drivers/phy/nuvoton/phy-ma35d1-usb2.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2024 Nuvoton Technology Corp.
   4  */
   5 #include <linux/bitfield.h>
   6 #include <linux/clk.h>
   7 #include <linux/delay.h>
   8 #include <linux/io.h>
   9 #include <linux/kernel.h>
  10 #include <linux/mfd/syscon.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/regmap.h>
  16
  17 /* USB PHY Miscellaneous Control Register */
  18 #define MA35_SYS_REG_USBPMISCR  0x60
  19 #define PHY0POR                 BIT(0)  /* PHY Power-On Reset Control Bit */
  20 #define PHY0SUSPEND                     BIT(1)  /* PHY Suspend; 0: suspend, 1: operaion */
  21 #define PHY0COMN                        BIT(2)  /* PHY Common Block Power-Down Control */
  22 #define PHY0DEVCKSTB                    BIT(10) /* PHY 60 MHz UTMI clock stable bit */
  23
  24 struct ma35_usb_phy {
  25         struct clk *clk;
  26         struct device *dev;
  27         struct regmap *sysreg;
  28 };
  29
  30 static int ma35_usb_phy_power_on(struct phy *phy)
  31 {
  32         struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
  33         unsigned int val;
  34         int ret;
  35
  36         ret = clk_prepare_enable(p_phy->clk);
  37         if (ret < 0) {
  38                 dev_err(p_phy->dev, "Failed to enable PHY clock: %d\n", ret);
  39                 return ret;
  40         }
  41
  42         regmap_read(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, &val);
  43         if (val & PHY0SUSPEND) {
  44                 /*
  45                  * USB PHY0 is in operation mode already
  46                  * make sure USB PHY 60 MHz UTMI Interface Clock ready
  47                  */
  48                 ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val,
  49                                                 val & PHY0DEVCKSTB, 10, 1000);
  50                 if (ret == 0)
  51                         return 0;
  52         }
  53
  54         /*
  55          * reset USB PHY0.
  56          * wait until USB PHY0 60 MHz UTMI Interface Clock ready
  57          */
  58         regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, (PHY0POR | PHY0SUSPEND));
  59         udelay(20);
  60
  61         /* make USB PHY0 enter operation mode */
  62         regmap_update_bits(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, 0x7, PHY0SUSPEND);
  63
  64         /* make sure USB PHY 60 MHz UTMI Interface Clock ready */
  65         ret = regmap_read_poll_timeout(p_phy->sysreg, MA35_SYS_REG_USBPMISCR, val,
  66                                         val & PHY0DEVCKSTB, 10, 1000);
  67         if (ret == -ETIMEDOUT) {
  68                 dev_err(p_phy->dev, "Check PHY clock, Timeout: %d\n", ret);
  69                 clk_disable_unprepare(p_phy->clk);
  70                 return ret;
  71         }
  72
  73         return 0;
  74 }
  75
  76 static int ma35_usb_phy_power_off(struct phy *phy)
  77 {
  78         struct ma35_usb_phy *p_phy = phy_get_drvdata(phy);
  79
  80         clk_disable_unprepare(p_phy->clk);
  81         return 0;
  82 }
  83
  84 static const struct phy_ops ma35_usb_phy_ops = {
  85         .power_on = ma35_usb_phy_power_on,
  86         .power_off = ma35_usb_phy_power_off,
  87         .owner = THIS_MODULE,
  88 };
  89
  90 static int ma35_usb_phy_probe(struct platform_device *pdev)
  91 {
  92         struct phy_provider *provider;
  93         struct ma35_usb_phy *p_phy;
  94         struct phy *phy;
  95
  96         p_phy = devm_kzalloc(&pdev->dev, sizeof(*p_phy), GFP_KERNEL);
  97         if (!p_phy)
  98                 return -ENOMEM;
  99
 100         p_phy->dev = &pdev->dev;
 101         platform_set_drvdata(pdev, p_phy);
 102
 103         p_phy->sysreg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "nuvoton,sys");
 104         if (IS_ERR(p_phy->sysreg))
 105                 return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->sysreg),
 106                                      "Failed to get SYS registers\n");
 107
 108         p_phy->clk = of_clk_get(pdev->dev.of_node, 0);
 109         if (IS_ERR(p_phy->clk))
 110                 return dev_err_probe(&pdev->dev, PTR_ERR(p_phy->clk),
 111                                      "failed to find usb_phy clock\n");
 112
 113         phy = devm_phy_create(&pdev->dev, NULL, &ma35_usb_phy_ops);
 114         if (IS_ERR(phy))
 115                 return dev_err_probe(&pdev->dev, PTR_ERR(phy), "Failed to create PHY\n");
 116
 117         phy_set_drvdata(phy, p_phy);
 118
 119         provider = devm_of_phy_provider_register(&pdev->dev, of_phy_simple_xlate);
 120         if (IS_ERR(provider))
 121                 return dev_err_probe(&pdev->dev, PTR_ERR(provider),
 122                                      "Failed to register PHY provider\n");
 123         return 0;
 124 }
 125
 126 static const struct of_device_id ma35_usb_phy_of_match[] = {
 127         { .compatible = "nuvoton,ma35d1-usb2-phy", },
 128         { },
 129 };
 130 MODULE_DEVICE_TABLE(of, ma35_usb_phy_of_match);
 131
 132 static struct platform_driver ma35_usb_phy_driver = {
 133         .probe          = ma35_usb_phy_probe,
 134         .driver = {
 135                 .name   = "ma35d1-usb2-phy",
 136                 .of_match_table = ma35_usb_phy_of_match,
 137         },
 138 };
 139 module_platform_driver(ma35_usb_phy_driver);
 140
 141 MODULE_DESCRIPTION("Nuvoton ma35d1 USB2.0 PHY driver");
 142 MODULE_AUTHOR("Hui-Ping Chen <hpchen0nvt@gmail.com>");
 143 MODULE_LICENSE("GPL");