drivers/phy/phy-lpc18xx-usb-otg.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
   4  *
   5  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/err.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 OTG PHY register offset and bit in CREG */
  18 #define LPC18XX_CREG_CREG0              0x004
  19 #define LPC18XX_CREG_CREG0_USB0PHY      BIT(5)
  20
  21 struct lpc18xx_usb_otg_phy {
  22         struct phy *phy;
  23         struct clk *clk;
  24         struct regmap *reg;
  25 };
  26
  27 static int lpc18xx_usb_otg_phy_init(struct phy *phy)
  28 {
  29         struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  30         int ret;
  31
  32         /* The PHY must be clocked at 480 MHz */
  33         ret = clk_set_rate(lpc->clk, 480000000);
  34         if (ret)
  35                 return ret;
  36
  37         return clk_prepare(lpc->clk);
  38 }
  39
  40 static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
  41 {
  42         struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  43
  44         clk_unprepare(lpc->clk);
  45
  46         return 0;
  47 }
  48
  49 static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
  50 {
  51         struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  52         int ret;
  53
  54         ret = clk_enable(lpc->clk);
  55         if (ret)
  56                 return ret;
  57
  58         /* The bit in CREG is cleared to enable the PHY */
  59         ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
  60                                   LPC18XX_CREG_CREG0_USB0PHY, 0);
  61         if (ret) {
  62                 clk_disable(lpc->clk);
  63                 return ret;
  64         }
  65
  66         return 0;
  67 }
  68
  69 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
  70 {
  71         struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  72         int ret;
  73
  74         ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
  75                                  LPC18XX_CREG_CREG0_USB0PHY,
  76                                  LPC18XX_CREG_CREG0_USB0PHY);
  77         if (ret)
  78                 return ret;
  79
  80         clk_disable(lpc->clk);
  81
  82         return 0;
  83 }
  84
  85 static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
  86         .init           = lpc18xx_usb_otg_phy_init,
  87         .exit           = lpc18xx_usb_otg_phy_exit,
  88         .power_on       = lpc18xx_usb_otg_phy_power_on,
  89         .power_off      = lpc18xx_usb_otg_phy_power_off,
  90         .owner          = THIS_MODULE,
  91 };
  92
  93 static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
  94 {
  95         struct phy_provider *phy_provider;
  96         struct lpc18xx_usb_otg_phy *lpc;
  97
  98         lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
  99         if (!lpc)
 100                 return -ENOMEM;
 101
 102         lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
 103         if (IS_ERR(lpc->reg)) {
 104                 dev_err(&pdev->dev, "failed to get syscon\n");
 105                 return PTR_ERR(lpc->reg);
 106         }
 107
 108         lpc->clk = devm_clk_get(&pdev->dev, NULL);
 109         if (IS_ERR(lpc->clk)) {
 110                 dev_err(&pdev->dev, "failed to get clock\n");
 111                 return PTR_ERR(lpc->clk);
 112         }
 113
 114         lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
 115         if (IS_ERR(lpc->phy)) {
 116                 dev_err(&pdev->dev, "failed to create PHY\n");
 117                 return PTR_ERR(lpc->phy);
 118         }
 119
 120         phy_set_drvdata(lpc->phy, lpc);
 121
 122         phy_provider = devm_of_phy_provider_register(&pdev->dev,
 123                                                      of_phy_simple_xlate);
 124
 125         return PTR_ERR_OR_ZERO(phy_provider);
 126 }
 127
 128 static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
 129         { .compatible = "nxp,lpc1850-usb-otg-phy" },
 130         { }
 131 };
 132 MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
 133
 134 static struct platform_driver lpc18xx_usb_otg_phy_driver = {
 135         .probe          = lpc18xx_usb_otg_phy_probe,
 136         .driver         = {
 137                 .name   = "lpc18xx-usb-otg-phy",
 138                 .of_match_table = lpc18xx_usb_otg_phy_match,
 139         },
 140 };
 141 module_platform_driver(lpc18xx_usb_otg_phy_driver);
 142
 143 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 144 MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
 145 MODULE_LICENSE("GPL v2");