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

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Renesas R-Car Gen3 for USB3.0 PHY driver
0004  *
0005  * Copyright (C) 2017 Renesas Electronics Corporation
0006  */
0007
0008 #include <linux/clk.h>
0009 #include <linux/delay.h>
0010 #include <linux/io.h>
0011 #include <linux/module.h>
0012 #include <linux/of.h>
0013 #include <linux/phy/phy.h>
0014 #include <linux/platform_device.h>
0015 #include <linux/pm_runtime.h>
0016
0017 #define USB30_CLKSET0       0x034
0018 #define USB30_CLKSET1       0x036
0019 #define USB30_SSC_SET       0x038
0020 #define USB30_PHY_ENABLE    0x060
0021 #define USB30_VBUS_EN       0x064
0022
0023 /* USB30_CLKSET0 */
0024 #define CLKSET0_PRIVATE         0x05c0
0025 #define CLKSET0_USB30_FSEL_USB_EXTAL    0x0002
0026
0027 /* USB30_CLKSET1 */
0028 #define CLKSET1_USB30_PLL_MULTI_SHIFT       6
0029 #define CLKSET1_USB30_PLL_MULTI_USB_EXTAL   (0x64 << \
0030                          CLKSET1_USB30_PLL_MULTI_SHIFT)
0031 #define CLKSET1_PHYRESET    BIT(4)  /* 1: reset */
0032 #define CLKSET1_REF_CLKDIV  BIT(3)  /* 1: USB_EXTAL */
0033 #define CLKSET1_PRIVATE_2_1 BIT(1)  /* Write B'01 */
0034 #define CLKSET1_REF_CLK_SEL BIT(0)  /* 1: USB3S0_CLK_P */
0035
0036 /* USB30_SSC_SET */
0037 #define SSC_SET_SSC_EN      BIT(12)
0038 #define SSC_SET_RANGE_SHIFT 9
0039 #define SSC_SET_RANGE_4980  (0x0 << SSC_SET_RANGE_SHIFT)
0040 #define SSC_SET_RANGE_4492  (0x1 << SSC_SET_RANGE_SHIFT)
0041 #define SSC_SET_RANGE_4003  (0x2 << SSC_SET_RANGE_SHIFT)
0042
0043 /* USB30_PHY_ENABLE */
0044 #define PHY_ENABLE_RESET_EN BIT(4)
0045
0046 /* USB30_VBUS_EN */
0047 #define VBUS_EN_VBUS_EN     BIT(1)
0048
0049 struct rcar_gen3_usb3 {
0050     void __iomem *base;
0051     struct phy *phy;
0052     u32 ssc_range;
0053     bool usb3s_clk;
0054     bool usb_extal;
0055 };
0056
0057 static void write_clkset1_for_usb_extal(struct rcar_gen3_usb3 *r, bool reset)
0058 {
0059     u16 val = CLKSET1_USB30_PLL_MULTI_USB_EXTAL |
0060           CLKSET1_REF_CLKDIV | CLKSET1_PRIVATE_2_1;
0061
0062     if (reset)
0063         val |= CLKSET1_PHYRESET;
0064
0065     writew(val, r->base + USB30_CLKSET1);
0066 }
0067
0068 static void rcar_gen3_phy_usb3_enable_ssc(struct rcar_gen3_usb3 *r)
0069 {
0070     u16 val = SSC_SET_SSC_EN;
0071
0072     switch (r->ssc_range) {
0073     case 4980:
0074         val |= SSC_SET_RANGE_4980;
0075         break;
0076     case 4492:
0077         val |= SSC_SET_RANGE_4492;
0078         break;
0079     case 4003:
0080         val |= SSC_SET_RANGE_4003;
0081         break;
0082     default:
0083         dev_err(&r->phy->dev, "%s: unsupported range (%x)\n", __func__,
0084             r->ssc_range);
0085         return;
0086     }
0087
0088     writew(val, r->base + USB30_SSC_SET);
0089 }
0090
0091 static void rcar_gen3_phy_usb3_select_usb_extal(struct rcar_gen3_usb3 *r)
0092 {
0093     write_clkset1_for_usb_extal(r, false);
0094     if (r->ssc_range)
0095         rcar_gen3_phy_usb3_enable_ssc(r);
0096     writew(CLKSET0_PRIVATE | CLKSET0_USB30_FSEL_USB_EXTAL,
0097            r->base + USB30_CLKSET0);
0098     writew(PHY_ENABLE_RESET_EN, r->base + USB30_PHY_ENABLE);
0099     write_clkset1_for_usb_extal(r, true);
0100     usleep_range(10, 20);
0101     write_clkset1_for_usb_extal(r, false);
0102 }
0103
0104 static int rcar_gen3_phy_usb3_init(struct phy *p)
0105 {
0106     struct rcar_gen3_usb3 *r = phy_get_drvdata(p);
0107
0108     dev_vdbg(&r->phy->dev, "%s: enter (%d, %d, %d)\n", __func__,
0109          r->usb3s_clk, r->usb_extal, r->ssc_range);
0110
0111     if (!r->usb3s_clk && r->usb_extal)
0112         rcar_gen3_phy_usb3_select_usb_extal(r);
0113
0114     /* Enables VBUS detection anyway */
0115     writew(VBUS_EN_VBUS_EN, r->base + USB30_VBUS_EN);
0116
0117     return 0;
0118 }
0119
0120 static const struct phy_ops rcar_gen3_phy_usb3_ops = {
0121     .init       = rcar_gen3_phy_usb3_init,
0122     .owner      = THIS_MODULE,
0123 };
0124
0125 static const struct of_device_id rcar_gen3_phy_usb3_match_table[] = {
0126     { .compatible = "renesas,rcar-gen3-usb3-phy" },
0127     { }
0128 };
0129 MODULE_DEVICE_TABLE(of, rcar_gen3_phy_usb3_match_table);
0130
0131 static int rcar_gen3_phy_usb3_probe(struct platform_device *pdev)
0132 {
0133     struct device *dev = &pdev->dev;
0134     struct rcar_gen3_usb3 *r;
0135     struct phy_provider *provider;
0136     int ret = 0;
0137     struct clk *clk;
0138
0139     if (!dev->of_node) {
0140         dev_err(dev, "This driver needs device tree\n");
0141         return -EINVAL;
0142     }
0143
0144     r = devm_kzalloc(dev, sizeof(*r), GFP_KERNEL);
0145     if (!r)
0146         return -ENOMEM;
0147
0148     r->base = devm_platform_ioremap_resource(pdev, 0);
0149     if (IS_ERR(r->base))
0150         return PTR_ERR(r->base);
0151
0152     clk = devm_clk_get(dev, "usb3s_clk");
0153     if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
0154         r->usb3s_clk = !!clk_get_rate(clk);
0155         clk_disable_unprepare(clk);
0156     }
0157     clk = devm_clk_get(dev, "usb_extal");
0158     if (!IS_ERR(clk) && !clk_prepare_enable(clk)) {
0159         r->usb_extal = !!clk_get_rate(clk);
0160         clk_disable_unprepare(clk);
0161     }
0162
0163     if (!r->usb3s_clk && !r->usb_extal) {
0164         dev_err(dev, "This driver needs usb3s_clk and/or usb_extal\n");
0165         ret = -EINVAL;
0166         goto error;
0167     }
0168
0169     /*
0170      * devm_phy_create() will call pm_runtime_enable(&phy->dev);
0171      * And then, phy-core will manage runtime pm for this device.
0172      */
0173     pm_runtime_enable(dev);
0174
0175     r->phy = devm_phy_create(dev, NULL, &rcar_gen3_phy_usb3_ops);
0176     if (IS_ERR(r->phy)) {
0177         dev_err(dev, "Failed to create USB3 PHY\n");
0178         ret = PTR_ERR(r->phy);
0179         goto error;
0180     }
0181
0182     of_property_read_u32(dev->of_node, "renesas,ssc-range", &r->ssc_range);
0183
0184     platform_set_drvdata(pdev, r);
0185     phy_set_drvdata(r->phy, r);
0186
0187     provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
0188     if (IS_ERR(provider)) {
0189         dev_err(dev, "Failed to register PHY provider\n");
0190         ret = PTR_ERR(provider);
0191         goto error;
0192     }
0193
0194     return 0;
0195
0196 error:
0197     pm_runtime_disable(dev);
0198
0199     return ret;
0200 }
0201
0202 static int rcar_gen3_phy_usb3_remove(struct platform_device *pdev)
0203 {
0204     pm_runtime_disable(&pdev->dev);
0205
0206     return 0;
0207 };
0208
0209 static struct platform_driver rcar_gen3_phy_usb3_driver = {
0210     .driver = {
0211         .name       = "phy_rcar_gen3_usb3",
0212         .of_match_table = rcar_gen3_phy_usb3_match_table,
0213     },
0214     .probe  = rcar_gen3_phy_usb3_probe,
0215     .remove = rcar_gen3_phy_usb3_remove,
0216 };
0217 module_platform_driver(rcar_gen3_phy_usb3_driver);
0218
0219 MODULE_LICENSE("GPL v2");
0220 MODULE_DESCRIPTION("Renesas R-Car Gen3 USB 3.0 PHY");
0221 MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");