drivers/phy/renesas/phy-rcar-gen3-usb3.c

   1 /*
   2  * Renesas R-Car Gen3 for USB3.0 PHY driver
   3  *
   4  * Copyright (C) 2017 Renesas Electronics Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/delay.h>
  13 #include <linux/io.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/phy/phy.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/pm_runtime.h>
  19
  20 #define USB30_CLKSET0           0x034
  21 #define USB30_CLKSET1           0x036
  22 #define USB30_SSC_SET           0x038
  23 #define USB30_PHY_ENABLE        0x060
  24 #define USB30_VBUS_EN           0x064
  25
  26 /* USB30_CLKSET0 */
  27 #define CLKSET0_PRIVATE                 0x05c0
  28 #define CLKSET0_USB30_FSEL_USB_EXTAL    0x0002
  29
  30 /* USB30_CLKSET1 */
  31 #define CLKSET1_USB30_PLL_MULTI_SHIFT           6
  32 #define CLKSET1_USB30_PLL_MULTI_USB_EXTAL       (0x64 << \
  33                                                  CLKSET1_USB30_PLL_MULTI_SHIFT)
  34 #define CLKSET1_PHYRESET        BIT(4)  /* 1: reset */
  35 #define CLKSET1_REF_CLKDIV      BIT(3)  /* 1: USB_EXTAL */
  36 #define CLKSET1_PRIVATE_2_1     BIT(1)  /* Write B'01 */
  37 #define CLKSET1_REF_CLK_SEL     BIT(0)  /* 1: USB3S0_CLK_P */
  38
  39 /* USB30_SSC_SET */
  40 #define SSC_SET_SSC_EN          BIT(12)
  41 #define SSC_SET_RANGE_SHIFT     9
  42 #define SSC_SET_RANGE_4980      (0x0 << SSC_SET_RANGE_SHIFT)
  43 #define SSC_SET_RANGE_4492      (0x1 << SSC_SET_RANGE_SHIFT)
  44 #define SSC_SET_RANGE_4003      (0x2 << SSC_SET_RANGE_SHIFT)
  45
  46 /* USB30_PHY_ENABLE */
  47 #define PHY_ENABLE_RESET_EN     BIT(4)
  48
  49 /* USB30_VBUS_EN */
  50 #define VBUS_EN_VBUS_EN         BIT(1)
  51
  52 struct rcar_gen3_usb3 {
  53         void __iomem *base;
  54         struct phy *phy;
  55         u32 ssc_range;
  56         bool usb3s_clk;
  57         bool usb_extal;
  58 };
  59
  60 static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)
  61 {
  62         u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |
  63                   CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;
  64
  65         if (reset)
  66                 val |= CLKSET1_PHYRESET;
  67
  68         writew(val, r->base + USB30_CLKSET1);
  69 }
  70
  71 static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)
  72 {
  73         u16 val = SSC_SET_SSC_EN;
  74
  75         switch (r->ssc_range) {
  76         case 4980:
  77                 val |= SSC_SET_RANGE_4980;
  78                 break;
  79         case 4492:
  80                 val |= SSC_SET_RANGE_4492;
  81                 break;
  82         case 4003:
  83                 val |= SSC_SET_RANGE_4003;
  84                 break;
  85         default:
  86                 dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,
  87                         r->ssc_range);
  88                 return;
  89         }
  90
  91         writew(val, r->base + USB30_SSC_SET);
  92 }
  93
  94 static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)
  95 {
  96         write_clkset1_for_usb_extal(r, false);
  97         if (r->ssc_range)
  98                 rcar_gen3_phy_usb3_enable_ssc(r);
  99         writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,
 100                r->base + USB30_CLKSET0);
 101         writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);
 102         write_clkset1_for_usb_extal(r, true);
 103         usleep_range(10, 20);
 104         write_clkset1_for_usb_extal(r, false);
 105 }
 106
 107 static int rcar_gen3_phy_usb3_init(struct phy *p)
 108 {
 109         struct rcar_gen3_usb3 *r = phy_get_drvdata(p);
 110
 111         dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,
 112                  r->usb3s_clk, r->usb_extal, r->ssc_range);
 113
 114         if (!r->usb3s_clk && r->usb_extal)
 115                 rcar_gen3_phy_usb3_select_usb_extal(r);
 116
 117         /* Enables VBUS detection anyway */
 118         writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);
 119
 120         return 0;
 121 }
 122
 123 static const struct phy_ops rcar_gen3_phy_usb3_ops = {
 124         .init           = rcar_gen3_phy_usb3_init,
 125         .owner          = THIS_MODULE,
 126 };
 127
 128 static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {
 129         { .compatible = "renesas,rcar-gen3-usb3-phy" },
 130         { }
 131 };
 132 MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);
 133
 134 static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)
 135 {
 136         struct device *dev = &pdev->dev;
 137         struct rcar_gen3_usb3 *r;
 138         struct phy_provider *provider;
 139         struct resource *res;
 140         int ret = 0;
 141         struct clk *clk;
 142
 143         if (!dev->of_node) {
 144                 dev_err(dev, "This driver needs device tree\n");
 145                 return -EINVAL;
 146         }
 147
 148         r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
 149         if (!r)
 150                 return -ENOMEM;
 151
 152         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 153         r->base = devm_ioremap_resource(dev, res);
 154         if (IS_ERR(r->base))
 155                 return PTR_ERR(r->base);
 156
 157         clk = devm_clk_get(dev, "usb3s_clk");
 158         if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
 159                 r->usb3s_clk = !!clk_get_rate(clk);
 160                 clk_disable_unprepare(clk);
 161         }
 162         clk = devm_clk_get(dev, "usb_extal");
 163         if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
 164                 r->usb_extal = !!clk_get_rate(clk);
 165                 clk_disable_unprepare(clk);
 166         }
 167
 168         if (!r->usb3s_clk && !r->usb_extal) {
 169                 dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");
 170                 ret = -EINVAL;
 171                 goto error;
 172         }
 173
 174         /*
 175          * devm_phy_create() will call pm_runtime_enable(&phy->dev);
 176          * And then, phy-core will manage runtime pm for this device.
 177          */
 178         pm_runtime_enable(dev);
 179
 180         r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);
 181         if (IS_ERR(r->phy)) {
 182                 dev_err(dev, "Failed to create USB3 PHY\n");
 183                 ret = PTR_ERR(r->phy);
 184                 goto error;
 185         }
 186
 187         of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);
 188
 189         platform_set_drvdata(pdev, r);
 190         phy_set_drvdata(r->phy, r);
 191
 192         provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 193         if (IS_ERR(provider)) {
 194                 dev_err(dev, "Failed to register PHY provider\n");
 195                 ret = PTR_ERR(provider);
 196                 goto error;
 197         }
 198
 199         return 0;
 200
 201 error:
 202         pm_runtime_disable(dev);
 203
 204         return ret;
 205 }
 206
 207 static int rcar_gen3_phy_usb3_remove(struct platform_device *pdev)
 208 {
 209         pm_runtime_disable(&pdev->dev);
 210
 211         return 0;
 212 };
 213
 214 static struct platform_driver rcar_gen3_phy_usb3_driver = {
 215         .driver = {
 216                 .name           = "phy_rcar_gen3_usb3",
 217                 .of_match_table = rcar_gen3_phy_usb3_match_table,
 218         },
 219         .probe  = rcar_gen3_phy_usb3_probe,
 220         .remove = rcar_gen3_phy_usb3_remove,
 221 };
 222 module_platform_driver(rcar_gen3_phy_usb3_driver);
 223
 224 MODULE_LICENSE("GPL v2");
 225 MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");
 226 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");