = dev->of_node; 141 struct usb2_clock_sel_priv *priv; 142 struct clk *clk; 143 struct clk_init_data init = {}; 144 int ret; 145 146 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 147 if (!priv) 148 return -ENOMEM; 149 150 priv->base = devm_platform_ioremap_resource(pdev, 0); 151 if (IS_ERR(priv->base)) 152 return PTR_ERR(priv->base); 153 154 memcpy(priv->clks, rcar_usb2_clocks, sizeof(priv->clks)); 155 ret = devm_clk_bulk_get(dev, ARRAY_SIZE(priv->clks), priv->clks); 156 if (ret < 0) 157 return ret; 158 159 priv->rsts = devm_reset_control_array_get_shared(dev); 160 if (IS_ERR(priv->rsts)) 161 return PTR_ERR(priv->rsts); 162 163 clk = devm_clk_get(dev, "usb_extal"); 164 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { 165 priv->extal = !!clk_get_rate(clk); 166 clk_disable_unprepare(clk); 167 } 168 clk = devm_clk_get(dev, "usb_xtal"); 169 if (!IS_ERR(clk) && !clk_prepare_enable(clk)) { 170 priv->xtal = !!clk_get_rate(clk); 171 clk_disable_unprepare(clk); 172 } 173 174 if (!priv->extal && !priv->xtal) { 175 dev_err(dev, "This driver needs usb_extal or usb_xtal\n"); 176 return -ENOENT; 177 } 178 179 pm_runtime_enable(dev); 180 pm_runtime_get_sync(dev); 181 platform_set_drvdata(pdev, priv); 182 dev_set_drvdata(dev, priv); 183 184 init.name = "rcar_usb2_clock_sel"; 185 init.ops = &usb2_clock_sel_clock_ops; 186 priv->hw.init = &init; 187 188 ret = devm_clk_hw_register(dev, &priv->hw); 189 if (ret) 190 goto pm_put; 191 192 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw); 193 if (ret) 194 goto pm_put; 195 196 return 0; 197 198 pm_put: 199 pm_runtime_put(dev); 200 pm_runtime_disable(dev); 201 return ret; 202 } 203 204 static const struct dev_pm_ops rcar_usb2_clock_sel_pm_ops = { 205 .suspend = rcar_usb2_clock_sel_suspend, 206 .resume = rcar_usb2_clock_sel_resume, 207 }; 208 209 static struct platform_driver rcar_usb2_clock_sel_driver = { 210 .driver = { 211 .name = "rcar-usb2-clock-sel", 212 .of_match_table = rcar_usb2_clock_sel_match, 213 .pm = &rcar_usb2_clock_sel_pm_ops, 214 }, 215 .probe = rcar_usb2_clock_sel_probe, 216 .remove_new = rcar_usb2_clock_sel_remove, 217 }; 218 builtin_platform_driver(rcar_usb2_clock_sel_driver); 219 220 MODULE_DESCRIPTION("Renesas R-Car USB2 clock selector Driver"); 221 MODULE_LICENSE("GPL v2"); 222