linux/drivers/phy/phy-lpc18xx-usb-otg.c
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   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
  21struct lpc18xx_usb_otg_phy {
  22        struct phy *phy;
  23        struct clk *clk;
  24        struct regmap *reg;
  25};
  26
  27static 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
  40static 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
  49static 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
  69static 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
  85static 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
  93static 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
 128static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
 129        { .compatible = "nxp,lpc1850-usb-otg-phy" },
 130        { }
 131};
 132MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
 133
 134static 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};
 141module_platform_driver(lpc18xx_usb_otg_phy_driver);
 142
 143MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 144MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
 145MODULE_LICENSE("GPL v2");
 146