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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Renesas R-Car Gen3 for USB3.0 PHY driver
   4  *
   5  * Copyright (C) 2017 Renesas Electronics Corporation
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/delay.h>
  10 #include <linux/io.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/phy/phy.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_runtime.h>
  16
  17 #define USB30_CLKSET0           0x034
  18 #define USB30_CLKSET1           0x036
  19 #define USB30_SSC_SET           0x038
  20 #define USB30_PHY_ENABLE        0x060
  21 #define USB30_VBUS_EN           0x064
  22
  23 /* USB30_CLKSET0 */
  24 #define CLKSET0_PRIVATE                 0x05c0
  25 #define CLKSET0_USB30_FSEL_USB_EXTAL    0x0002
  26
  27 /* USB30_CLKSET1 */
  28 #define CLKSET1_USB30_PLL_MULTI_SHIFT           6
  29 #define CLKSET1_USB30_PLL_MULTI_USB_EXTAL       (0x64 << \
  30                                                  CLKSET1_USB30_PLL_MULTI_SHIFT)
  31 #define CLKSET1_PHYRESET        BIT(4)  /* 1: reset */
  32 #define CLKSET1_REF_CLKDIV      BIT(3)  /* 1: USB_EXTAL */
  33 #define CLKSET1_PRIVATE_2_1     BIT(1)  /* Write B'01 */
  34 #define CLKSET1_REF_CLK_SEL     BIT(0)  /* 1: USB3S0_CLK_P */
  35
  36 /* USB30_SSC_SET */
  37 #define SSC_SET_SSC_EN          BIT(12)
  38 #define SSC_SET_RANGE_SHIFT     9
  39 #define SSC_SET_RANGE_4980      (0x0 << SSC_SET_RANGE_SHIFT)
  40 #define SSC_SET_RANGE_4492      (0x1 << SSC_SET_RANGE_SHIFT)
  41 #define SSC_SET_RANGE_4003      (0x2 << SSC_SET_RANGE_SHIFT)
  42
  43 /* USB30_PHY_ENABLE */
  44 #define PHY_ENABLE_RESET_EN     BIT(4)
  45
  46 /* USB30_VBUS_EN */
  47 #define VBUS_EN_VBUS_EN         BIT(1)
  48
  49 struct rcar_gen3_usb3 {
  50         void __iomem *base;
  51         struct phy *phy;
  52         u32 ssc_range;
  53         bool usb3s_clk;
  54         bool usb_extal;
  55 };
  56
  57 static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)
  58 {
  59         u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |
  60                   CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;
  61
  62         if (reset)
  63                 val |= CLKSET1_PHYRESET;
  64
  65         writew(val, r->base + USB30_CLKSET1);
  66 }
  67
  68 static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)
  69 {
  70         u16 val = SSC_SET_SSC_EN;
  71
  72         switch (r->ssc_range) {
  73         case 4980:
  74                 val |= SSC_SET_RANGE_4980;
  75                 break;
  76         case 4492:
  77                 val |= SSC_SET_RANGE_4492;
  78                 break;
  79         case 4003:
  80                 val |= SSC_SET_RANGE_4003;
  81                 break;
  82         default:
  83                 dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,
  84                         r->ssc_range);
  85                 return;
  86         }
  87
  88         writew(val, r->base + USB30_SSC_SET);
  89 }
  90
  91 static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)
  92 {
  93         write_clkset1_for_usb_extal(r, false);
  94         if (r->ssc_range)
  95                 rcar_gen3_phy_usb3_enable_ssc(r);
  96         writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,
  97                r->base + USB30_CLKSET0);
  98         writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);
  99         write_clkset1_for_usb_extal(r, true);
 100         usleep_range(10, 20);
 101         write_clkset1_for_usb_extal(r, false);
 102 }
 103
 104 static int rcar_gen3_phy_usb3_init(struct phy *p)
 105 {
 106         struct rcar_gen3_usb3 *r = phy_get_drvdata(p);
 107
 108         dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,
 109                  r->usb3s_clk, r->usb_extal, r->ssc_range);
 110
 111         if (!r->usb3s_clk && r->usb_extal)
 112                 rcar_gen3_phy_usb3_select_usb_extal(r);
 113
 114         /* Enables VBUS detection anyway */
 115         writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);
 116
 117         return 0;
 118 }
 119
 120 static const struct phy_ops rcar_gen3_phy_usb3_ops = {
 121         .init           = rcar_gen3_phy_usb3_init,
 122         .owner          = THIS_MODULE,
 123 };
 124
 125 static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {
 126         { .compatible = "renesas,rcar-gen3-usb3-phy" },
 127         { }
 128 };
 129 MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);
 130
 131 static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)
 132 {
 133         struct device *dev = &pdev->dev;
 134         struct rcar_gen3_usb3 *r;
 135         struct phy_provider *provider;
 136         int ret = 0;
 137         struct clk *clk;
 138
 139         if (!dev->of_node) {
 140                 dev_err(dev, "This driver needs device tree\n");
 141                 return -EINVAL;
 142         }
 143
 144         r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
 145         if (!r)
 146                 return -ENOMEM;
 147
 148         r->base = devm_platform_ioremap_resource(pdev, 0);
 149         if (IS_ERR(r->base))
 150                 return PTR_ERR(r->base);
 151
 152         clk = devm_clk_get(dev, "usb3s_clk");
 153         if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
 154                 r->usb3s_clk = !!clk_get_rate(clk);
 155                 clk_disable_unprepare(clk);
 156         }
 157         clk = devm_clk_get(dev, "usb_extal");
 158         if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
 159                 r->usb_extal = !!clk_get_rate(clk);
 160                 clk_disable_unprepare(clk);
 161         }
 162
 163         if (!r->usb3s_clk && !r->usb_extal) {
 164                 dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");
 165                 ret = -EINVAL;
 166                 goto error;
 167         }
 168
 169         /*
 170          * devm_phy_create() will call pm_runtime_enable(&phy->dev);
 171          * And then, phy-core will manage runtime pm for this device.
 172          */
 173         pm_runtime_enable(dev);
 174
 175         r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);
 176         if (IS_ERR(r->phy)) {
 177                 dev_err(dev, "Failed to create USB3 PHY\n");
 178                 ret = PTR_ERR(r->phy);
 179                 goto error;
 180         }
 181
 182         of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);
 183
 184         platform_set_drvdata(pdev, r);
 185         phy_set_drvdata(r->phy, r);
 186
 187         provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
 188         if (IS_ERR(provider)) {
 189                 dev_err(dev, "Failed to register PHY provider\n");
 190                 ret = PTR_ERR(provider);
 191                 goto error;
 192         }
 193
 194         return 0;
 195
 196 error:
 197         pm_runtime_disable(dev);
 198
 199         return ret;
 200 }
 201
 202 static int rcar_gen3_phy_usb3_remove(struct platform_device *pdev)
 203 {
 204         pm_runtime_disable(&pdev->dev);
 205
 206         return 0;
 207 };
 208
 209 static struct platform_driver rcar_gen3_phy_usb3_driver = {
 210         .driver = {
 211                 .name           = "phy_rcar_gen3_usb3",
 212                 .of_match_table = rcar_gen3_phy_usb3_match_table,
 213         },
 214         .probe  = rcar_gen3_phy_usb3_probe,
 215         .remove = rcar_gen3_phy_usb3_remove,
 216 };
 217 module_platform_driver(rcar_gen3_phy_usb3_driver);
 218
 219 MODULE_LICENSE("GPL v2");
 220 MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");
 221 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");