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

   1/*
   2 * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
   3 *
   4 * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 *
  10 */
  11
  12#include <linux/clk.h>
  13#include <linux/err.h>
  14#include <linux/mfd/syscon.h>
  15#include <linux/module.h>
  16#include <linux/of.h>
  17#include <linux/phy/phy.h>
  18#include <linux/platform_device.h>
  19#include <linux/regmap.h>
  20
  21/* USB OTG PHY register offset and bit in CREG */
  22#define LPC18XX_CREG_CREG0              0x004
  23#define LPC18XX_CREG_CREG0_USB0PHY      BIT(5)
  24
  25struct lpc18xx_usb_otg_phy {
  26        struct phy *phy;
  27        struct clk *clk;
  28        struct regmap *reg;
  29};
  30
  31static int lpc18xx_usb_otg_phy_init(struct phy *phy)
  32{
  33        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  34        int ret;
  35
  36        /* The PHY must be clocked at 480 MHz */
  37        ret = clk_set_rate(lpc->clk, 480000000);
  38        if (ret)
  39                return ret;
  40
  41        return clk_prepare(lpc->clk);
  42}
  43
  44static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
  45{
  46        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  47
  48        clk_unprepare(lpc->clk);
  49
  50        return 0;
  51}
  52
  53static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
  54{
  55        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  56        int ret;
  57
  58        ret = clk_enable(lpc->clk);
  59        if (ret)
  60                return ret;
  61
  62        /* The bit in CREG is cleared to enable the PHY */
  63        return regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
  64                                  LPC18XX_CREG_CREG0_USB0PHY, 0);
  65}
  66
  67static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
  68{
  69        struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
  70        int ret;
  71
  72        ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
  73                                 LPC18XX_CREG_CREG0_USB0PHY,
  74                                 LPC18XX_CREG_CREG0_USB0PHY);
  75        if (ret)
  76                return ret;
  77
  78        clk_disable(lpc->clk);
  79
  80        return 0;
  81}
  82
  83static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
  84        .init           = lpc18xx_usb_otg_phy_init,
  85        .exit           = lpc18xx_usb_otg_phy_exit,
  86        .power_on       = lpc18xx_usb_otg_phy_power_on,
  87        .power_off      = lpc18xx_usb_otg_phy_power_off,
  88        .owner          = THIS_MODULE,
  89};
  90
  91static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
  92{
  93        struct phy_provider *phy_provider;
  94        struct lpc18xx_usb_otg_phy *lpc;
  95
  96        lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
  97        if (!lpc)
  98                return -ENOMEM;
  99
 100        lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
 101        if (IS_ERR(lpc->reg)) {
 102                dev_err(&pdev->dev, "failed to get syscon\n");
 103                return PTR_ERR(lpc->reg);
 104        }
 105
 106        lpc->clk = devm_clk_get(&pdev->dev, NULL);
 107        if (IS_ERR(lpc->clk)) {
 108                dev_err(&pdev->dev, "failed to get clock\n");
 109                return PTR_ERR(lpc->clk);
 110        }
 111
 112        lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
 113        if (IS_ERR(lpc->phy)) {
 114                dev_err(&pdev->dev, "failed to create PHY\n");
 115                return PTR_ERR(lpc->phy);
 116        }
 117
 118        phy_set_drvdata(lpc->phy, lpc);
 119
 120        phy_provider = devm_of_phy_provider_register(&pdev->dev,
 121                                                     of_phy_simple_xlate);
 122
 123        return PTR_ERR_OR_ZERO(phy_provider);
 124}
 125
 126static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
 127        { .compatible = "nxp,lpc1850-usb-otg-phy" },
 128        { }
 129};
 130MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
 131
 132static struct platform_driver lpc18xx_usb_otg_phy_driver = {
 133        .probe          = lpc18xx_usb_otg_phy_probe,
 134        .driver         = {
 135                .name   = "lpc18xx-usb-otg-phy",
 136                .of_match_table = lpc18xx_usb_otg_phy_match,
 137        },
 138};
 139module_platform_driver(lpc18xx_usb_otg_phy_driver);
 140
 141MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
 142MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
 143MODULE_LICENSE("GPL v2");
 144