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

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * PHY driver for NXP LPC18xx/43xx internal USB OTG PHY
0004  *
0005  * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
0006  */
0007
0008 #include <linux/clk.h>
0009 #include <linux/err.h>
0010 #include <linux/mfd/syscon.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/regmap.h>
0016
0017 /* USB OTG PHY register offset and bit in CREG */
0018 #define LPC18XX_CREG_CREG0      0x004
0019 #define LPC18XX_CREG_CREG0_USB0PHY  BIT(5)
0020
0021 struct lpc18xx_usb_otg_phy {
0022     struct phy *phy;
0023     struct clk *clk;
0024     struct regmap *reg;
0025 };
0026
0027 static int lpc18xx_usb_otg_phy_init(struct phy *phy)
0028 {
0029     struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
0030     int ret;
0031
0032     /* The PHY must be clocked at 480 MHz */
0033     ret = clk_set_rate(lpc->clk, 480000000);
0034     if (ret)
0035         return ret;
0036
0037     return clk_prepare(lpc->clk);
0038 }
0039
0040 static int lpc18xx_usb_otg_phy_exit(struct phy *phy)
0041 {
0042     struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
0043
0044     clk_unprepare(lpc->clk);
0045
0046     return 0;
0047 }
0048
0049 static int lpc18xx_usb_otg_phy_power_on(struct phy *phy)
0050 {
0051     struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
0052     int ret;
0053
0054     ret = clk_enable(lpc->clk);
0055     if (ret)
0056         return ret;
0057
0058     /* The bit in CREG is cleared to enable the PHY */
0059     ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
0060                   LPC18XX_CREG_CREG0_USB0PHY, 0);
0061     if (ret) {
0062         clk_disable(lpc->clk);
0063         return ret;
0064     }
0065
0066     return 0;
0067 }
0068
0069 static int lpc18xx_usb_otg_phy_power_off(struct phy *phy)
0070 {
0071     struct lpc18xx_usb_otg_phy *lpc = phy_get_drvdata(phy);
0072     int ret;
0073
0074     ret = regmap_update_bits(lpc->reg, LPC18XX_CREG_CREG0,
0075                  LPC18XX_CREG_CREG0_USB0PHY,
0076                  LPC18XX_CREG_CREG0_USB0PHY);
0077     if (ret)
0078         return ret;
0079
0080     clk_disable(lpc->clk);
0081
0082     return 0;
0083 }
0084
0085 static const struct phy_ops lpc18xx_usb_otg_phy_ops = {
0086     .init       = lpc18xx_usb_otg_phy_init,
0087     .exit       = lpc18xx_usb_otg_phy_exit,
0088     .power_on   = lpc18xx_usb_otg_phy_power_on,
0089     .power_off  = lpc18xx_usb_otg_phy_power_off,
0090     .owner      = THIS_MODULE,
0091 };
0092
0093 static int lpc18xx_usb_otg_phy_probe(struct platform_device *pdev)
0094 {
0095     struct phy_provider *phy_provider;
0096     struct lpc18xx_usb_otg_phy *lpc;
0097
0098     lpc = devm_kzalloc(&pdev->dev, sizeof(*lpc), GFP_KERNEL);
0099     if (!lpc)
0100         return -ENOMEM;
0101
0102     lpc->reg = syscon_node_to_regmap(pdev->dev.of_node->parent);
0103     if (IS_ERR(lpc->reg)) {
0104         dev_err(&pdev->dev, "failed to get syscon\n");
0105         return PTR_ERR(lpc->reg);
0106     }
0107
0108     lpc->clk = devm_clk_get(&pdev->dev, NULL);
0109     if (IS_ERR(lpc->clk)) {
0110         dev_err(&pdev->dev, "failed to get clock\n");
0111         return PTR_ERR(lpc->clk);
0112     }
0113
0114     lpc->phy = devm_phy_create(&pdev->dev, NULL, &lpc18xx_usb_otg_phy_ops);
0115     if (IS_ERR(lpc->phy)) {
0116         dev_err(&pdev->dev, "failed to create PHY\n");
0117         return PTR_ERR(lpc->phy);
0118     }
0119
0120     phy_set_drvdata(lpc->phy, lpc);
0121
0122     phy_provider = devm_of_phy_provider_register(&pdev->dev,
0123                              of_phy_simple_xlate);
0124
0125     return PTR_ERR_OR_ZERO(phy_provider);
0126 }
0127
0128 static const struct of_device_id lpc18xx_usb_otg_phy_match[] = {
0129     { .compatible = "nxp,lpc1850-usb-otg-phy" },
0130     { }
0131 };
0132 MODULE_DEVICE_TABLE(of, lpc18xx_usb_otg_phy_match);
0133
0134 static struct platform_driver lpc18xx_usb_otg_phy_driver = {
0135     .probe      = lpc18xx_usb_otg_phy_probe,
0136     .driver     = {
0137         .name   = "lpc18xx-usb-otg-phy",
0138         .of_match_table = lpc18xx_usb_otg_phy_match,
0139     },
0140 };
0141 module_platform_driver(lpc18xx_usb_otg_phy_driver);
0142
0143 MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
0144 MODULE_DESCRIPTION("NXP LPC18xx/43xx USB OTG PHY driver");
0145 MODULE_LICENSE("GPL v2");